Anyone have luck making a clear dust boot brush that doesn’t get sucked in by the dust collector? Here’s one experiment I did; but the PVC wasn’t strong enough to avoid getting sucked in.
Any ideas?
I’m printing you boot out now.
On another design that I purchased it used 3 inch brush and it was getting destroyed by any large bit so he designed an extension that then used shorted brush and it works great. here is a pic
also did I miss the assembly instructions that recommended bolts and nuts? Sorry I just went back and read the message, magnets hold it together…
Awesome! I was thinking about making extensions that are stackable; one could toss one in the middle to get more length when needed. I’m using a 3" brush for my deep carvings, but it has been causing issues with brush pieces getting stuck in the ATC spindle. I switched to a 2" brush, which doesn’t do as good of dust collection, but doesn’t have any issues with the ATC. I’ve got a new 3" brush that arrived today for testing.
Yeah, no real directions: Use a 1/4-20 nut and bolt for the clamp; the nut should easily fit in with some pressure. 3/8 by 1/8" magnets for the other areas. You can super glue them in, or just use pressure (mine stay in with pressure). Let me dig up what I got on amazon…
Magnets:
or the same size from K&J magnets. The above were cheaper based on my location; I bought 100 of them.
The higher the N-rating the stronger they are.
I have the 2.2kw avid spindle it measures 79.07mm so I printed the 80mm base and it is way big opening measures 89.4. should I print the 75mm ver?
Oh man, that’s my mistake - I exported the files from fusion but didn’t double check them. It looks like I exported that one as the 90mm one. Here’s one set as 80mm. Sorry for that mistake!
base 80mm.stl (302.7 KB)
thanks man, I suk at F360…lol
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Corbin, I have not tested this, but my theory is you are not allowing enough airflow between the flaps. It looks like you might have made cuts with a utility knife to create the flaps (so no gap). I think you’ll want 1/8" gaps between each flap. Providing no pathway between the flaps builds more pressure on the surface of the flap than it can withstand. I would try drilling a 3/16" hole at the root of the slits then cut with a utility knife a 1/8" slot.
It’s a problem of surface area and stiffness. The individual nylon bristle has a super low surface area that airflow can enact pressure on. The flaps of the PVC have a super high surface area in comparison. That, plus the nylon bristle is stiffer and there are many passages between the thousands of bristles for the air to flow.
Because the PVC is so flexible, I imagine you will run into a flap length limitation even with the 1/8" slots. I think there’s 3 variables you can manipulate:
- PVC thickness (you’ll get more stiffness with thicker material)
- Slot width
- Flap length
Hope that helps!
Seth
Seth - this is a great observation! I think those are some awesome ideas that I can play with to try to make this work. Thanks for the ideas!!! This helps me a ton.
Corbin
Some things to think about on this topic;
In these sorts of “dust shoe” style manifolds where you dramatically widen the suction orifice, you must use thicker and stiffer brushes. Really heavy gauge vinyl will work but will not last as long as a good brush.
The reasoning is that you are trying to “trap” the suction under the skirt and thus restore the airflow around the cutting tool.
You will see many pro systems where they use strip brushes that are longer than the actually distance around the skirt. This is done so as to double the brush thickness in certain areas and thus reduce airflow through the brush at those points. In this case the doubled brush would be around the actual orifice for the vacuum hose whereas the single brush thickness would be around the cutter. Thus the airflow will be greater around the cutter and pull more swarf to the vacuum hose.
In commercial settings you will also see high pressure lines run to “dust shoes” and if you look up inside you will see a ring with many tiny nozzles that are pointed up the vacuum hose. The principle is reducing the boundary layer friction at the edges of the vacuum hose and thus enabling a higher volume of material to be suspended in the airstream.
Of the two items above I think the “half doubled brush” is actually the cheapest and easiest option. Of course the pressure assisted manifolds are superior for high volume machining but are hard to tune and expensive.
When I was still using that style of manifold I used the cuttable T-slot brushes from McMaster-Carr. It is extremely easy to 3d print the slots for those brushes. In your design you can easily make the loop of the track to double in the right places.
And yes, I do realize I took all the fun out of watching the cutter do its thing. Either you go dust and swarf everywhere and get to see it or you just witness the results when it moves 
Thanks! that is a lot of good info and ideas. Doubling up on the input area might work great too. I’ll do some experiments. I mainly want a clear brush to see when I’m making mistakes on new items I’m cutting.
Oh, completely understand. I did like you and tried every trick in the book to see under that dern thing and finally gave up.
Now I just use a camera. It seems to work well but I need to get into heavy use before I will make it an official release for the dust manifold on the S30 spindle kit.
Ah shoot! I haven’t had mine pop off yet, and I’ve done some pretty aggressive deep cuts, but I think it would be good to have some pins . I bet you could modify it by just drilling 1/4" holes in it and gluing a dowel on one side.
What strength magnets are you using? Maybe that is key to having it stay on for me. I think mine are N52.
I’ll update the model with some pins and do some more testing myself; I also want to make it so the dust port easily attaches/detaches for use as a vacuum on the table.
I also have a reworked design that pushes the clamp down to the main body. I think this will be better to allow the boot to go up higher. Then I can add some adapters w/magnets to get various heights.
Thanks for testing it out!
Yeah I could fix this one I was just giving some feedback. I have many many dust boots of different designs that I got from makers like yourself
I wonder if you have the first layer a solid one inch and two outside layers with finally cut flaps if that would work 
That would effectively reduce the flap length which would stiffen the flaps. So definitely helpful, but you also don’t want the solid region to be below the max machinable depth. There would be a limit to that solid region.