High ambient temperatures

First post, i did a search and couldnt find anything relevant…what kind of ambient temps can these mpcnc machines operate at? I really want to pull the trigger and get one of these, i would have to have it in my garage (not climate controlled). I live in las vegas and am worried about the stability of the machine during summer time, ambient temp in my garage is easily 120 degrees during daylight hours and into the evening. Thanks for any info.

All of this is a guess with a bit of logic thrown in.

  1. The transition temp of PLA is somewhere between 50-60°C (50 is about 122f) In engineering terms that’s a bit marginal but you can easily find PLA blends or even carbon which will work above that temperature.

  2. Prusa advise that for their printers, electronics “don’t like” being above 40°c (104f) and that operating the PSU above the 40-50 range will “shorten its service life”. I assume that since they are using similar electronics the same will apply.

  3. Are you seriously going to sit and watch your machine operating for hours on end in that temperature? I tend to give up these days when the temperatures in the mid 30’s (mid 90’s) because I just hate that combination of sweat and wood dust. (I live in a high humidity area to make things just a lot more unpleasant!)

I reckon it will be fine, (not sure about the router life) but you will give up before the machine! Is it time to think about insulation in the garage?

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I wouldnt be watching the machine operate during the day, i would be running it for a 1-2 hours after work. If your not familiar with the weather in the desert, night time lows are still in the high 80s most of the time during the summer. My garage is drywalled, i dont know if theres insulation behind it. I can insulate the garage door with som foam.
I would be ordering the 3d printed parts from v1 if that helps any. Does anybody know what the 3d printed parts from v1 are made from?


Pla. Ryan runs his in his garage in Cali. I can’t remember if the new place is airconned or not.

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I messaged a guy from arizona, he recommended abs for 3d printed parts.

My mpcnc is in my garage in Florida. High heat and humidity. Have had no issues except operator excessively leaking bodily fluids (sweat) during jobs… I would add my 2 cents and strongly advise not using mdf as a spoil board in high humidity areas. It would soak up the moisture and swell/ warp.


Yea, I haven’t decided what I want to use for a spoil board yet. Going to have to figure that out soonish.

Maybe some cheap plastic cutting boards could do the trick?

That’d be a lot of boards for a lowrider.

I am among the great over-thinkers, and live in an area where humidity is so hight that raw MDF grows blue fluffy mould!

HOWEVER - Even I use MDF for a spoil board :shushing_face:- a single coat of clear polyurethene or shellac is more than enough to keep the airborne moisture out - just don’t put cold beer on it. It IS stable if you keep both sides at the same moisture content.

I tried mdf but I had issues with it swelling with humidity. Granted i didn’t seal it at all. My wife buys those decorations made of mdf and completely sealed with paint. They start to look like a wilting plant after a few days. Just my 2 cents from my experiences. Others may have better luck with mdf. I did not.

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I’ve been wondering that myself as I live in the Phoenix area. Moisture isn’t really an issue, maybe a month or so of high humidity during monsoon season.

Yep…the humidity is about 4% now…

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Jeez, yeah 120 for extended periods is going to be challenging to deal with. As mentioned above, that’s getting a bit close to the Tg for PLA. There’s always PETG if PLA starts warping on you. Since PLA is stiffer, I’d start off with PETG for the motor mount parts, then replace other parts with PETG only if they appear to creep when the heat is on.

You might also consider doing other things to help keep motor heat from melting plastic. Titanium bolts conduct less heat, and when used with non-conductive washers (phenolic) you might even be able to get away with PLA motor mounts.

Peter’s comment on electronic temperatures is also very valid. You’ll definitely need a strong active cooling solution for your motor drivers at least. Drivers and some other IC’s are allowed to get pretty dang hot, but you’re operating in the extreme and need to plan more extreme. However there are bound to be some sketchy components here and there (85C caps etc). You also have to somehow feed it with gcode, and with cnc that usually is a computer of some sort nearby the machine. Most computers will frown at you running them in a 120F room.

My garage gets to 102F sometimes, but I avoid milling when it’s above like 95F in there. It only gets that hot if I leave one of the exterior doors open all day. If I have a long cnc mission planned, I keep the doors shut. Then it never peaks above like 92F throughout the day. The walls are insulated but it has no ceiling and the roof is well vented. Maybe there’s something you can do to improve your garage’s thermals? I mean, I’d start showing signs of heat stroke after a few hours working in conditions like that anyways. I know this cause sometimes I have to do emergency work in ppl’s attics in California summers… 120F, 140F… it’s all the same lol… IMHO not something I can do cnc in.

Eew gross! LOL!

I live a few .iles south of Phoenix. I built my Primo using PLA last year. It sat idle for several weeks qhile I was busy with home renovations. When I was ready to use it I could see the motor mounts on the trucks were sagging noticeably. Also the parts that hold the core to the tubing were deformed. I reprinted everything in ABS since I find it to be as easy to print as PLA here with our high tempa and low humidity.


I would be using the machine more during non summertime, im not trying to sweat myself to death in the garage. Right now im just in the info gathering stages, i want to eventually get a mpcnc together so all this is good info.

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That is good to know, I’m in Tempe, and while my garage walls are insulated (door is not), there’s no AC out there, other than a roll-around swamp cooler which is really only effective on the person standing directly in front of it. I also don’t expect I’d use a CNC too much in the hot months. I haven’t printed in ABS before, my only concern with that is my Prusa is inside and my understanding is that ABS is smellier to print with and I may get some pushback from family members if I’m stinking up the house for an extended period.

PETg is about as temperature tolerant as ABS and doesnt stink as much, also more dimensionally accurate.

ASA is even better temp wise, but I haven’t used it myself.

My Ender 3 is out on tge shop floor so I don’t notice the smell…