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The Wife Approval Factor / Vacuum Systems

A project log for Sexy Gantry

Documentation of my journey to a commercial enterprise around hobby machining, specifically cnc, even more specifically 3d printing.

Daniel GraceDaniel Grace 08/17/2022 at 15:340 Comments

My wife is a reasonable lady. Any implication otherwise in this post is unintended.

We have two cats and a two year old daughter and we have found a few aluminum chips in the house. I've been pretty diligent about vacuuming after cuts but somehow, some way, aluminum chips are invading the house. I have my theories (hitching a ride on clothing, missed surfaces, surfaces that are craggly enough that they hold on in the face of vacuum pressure, etc.), but the fact is that I have a limited amount of time to find a solution before the danger to family outweighs the project.

My desired solution is to hook up an automatic vacuuming system. BUT I have heard, vaguely, of some dangers. I wanted to learn more about said dangers, evaluate how much I personally care, and then arrive at a solution for our household.

It's really hard to find solid information about these things. Aluminum dust is a terrifying thing that comes up in google searches... but also not what I'm making. My chips are quite large. Aluminum vacuums are vacuums that are made of aluminum, not vacuums that suck up aluminum. When you find anything relevant at all, it's commercial entities telling you that it's terrifying and the only way to be safe is with their $8,000USD vacuum systems.

I went to some chats/forums, talked with real hobby machinists and have come to the following conclusions (note: I am a hobbyist trying to learn, don't interpret this as an expert -- half the reason I'm posting is to give people one last chance to tell me I'm horribly wrong):

  1. There is a non-zero amount of danger inherent in hooking up a vacuum system to immediately collect metal shavings, but the risk is relatively small and/or manageable.
  2. It is not impossible for hot metal to ignite flammable material that happens to be in the vacuum (wood shavings, etc.). This is relatively unlikely because the aluminum doesn't catch much heat, cools down quickly, and would have to be quite hot to ignite wood. But it's not impossible, and ideally we never mix vacuum systems. I plan on disallowing wood on this tool and making sure to empty the vacuum before using it again.
  3. Shop vacs should not add any inherent danger by their design. They are by their very nature designed to protect the motor from the random crap you might be picking up in the shop, which includes metal, wood, and dust.
  4. It would reduce the risk even further to run the vacuum in wet mode and make sure that there is always moisture in the reservoir. This does increase maintenance simply because wet vacs need more inherently (stagnant liquid in the tank longer term is bad). I am currently not planning on going this far, since it's more maintenance AND my current plan is no cutting fluid. It is something to keep in mind as an inherent benefit to switching to cutting fluid though.

I have a plan of attack for the first attempt with a vacuum system: empty the vacuum, physically isolate the chamber as much as possible, make extra sure the fire extinguisher is close at hand, check for smoldering/warmth after the cutting session, etc. That will be delayed somewhat though, I have surgery today and probably shouldn't be doing active shop work while under the effects of that kind of medicine...

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