# Seeking Advice First Router Project



## hyped (Jan 22, 2018)

Hi Guys,
Stumbled across this forum when I was looking for some advice on routers seems to be great forum! I was hoping I might be able to get some guidance and advice on some questions I have?

Now I’ll premise my questions by saying that My woodworking skills are very limited (and that’s being kind) so please forgive my questions in advance for the newbieness 

I’m looking to build a speaker project that uses two bamboo IKEA bowls joined together to make sphere speakers.

I couldn’t include a link as I’m new but they are two bowls 11inches in diameter joined together.

Here’s a pic of one









The speaker driver cutout is meant to go on the bottom base.

Now my main question is what is the best approach using a router to make a recessed hole so that the speaker is flush mounted in one half (bowl) I could use a hole saw but then I wouldn’t be able to have a 4mm recess to make the speaker driver flush.

I’ve bought a jasper jig to make the circular holes but I’m not sure (given it’s not a flat surface) how I would go about doing the cut out.

I haven’t bought a router yet so any suggestions would be appreciated I’ve looked at a couple of routers that are both plunge and fixed but they are getting up there in price and I’m assuming I would also potentially need a router table as well?

If anyone could offer some advice on how best to approach making a circular rebate/recess that would be really appreciated. Baring in mind this will be my first router project and generally new to woodworker.

Also, any comments on a reasonable price setup that would do the job. I don’t want to go too cheap but also would like to keep as cheap as possible given my current skill set! 

Any advice would be greatly appreciated


Thanks guys



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## DaninVan (Jan 1, 2012)

Hey, Hyped; welcome!
If you fill out your profile the members will know what equipment you have available to you, a first name maybe also? 
In any case, if it were me, I think I'd drill out the smaller diameter with a holesaw first, then use that as a template to rout out the slightly larger rebated diameter (the actual recess that the speaker sits flush in).
I'd be a lot more comfortable using a drill press for the smaller diameter hole, with the bowl firmly clamped to the table.
If a guy had a lathe, that'd be another approach.
Having said all that, what you want to do is pretty sophisticated if you've never used a router. For one thing, a handheld router is normally used on a flat surface; you want to do it on a sphere. Not saying it can't be done but I think I'd be using a small trim router to do the rebate.


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## JOAT (Apr 9, 2010)

I would say farm it out to someone that knows what they are doing.


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## kklowell (Dec 26, 2014)

When the cost of the equipment to do this is factored in, I'd say that Theo's advice is best, unless you plan on making a whole bunch of these and selling them, In that case you might want to check costs both ways.


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## RainMan 2.0 (May 6, 2014)

Guys , wouldn’t a router on a circle jig work perfectly for this? 

Btw , welcome to the forum N/a . This is an interesting project ,and looks very cool also . Hope you keep us updated. I often wish I built my home theatre speakers instead of just buying them


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## hyped (Jan 22, 2018)

DaninVan said:


> Hey, Hyped; welcome!
> If you fill out your profile the members will know what equipment you have available to you, a first name maybe also?
> In any case, if it were me, I think I'd drill out the smaller diameter with a holesaw first, then use that as a template to rout out the slightly larger rebated diameter (the actual recess that the speaker sits flush in).
> I'd be a lot more comfortable using a drill press for the smaller diameter hole, with the bowl firmly clamped to the table.
> ...




Thanks mate and noted on the profile I’ll updated.

Yeh maybe I’ve bit off more than I can chew  if I took the smaller hole out first I was thinking I could build a small box around the bowl where the box is level, flush with the bowl to at least give me a level surface, make sense?


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## hyped (Jan 22, 2018)

JOAT said:


> I would say farm it out to someone that knows what they are doing.




Yeh maybe I’m looking to walk before I crawl!


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## hyped (Jan 22, 2018)

kklowell said:


> When the cost of the equipment to do this is factored in, I'd say that Theo's advice is best, unless you plan on making a whole bunch of these and selling them, In that case you might want to check costs both ways.




If I can get there with trial and error without killing too many bowls I’m kinda ok with that I guess  and I’m hoping to do more stuff in future so don’t see investment as a waste if I can reuse the gear.

However as noted above maybe I’ve bitten more than I can chew! 


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## hyped (Jan 22, 2018)

RainMan 2.0 said:


> Guys , wouldn’t a router on a circle jig work perfectly for this?
> 
> Btw , welcome to the forum N/a . This is an interesting project ,and looks very cool also . Hope you keep us updated. I often wish I built my home theatre speakers instead of just buying them




Thanks rainman appreciated and depending how I go be sure to post and update 


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## RainMan 2.0 (May 6, 2014)

With a perfect circle jig like mine , the main thing would be making sure you find dead centre .
Once you establish that, the jig I have has a 1/8” pin that requires you to drill a 1/8” hole obviously in the bowl .
From there you do the recess first going around the perimeter with the router on the jig till you achieve your depth , then change the circle jigs distance inwards for a smaller diameter hole that copies the diameter of the speakers inner basket where it seats. 
This final hole would go right threw, and presto your done


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## RainMan 2.0 (May 6, 2014)

You don’t have to buy one ,as there easy to make , but this is what I’m referring too


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## DaninVan (Jan 1, 2012)

Tricky on a dome, Rick. How would you control the depth accurately? Again, not saying it can't be done, but i'd like to know it works first... 

Rick's got the jig; I nominate Rick!


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## hyped (Jan 22, 2018)

RainMan 2.0 said:


> You don’t have to buy one ,as there easy to make , but this is what I’m referring too
> 
> https://youtu.be/UkRh68OC_lM




I’ve actually got a jasper jig mate. It’s how to run it on flat surface seeing your working on a dome. Hence my comment about building a box around it flush to give a horizontal surface to anchor from 




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## Nickp (Dec 4, 2012)

Excellent idea to build a flat surface for it...box would be perfect...

Then a template for the circle and recess...trim router would be easier...Bosch Colt or Ridgid...

Rough cut with jig saw first...use your box for base for the saw...


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## hyped (Jan 22, 2018)

Nickp said:


> Excellent idea to build a flat surface for it...box would be perfect...
> 
> Then a template for the circle and recess...trim router would be easier...Bosch Colt or Ridgid...




Cheers for feedback Nick. I think I might give that a go mate. I’ve got two extra bowls in case (well in the highly probable event I stuff one up) 

Even if I hole saw out the first cut and then build a circle template for the recess


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## Nickp (Dec 4, 2012)

Use thin material for the top of the box so you don't need to over-extend the bit...


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## hyped (Jan 22, 2018)

Nickp said:


> Use thin material for the top of the box so you don't need to over-extend the bit...




Thanks for advice makes sense! Recess only needs to be like 4mm so assuming if I keep the thickness of template under say 6-7mm should be ok for most decent routers?



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## Nickp (Dec 4, 2012)

Some additional info...make sure you route in the correct direction...handheld would be left to right or clockwise in your case...maybe you know that already...


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## hyped (Jan 22, 2018)

Nickp said:


> Some additional info...make sure you route in the correct direction...handheld would be left to right or clockwise in your case...maybe you know that already...




I do now 

Thanks nick?


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## gmercer_48083 (Jul 18, 2012)

I agree with Nick. Just make sure the bowl is secured (sandwiched) to the box well.


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## Nickp (Dec 4, 2012)

hyped said:


> Thanks for advice makes sense! Recess only needs to be like 4mm so assuming if I keep the thickness of template under say 6-7mm should be ok for most decent routers?
> 
> 
> 
> Sent from my iPhone using Tapatalk


Yes...should be...keep in mind that you will also need to select the right bit, for example, in your case a flush trim bit of the right length would work...a straight bit, no bearing, but then your template would need to use the router base as a guide...a rabetting bit will also work...

The size and shape of the template will be important...it needs to be sized appropriately to allow support of the router on the box (base) even though only part of the router base will have support.

The intent is to create as much support for the router as you can...select the method of template that provides that.

Since you are new to routing, I suggest you make LOTS of practice cuts on different types of wood...the router and bit combination will behave differently for different woods and you don't want to be surprised by how it will feel on bamboo.

Note also that bamboo will tend to splinter due to it's stringy fiber grain. Be careful as you transition from end grain to long grain (it appears the bowl has both...)

...and do not try to make complete cuts...small bites...like eating an elephant (small bite at a time)  Use your bit height adjustment to take vertical bites into your profile rather than trying to accommodate a horizontal cut. You will likely use two templates...one for cleaning the bottom hole after rough cut and then another for creating your recess...alignment of each will be important...

Ask away...lots of folks here that will help...


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## woodknots (Mar 7, 2012)

OK, I'll add my 2 cents to all the other great comments. Since you are joining two bowls together (I presume) to form the sphere, you will be working on one bowl that will house your speaker. Have you considered creating the hole with a band saw first. Once you cut the bottom off the bowl, you could then consider creating your rabbet with a router/template or any other method you choose. That will allow the bowl to sit on it's flat side, held securely by clamps or otherwise and not have to worry about the bowl rolling or rocking. Once you've got the hole/rabbet created for the speaker, then you could join the two bowls together to form the sphere.


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## Herb Stoops (Aug 28, 2012)

hyped said:


> I do now
> 
> Thanks nick?
> 
> ...


You are on the right path here, might consider after you get the large hole cut to use a Rabet bit with an 1/8" smaller bearing to cut the rabet around the hole. By removing the bushing it will give the bearing clearance to make the cut. I like the Box Idea with the top the template for routing the large hole.

Herb


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## hyped (Jan 22, 2018)

vchiarelli said:


> OK, I'll add my 2 cents to all the other great comments. Since you are joining two bowls together (I presume) to form the sphere, you will be working on one bowl that will house your speaker. Have you considered creating the hole with a band saw first. Once you cut the bottom off the bowl, you could then consider creating your rabbet with a router/template or any other method you choose. That will allow the bowl to sit on it's flat side, held securely by clamps or otherwise and not have to worry about the bowl rolling or rocking. Once you've got the hole/rabbet created for the speaker, then you could join the two bowls together to form the sphere.




Hi Vchiatelli

The hole cuts will be made before they are joined. 
The problem I’m trying to solve is how to keep a Router perfectly level as are moving it around given u don’t have a level flat surface for the router



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## DaninVan (Jan 1, 2012)

The box + flat top solves a whole bunch of issues. Your rebated circle will have it's wall dead perpendicular, and the rim where the speaker sits will be in a perfectly flat plane, perpendicular to the wall of the rebate; more than that you couldn't ask for.
If you haven't bought a router yet, you need :grin: a Bosch 1617EVSPK kit!!!


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## MT Stringer (Aug 15, 2012)

From looking at the finished product, and what it might take to accomplish the result, I think I would probably screw it up! Better buy a couple of those bowls.

It might be possible to do with a CNC, but even then it would take some careful measuring, clamping (UGH!) and getting the piece exactly centered. So, I think I would probably screw it up! Better buy a couple of those bowls. :surprise::grin:


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## hyped (Jan 22, 2018)

DaninVan said:


> The box + flat top solves a whole bunch of issues. Your rebated circle will have it's wall dead perpendicular, and the rim where the speaker sits will be in a perfectly flat plane, perpendicular to the wall of the rebate; more than that you couldn't ask for.
> 
> If you haven't bought a router yet, you need :grin: a Bosch 1617EVSPK kit!!!




Hey DaninVan,
I’ve been looking at dual routers to give me some flexibility which I assume will help as I don’t have a dedicated router table.

The Bosch looks the goods unfortunately down under we have limited options and Bosch don’t range a 240v for oz.


Seemingly the only dual routers I can find are Dewalt D26204K-XE and Triton (MOF001) never used any of their products so don’t know what they are like.

Makita you can also buy a smaller 700w and buy the plunge base separately almost works out same price as the Dewalt and Triton though which are 900 and 1400w if I recall


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## DaninVan (Jan 1, 2012)

*Down Under?!* See? This is why we really encourage folks to fill out their profiles! Your current one says you're in the US, by default.
There are a few Ozzie members; maybe they can help you out.
By the way, Amazon is pending in Oz.


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## JFPNCM (Dec 13, 2009)

An interesting project. 

If the bowls are relatively cheap I would try the following:

1) With either hot glue or good double sided tape I would afix the bowl to a reasonably sized piece of 1/4" Baltic birch.
2) Use a drill press and hole saw to cut the large circle through both the bowl and the Birch piece
3) Use a rabbet bit with a bearing or bushing to route the recess while the bowl sits on its "larger" end for stability. Use a quality trim router for the project. If you have problems locating a router, contact the "locals" as Dan advised.

Thus be my 1 cents worth in deference to Vince. :wink:


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## DaninVan (Jan 1, 2012)

Jon; minor edit (I think). The smaller inside diameter needs to be removed first to allow the rebate to expand to the larger outer diameter. ie the opening for the outer edge of the speaker is the final dimension.


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## Cherryville Chuck (Sep 28, 2010)

The uses of the words "rebate" and "mate" mean the UK, Oz, or NZ. It does make a difference Hyped because here in North America we operate on a different power system than you do so our power tool models are different and mutually incompatible. You should edit your profile when you have a minute.

The box is a brilliant idea. Actually 2 boxes is an even better idea. Use the Jasper jig to make a hole in a panel for one box that is the size that you need for the through hole. Use the jig to make a second hole in another piece that is the same size as the rebate you want to make in the rim of the bowl. You can use a pattern bit like one of these: Freud Tools - Search Results for top bearing flush trim bits to follow around the edge of the hole at the depth you want to make the rebate. You'll have to make sure you buy one that is of a length that is compatible with your project. That is, it must be short enough to allow the bearing to follow the edge of the hole in your box while still able to reach the depth you want.

I'm not clear if there is any machining to be done in the bottom bowl other than possibly a hole for a power cord. Most router bits aren't very long so reaching in from the rim of the bowl could be a problem if that was part of the plan. To rout out the bottom of the first bowl you'll either need to drill a starter hole or use a plunge router with a plunge capable bit.


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## hyped (Jan 22, 2018)

Cherryville Chuck said:


> The uses of the words "rebate" and "mate" mean the UK, Oz, or NZ. It does make a difference Hyped because here in North America we operate on a different power system than you do so our power tool models are different and mutually incompatible. You should edit your profile when you have a minute.
> 
> The box is a brilliant idea. Actually 2 boxes is an even better idea. Use the Jasper jig to make a hole in a panel for one box that is the size that you need for the through hole. Use the jig to make a second hole in another piece that is the same size as the rebate you want to make in the rim of the bowl. You can use a pattern bit like one of these: Freud Tools - Search Results for top bearing flush trim bits to follow around the edge of the hole at the depth you want to make the rebate. You'll have to make sure you buy one that is of a length that is compatible with your project. That is, it must be short enough to allow the bearing to follow the edge of the hole in your box while still able to reach the depth you want.
> 
> I'm not clear if there is any machining to be done in the bottom bowl other than possibly a hole for a power cord. Most router bits aren't very long so reaching in from the rim of the bowl could be a problem if that was part of the plan. To rout out the bottom of the first bowl you'll either need to drill a starter hole or use a plunge router with a plunge capable bit.




Hi Cherry 
Thanks for feedback and guidance appreciated. I haven’t been close to PC as I’ve been using Tapatalk but I’ll definitely update profile shortly.

Regarding other holes and the rest of the construction the speakers are passive so I will have two terminals on back probably 1/3inch 8mm holes.

The only other consideration is joining the two halves and also potential way to fix to a stand.

The two bowls together aren’t a perfect sphere ideally you would want a 10mm spacer between the bowls to make it ideal (acoustically)

I’ve sketched up a metal spacer ring which has a cross section in it. This would allow a threaded rod of some sort to go into the speaker from the back and could attach to the internal cross section.

I think it will work however I’m not sure getting it CNC is going to be cheap, well I know it isn’t going to be cheap so I might need to look at other things I can hack to give me a 11inch diameter 10mm thick spacer.

The speaker may measure ok without it, if so, it’s just a matter of glueing I suppose???? I can then just look at a stand or legs for the speakers

Im assuming a good wood glue will be more than enough to get a solid bind between the two bowls??? The speaker driver is only 2.5kg so isn’t heavy.

There’s some internal dampening and stuffing but really the last big one is finishing.

That’s a hole other topic within itself I suppose 

My skills are pretty limited but if I can get a half decent job on the speaker driver holes it’s a battle half won I guess!!


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## hyped (Jan 22, 2018)

MT Stringer said:


> From looking at the finished product, and what it might take to accomplish the result, I think I would probably screw it up! Better buy a couple of those bowls.
> 
> 
> 
> It might be possible to do with a CNC, but even then it would take some careful measuring, clamping (UGH!) and getting the piece exactly centered. So, I think I would probably screw it up! Better buy a couple of those bowls. :surprise::grin:




I bought an additional 3. Hopefully its enough !!! I suppose not even talking about my skill (or lack there of) 

From what little I know bamboo is dam hard and fibrous and maybe a pain in the butt for even decent wood workers

Measure twice cut once as they say I’ll try and do all I can before I tackle a bowl 


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## hyped (Jan 22, 2018)

Just wanted to say quick thank you to all the feedback it’s been really helpful. Hopefully this weekend I’ll go to local hardware and pickup a few things to build up a box etc 

I’ll definitely post update for what it’s worth and I’ll post a pic of what I’m planning to do before I cut!

Thanks again all


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## Rogerdodge (Apr 24, 2014)

Hello Hyped and welcome. This is a great project and you have been given lots of advice, which you have processed and added to your own ideas, all of which will stand you in good stead , both for this project and others further down the line. Good for you. Don't forget, though, Pics or it never happened ......


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## DaninVan (Jan 1, 2012)

Hyped; on the joining the two halves thing. Use contact cement to glue a thin band around the inside bottom edge of one of the bowls; it needs to stick up maybe 1/4" or more to form an inside lip. basically you'll create a rebate allowing the other bowl to be self locating when you assemble them. Just a thought. 
By the way, Harry (Harrysin) says Bosch _are_ available in Oz! Different model #s than here in N. America. He posted a link this morning...
Power Tools | Bosch Australia


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## JFPNCM (Dec 13, 2009)

DaninVan said:


> Jon; minor edit (I think). The smaller inside diameter needs to be removed first to allow the rebate to expand to the larger outer diameter. ie the opening for the outer edge of the speaker is the final dimension.


Thanks Dan, missed that point.


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## hyped (Jan 22, 2018)

DaninVan said:


> Hyped; on the joining the two halves thing. Use contact cement to glue a thin band around the inside bottom edge of one of the bowls; it needs to stick up maybe 1/4" or more to form an inside lip. basically you'll create a rebate allowing the other bowl to be self locating when you assemble them. Just a thought.
> By the way, Harry (Harrysin) says Bosch _are_ available in Oz! Different model #s than here in N. America. He posted a link this morning...
> Power Tools | Bosch Australia




Hi mate

Yeh they sell here it’s that they don’t range same models and in oz (and suspect euro) they only sell one model 


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## hyped (Jan 22, 2018)

Rogerdodge said:


> Hello Hyped and welcome. This is a great project and you have been given lots of advice, which you have processed and added to your own ideas, all of which will stand you in good stead , both for this project and others further down the line. Good for you. Don't forget, though, Pics or it never happened ......




I’ll post undoubtedly, the result on the other hand...... 


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## DesertRatTom (Jul 3, 2012)

Sorry to have missed this post til now. Securing the bowl so it doesn't move at all is the very first order of business no matter what method you choose. You'll be working on the top half of the speaker for the most part. I would cut a circle through a chunk of ply slightly larger than the open side of the bowl, then at least four trapezoid pieces you can move forward and back so they hold the bowl securely. Cut a slot through the trapezoids so they can be cinched down into a threaded insert in the plywood base. This will give you a pretty secure base. 

The base will allow you to mount a top 18mm ply flat top plate, to which you can secure template(s). 

I'd mark a circle on the bottom of the inverted bowl slightly smaller than the final dimension. Later you'll use a bit to form a rabbet there which will hold the speaker in place.

Drill a hole and use a jig saw to cut out this smaller circle just inside the line. This will open up the bottom of the bowl. If you want to, you can smooth this inner circle with a template that's the exact size of the smaller, inner hole, but you may not need to except for appearance sake.

You will center and then affix the templates to the top plate. I would make the templates out of 3/4 MDF so you have some thickness for the bearing to ride on as you route deeper in 2-3 steps. I'm assuming the bowls are not more than about 12mm thick, maybe a bit more than that on the flat bottom. 

The thickness of the bowl must be more than the depth required to secure the speaker in place.

Now you have the smaller diameter opening cut.

Make, center and secure a second template, which will be the size required to house and secure the speaker. Use a motrising bit with a bearing to cut the rabbet using this larger opening template. You'll make several shallow passes to form the rabbet. 

Personally, I'd use a trim router with this method since the heavy cuts will be made with a jig saw.

In putting the bowls together, I'd take each bowl and sand the rounded edge flat on an oversized piece of sandpaper so there's plenty of glue surface and stronger joint.

You'll need to drill a hole and mount an appropriate connector in place for the audio source. A powered speaker will require a second connector, and a blutooth connection will require some way to charge (and eventually replace) the battery. I'd stick with wire with a 1/8th inch (3mm ?) stereo plug.

attached is a rather simple drawing of the trapezoid hold downs and the base. You would attach the top plate to the bottom and the templates would go on top of that upper plate. This should hold things in place for you, and reduce the complexity of your build. Hope I've been clear.


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## DesertRatTom (Jul 3, 2012)

Sorry to have missed this post til now. Securing the bowl so it doesn't move at all is the very first order of business no matter what method you choose. You'll be working on the top half of the speaker for the most part. I would draw a circle on a chunk of ply slightly larger than the open side of the bowl, then at least four trapezoid pieces you can move forward and back so they hold the bowl securely. Cut a slot through the trapezoids so they can be cinched down into a threaded insert in the plywood base. This will give you a pretty secure bowl to work on. 

The base will allow you to mount a top 18mm ply flat top plate, to which you can secure template(s). I'd consider doing this with four bolts so you can raise and lower the top plate to manipulate the bowl.

I'd mark a circle on the bottom of the inverted bowl slightly smaller than the final dimension. Later you'll use a bit to form a rabbet there which will hold the speaker in place.

Drill a hole and use a jig saw to cut out this smaller circle just inside the line. This will open up the bottom of the bowl. If you want to, you can smooth this inner circle with a template that's the exact size of the smaller, inner hole, but you may not need to, except for appearance sake.

You will center and then affix the templates to the top plate. I would make the templates out of 3/4 MDF so you have some thickness for the bearing to ride on as you route deeper in 2-3 steps. I'm assuming the bowls are not more than about 12mm thick, maybe a bit more than that on the flat bottom. (I've seen clear plastic sheets with multiple circles printed on it that you could use for centering but not sure what it's called.)

The thickness of the bowl must be more than the depth required to secure the speaker in place.

Now you have the smaller diameter opening cut.

Make, center and secure a second template, which will be the size required to house and secure the speaker. Use a motrising bit with a bearing to cut the rabbet using this larger opening template. You'll make several shallow passes to form the rabbet. 

Personally, I'd use a trim router with this method since the heavy cuts will be made with a jig saw.

In putting the bowls together, I'd take each bowl and sand the rounded edge flat on an oversized piece of sandpaper so there's plenty of glue surface and stronger joint.

You'll need to drill a hole and mount an appropriate connector in place for the audio source. A powered speaker will require a second connector, and a blutooth connection will require some way to charge (and eventually replace) the battery. I'd stick with wire with a 1/8th inch (3mm ?) stereo plug.

attached is a rather simple drawing of the trapezoid hold downs and the base. You would attach the top plate to the bottom and the templates would go on top of that upper plate. This should hold things in place for you, and reduce the complexity of your build. Hope I've been clear.


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## DesertRatTom (Jul 3, 2012)

Oops, forgot the finishing item. Many bowls come pre finished with some food safe stuff. Glue doesn't stick to some of these oils, which means you'll want to sand down the edges you plan to glue together. Invert the bowl over a large sheet of sandpaper, or glue several large pieces onto ply substrate, then move the bowl around, open side down, on the sandpaper. Take off enough of the edge so you're putting flat to flat. Both bowls will need sanding. 

If the bowls are pre finished (most likely) you will find it difficult to find a finish to go over the existing food safe one. Sanding might not be enough since food safe finishes soak pretty deep into the wood. You might be able to use some solvent to reduce it, but I doubt you'll like the result. I guess you could try to get some unfinished bowls. 

Finishing for me is pretty simple, Sand down to 150 grit. clean it off. Apply sanding sealer, dry, then sand down to 220 grit (seldom finer than that). Clean surface of all sawdust.

Apply pre stain and in the same session, apply stain. Prestain makes for more consistent staining. Rub off excess and apply more stain until you get the color you want. (I use mostly Minwax water based stain. Rub off all excess stain and allow to dry thoroughly.

Apply wipe on poly, which you can thin and apply several layers for a smooth finish. Pretty simple finish. You could also do the sanding mentioned, then finish with a few layers of spray on laqquer applied as evenly as you can manage.

You will have to make sure all connections are installed and soldered on correctly. I suspect you will have to line this with some amount of sound dampening material, but I'm not an audiophile. Once you glue the two halves together, it's NOT coming apart.


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## hyped (Jan 22, 2018)

DesertRatTom said:


> Oops, forgot the finishing item. Many bowls come pre finished with some food safe stuff. Glue doesn't stick to some of these oils, which means you'll want to sand down the edges you plan to glue together. Invert the bowl over a large sheet of sandpaper, or glue several large pieces onto ply substrate, then move the bowl around, open side down, on the sandpaper. Take off enough of the edge so you're putting flat to flat. Both bowls will need sanding.
> 
> If the bowls are pre finished (most likely) you will find it difficult to find a finish to go over the existing food safe one. Sanding might not be enough since food safe finishes soak pretty deep into the wood. You might be able to use some solvent to reduce it, but I doubt you'll like the result. I guess you could try to get some unfinished bowls.
> 
> ...




Hey Desert rat,

Thanks for all the great info and taking the time with such a detailed response! You have definitely shown some great options to get a good finish!!

I may have a few questions re your approach for the drilling and routing but I’ll have a look at what I have around first to do the job and go from there.
As I am just getting started I don’t have as many tools, offcuts and various screws, threaded inserts, clamps etc so trying to get a good job done but also not have to buy lots of items at once if that makes sense?! Death by a thousand cuts as they say!!!! 


You did raise finishing. As you pointed out it does have some sort of finish on it and surface is quite smooth. To your point I was going to sand it holistically and as u mentioned sand abit more on the rim to remove the slight round over in the bowl. Which should make the glue area for joining the two bowls around 12mm once flat I’m guessing it’s around 10mm right now.

Finish wise I wanted to go a gloss black. Now I’m guessing being gloss it’s going to harder to get a smooth looking finish as it will show up any imperfections but I’m willing to give it ago.

I’d be interested in your thoughts on painting it? 

Should I give it a sand with 220 apply some sort of seal undercoat, resand lighter with 220 or higher again do second coat or primer/undercoat and then paint? Paint/spray coat + sand 800, again spray paint + 800/1200 final coat if it still isn’t right maybe one more coat with one more sand of like 1600? Then a clear top coat of some sort?

To be honest I’m not sure what the best prep primer/undercoat would be and best type of black gloss paint to go with. I assumed if done right using a spray can should be able to give me a decent result and give a smoother finish then any brush (even if it’s not a professional spray gun.)

I’m happy to put in the effort. Whilst I’m kinda new to work working and staining/painting woods etc (outside painting rooms lol) if I’ve taken in anything from reading is that preparation is everything for painting/staining! 

Thoughts on approach and best paints/prep coats?

Oh and also should I look for an specific wood glues for joining the two spheres?

Any wood glues should avoid or ones I should go for?

Thanks heaps Tom





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## DesertRatTom (Jul 3, 2012)

Hi Jules:

I tried to keep my suggestions cheap and simple. You don't need threaded inserts, simple T-nuts will work. You would cut a slot through the top of the trapezoids. The star knobs you can get in the specialty nuts and bolt sections of HD or or Lowes. To cut the groove, Find some really good hard wood and drill 3 or 4 overlapping holes down the length of the groove, then glue sandpaper on a stick and use it to smooth out the grooves. Use a coarse grit 80 will do, to smooth the groove.

You can buy a 2x4 foot rectangle of ply from HD or Lowes, which will be enough to make the top and bottom layers. T-nuts are simple and cheap. Get them at the same time you buy the star knobs and make sure they match. Drill a slightly larger hole than the thread size (a 14 inch threaded nut requires a 5/16th hole. Pound the T-nut through the underside of the bottom layer with a hammer. 

The top has to connect with the bottom and be adjustable, which suggests four bolts through the base, then a double nut on top of each bolt with one nut below the top and the second above so you can set the height precisely.

Now, all that may sound complicated, but it isn't. All of that jig stuff is about safely cutting an opening in one bowl. The second will be the bottom and doesn't need a jig

Using a jig saw to cut the rough opening is simple enough, just take your time.

Spray paint can produce a very nice glossy finish. I don't ever use more than 320 grit sand paper for wood. It can gum up the surface and doesn't necessarily improve smoothness. So forget the high grit papers. I do like the new 3M translucent sand"paper". conforms to shapes very well and lasts a long time.

I hope all this helps. What you're trying to produce is pretty interesting. Do a couple of test runs and see how it works out. The few tools you'll need to buy to do it are tools you'll always use. 

I'll try to answer any questions I can. Just dive in and do it. You'll learn a lot whether or not your project turns out perfect.


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## hyped (Jan 22, 2018)

Well not as far as I would like but I’ve made some progress on the project.

To cut out the first hole I decided to use a hole saw. To secure the bowl I cut out a hole in 1/2 mdf a mm or so smaller than the top of bowl sanded it slowly until I got a tight fit for the bowl.

I took the idea of desert rat (thx mate) and used some trapezoid shape around the sides to secure the bowl in more. I didn’t use tnut simply screwed to mdf base.

My cordless just didn’t have the grunt for hole saw so I had to use a corded drill. I think for the second cut out I’ll use a better hole saw. Bamboo was dam hard to cut through no wonder they say it is hardest wood!!! It was bloody tuff!

Despite it being hard to get through it cut through pretty well only a few splintered areas

Next to build the box around the bowl to give me a flat surface to router out the recess.

I’ve cut the out diameter circular template in a piece of plywood 1/2 inch. I was planning to use the inner bamboo cut out from the bowls Center point to help align the top template to ensure the recess is even around the bowl. I don’t have a rabit bit large enough, I only have a 9mm bit so I am assuming that I can use a 12mm straight bit and it should be ok?!? I want the recess depth to be around 4mm that should still leave a think enough surface for the speaker to sit in.

I’ve attached a pic of speaker sitting in the inner hole. Obviously not recess yet but it sits in the inner hole nice and snug!

Thanks again for everyone’s thoughts, advice and encouragement. It’s been great and happy to hear any thoughts people have on next steps. I’m still very new to woodworking and it’s been slow and some trial and error but hopefully I’ll get there!!!

















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## harrysin (Jan 15, 2007)

The simple and quick way is in a lathe, held in place with a Longworth chuck like this one that I made and posted a pdf showing HOW I made it. I don't suppose that you live here in WA.
As for the sphere itself, you mentioned that the driver was passive, yet you also mention terminals. In my specialist audio days a passive radiator was a driver without a magnet and the air pressure in the cabinet caused the cone to move which improved the low frequencies. Could you post an explanation of the system that you're building.


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## hyped (Jan 22, 2018)

harrysin said:


> The simple and quick way is in a lathe, held in place with a Longworth chuck like this one that I made and posted a pdf showing HOW I made it. I don't suppose that you live here in WA.
> 
> As for the sphere itself, you mentioned that the driver was passive, yet you also mention terminals. In my specialist audio days a passive radiator was a driver without a magnet and the air pressure in the cabinet caused the cone to move which improved the low frequencies. Could you post an explanation of the system that you're building.




Hi harry
Thanks for your email unfortunately I don’t have a lathe and I’m in nsw so long way from good old Perth.

You are correct, they are passive speakers with full range drivers (not passive radiators).
They will be augmented by a small sub crossed over externally by minidsp board at 100hz in 18db slope. Amplification will be an external amp I build.

I’ll house the dsp board, amp, preamp and Bluetooth module all in the same external chassis.

So they speaker themselves will just have some sort of dampening and filling to help with resonances and the cross over will be external to the speakers spheres




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## DesertRatTom (Jul 3, 2012)

Nice job so far Jules. Rather than cutting such a wide rabbet, could you just mount the speaker to the inside of the opening? Might be easier and might make putting a cover on easier? Just trying to think simple here. 

Your comment on nsw had me look at a map of Australia. Sure a lot of open space there. I know it's about the same size as USA, it also seems to have been settled mostly in the East, with large open deserts in the West. You're about the same parallel as Perth, but a whole continent away. You aussies seem to have a pretty strong interest in woodworking. I also read a lot about "sheds", kind of mens' clubs? Population's kind of small, you fellas need to get busy on that.


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## hyped (Jan 22, 2018)

DesertRatTom said:


> Nice job so far Jules. Rather than cutting such a wide rabbet, could you just mount the speaker to the inside of the opening? Might be easier and might make putting a cover on easier? Just trying to think simple here. .


Hey desert Rat
I thought of Mounting some sort of inner ring base inside the sphere, however, I couldn’t think of the best way to do it and have it hug the inside of the bowl.

So say I cut out a donut shape how do I then curve over the sides/top so that it hugs the inside of bowl to give me enough contact to glue it to the inside of the bowl??

This would actually be the ideal approach as I will give me of a solid lip for the speaker to sit on it’s just getting it to sit molded in.

I’m sure there is a logical way to do it this newbie just can’t think of it 




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## hyped (Jan 22, 2018)

DesertRatTom said:


> Your comment on nsw had me look at a map of Australia. Sure a lot of open space there. I know it's about the same size as USA, it also seems to have been settled mostly in the East, with large open deserts in the West. You're about the same parallel as Perth, but a whole continent away. You aussies seem to have a pretty strong interest in woodworking. I also read a lot about "sheds", kind of mens' clubs? Population's kind of small, you fellas need to get busy on that.



Haha yes for a country the size of USA or slightly bigger we don’t have a huge population. As you rightly pointed out most population is hugging the coast with 3/4 in east and 7m alone in the state I live in NSW, Sydney has 5m so it’s a pretty large city.

We have a pretty unforgiving environment with a huge portion of land which are desert, but on the coasts we have loads of beautiful beaches and reefs along 1000s miles of coast.

Summer I would say it’s not a stretch to say half of down under has days on end of close to or past 110-120f

From Sydney where I live to Perth in WA it’s 5hrs or so by plane so long flight.

Shed, garage, man cave, name differs but need is universal - a place to tinker and escape the kids and mrs for a while  (I’m sure a few wifes as well)



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## hyped (Jan 22, 2018)

DesertRatTom said:


> Nice job so far Jules. Rather than cutting such a wide rabbet, could you just mount the speaker to the inside of the opening? Might be easier and might make putting a cover on easier? Just trying to think simple here.



I suppose either way I’m going to have to cut out a larger hole. Be that half way or all the way.
If I did go all the way I suppose I could just put a block of wood to give a pilot spot for the drill.

That bamboo stuff was dam hard so I think I would better of using a TCT hole saw, my gut tells me though it will probably kick abit to start so it might be better off using my bi metal tooth saw first then changing to the other hole saw.

Or I could just route it out I suppose.

If I was using the router Whether I am doing the recess or cutting all the way to make a larger hole with straight bit. is it better coming in from side or down from the top??? I’ve got a fixed and plunge base for the router. Just not sure what the best approach would be for cleanest cut.




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## harrysin (Jan 15, 2007)

Why not contact a local turning club, I'm sure that a member would do it all for you and I doubt if any cost would be involved.
Are these speakers being made from an established design, I ask because I'm intrigued, having never come across anything like it.


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## hyped (Jan 22, 2018)

harrysin said:


> Why not contact a local turning club, I'm sure that a member would do it all for you and I doubt if any cost would be involved.
> Are these speakers being made from an established design, I ask because I'm intrigued, having never come across anything like it.




Hi Harry
Good suggestion and I may very well do that. I suppose I would like to try and fail first before I rely on someone  if I can learn through the process even if I stuff up along the way then I’m happy with that 

The idea of the sphere bowls has been used before. However, From a speaker, amp, etc etc perspective I’m doing my own design, will do my own acoustic measurements and tweaking to my liking I suppose.

Whilst spheres do pose their own challenges they also have some advantages. Flat surface front baffles need what’s called baffle Step compensation which without going into too much detail is the tuning of the speakers to accomodate for reflections of sound waves off the surface surrounding the driver. Spheres have significantly less impacts from this effect and also the internal standing waves don’t impact the same way a traditional speaker box does.

So for me it’s an interesting concept to see how it turns out





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## harrysin (Jan 15, 2007)

The only spherical speaker that I've come across has two identical drivers bolted together face to face and connected in parallel but 180° out of phase. Such spheres have lots of small holes. Such speakers are intended to hang from a ceiling and are omni-directional. I have no idea what such a design sounds like!


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## hyped (Jan 22, 2018)

harrysin said:


> The only spherical speaker that I've come across has two identical drivers bolted together face to face and connected in parallel but 180° out of phase. Such spheres have lots of small holes. Such speakers are intended to hang from a ceiling and are omni-directional. I have no idea what such a design sounds like!




I’ll let you know in due course 


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## hyped (Jan 22, 2018)

Well I have build a frame around the bowl. I cut out a recess but I I’m not confident in the strength of the recess so I’m going to try and make a recess out of mdf and place it on the inside of the bowl. The cut out went fine but it’s going to be a pain to sand it to curve to hug the inside of the bowl so it can be glued.

I’ll post some more pics and update soon











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## gmercer_48083 (Jul 18, 2012)

Jules, I commend you! Such an ambitious project. I have no doubt...it will come out excellent!


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## Cherryville Chuck (Sep 28, 2010)

It looks like you're off to a good start.


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## hyped (Jan 22, 2018)

gmercer_48083 said:


> Jules, I commend you! Such an ambitious project. I have no doubt...it will come out excellent!





Cheers mate appreciated. For my first wood work project I’ve got to admit it’s above my pay grade 

People have been generously offering great advice. Taking it slowly (well there’s not much choice there anyway) haha

Hopefully I’ll get there and persistence can make up for the skill gap!



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## hyped (Jan 22, 2018)

So I’ve glued the molded recess into place. I just epoxy. I sanded the disc to hug the inside of the bowl as best I can but there are a few areas where it’s not flush. So I though epoxy would expand better???
I made a kinda vice out of some off cuts a threaded rod and wingnuts to hold it In place.

The inner recess is about 1/4 lower than I want so I’m going to cut some smaller rings out to sit in inside so the speaker is perfectly flush

I’m going to try and build an internal brace as well. As I don’t trust the epoxy alone.

Here is the bowl after clamping I placed a towel on in top to protect the top edge











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## hyped (Jan 22, 2018)

Recess is complete. When the speaker sat on the lip it was 5mm under level of bowl because of thickness of the bowl. Cut out some spacer rings and now perfectly flush!!!  

One speaker front down. Onto the other and then I’ll build internal brace, spacer disc between the bowls and get ready to join them together!

I’m hoping I’ve worked out the trickiest bit now (well tricky for me). 











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## DaninVan (Jan 1, 2012)

Nicely done, Jules!


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## hyped (Jan 22, 2018)

Well it’s been a while since I last posted but we have made some progress after a set back or two.

I sprayed a coat of primer on the bowls in prep for glueing together.

I realised I was going to have to sand back some small areas near the join in bowl but wanted to get a coat down.

Well the primer coat stuck well to the bowls after I sanded back all the vanish but I wasn’t happy with finish it had orange peels so I hand sanded it back to 240.

The finish is smooth again now and a lot of the primer is still on bowl it adhered to the bowls really well.

So tonight I’ve glued the bottom of bowls to the middle spacer and bolted into place.

I’m leaving 6 inches of the threaded rod exposed at the bottom for now. That way I can amount it on t nut and place on lazy Susan to make it easier to paint 

Next step is to glue the top on and it’s ready to put a top coat on.

The spacer will be wrapped in a metal copper strip.

Slowly getting there 











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## harrysin (Jan 15, 2007)

A really excellent job Jules. I'm still very interested to hear your honest opinion as to how it sounds.


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## hyped (Jan 22, 2018)

harrysin said:


> A really excellent job Jules. I'm still very interested to hear your honest opinion as to how it sounds.




Hi harry
Thanks - for sure I will give some info as soon as I’m close to done before stands are done 


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## harrysin (Jan 15, 2007)

Hi Jules, have you any news regarding the fidelity of the speaker? I'm still very interested.


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## hyped (Jan 22, 2018)

Hi all,

Sorry it’s been a while since I posted. It’s been pretty hectic lately and the effort needed to get these speakers done took more effort than anticipated.

But finally there finished!!  there has been many learnings along the way to get these done and a few times I felt like throwing in the towel I can tell you that! But I’ve learnt a lot along the way!

I finished them in gloss black with gloss clear coat sanded and polished to 2500 grit. I used brushed aluminium between the two spheres. I’m still playing with various legs but for now I’ve used some 3/8 metal legs with round ball feet.

The subwoofer box you see was made out of 3/4 and 1/4 mdf and is about 11inches square. Simply glued didn’t need bracing as it’s quiet small.

To deal with end grain I saw a suggestion to use drywall, normally for plaster sheeting. Some seem to say it is a pain and messy to work with, sure when wet it made abit of mess but it sanded down really well.

To seal it I used bins shellac primer in spray. I’m not sure if it was normal but it came out of can somewhat grainy, but it sanded really well and gave a smooth finish which covered well.

Despite the grainy nature of spray I really liked the bin product.

The sub was done in flat black this time and whilst it’s not quiet complete I’m happy so far and I’ll post some pics when finished 


Harry, sorry for lat reply mate. How do they sound. Great, couldn’t be happier. There is a slight bump at about 8k which when I get them up and running with DSP and do room correction I’ll smooth out but it’s just over 2db so it isn’t to much. I tried lining speaker but it really didn’t need it and showed no noticable difference. Couple handful of poly fill in each speaker did the job. The speaker is sealed and has a f3 of 90hz. Which is fine as I’ll be using with a sub. Running a port in the enclosure was somewhat tricky and given I was crossing over I thought I’ll leave it o could have got it down to around 50hz.


Thanks to everyone for their help and advice along the way it’s been greatly appreciated guys thanks heaps 


































































































View attachment 1









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## hyped (Jan 22, 2018)

Always hard to tell audio but he’s a quick video 
https://www.dropbox.com/s/q6ovhnha5ta1dzp/Video 15-4-18, 7 09 52 pm.mov?dl=0




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