Best way to tighten belt on X & Y for already assembled printer
Hello
I am experiencing layer shift and my belt tension values were way too high.
Y: 284
X: 304
I tightened the screws for the X Axis motor but it looks like I actually need to tighten it a notch but I am a bit worried about the best way to get back there and do this. What is the best approach to minimize accidentally causing another problem?
RE: Best way to tighten belt on X & Y for already assembled printer
Actually at 304 you need to loosen your X up considerably. Even your Y is a bit on the tight side too (you'll get ghosting).
I'm not sure what you mean about "getting back there". All the bolts for adjusting your X are accessible from the front of the printer. Loosen all 3 on the face of the printer and then loosen the angled bolt on top to let the motor rotate inward toward the extruder. Then tighten the 3 bolts back up and test.
I suggest grabbing a XYZ calibration STL to help you out. Make adjustments, then print the test to see the results.
RE: Best way to tighten belt on X & Y for already assembled printer
A higher number means looser belt. 304 is rather loose. Good numbers are supposed to be around 270. Belt status numbers are updated during "Self test" only, so "Self test" is required after tightening if you want to see the updated numbers.
On a standard Mk3, the access to the inside of the X carriage isn't easy. What you need to do is to remove the fans, remove PINDA, remove the thermistor and the heater from the heater block and then you can disassemble the X carriage without disassembling the extruder. Then you can move the belt in the X carriage by one tooth, and reassemble. On a Mk3S it's supposed to be a lot easier as there should be open belt access.
RE: Best way to tighten belt on X & Y for already assembled printer
The numbers given by the printer for belt tension are meaningless. My belt is near the limit for the motor bearing load and it reports 294. lol. It was at 285 when I exceeded the motor specs. The number in the printer reflects rod bearing friction - and greased bearings have almost zero.
A tension gauge is the only way to know belt tension.
Here's a way to do it correctly: but you'll need to 'twang the belts' to get a good reading. Anything close (+/- 25%) is good.
https://www.thingiverse.com/thing:3569297
I was able to change the X belt a tooth by removing the back of the extruder housing. It was pretty easy.