Enclosures and PLA temperature

Hello, I’m planning to build an enclosure for the Lowrider. However, the temperature inside these structures is known to be high when the router is in operation. On the other hand, PLA is not adequate for temperatures higher than 50º.

Has anyone who has built enclosures for lowrider or mpcnc (made of PLA) and faced any kind of problem?

I’ve had a problem. I made the mistake of using foam board insulation to dampen the sound coming from the enclosure. The ambient temperature was around 30C, and after two hours of running time, I found slack in the belts and the trucks drooped slightly. I’d done similar jobs in similar temperatures before installing the insulation board (just plywood sides) and had no issues. I also suspect that had I been running the vacuum on the job, it would have imported enough air to mitigate the problem.

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My guess is the volume of any lowrider enclosure would be big enough to be significantly lower than an MPCMC enclosure.

I bet the heat capacity is close to proportional to the volume (for the air) and the area of the walls (because of the plywood).

The amount heat dissipated is probably proportional to the area of the enclosure (because of the heat seeping through the walls).

So my guess is it will be at least the squared of the size better, but in some ways, closer to the cubed.

There have been a few MPCNC enclosures and I haven’t heard of them melting the parts. The biggest danger is the motor current, which heats up the motors. We have found a decent sweet spot between too hot and not strong enough.

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That’s bizarre!

I live in an ambient temperature of 30° - I try to control my printer enclosure to keep the temp below that or just above it, and have never had a problem with PLA moving until the temp gets to about 50 plus. I have very fine threaded canisters for dessicant which I recharge at 45 for six hours in a food dehydrator. Curious!

My Primo is in an unheated space that takes on the outside temperature. It was about 90F the day of the incident. When I opened the doors at the end of the two-hour run, there was a blast of hot air from inside the enclosure. Not sure how hot, but it felt like the blast you get when opening a car on a hot, sunny day. Without ventilation, the insulation did too good a job of keeping heat in.

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Did it keep the noise down? I run a 90mm fan in my printer enclosure, exhausting from the top back, with the doors open, but that won’t help noise much (it does a little) but the printer isn’t a router.

The 1" hard foam makes a notable but not extreme difference. I wish I’d done sound measurements before and after so I’d have a more objective measurement. And while the insulation helps with the router noise, I’ve not done anything about the vacuum noise. The other thing I considered was using acoustic panels like these, but I was concerned that the sawdust would collect on the “fins” and create a fire hazard.

Regarding the noise isolation, maybe something like this would help and avoid the dust problems:

What is it?

Reverse image search leads here. Cool product but probably expensive. Related images yielded cork as a sound dampening material, which is new to me.

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This is an acoustic panel, but I think glass wool could also be used, which is way less expensive. As the router will run inside my house I’m worried about noise.

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Now that’s something you don’t see every day… operating a cnc inside living quarters!

One of the tricks I used to do with car audio setups, is sticking sheets of dynamat to door panels and other items that reflect/rattle. That’s spendy stuff, but maybe searching for “sorbothane” would return better pricing (that’s the generic name for the stuff). You can find stuff that comes in sheets with adhesive backing, which would be easy to apply to a plywood structure. It’s engineered to turn vibes into heat, and is a hard material to beat at killing sound. That also means it will be kinda spendy, even with good pricing.

Besides converting motion to heat, you can also reduce the motion… ie add mass. A very cost effective way would be a double drywalled enclosure. It would be heavy and not portable, but easy to DIY using standard open framing methods (plates/studs/joists), and would be very safe wrt fires.

Another consideration… it’s awfully risky to run untested operations on a new project, without being able to watch it as it goes. So you may have to consider adding a sound proof window of some sort. You could fashion a glass door out of an old double pane glass assembly. Try calling up glaze contractors or other window related businesses in your area. Those guys are constantly throwing out old glass that could work perfect for this.

For noise reduction, a few concepts might help :

  • a mass / spring / mass system is the right way to reduce noise. For example plywood / foam / plywood.
  • a 1% hole in the enclosure let 50% of the noise get out (!)
  • you can design an exhaust for fans that is not a straight out, but a kind of labyrinth tunnel, to reduce noise getting out of the beast while still have air flow.

For the printed parts, does anyone tried petg? Seems to be slightly better at heat resistance.