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charlieuk
04-11-2014, 07:46 PM
I have been looking for some bristles to make a dust shoe however I need them to be as long as posable ie maybe something like 100-150mm. All the door dust strips I have found are normally only sold in 3m lengths and mounted in a metal track so no good for a curved shoe , it was also incredibly expensive for long bristles. Are there any other solutions to the problem or somewhere were I can get shorter lengths? Many thanks

EddyCurrent
04-11-2014, 08:14 PM
http://www.formseal.co.uk/camstrips.html

It should be possible to bend it.

CAMSTRIP is the required search term I think, I did see it on a roll once.

dstivens
04-11-2014, 08:46 PM
what i did was cut a channel and then i found a paint brush and cut the bristles off. I then super glued them into the channel. Its held up quite well so far and pretty cheap.

EddyCurrent
04-11-2014, 09:50 PM
I'd forgotten about that, someone mentioned it a while back, hot melt glue would work well too I imaging, I think that's the right answer for me.

dstivens
05-11-2014, 07:07 AM
the only problem i had with super glue was it creeped up the bristles a bit so maybe a resin/epoxy might be better or even hot glue as mentioned.

cropwell
05-11-2014, 10:47 AM
Does it have to be bristles ? Could a sheet of vinyl be sliced to make a comb ?

cncJim
05-11-2014, 10:59 AM
Does it have to be bristles ? Could a sheet of vinyl be sliced to make a comb ?


I think this is the method I will be trying.

Cut a strip of vinyl, double sided tape to stick it down, cut very thin "combs" using a metal ruler and sharp blade, layer maybe 2 or 3 strips and glue/attach to the shoe.

Jim

EddyCurrent
05-11-2014, 11:06 AM
Jim, do you think that is more efficient with regard to suction ? what is the advantage over bristles ?
I tried it with one layer of plastic but large gaps opened up as the shoe went down.

cncJim
05-11-2014, 11:18 AM
Hey Eddy - I would think bristles would be best as far as suction goes? - But I like the idea of giving it a try with plastic. I would also try and cut the combs as thin as possible (double sided tape should help with that) and then have a few layers to prevent/minimise the gaps you mentioned. One problem I have seen with some diy plastic jobs online is the combs being sucked into the shoe/cutter so I would need to consider that!
For me, my main aim isn't best/most efficient suction, it just to stop the majority of the wood chips being launched around my garage.....

cropwell
05-11-2014, 12:10 PM
At the moment my machine is lying dead, Its beating heart of a BoB stilled when the magic smoke escaped. When it lives again, I will have to try out the drag knife, cutting A4 sheets of thin vinyl with rows of closely spaced parallel lines. Then I can divide the sheets down the middle, to make combs fine enough for mermaid's hair.:beguiled:

I saw one good idea - to hinge the front section of the comb. It made tool changing easier.

dstivens
05-11-2014, 01:28 PM
a hinge is a good idea. I based my design on this http://www.kentcnc.net/nc/products/94-standard-dust-shoe.aspx
using magnets.

firetrappe
05-11-2014, 01:31 PM
I made 2 attachments for my DIY shoe, one with bristles and one with plastic.

I figured the clear plastic would be nice so that I could watch the tool cutting. The trouble is, if you cut loads of strips then you lose the transparency as the cut edges of the plastic refract (I think that's the word?) the light. With 10mm wide strips as I have then, like Eddy says, large gaps appear when the shoe presses onto the workpiece. I toyed with the idea of adding another layer of strips inset from the existing ones, but the other attachment with the bristles worked that well that I've never bothered.

Si.

charlieuk
05-11-2014, 01:53 PM
Yea I was a bit worried that PVC or that type of thing would not be stiff enough to resist the vacume but it would be nice to partly see through it to see how it was going. I will have to look into what thickness PVC is available

cncJim
05-11-2014, 01:54 PM
Really nice Si - Like the use of magnets and the spacer sections. The bristles attachment looks good, where did you source them from?
Jim

EddyCurrent
05-11-2014, 10:20 PM
You will like this one; http://www.kronosrobotics.com/dust-shrouds/

http://www.mycncuk.com/threads/7917-Brush-Strip?p=61814#post61814
Relisted: only 30mm bristles though http://www.ebay.co.uk/itm/Flexible-Brush-Strip-0-5m-/161456197558?


http://www.mycncuk.com/threads/6388-Open-Source-Dust-Shoe-Designs?p=47640#post47640

https://www.mink-buersten.com/en/products-shop/strip-brushes/flex-system.html

firetrappe
05-11-2014, 10:28 PM
Charlie, I used this 2mm PVC for the plastic skirt : http://www.ebay.co.uk/itm/Clear-Flexible-PVC-Door-Strip-Curtain-200mm-x-2mm-x-1-metre-length-/250981624261
I had no problems with the vacuum sucking the skirt into the tool, just issues with fine MDF dust getting through the gaps.

I can actually see the bit through my dustshoe when cutting. Because the lower section of the shoe is larger than the spacers that it attaches to, there is a ~10mm wide lip between the bristles and the spacers which I can look through to keep an eye on things.

Jim, the bristles I used came from a section of Garage Door Brush Strip from B&Q. I can't find it on their website now, but toolstation do the same brand/size : http://www.toolstation.com/shop/Ironmongery/d170/Draught+Excluders/sd2802/Extra+Heavy+Duty+Brush+Strip/p84655
The brush strip slides out of the aluminium mounting rail really easily. Unfortunately the bristles are crimped into a steel channel to hold them in place, and that steel is almost impossible to bend by hand! I tried everything I could think of to try and form it into a circular brush using hand tools. In the end I had to resort to making a very crude metal bending jig using some skateboard bearings a socket set and a steel plate and I had lying around. If I were you i'd look for an alternative strip constructed from plastic or aluminium!

I've attached the basic design files for my dust shoe below if anyone want's to copy or modify it. The largest part is machined both sides (pockets for magnets one side, pocket for brush strip on the other) which is why it's drawn with a couple of extra holes for registration purposes. It should make sense if you refer to the earlier photo I posted.

Si.

charlieuk
06-11-2014, 09:12 AM
Cheers many thanks I guess I will start playing with some of those ideas the foam looks interesting too and can get that locally so will give that a try

jimbo_cnc
06-11-2014, 01:00 PM
I think I need a dust shoe. At the moment I'm prototyping so I hold the vac nozzle for the 10min that the job takes. But if I'm goingto run a 1hour production job then I need something to suck the swarf out of the work.

I'm using acetal down to a depth of 20mm, and the swarf builds up in the hole, I suspect it would clog up a bit and spoil the finish if left. On the other hand I might be able to rough everything out without suction, and then just attend with the vac to the finishing passes. So much to learn/try!

With 20mm travel do you think attaching to the spindle will work OK? I was thinking the dust shoe would have to be fixed height.

EddyCurrent
06-11-2014, 02:45 PM
With 20mm travel do you think attaching to the spindle will work OK? I was thinking the dust shoe would have to be fixed height.

If using flat sheet material I would have the dust shoe fixed height but then I'd like the height to be adjustable for different thickness sheets, just so it's skimming the surface.