Belt Status Numbers do not change?  

RE: Belt Status Numbers do not change?

Got it .. need to rerun selftest or best test under calibration..

RE: Belt Status Numbers do not change?

@sink

And - the belt tension number are meaningless. They are generated by the currents needed to move the axis and have nothing to do with belt tension. Don't waste time there.

Prusa has finally came out with tension gauges for the belts - they must be printed in Prusament PETG, or purchased from the store.

Or, use the deflection test Gates recommends.

Move the bed to the rear, the extruder far left.  Use a spring gauge or weight to press down on the middle of the lower belt in the pairs: 0.45 pounds (200 grams).  The X belt should deflect 15/64ths inch. The Y belt should deflect 12/64th inch.

This deflection sets the belts just under 6 lbf tension. The 0.25 inch Gates belt is spec'd for a minimum 2 lbf, and the motors are spec'd for around 8 lbf radial 1/2 inch up the shaft.

RE: Belt Status Numbers do not change?

@sink

Oh - and shifting of X is usually the screws on the back of the extruder near the bearings are over tightened. This crushes the bearings making them seize. Or, if installed without cleaning and packing with suitable grease, the dry bearings will seize all by themselves.

RE: Belt Status Numbers do not change?

@tim-2

Thanks for the info, with check the screws on the back of the extruder. The new bearings all come packed in oil, you don't use them that way?

Do you clean and repack?

Regards

RE: Belt Status Numbers do not change?

@sink

The oil in that shipping packet is anti-rust preservative -- NOT a lubricant.  Misumi has stern instructions to wash the preservative off the bearings then lubricate with suitable lubricant. For example, here's Misumi's grease guide for ordering their linear bearings for being "pre-greased". The packets do not have anything in them resembling grease.

RE: Belt Status Numbers do not change?

@sink

Here's a snip of Misumi's latest pdf covering the linear bushings Prusa is using today:

https://us.misumi-ec.com/pdf/fa/2012/p1_0265.pdf

The key ingredient here is the simple text that Prusa can't read or tell users: BEFORE USAGE, APPLY GREASE ... lmao.

RE: Belt Status Numbers do not change?

@tim-2

Lovely .. ah you learn something every day ..

Thanks for the info ..

Best Regards

RE: Belt Status Numbers do not change?

@sink

By the way - in talking with a Misumi engineer about filled greased like SuperLube with PTFE, he indicated that even oils are appropriate in some applications - and that a few drops of motor oil is better than nothing; and it's worth noting a few folk here simply apply light machine oil to the rods on occasion and they say they have not suffered bearing failures.  But I'm a grease fan.

RE: Belt Status Numbers do not change?

I like to use motor oil for slide bearings and prefer grease for the linear ballbearings - fewer maintenance intervals and less risk of dripping (onto the print bed).