# Dust shoe reboot (no pun intended)



## difalkner (Jan 3, 2012)

I made an MDF dust shoe a few weeks ago and thought I'd make another one to try some different things on for size (sorry, another 'shoe' reference... ugh!). The first thing I did was to make the holes the correct size. On the first one I made the spindle hole 4" dia. when in fact it is 100mm (3.93"). That meant I had to do some makeshift shimming and it was only holding so-so and I wanted a better fit. The second thing I did is to label the sides 'Dust' and 'No Dust' so the dust and chips will know which side is which... :nerd:

This is as far as I got on the little project - more later. Ultimately I want to make one out of Acrylic or Plexiglas but right now MDF will suffice.


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## 4DThinker (Feb 16, 2014)

Looks good David. Love the labels! 

I do have serious reservations about how long the MDF will survive, mainly at the tightening points. A version done in 1/2" aluminum or a good acrylic/HDPE/whatever plastic might do better in the same configuration. Keep us updated on how well it works, and if the dust behaves better thanks to carved instructions. 

4D


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## difalkner (Jan 3, 2012)

Well, first testing shows that it followed directions perfectly - there are no chips or dust on top... :wink:

Now I'll see what I can do about getting a brush or clear shield to contain the dust and chips even though Walnut is such an awesome wood even in chip form.


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## difalkner (Jan 3, 2012)

Here's an update on the dust shoe but I had to upload it as a wmv instead of my normal mp4 so the video quality isn't quite as good as my normal high-quality cutting edge videos... :wink:


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## RainMan 2.0 (May 6, 2014)

I liked the fact that it was clear and you could see inside , but I thought it was rubber , not a tupaware bowl lol .
Good try though.

This is the stuff I thought it was . Wonder how much it costs ? 
http://www.silex.co.uk/products/silicone-rubber-sheet-(solid)/superclear-silicone-sheet/


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## difalkner (Jan 3, 2012)

That's more like I wanted, Rick, but it seems you have to buy so much of it that it becomes prohibitive for what little I'll use. My 'bowl' certainly didn't work!! LOL!


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## honesttjohn (Feb 17, 2015)

Dave,

You can buy just the brush part from, I think McMaster and a couple other places. Then you fit it to your piece. Should be fairly cheap.

HJ


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## SteveMI (May 29, 2011)

I have used these, Easy-Cut Strip Brush, 1/4" Wide x 3/16" High Backing, 3" Overall Height - https://www.mcmaster.com/#conveyor-brushes/=15r3gm6 $4.39 per foot.

One consideration is the stiffness. If mounted true vertical, any dust screen will add Z axis resistance. Softer or more pliable the better. When I put the short 1" easy-cut conveyor brushes on mine the added resistance really was significant. Since then I angle them out about 10 degrees. I bought 3 feet of 1", 2" and 3" to evaluate and am now just using the 3".

In the near future, in my next order from McMaster Carr, I will probably try the soft horsehair brushes - Galvanized Steel-Backed Conveyor Strip Brush, Horsehair Bristles, 3/16" Wide x 7/32" High Back, 3" Overall Height - https://www.mcmaster.com/#conveyor-brushes/=15r3k0q Of course they are more than double the cost at $9.58 per foot, but dust foot doesn't take much.

Neither of these lets you see the cutting going on.

Steve.


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## bgriggs (Nov 26, 2008)

I used a similar design years ago. You have to curl the ends up to make it work. In fact I ended up with a "J" shape at the base of the fingers.






Bill


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## difalkner (Jan 3, 2012)

That's very close to the one I did, Bill, very close. Did the sharp edges scratch softer woods? I definitely like being able to see the cutter as it works.


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## Cherryville Chuck (Sep 28, 2010)

What about mounting it on slotted holes that the whole assembly slides up and down as needed?


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## difalkner (Jan 3, 2012)

Cherryville Chuck said:


> What about mounting it on slotted holes that the whole assembly slides up and down as needed?


I've seen some that do that, Chuck. There's a fair bit of engineering involved to get it to respond properly and not jam. For instance, when the shoe comes in contact with a clamp or hold down or other obstruction or passes over a void area large enough for the shoe to drop only to hit the next machining section (does that make sense?). If it is free floating then it drops to its lowest extent where possible. 

Of course, if you're always doing large flat sheets then that would be ideal but if you're doing lots of contours or 3D there might be issues. It is definitely an intriguing area of CNC, one I wish to pursue in greater depth (beyond just toying around with plastic containers and $5 brooms).


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## bgriggs (Nov 26, 2008)

Just bend the ends back around on them self. The rounder profile will stop jamming and scratching.


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## SteveMI (May 29, 2011)

bgriggs said:


> I used a similar design years ago. You have to curl the ends up to make it work. In fact I ended up with a "J" shape at the base of the fingers.
> Bill


Bill - The J feature has merit to me. There was always a trade-off between a smaller vacuum area and length of the skirt so it didn't get caught into the router bit. A bigger vacuum footprint and it goes off the end of what you are cutting to lose vacuum and throw dust. My 10 degree slant works "most" of the time, but can fail when the angle edge contacts something vertical.

Steve.


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## SteveMI (May 29, 2011)

For a Rube Goldberg approach, how about another stepper motor that keeps the bottom of the dust skirt at the top of the material. It would just be the full cutting depth from Z zero. Maybe a chain 360 degrees around the spindle driving 4 acme rods so it rises and lowers evenly. Then a webcam mounted underneath with LEDs to show progress on a Raspberry Pi bluetooth display. 
(maybe too much coffee this morning?)
Steve.


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## 4DThinker (Feb 16, 2014)

I've seen a few solutions that mount the dust collector on a non-moving part of the Z axis. You can slide and lock it to the height you want it to be (top of material usually) then it stays there no matter how much the bit moves up and down. I've looked into doing this on my Probotix Meteor, but their Z axis design makes this not-so-easy. 

Still, as my students are rarely just cutting profiles on flat boards I've given up all hope that there will be any one dust collection solution that works with every project. The fan on the Dewalt routers we use defeats most attempts even on flat board. Make a great argument for water cooled spindles with no fan. 

4D


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## difalkner (Jan 3, 2012)

SteveMI said:


> For a Rube Goldberg approach, how about another stepper motor that keeps the bottom of the dust skirt at the top of the material. It would just be the full cutting depth from Z zero. Maybe a chain 360 degrees around the spindle driving 4 acme rods so it rises and lowers evenly. Then a webcam mounted underneath with LEDs to show progress on a Raspberry Pi bluetooth display.
> (maybe too much coffee this morning?)
> Steve.


I like the way you think, Steve!! I'll get started on that one right away!


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## swcrawford (Aug 26, 2010)

For a cheap, clear, flexible material I have used clear extruded vinyl carpet runner. Its available at your local blue big box home center in the flooring department. Its comes in 27" roll and is sold by the foot for less than $3. It is quite flexible so perhaps a hybrid of your tupperware solution may work. Just cut the tupperware part off even with or just below the collet and glue on a fringe of the vinyl material.


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## difalkner (Jan 3, 2012)

Thanks, SW! And welcome to the forum. I was just there today but I'll go back tomorrow and take a look.


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## RainMan 2.0 (May 6, 2014)

This is going to sound dumb , because I haven't seen it done before . But my idea is to blow compressed air with a nozzle aimed at the bit , then have a dust extraction shroud on the other side picking up the debris . This way the router bit would be unobstructed visually .


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## difalkner (Jan 3, 2012)

Sometimes you need to blow compressed air to clear the channel being cut. Depending on the bit chips can sling out far and wide. I don't use the DC when I engrave or use a 1/8" end mill because there's just not enough dust and chips to put up with the noise of the DC. It's during those times I get to enjoy the quiet spindle with no hearing protection. But I used a 1.5" two-flute bottom-clearing bit the other day with no shield or DC at all and it flung chips 15' away!

To blow air and catch the chips you'd have to work with the air pressure/volume carefully so as to not blow so hard the DC can't suck it in but the idea has merit, Rick. I've worked up a couple of designs using that very combo but haven't built a model yet - one day, maybe.


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## difalkner (Jan 3, 2012)

After slinging chips all over the shop when I cut that Pecan slice sign I decided it was time to review the homemade dust shoe. I have about $5 in this dust shoe, maybe $6, and it works to about 50% efficiency on chips and about 90% on MDF dust. 

So I looked at the airflow in and around the dust shoe with the DC on and decided that the broom bristles are just spaced out too far a the top. This does two things - the chips can fly through the openings and also the air being pulled in by the DC is taking a shortcut through those gaps instead of pulling chips from the work piece.

I picked up some carpet runner, fairly flexible and sort of transparent, and wrapped it around the dust shoe. I just stapled it in place to test but the good thing is it worked. I cut a pocket 4" x 6" x 3/8" deep into a piece of Cherry and I didn't see more than 6-8 little chips when it was all said and done. And chips that manage to escape are picked back up when the brush comes back around on subsequent passes. So I'll probably use it like this for a while and then do a cleaner version at some point.

Some of the chips get stuck between the bristles and vinyl but those are easily dislodged and cleaned up.









Clean pocket; previously there would have been a lot of dust and chips on the work piece and in the pocket. The chips on the spoilboard are from messing with the dust shoe and some of it falling.









I still have some other ideas for a better performing dust shoe but I have too many projects that need my attention first.

David


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