# Precision Machined Bushings - Some Guidance Needed Please



## TinyTiger (Mar 9, 2013)

I'm looking for some guidance from our brain trust here (please!) I searched quite a bit for the answer and didn't find it in any of the existing threads. Perhaps I missed it. If so, please point me in the right direction....

I want to cut dadoes on cabinet sides using an exact-width dado jig. The jig involves running a straight bit and guide bushing along the jig. I've been using a Dewalt 718 with a standard PC (1-3/16") hole in the base and a brass bushing. Easy peasy, huh? Wrong - I fought with it and fought with it and couldn't get things to fit properly. It turns out that the bushing was of such poor machining that it slops side-to-side inside the base hole, even when tightened. :angry: Bottom line - I need some better and more accurate bushings! 

I'm looking for advice based on your experience - which brand(s) of PC-style brass bushings have the most precise machining so they fit well in the base and won't move side-to-side on me? I want the best quality I can get. I'm looking for a complete set and have been looking at all the usual suspects - Lee Valley, Hartville Tools (which advertises CNC machining on theirs), Woodhaven, Rockler, MLCS, etc., etc. Unfortunately Whiteside and Leigh only make a few sizes and not a complete set. 

Please let me know who does the best job of machining them. Thanks for your help!


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## clarksvilleal (Jan 2, 2009)

TinyTiger said:


> I'm looking for some guidance from our brain trust here (please!) I searched quite a bit for the answer and didn't find it in any of the existing threads. Perhaps I missed it. If so, please point me in the right direction....
> 
> I want to cut dadoes on cabinet sides using an exact-width dado jig. The jig involves running a straight bit and guide bushing along the jig. I've been using a Dewalt 718 with a standard PC (1-3/16") hole in the base and a brass bushing. Easy peasy, huh? Wrong - I fought with it and fought with it and couldn't get things to fit properly. It turns out that the bushing was of such poor machining that it slops side-to-side inside the base hole, even when tightened. :angry: Bottom line - I need some better and more accurate bushings!
> 
> ...


Me, too. Just "won" my first router on E-bay today, a PC 690lrvs (variable speed). Can't wait to get it, and wanted to get a template bushing kit to use with it. However I'm a complete noobie to routers, so need same guidance as you, Tiger. 

Also, my first project is in fact a cabinet that will require a number of dadoes, so I am looking for ideas for a good dado jig. So Tiger, what dado jig you are using? Did you make it yourself, and if yes, did you get the plans from a book or mag? 

Thanks,
Al


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## jw2170 (Jan 24, 2008)

TinyTiger said:


> I'm looking for some guidance from our brain trust here (please!) I searched quite a bit for the answer and didn't find it in any of the existing threads. Perhaps I missed it. If so, please point me in the right direction....
> 
> I want to cut dadoes on cabinet sides using an exact-width dado jig. The jig involves running a straight bit and guide bushing along the jig. I've been using a Dewalt 718 with a standard PC (1-3/16") hole in the base and a brass bushing. Easy peasy, huh? Wrong - I fought with it and fought with it and couldn't get things to fit properly. It turns out that the bushing was of such poor machining that it slops side-to-side inside the base hole, even when tightened. :angry: Bottom line - I need some better and more accurate bushings!
> 
> ...


Hi Russ,

Bottom line - most of them are probably made in the same factory. Are you sure it was the bushing and not the base that was out.

I have used Oak Park guide bushings and the "universal" set without any problems.

Brass Router Bushing Set : CARBA-TEC


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## jw2170 (Jan 24, 2008)

clarksvilleal said:


> Me, too. Just "won" my first router on E-bay today, a PC 690lrvs (variable speed). Can't wait to get it, and wanted to get a template bushing kit to use with it. However I'm a complete noobie to routers, so need same guidance as you, Tiger.
> 
> Also, my first project is in fact a cabinet that will require a number of dadoes, so I am looking for ideas for a good dado jig. So Tiger, what dado jig you are using? Did you make it yourself, and if yes, did you get the plans from a book or mag?
> 
> ...



Welcome to the forum, Al.


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## jw2170 (Jan 24, 2008)

PS. this jig does not require a guide bush as the router plate references off of the fence.


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## jw2170 (Jan 24, 2008)

http://www.routerforums.com/jigs-fixtures/30181-can-man-have-too-many-jigs.html


http://www.woodsmithshop.com/download/204/adjustabledadojig.pdf


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## Cherryville Chuck (Sep 28, 2010)

James jig is the easiest way to cut dadoes or grooves. There are no offsets to calculate as there would be with bushings. The only drawback is that you must use the same size bit as you used to cut the groove between the two guide strips. The best way to use it to take a piece of your shelving material and scribe a line down either side where you want it and then line the edge of the jig groove with each side.


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## TinyTiger (Mar 9, 2013)

clarksvilleal said:


> Me, too. Just "won" my first router on E-bay today, a PC 690lrvs (variable speed). Can't wait to get it, and wanted to get a template bushing kit to use with it. However I'm a complete noobie to routers, so need same guidance as you, Tiger.
> 
> Also, my first project is in fact a cabinet that will require a number of dadoes, so I am looking for ideas for a good dado jig. So Tiger, what dado jig you are using? Did you make it yourself, and if yes, did you get the plans from a book or mag?
> 
> ...


Hi Al! First of all, welcome to the family! Also, congratulations on your new router. I love those Porter Cables. It should be a real treat to use.

You and I are definitely in the same boat with our projects. I built my own adjustable-width jig (shown in the pictures) based on the one Marc Spagnuolo ("The Wood Whisperer") built on his website: 

139 – Exact-Width Dado Jig | The Wood Whisperer

I made mine with top sections that were wider than his (the fixed arm is 6" wide, and the movable arm is 4" wide). That way I could put the wing nuts on top and still allow the router base to pass. That lets me clamp and work with it on top of the bench instead of having to cantilever it off the bench. It's MUCH easier working on the top!



















I also made one other critical change from Marc's design based on my original post. Instead of depending on a bushing riding against a rabbet on the inside of the jig, I made the inside of the jig flat and use a bearing-guided bit to run against the jig. That worked a lot better than my sloppy bushings! The bit I use is shown in the router (sticking out quite a bit further than usual so you can see it).

I hope that helps. Let me know if you'd like any more info on it. I hope whichever one you build works well. Let me know which one you decide on when everyone weighs in with their good ideas too. Talk to you later!


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## TinyTiger (Mar 9, 2013)

jw2170 said:


> Hi Russ,
> 
> Bottom line - most of them are probably made in the same factory. Are you sure it was the bushing and not the base that was out.
> 
> ...


Thanks a bunch James! I really appreciate the info.


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## clarksvilleal (Jan 2, 2009)

Thank you all for the welcome greetings and for taking the time to help a rookie. I expect I'll be checking back here often once my "new" PC 690 router arrives in the mail. It's not fancy, but the price was good and for a used router it appears to be in excellent condition, plus it seems to be a classic from my research, and I think it's simplicity will be a plus for a beginner like myself. Maybe later I can graduate to something fancier, but I'm hoping this one will serve me well to start with.

Now, a couple of questions:

James and Chuck - I like the variable spacing dado jig that James built, as it looks pretty simple and foolproof to build and use, and does not require template bushings. But a couple of questions:

1) Regarding Chuck's comments: _*"The only drawback is that you must use the same size bit as you used to cut the groove between the two guide strips. The best way to use it to take a piece of your shelving material and scribe a line down either side where you want it and then line the edge of the jig groove with each side."*_

So you can never use a different size bit without making a whole new template, right? That does seem a little limiting. Also, that implies that if you have a bit sharpened, which I assume would make the diameter slightly smaller, then that bit could no longer be used with the jig, correct?

2) James - is there a reason you used plywood and not hardboard for the base and guide strips as was recommended in the Woodsmith Plans article you referenced in the other thread? I would think tempered hardboard's slick surface would allow the router to slide more easily along the jig.

3) James - Is that hardboard that you used for the square auxiliary router plate you attached to the router base? And why did you make this auxiliary plate when you could have just used the router base itself? Is it because the router bit might not be exactly centered in the original router base?

Thanks again,

Al


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## clarksvilleal (Jan 2, 2009)

*Why so many template guide bushing sizes?*

So it looks like the typical template bushing kit has 7 or 8 sizes of bushings. Now, this is probably a really dumb question, but why do you need so many different size bushings? Won't any one bushing follow a template as well as any other?

Also, is the bushing size somehow related to or constrained by the radius of an inside or outside you may have in your template? I'm a little geometrically challenged, so don't make too much fun of my ignorance here, but my limited brain seems to tell me that the the curves and angles created from a template would be the same regardless of bushing diameter. Different bushing diameters will obviously change the offset of the bit from the edge of the template, which may affect the final size of an article being routed on more than one or two sides from a template. But other than that wouldn't the shape of the end product be the same?


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## Dmeadows (Jun 28, 2011)

clarksvilleal said:


> So it looks like the typical template bushing kit has 7 or 8 sizes of bushings. Now, this is probably a really dumb question, but why do you need so many different size bushings? Won't any one bushing follow a template as well as any other?
> 
> Also, is the bushing size somehow related to or constrained by the radius of an inside or outside you may have in your template? I'm a little geometrically challenged, so don't make too much fun of my ignorance here, but my limited brain seems to tell me that the the curves and angles created from a template would be the same regardless of bushing diameter. Different bushing diameters will obviously change the offset of the bit from the edge of the template, which may affect the final size of an article being routed on more than one or two sides from a template. But other than that wouldn't the shape of the end product be the same?


You are right about the shape, it will be the same as long as the diameter of the guide can follow the pattern. Making cutouts for inlay and the inlayed piece to match is one of several reasons!


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## TinyTiger (Mar 9, 2013)

jw2170 said:


> Hi Russ,
> 
> Bottom line - most of them are probably made in the same factory. Are you sure it was the bushing and not the base that was out.
> 
> ...


It was definitely the bushing. The base is fine, and a PC Steel Bushing I have fits well and locks down tightly in the same one. I also tried two other "spare" bases I have with the same result.

I checked out Oak Park, and it looks like the only bushings they have are 1-1/2" instead of 1-3/16". It also looks like they are closing out what they have! Do you have any others that have worked well? Are the Carba-Tecs the next best thing?

Thanks again for all your help!


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## DaninVan (Jan 1, 2012)

Russ; Oooooo...nice workbench top!!! I like!


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## JCJCJC (May 15, 2012)

TinyTiger said:


> It was definitely the bushing. The base is fine, and a PC Steel Bushing I have fits well and locks down tightly in the same one. I also tried two other "spare" bases I have with the same result.
> 
> I checked out Oak Park, and it looks like the only bushings they have are 1-1/2" instead of 1-3/16". It also looks like they are closing out what they have! Do you have any others that have worked well? Are the Carba-Tecs the next best thing?
> 
> Thanks again for all your help!


I'd try plumber's PTFE tape around the threads of the bushing as a temporary McGyver solution maybe, just to take up the slop.


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## Cherryville Chuck (Sep 28, 2010)

clarksvilleal said:


> Now, a couple of questions:
> 
> James and Chuck - I like the variable spacing dado jig that James built, as it looks pretty simple and foolproof to build and use, and does not require template bushings. But a couple of questions:
> 
> ...


I've also seen this jig with only one guide strip and side to it and I have a circular saw guide built on the same principle as that. The principle is the same for both. On your first cut, with the single guided one and the circular saw guide, you cut off the excess width of the base. That edge is where your bit or blade will cut from then on as long as you use the same diameter cutter or thickness of saw blade. A sharpening or two won't make much difference, you are only talking about a few thousandths difference. If you plan on using it to do a lot of one size groove then it may prove more efficient to make a jig for just that size bit but keep in mind that a 3/4" piece of mdf with glue on it may not fit in a 3/4" dado. Also consider that if you are using plywood it isn't likely to be a full 3/4". The best way to avoid these problems is to use an undersize bit and rout to both sides by repositioning your jig.

You could speed things up a bit by taking James' jig and slotting the ends of one side where it attaches to the stop blocks underneath. A one inch long slot would be lots of adjustment. Then you just line one side up with one scribed line and clamp the whole jig to the work piece and lock the other side down on the other scribed line. No repositioning that way. 

You could even build this jig so that it swiveled on the stop blocks, although you wouldn't be any good as stop blocks then. This would open and close a parallelogram. You would just line one side up and clamp it to the workpiece, then open or close the parallelogram until the other side matched up and then clamp that side down. As you can see, you can take one jig and often make a number of variations in it to suit your purposes and preferences.


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## jw2170 (Jan 24, 2008)

*dado jigs.....*

My response........



clarksvilleal said:


> Now, a couple of questions:
> 
> James and Chuck - I like the variable spacing dado jig that James built, as it looks pretty simple and foolproof to build and use, and does not require template bushings. But a couple of questions:
> 
> ...


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## jw2170 (Jan 24, 2008)

Hi Al,



clarksvilleal said:


> So it looks like the typical template bushing kit has 7 or 8 sizes of bushings. Now, this is probably a really dumb question, but why do you need so many different size bushings? Won't any one bushing follow a template as well as any other?


Different size guide bushings with different size cutter allows for different "off set".


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## jw2170 (Jan 24, 2008)

My jig has the slots and the knobs under the side blocks.


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## clarksvilleal (Jan 2, 2009)

Thank you, Chuck and James, for the very complete replies. 

James - I did see that your jig had the slots underneath. I think I will use your design for my dado jig. I will probably also use plywood for mine because it is more durable and rigid than hardboard, although I may use some 1/8" hardboard I have on hand as a surface layer on top of the base for lower sliding friction, even though I know you said that was not a problem.

Wish me luck. Routing is a new experience for me. I'm really eager to try it out and learn as much as I can. I'm hopeful that it will add a whole new dimension to my formerly boring woodworking projects.


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## jschaben (Jun 21, 2009)

TinyTiger said:


> It was definitely the bushing. The base is fine, and a PC Steel Bushing I have fits well and locks down tightly in the same one. I also tried two other "spare" bases I have with the same result.
> 
> I checked out Oak Park, and it looks like the only bushings they have are 1-1/2" instead of 1-3/16". It also looks like they are closing out what they have! Do you have any others that have worked well? Are the Carba-Tecs the next best thing?
> 
> Thanks again for all your help!


I'm surprised the bushing was that far off. I have several sets of different branded bushings, including harbor freight, and the big issue I run into with different brands are thread pitch issues on the lock ring.

I am a proponent of the bushing guided dado jig though. Two advantages I see are the overall width doesn't need to be so large. The guide rails just need to be far enough apart to accomadate a guide bushing, not the entire base plate.
The main advantage is that you aren't locked into a specific router held in a specific orientation. I built mine with a 1/8" offset so I can use any router with any bit/bushing offset of 1/8", that would be a 1/4" difference between the bushing diameter and the bit diameter; 1/2" bushing-1/4" bit up to a 1" bushing with a 3/4" bit. 

"Do you have any others that have worked well?"
I also prefer short barrel bushings, <1/4", and EagleAmerica sells a set with a 0.201" barrel. A bit spendy at $40 a set but they work well. I think I also saw a post once that said Woodcraft also had a set of short barrel bushings but I haven't personally checked there. I like the short barrels as you can use thinner stock for templates. I'm partial to 1/4" MDF.


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## clarksvilleal (Jan 2, 2009)

jschaben said:


> I am a proponent of the bushing guided dado jig though. Two advantages I see are the overall width doesn't need to be so large. The guide rails just need to be far enough apart to accomadate a guide bushing, not the entire base plate.
> The main advantage is that you aren't locked into a specific router held in a specific orientation. I built mine with a 1/8" offset so I can use any router with any bit/bushing offset of 1/8", that would be a 1/4" difference between the bushing diameter and the bit diameter; 1/2" bushing-1/4" bit up to a 1" bushing with a 3/4" bit.


_
Aha!_ :yes4: Yet another good reason for multiple bushing sizes. And I'm sure there are dozens more good reasons lurking out there. 

Though I only plan to use one router for now, I do like the idea of not being locked into a particular size router bit. If I want to use a bigger bit to cut a wide dado in fewer passes, or a smaller bit to cut a narrower dado than the bit I originally chose for the jig, then obviously the jig that uses the guide bushing is a better choice.

However, just to get myself going quickly, I think I will still start with James' type jig. It will be a bit easier to build, and I don't need to rush into choosing a particular set of bushings yet. OTOH, once I do settle on a bushing set I may go back and build the bushing-style jig. But I want to get going quickly on this first cabinet project.

So, James -- :sold: _You' the man!_ (as we yanks have been known to say).


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## TinyTiger (Mar 9, 2013)

DaninVan said:


> Russ; Oooooo...nice workbench top!!! I like!


Thanks!  Made it myself.


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## TinyTiger (Mar 9, 2013)

JCJCJC said:


> I'd try plumber's PTFE tape around the threads of the bushing as a temporary McGyver solution maybe, just to take up the slop.


Good idea John. Thanks for that!


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## jw2170 (Jan 24, 2008)

> So, James -- You' the man! (as we yanks have been known to say).


I don't think so, Al. There are many,on the forum, professionals and amateurs, who are more knowledgeable that I. I have just developed a thick skin after being on the forum so I put on "my big boy pants" and say what I believe to be correct. I feel that some hold back for fear of being questioned.

The forum has been a great education to me over the years and there is always another way to 'skin the cat'.

Plus, being retired, I can spend all day on the forum if I want. Not everyone has that chance.


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## TinyTiger (Mar 9, 2013)

jschaben said:


> I'm surprised the bushing was that far off. I have several sets of different branded bushings, including harbor freight, and the big issue I run into with different brands are thread pitch issues on the lock ring.
> 
> I am a proponent of the bushing guided dado jig though. Two advantages I see are the overall width doesn't need to be so large. The guide rails just need to be far enough apart to accomadate a guide bushing, not the entire base plate.
> The main advantage is that you aren't locked into a specific router held in a specific orientation. I built mine with a 1/8" offset so I can use any router with any bit/bushing offset of 1/8", that would be a 1/4" difference between the bushing diameter and the bit diameter; 1/2" bushing-1/4" bit up to a 1" bushing with a 3/4" bit.
> ...


Many thanks John! I looked at the Eagle America ones as well, but I forgot to mention those. I use 1/4" length as much as I can too since most of my templates are thinner. That sounds like the way to go since they have been "validated" by one of our other users.


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## damnitboy (Mar 3, 2012)

FYI Infinity sells what I feel is the best guide available. I use the Festool for dados over 4' But that Infinity jig is an example of the genius is in its simplicity as well it has a fine adjustment to locate your dad where you want it.
-Eloy


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## Mike (Nov 22, 2004)

The brass guide bushings that are sold by Woodcraft are what I use and recommend. For Canadian members go for Lee Valley/Veritas.


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## TinyTiger (Mar 9, 2013)

Mike said:


> The brass guide bushings that are sold by Woodcraft are what I use and recommend. For Canadian members go for Lee Valley/Veritas.


Thanks Mike! That's helpful. I wasn't sure how their quality stacked up against the others.

Between a Pat Warner Precision Base and a set from one of the places listed in the thread here, I'll be a lot better off now. I'm glad there are some sets that have been found to work well.


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## Nickp (Dec 4, 2012)

TinyTiger said:


> I'm looking for some guidance from our brain trust here (please!) I searched quite a bit for the answer and didn't find it in any of the existing threads. Perhaps I missed it. If so, please point me in the right direction....
> 
> I want to cut dadoes on cabinet sides using an exact-width dado jig. The jig involves running a straight bit and guide bushing along the jig. I've been using a Dewalt 718 with a standard PC (1-3/16") hole in the base and a brass bushing. Easy peasy, huh? Wrong - I fought with it and fought with it and couldn't get things to fit properly. It turns out that the bushing was of such poor machining that it slops side-to-side inside the base hole, even when tightened. :angry: Bottom line - I need some better and more accurate bushings!
> 
> ...


Russ...welcome...if you look to the left you will see "view Nickp's uploads" where you will find pics of the jig I use for dados n grooves n recesses...as an adjustable parallelogram it allows me to make parallel and non-parallel slots...I used this jig to make closed stringer for my stairs by placing a piece of the tread and the wedge in the jig to make the right size groove. And yes, if you use a different bit or base plate it will change the cut but small price to pay for the convenience. I also used the same technique to clean the slot after applying poly...this particular jig uses a trim router and dedicated 1/2 in straight bit...many thanks are owed to those same folks who responded to you as well...Nick...


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## TinyTiger (Mar 9, 2013)

Nickp said:


> Russ...welcome...if you look to the left you will see "view Nickp's uploads" where you will find pics of the jig I use for dados n grooves n recesses...as an adjustable parallelogram it allows me to make parallel and non-parallel slots...I used this jig to make closed stringer for my stairs by placing a piece of the tread and the wedge in the jig to make the right size groove. And yes, if you use a different bit or base plate it will change the cut but small price to pay for the convenience. I also used the same technique to clean the slot after applying poly...this particular jig uses a trim router and dedicated 1/2 in straight bit...many thanks are owed to those same folks who responded to you as well...Nick...


Thanks Nick! I really appreciate the ideas.


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