Simple $0.02 spindle fan solution

How To
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This afternoon I needed a spindle fan solution for machining MDF and clearing out the dust. Here it is!

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It’s just two pieces of blue painters tape (any tape will do really), adhered around the spindle to create two short flaps. The picture doesn’t show it well, but I did try to align the tabs to be more fan blade like and angle them. I don’t think it matters though. It produced enough turbulent air around the cutter that the dust was moved out and away.

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As you can see, the dust is all spewed all around the bed, but mostly clear of the job. It’s not perfect, but I would say it’s more than 90% effective. In deep ruts, the “fan” can’t get everything out, but the cutter will generally move things out enough to blow away if it gets too deep.

Just as a comparison, I machined the lower part without any fan beforehand. Anyone that has machined MDF knows that the cutter just regurgitates the dust and makes are really fine powder that’s like concrete. It all just sits there and piles up. Not good for the cutter or lungs.

So, a little background. I need to machine about 100 small MDF parts, would like to leave the machine unattended for short periods, keep the dust contained inside the Nomad, and not have to manually clean out the dust with a air compressor or brush. I have a hydroponic air pump that I use to continuously blow out chips for metal jobs and keep the tool cool, but this is too powerful and would blow dust everywhere and out into the shop.

I like the idea of spindle fan solutions, but they usually have way too much mass and are overbuilt. (I tried one once. There was too much drag on the spindle motor and doesn’t work that much better.) I hope this solution will help some people, because it’s really simple, cheap, easy-to-replace/modify, and it works.

EDIT: For lower rpm jobs, if the “fan” isn’t blowing enough, just make the flaps longer. This is something you can’t do with a fixed spindle fan.

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LOVE this!!! We often forget the simple things…

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These propellors work wonders clearing the work area, however they maximize ones exposure to hazardous materials. Any friable (“easily crumbed”) material (e.g. MDF, wood, FR4, Fiberglass, carbon composite) releases particles that are extremely damaging to the lungs. MDF is one of the worst offenders.

If you’re not going to have a dust head, please, please, put a hole in the side of the Nomad, add a fitting and use your dust collector (e.g. shop vac) to keep a negative pressure on the enclosure (so nothing escapes). The dust collector should have a HEPA filter rated for 0.3 microns. Adding a dust separator - a cyclone - will dramatically reduce the cost of replacing HEPA filters.

mark

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Agreed. MDF dust is horrible. However, the idea here is to prevent the cutter from regurgitating the chips and making even finer dust by blowing it out and away. This tape “fan” idea doesn’t create a lot of air movement. Just enough to push the chips out and away.

As a comparison, when I had my hydroponic air pump blowing into the Nomad, it blew so hard that the entire Nomad was filled with a thick cloud of MDF powder. You could barely make out the inside.

That said, I thought about using my loud shopvac and placing its hose into the chamber, but I’d rather not have it running constantly over several days for this job. Shopvacs aren’t built for continuous duty like that. A whole-shop vacuum system is the ideal solution, but I don’t have one.

However, I do have a box fan with a 20"x20" furnace filter taped to its backside. It sits near the Nomad and runs on low (don’t run high! it’ll burn out the motor). It pulls and filters the air quite effectively around where it sits.

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The most dangerous particles are those one does not see. Those are lofted trivially. Fan or not they are there… sadly MDF is just about the worst for this.

Yes, clearing the work area so there is little to machining of the swarf is a very good thing to do. It’s critical in many types of machining (which is why you see the high end machines with the deluge of lubricant poring on the stock - it’s not for cooling). It certainly reduces the amount of fine particles generated.

I did say “dust collector”. :wink:

Some people sacrifice a shop vac to the cause, periodically replacing it since they usually don’t cost much. True, they aren’t designed for long running.

A furnace filter won’t stop the nasty stuff - not even close. That said, anything is MUCH BETTER than nothing.

It’s been suggested elsewhere - a very good idea - that a simple, inexpensive recirculating system with a HEPA filter can be designed. To work, it would require buttoning up the Nomad enclosure. A few minutes after the job stops, the air will be cleared of anything nasty.

mark

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Agreed. A furnace filter on a box fan isn’t ideal, but will get a good portion of the bigger particles down to 30 microns or so with the cheap filters I have (MERV8). You can also buy furnace filters that can filter sub-micron particles (HEPA level) at the big box store though. Tape it on the backside of a fan, you have a shop HEPA filter.

Anyhow, my general dust management workflow goes like this.

  • Use the spindle fan during the job to clear out chips from tool path.
  • Keep the Nomad door closed at all times. Try to avoid air leaks and letting the dust out.
  • Keep the box fan on nearby during the job to pick out any escaping dust.
  • When opening the Nomad, use my shop-vac (with a nice filter) to suck out the air and clean the chips out.
  • Rinse and repeat.

Not quite perfect, but it should work much better than no dust management.

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Apparently these are a thing in industry:

http://www.woodworkingnetwork.com/wood-machinery-supplies/cutting-tools-grinders/Collet-Nut-for-Dust-Removal-210315341.html

not available for ER11 collets, and given the prices, just was well.

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Plus, the 2 cent version clears the bottom of the carriage on a Pro, whereas the 3d printable collet fan does not.

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You could probably 3D print something very similar with a 1/8" or 1/4" hole in it that mounts to the tool itself instead. 3D printing would mean it would be cheap enough to make a bunch of them and have them double as a positioning ring for quicker tool changes as well.

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Hey Buddy, I know what you are making, the 100 pcs was enough of a clue and the part shown, well there is only one use for it. I’ll keep your secret for you. I’m making a sculpted one for my grandson’s birthday except I don’t have my cnc yet so I’m hand cutting and sculpting with rotary tools and probably 3 times bigger. Good Luck ! If you have future plans about them I’ll be happy to talk just PM me so the “word” doesn’t get out. Happy Creating.