Dust extraction from for mitre saws

[BobL]

Interesting attempt at a solution to Mitre saw dust extraction from Rousseau.
http://rousseauco.com/rousseau-5000-...or-miter-saws/

A couple of minor issues I can see are'
- only a 4" dust port but this could probably be readily enlarged to larger.
- in general dust extraction systems that contain components that can flap around even slightly will reduce air flow, This effect will be small with 4" dusting airflow but will be significant for 6" or greater flow.

Nevertheless being light weight it will be very useful for mitre saw users who move their saws around in the course of their work.

[Opelblues2]

At least somebody is tiring to come up with ideas, good on them for having a go

[mark david]

looks,nifty.
Mitre saws,mine especially is totally useless at capturing dust,the small fabric zip bag is as useless as the preverbial you know what's on a bull.
Even when the vacuum is connected to the dust port it is only slightly less useless.
Suppose you could fabricate something similar yourself with some wire and fabric or plastic sheet,as it's not exactly cheap to buy this.

[John Samuel]

Mark David,

If your saw is a drop saw rather than a sliding CMS, have a look at this https://www.youtube.com/watch?v=p2tHtOyOIrY

SCMS are more difficult, but it is not difficult to get good dust capture with a drop saw of the non-sliding variety.

[Chris Parks]

John, how does that go for mitre cuts?

[John Samuel]

John, how does that go for mitre cuts?

Chris,

It works like a charm. There are two removable pieces of MDF (fastened with Velcro) on the top that allow the saw to swing through its full range. Seperate pieces of MDF are fitted depending on which way the saw is swung. See more detail at ... https://www.woodworkforums.com/showth...150+dust+ports

This was once a very messy tool. Now dust collection is great and I use it on nearly every job. Cutting web frames and similar is a breeze. On the latest job I cut 60 pieces for 15 web frames in a few minutes, and because the drop saw was used got near enough to perfect repeatability, piece after piece ... and bugger all dust. I think the secret is to blank off the top and to pull all the air through the front.

The bench with drop "wings" made for the saw is a delight. It folds away for easy storage, but erected provides a great working area. These shots were taken just before the dust collection system was installed.
Mitre Saw Station Open.jpgMitre Saw Station Folded.jpg
Cheerio!

John

[Chris Parks]

Thanks John. The slider type saw like mine is a big issue because the blade is so far in front of the fence at full extension the dust and debris cannot be captured or another way of saying it is I haven't come up with an effective idea to do it. The fence and the height of the material being cut stops the sawdust being ejected to the back of the saw and what is not picked up by the gullets of the blade and ejected out of the chute is sprayed everywhere.

[John Samuel]

Chris,

I had trouble with dust collection with a zero tolerance fence fitted on the saw. My original fence (now back on) allows dust to be drawn from around the blade back into the port. Would a fence similar to mine help?

As you said, dust collection for a SCMS is problematic. Was talking with a woodie about it a couple of years ago. Seemed to me that what is needed is side and top curtains that extend with the saw ... perhaps like a pleated blind ... I am sure the trick is to pull all the air through the front, which means blanking off the top somehow, as well as the sides.

I'd love to tackle dust collection on a SCMS, just for kicks, but don't own one and after looking at the price have no intention of buying one ... but you could send me yours so I could play with it and make a prototype system ... might take a few years ...

[Chris Parks]

I think your workshop would finish up with dust all through it so that is not a good idea.

[John Samuel]

I think your workshop would finish up with dust all through it so that is not a good idea.

Bugger!

[BobL]

When all else fails in laboratories, reducing dust scatter usually makes use of booths or small enclosures to restrict the movement of dust in/out of a machine/area/process.

If the SCMS was in a fixed place a small 3 sided booth with a roof surrounding the saw and curtain at the front could be used.
Narrow gaps protected by bristle guard material could be cut into the side walls to allow material to be placed under the saw.
Attach booth to 6" ducting and away you go.

I recommend the same thing for lathes and CNCs.
The enclosure could be made out of PVC pipe and clear plastic film of sheet with a plastic curtain entryway.

If the enclosure was 6 ft long x 4 ft deep and 7 ft high thats 168 CF.
using 1200 CFM extraction that's 7.4 room air changes per minute which would easily handle the fine dust while the enclosure itself would restrict chip scatter keeping the rest of the shed very clean.

The main problem with this idea is few DIY have enough room in their sheds but if you do then its a viable option.

[Chris Parks]

Bob, the dust and debris simply bounce back to the operator due to the fence and material that are being cut forming a dam to prevent it being carried forward. It gets worse as the depth of cut is made deeper (vertically) and the debris simply can't be carried forward into the enclosure. Believe me, I have tried to prevent it with no success. All the theory in the world can't overcome the physical facts, go and buy a Bosch Glide saw and try it. I helped design and such a room as you speak of in WA some years ago and vented it using a Max strictly for sanding and it worked well.

[BobL]

Bob, the dust and debris simply bounce back to the operator due to the fence and material that are being cut forming a dam to prevent it being carried forward. It gets worse as the depth of cut is made deeper (vertically) and the debris simply can't be carried forward into the enclosure. Believe me, I have tried to prevent it with no success.

That's why there's a curtain behind the operator as part of the enclosure to contain the chips inside the enclosure.
I was just suggesting a way to reduce the chips being sprayed all over the shed although the operator still gets covered in crap which is not good.

Ultimately these sorts of operations will be carried out remotely in fully enclosed cabinets like CMC mills. i.e. open a cabinet, lock wood in place - close cabinet, cut wood etc

[Chris Parks]

The Bosch Glide saw has a reputation for very poor dust control and there are some videos on YT comparing it to other SCMS saws like this as basic as the test is....https://www.youtube.com/watch?v=s-phjDivlCc

My saw is the poorest of the lot. I suspect it needs a very high performing vacuum to minimise the dust ejected from the blade but I haven't got that far yet. On top of that it needs a overall cover at the back of it which it already has being and this is vented by an 1800 with a 150mm line. Having a dedicated vacuum just for the saw presents other problems in packaging the whole thing and being able to access the vacuum to empty it but I might have a way around that. I am having thoughts of using the vacuum exhausting straight into the mitre saw dust hood without the vacuum body that normally collects the dust and needs emptying. The debris will then be picked up by the cyclone extraction and this eliminates the need to empty the vac. The body/motor of the vac will sit on the top of the enclosure that is vented by the cyclone and the exhaust of the vac dumps straight into the enclosure. The problem with that little scenario is the cost of a high performance vac and which type will be suitable and it is all conjecture as to it being effective enough to be worth the trouble and money. In a hobby workshop there are always practical limits and constraints, in a commercial situation those issues are not usually a problem and it just gets done regardless.