I don't know enough about those plastics to know how hot you will need to run your enclosure to control shrink. I also don't know enough about them to know if there is a temperature where shrink is a lesser issue and you still can control the print (ooze and sag issues). My *guess* is that you will have to run it fairly hot (50 to 80C).
What I do know is that if it's hot enough, you will have problems with your electronics. None of this stuff is rated past about 50C. Inevitably that's in fast moving air or it's case temperature(!!!). If you will have the motors inside the enclosure, you will need to derate them. Their insulation is good to 130C. The current rating is based on an 80C internal rise relative to 50C outside. I believe that's one of the "forced air at 599 mph" ratings. You normally run the motors at half current to keep the case at a reasonable temperature. If you want to be able to get to 90 or so outside, you would need to cut the current in half again. Your 400 oz-in motors went to 200 oz-in and now to 100 oz-in. The power supply and drivers will need to be outside the enclosure as will the Mega / Ramps combo. I *could* design stuff that would run in that environment, you very much would not want to see what it costs done with all high temp parts in small volume.
Possibly easier alternative:
Just heat the printing area. Use some sort of foam / plywood clip on doors. It's less volume to heat, and a lot easier to build. If you have a few fans, gradients should not be to bad.
What I do know is that if it's hot enough, you will have problems with your electronics. None of this stuff is rated past about 50C. Inevitably that's in fast moving air or it's case temperature(!!!). If you will have the motors inside the enclosure, you will need to derate them. Their insulation is good to 130C. The current rating is based on an 80C internal rise relative to 50C outside. I believe that's one of the "forced air at 599 mph" ratings. You normally run the motors at half current to keep the case at a reasonable temperature. If you want to be able to get to 90 or so outside, you would need to cut the current in half again. Your 400 oz-in motors went to 200 oz-in and now to 100 oz-in. The power supply and drivers will need to be outside the enclosure as will the Mega / Ramps combo. I *could* design stuff that would run in that environment, you very much would not want to see what it costs done with all high temp parts in small volume.
Possibly easier alternative:
Just heat the printing area. Use some sort of foam / plywood clip on doors. It's less volume to heat, and a lot easier to build. If you have a few fans, gradients should not be to bad.