Hi All.
I just pulled the trigger on a lr3 kit and jackpot board. goal is a 4x4 machine to start with a 4x8 option.
I live in hot humid south Florida and the lr3 will be in an outbuilding. I plan to add an ac and dehumidifier but am still concerned about pla printed parts and the oppressive heat here. power outages and such could bake the machine now and then. Ive searched the forum and haven’t found a clear answer on this. I am thinking to print my parts in ASA. perhaps even carbon fiber ASA. I purchased the aluminum xz plates and will cut the yz plates out of some rigid material (mdf. marine ply etc) on my 450x450 cnc. my question…do you think I will suffer much from the lower rigidity of the asa vs pla? what components would you say are most critical as far as stiffness? has anyone here used ASA with no ill effects? Is there another material I should look at? thank you for your consideration of my question.
I live in the Florida panhandle and have mine in a garage with no cooling or dehumidifier and the pla does just fine. Just keep an eye on the motor temps and you’ll be just fine
With @Jonathjon here. PLA should be OK and that’s what’s supported for the LR. If you’re really concerned a good alternative is 3DXTech PETG+CF. Easy to print on an open machine, higher temp tolerance, and more rigid than PLA. You just need to swap in a hardened nozzle to print it.
Same here - it’s regularly 30°C+ in my garage which is still not quite half the glass transition temp of PLA. I wouldn’t use it on a car dashboard, but human beings melt a long time before PLA does! 
yeah, michigan here, one day it is a 100 plus, next it can be 60 anymore. Now, there have been discussions of changing to pla+ etc around here. The recommendation is to stay with PLA.
Pla has been proven to be the best for the machines. (that said at the time all I had was esun pla+ so my mpcnc is made of it.)
Good luck with your decision.
and welcome to the fold!
Welcome! This forum is a great place to get information and feedback on ideas you may have.
TL;DR My suggestion is to stick with PLA unless necessary. PETG-CF was easier/better than HTPET. PA6-GF is hard to print, but may be a rigid option if your printer can print at 300℃.
I’m in Arizona, so my garage does get to about 115℉ (46.1℃), and when I first built my MPCNC I worried quite a bit about sag over time. So I printed that machine from HTPET (Fusion Filaments.) It prints at a high temp (280-300℃ ish on my home-built printer.) I thought is worked fine, but the rigidity of the machine was always a question on my mind. There were a lot of factors, so I’d say the HTPET was “fine.”
A few months later I was facing a table rebuild, and I decided that the LR3 was a better form factor, so this time I chose PETG-CF. It also appears to be “fine.” I wish I had the rigidity of PLA, but I worry about the stepper mounts during long cutting sessions in such hot weather (the stepper may have trouble dissipating heat and may run hotter.)
While I was working alone in my shop (on my LR3 table) some knucklehead snagged the loose gantry on his pants and it fell about 3 feet onto the concrete. The core cracked across the layers near the top bearings. I felt like the the layer adhesion was good, and I had used 3 x 0.6mm perimeters, which was insufficient to withstand the drop.
So, I’d recommend using PLA first, even if it’s to get an idea of how the machine performs according to spec. But, in my extreme climate, I felt like PETG-CF was a better option, since it printed easier, and seemed a little more rigid than the HTPET. The main area than I struggle is with the nut traps. I struggle with the nuts spinning, so I’ve started epoxying them in place. This works “fine.”
I have started experimenting with Polymaker PA6-GF (I was too cheap to get CF.) The nut traps work pretty consistently! I am focused first on the stepper motor mounts, since I feel like those are the main concern in the heat. However, (of course) I tried printing the core. It appears that once the heat from the bed is sufficiently far from the newly printed layer, slight curling begins to occur, which leads to print failure. So I’ll hold off on the core until I have the other parts printed and have used my LR3 to build an enclosure. It “feels” more rigid to me (and my fingernails), and I think the stats support it, so I did use it for Doug’s “hidden Y mod” where the idlers are extended. Might be placebo?
Note - I once got in my Truck and the dashboard said the exterior temp was 137℉ (58.3℃). I don’t believe it was that hot outside, but I did want to have the option to move my table out onto the driveway for big projects that may be awkward in my garage. At least I use that scenario to explain why I’ve burnt through so much filament in the name of heat tolerance… 
I’m sorry/not sorry for my flippancy above, and as someone who worries way too much about stuff that seems to work for everyone else in the world, I like to counsel others not to do that!
Have we ever had a report of PLA deformation from ambient temperatures on an MPCNC derivative? I don’t think so.
I can recall warping mentioned from over heated steppers and routers (it wasn’t the print that was the problem) a fire, and a roof collapse, but no problems experienced from ambient temperature.
I know that many of us have sheds that sometimes enjoy balmy temperatures in the 90-100f range without issue, but I think if anyone reading this has actual experience of warping of parts due to climatic reasons, it would be useful to understand the circumstances.
I found a bunch of my PLA parts falling apart when I was taking my stuff apart to pack. Pretty sure the humidity killed them.
When I was asking about Arizona heat, this post fed my fears. This was a while ago, and it pertained to an MPCNC. I’m not sure the risk of sagging is as much of a concern in a LR3.
I didn’t feel you were being flippant…I am looking for first hand experience and I think that’s what you gave. I can tell you with my experience I’m really dubious about pla in my location. I’ve printed some pla prototype outdoor parts and they didn’t last 24 hours before showing noticeable sag and or creep. the final parts I printed in asa are still holding up a year or more later. though it of course doesn’t get hot enough here to melt pla it sure can induce creep and Im afraid I could end up with parts suffering some deformation that induces errors in the positioning of the machine. and that that would be a pain to track down. also the near constant 80%+ humidity for months on end may be an issue for pla as another poster hinted at. I think I will print some test parts and measure the difference in rigidity. asa/asa cf/ petg cf. vs pla. as an aside I printed some kayak parts in petg and though they didn’t fail I did notice some deformation over time…and they were stored in a shaded spot.
yup…that is my worry. i go out to bang out a quick job and something has changed shape and I can’t sort it out quickly.
heh yeah…and here its 80-90% humidity often. heck I was building the shed today and my clothes are soaked…its dec 12 LOL
Thank you all for the input so far. I appreciate it. one thing I should mention is that I have the machines capable of printing some engineering materials. and I have petg, ASA and abs on hand in quantity in regular and Carbon fiber flavors. so its not an added expense to go any of those routes. I think I will print some lr3 parts in pla and asa cf and do some simple testing.
I live in a similar climate - and I agree with PLA outdoors, I don’t know what the scientific term is, but in direct sunlight the surface temperature continues to build - hence frying an egg on a road when clearly if that was the ambient temperature we’d be dead.
I have had no issues at all with prints due to humidity (printing is another matter entirely) and our annual AVERAGE is in the high seventies - my dryboxes currently keep my filament down to a balmy 55% 
Clearly the dessicant needs attention!
(I do dry filament in use).
I might just soak some of the old LR2 parts in water for a couple of weeks and see what happens, but I don’t expect a result.
I have had PLA warp here in direct sunlight near concrete, but all black plastic in the direct sun that day was measuring 140-150ºF surface temps.
In my garage this summer, I had temps between 100-110 for like 2 months straight, but this year was an anomaly.
I think in those temps, it’s generally ok sitting.
If you try to run a long job in those temps, that might be a different story as the routers may not be able to cool down with such high ambient temps.
I do know first hand that a Makita that is struggling to cool down will definitely warp your tool mounts.
I purchased a Kobalt router for the initial build but I will likely replace it with a water cooled spindle if I like the way the lr3 performs for my projects. mostly because of the difference in sound quality and volume. I really hate the way trim routers sound. I have a air cooled spindle on my small 450x cnc and after carefully balancing the cooling fan it is really not annoying at all to be in the same space with it. A router however…not so much LOL and my assumption is that the water cooled spindle should solve motor heat issues.
I used to feel the same way when my Makita was on the 6 - fastest speed setting. You should be somewhere between 1-3 usually. Once I found that out, I can’t stop telling people 
Or you just double the speed. 
My current core is printed in HIPS, which is stiffer than PLA. Not as impact resistant, but we’re generally not hitting the thing with a hammer. I’ll prolly print my broken parts in hips, or asa once we’re settled into the new place.