Screws for the heat bed
I have a few issues with my 3d printer (Original Prusa I3 MK1 upgraded to a MK2) that I am working through, and I am hoping someone can help me with a couple of questions.
One is, somehow one of the screws that holds the heatbed to the bed x-frame thing have come loose and disappeared. I'd like to buy a few for spares. But, I need to know what exactly I am looking for. I searched around and found in the installation guide for the MK2 that they are "m3x8r" screws. I know what an M3 is, and I assume the 8 is for 8mm in length (i could remove one and verify) but what is the "r" for?
Second, it fails the self test when it tests the x-axis, when it moves to the left side, it hits the limiter, I can hear it click. Then it moves about 10mm to the right and goes back and forth a few times, failing with an error that indicates a possible loose pulley. I have checked the x-axis stepper pulley and it seems quite tight, and I can't figure out what other pulley it could be referring to. Also of note, when printing, sometimes during the calibration when it does point 4, way on the middle left of the bed, it makes a weird noise that almost sounds like the belt is skipping, but when I watch
very carefully, I can't see any skipping or anything of the sort. I can't visually tell any reason for the noise.
Finally, when printing, and making x-axis movements, it makes a weird... almost metal on metal sound. But, with it off, if I move the x-axis I don't really feel anything except when I get to the left side, it sort of wants to bind and I can't tell why. I have thought about getting some lubricating oil and putting a very thin coating on the 2 rods, thinking that might help with the noise. Is that a bad idea?
Thanks for any advice!
Edit: I forgot to mention that the x-axis issue with the strange noise on the left side is intermittent, doesn't happen all the time.
Re: Screws for the heat bed
I don't have an MK1 so I don't know much to recommend as far as the pulley and axis issues except going back over everything and making sure all screws are tight, everything is lined up correctly, all belts are tight, etc. As far as the screws go I think they may just be referring to them as M3x8r because they have a round head, although I've always referred to round head screws as button head screws. Looking at the ones on my MK2s I don't see any difference in those and other button head screws that I have so I would just get some M3x8 button head screws and if they fit correctly they should be fine.
Re: Screws for the heat bed
Hi Michael,
round or button head screw is correct, and I would give some light oil a try!
regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Screws for the heat bed
I use sewing machine oil - very sparingly. I apply to a piece of tissue and use that to wipe the rods before slowly sweeping the axis back and forth - slowly to minimise the backfeed generated in the motors. Better yet is to use settings - move axis to do the movements.
Bill
Tagaytay City, Philippines
Founder member of Philippines Prusa Printer Owners FB Group
Sponsor Pillars of God Academy in Bacoor