Ambient temp effecting limit stops
If Prusa had done their homework this would not be happening…
We are having a cold snap here and the XL is in the garage. I just tried to print and it’s incapable of aligning with the parking place. Why? Simple, ambient temps affect the accuracy when you use motor current sensed stalls as a limit switch.
We saw this with the E3d machine and switched over to simple Omron switches as limit stops.
way to go Jo!
RE: Ambient temp effecting limit stops
It could also be that the tolerances on the docks are just to high and the temperature can change the materials used in the structure as well as the docks. Again, real testing would have shown this.
Check page 7 of your XL 3D printing handbook and in case you missed it it's on page 75 as well:
Operating temperature: 18°C - 38°C.
Cheerio,
RE: Ambient temp effecting limit stops
I have nine printers besides the XL in my garage. None of them are limited this much by ambient temps.
RE: Ambient temp effecting limit stops
No doubt it’s the ambient temp effect on the current draw. How to tell? Home it a couple of times until it can pick up and park each tool. The temp effect is a random thing. Sometimes it’s spot on sometimes it’s not. It’s about 55 degrees in my garage and now I’m getting tool pickup/park reliability. This clients’ print will be completed.
RE:
Really? So anything colder than 64 degrees Fahrenheit? Thats seriously unrealistic. So according to you Diem that’s ok?
According to Prusa, that's the operating temperature. For a high-end hobbyist machine to require typical domestic temperatures seems reasonable. With so many heaters to manage any colder conditions would demand much bigger power supplies.
I have many hobbies.
Cheerio,
RE: Ambient temp effecting limit stops
It’s debatable that the XL is a just a hobby machine. Looking at other posts here as a sample there are folks using the XL in a business or Engineering context. Mine is well on its way for paying for itself already as my other machines have years ago. For that matter one can argue the same for the Mk2 to 4 machines as well. After all the MKIII was used to make many of the parts on the XL.
However, that’s irrelevant to the OP which was meant to point out that using stepper current draw as a limit stop puts an operating constraint on the XL which is unnecessary and can very easily limit its market. If 64 degrees F is the lowest ambient temp it can operate within than many professional and production applications will not be able to use it. Had it been fully enclosed or had they used physical switches for the limits stops this would not be an issue.
RE: Ambient temp effecting limit stops
I found an ideal work around. Simply home the machine and keep the X/Y steppers energized for about ten minutes. This warms them up. Then home again and the accuracy should then be within tolerance for reliable toolchanges. It works even when the ambient temp is 50 degrees Fahrenheit.