Issue with the Y axis: is the belt worn out?

Hi dear IGRAUDINS. !!

I was reading the adjustment you made with the Y-axis and the ball screws ... and interested me as you did the adjustment of this Y-axis, You say that I moved the screws with the hand from one end to the other ... But I ask how you did it because it is impossible to move with the hands because it is very hard this movement being all the machine assembled.

Please you can give me more details, since I have problems in the Y axis, since I can not reach to any end of the Y axis, neither the minimum nor the maximum, because the movement is locked, it does not move more and it sounds very wrong. This is why my work area has been reduced by 5 cm at each end. Thanks for your help.

"...First what I did, to align ballscrews was to loosen four corner screws in the front and four in the back of the machine, then moved (screwed) with my hands both ballsscrews till the end, tightened first four screws. After that moved along the Y axis till the other end and tightened another four screws. Now everything works like a charm."

Hi, to be able to turn the screws by hand the Unit must be turned off, because when power is going to a stepper motor it is active even when not turning.

Hi dear IGRAUDINS. !!

Please you can give me more details, since I have problems in the Y axis, since I can not reach to any end of the Y axis, neither the minimum nor the maximum, because the movement is locked, it does not move more and it sounds very wrong. This is why my work area has been reduced by 5 cm at each end. Thanks for your help.

"...First what I did, to align ballscrews was to loosen four corner screws in the front and four in the back of the machine, then moved (screwed) with my hands both ballsscrews till the end, tightened first four screws. After that moved along the Y axis till the other end and tightened another four screws. Now everything works like a charm."

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mechanical tuning v important

https://www.youtube.com/watch?v=MO5f8AyVFWs

https://www.youtube.com/watch?v=Ro6V2G7c5s0

Hi this is Max from Argentina.. My 420/2 started drawing ellipses instead of circles yesterday. I thought it could be some dirt in the rods, but finnaly I realized that the belt was worn out! The machine was running well for about a month of soft use, so I'm very disappointed right now.. And frustrated because is not that easy for me to order a spare and receive it quickly.
I guess something in the construction must change so that normal users like me don't have to deal with too much precision during the assembly.

Rory,

Those videos are excellent, and will hopefully lay to rest problems with Y axis lockups for good and all.

One minor point though - I had to relieve the Y axis remote end bearing housings on my SC420/2 before I could achieve the sort of free movement you demonstrated. Something for builders to bear in mind and not be frightened to do should the occasion arise.

Peter

I've seen Nobel Prizes awarded for less than those two videos :woohoo:

I was indeed moved to get off my ass and follow them and in fact the it's all so simple, so common-sense that even I was able to arrive at a safe harbour! I was staggered by seeing Y moving at 5000 mm/min, I don't think I'll try that stunt, not even after testing the latest Loch Lomond batch!

Even so I managed to f*** up my timing belt due to excessively enthusiastic manual testing, but it had a dodgy splice already. So as a warning, everybody check those belts, that was my second already! I suppose they are purchased in bulk -
ready spliced or spliced in-house, I dunno - and then with the haste inspection if any is cursory. So do check your belts please!

MMorao, you are one of the most entertainingly tongue-in-cheek forum people I have ever come across.

Keep up the good werks mein freund.

Doug

I had the same with my D600 v2 two times. the problem is that the set screws in the pulleys are coming loose because of vibrations. This will result in the fact that the pulleys are moving sperate and the whole Y is worn. It should also be mounted with loctite to prevent this.
This timing belt is a very weak part of this machine. You should never transfer moments with round axis on round holes only secured by set screws. It would be better if they designed the pulleys with a flat surface and the hole on the pulley equally. I am changing the pulleys with wider ones and changing the belt with a wider one (steel reinforced) and secure all bolts with loctite 243. If this will not help I will purchase the performance upgrade kit with 2 stepper motors.

Peter.