PM 833-T Backlash

[ahazi]

Ariel, I keep telling you, you should buy German engineering. Taiwan is chasing the "value engineering" curve to compete with the motherland.

Das est gut.

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Yes David, it is a super nice machine, just too much for my skills and needs... Also what will I do if everything worked out of the box, nothing to fix and the factory technician will fly from Germany to set it up?

Anyway, I fixed my machine's problem, Y-axis backlash is now 0.005", same problem as the other posts. No need to disassemble anything in the machine. 99% of the time was spent building the tool to turn the loose Allen screw (6 mm tip) from underneath the table.

See pictures of the tool and also few more pictures and description in the PDF document attached. I hope this will help others facing the same problem.

Ariel

 

[Bill Kirkley]

Ariel, It's good to see you got it to work. It has been awhile but I think I just moved the table to the right to access the third screw.

Bill

 

[davidpbest]

Ariel, you know I was just jerking your chain about the Deckel, right? I love the tool you came up with. Might be a new business opportunity there.

 

[ahazi]

Ariel, you know I was just jerking your chain about the Deckel, right? I love the tool you came up with. Might be a new business opportunity there.

Of course I know. I also know that this is the Silicon Valley shop of David C. from the FOG forum. Beautiful machines with amazing engineering and manufacturing that probably are less relevant now with today's new multi-axis CNC and metal 3D printers taking over even for prototype work.

I was very happy and proud of my little tool at 2AM... it solved the problem. My son also made fun of me "...lol... you used a welder to make that tool?..."

Ariel

 

[borges1]

I was having big backlash in the X direction on my basically new (a few hours of use) pm833. backlash was +/-.160. over a full turn of the handle. it has always been that way from new, and i sort of didnt know any better. as i work toward being more accurate it was really making things hard. much fussing and poking i could see the bolt in this picture at the top of the three bolts, visibly wiggling. that bolt goes through the saddle and i assume connects to the X split nut. is the hidden X-axis split nut held on with this single bolt? After removing the power feed, and table i was able to access the bolt and tighten it - so now i have +/-.08" backlash - which is way better, but still more than id like. another demerit for quality control.

the exploded parts diagram doesn't show these parts/configuration, and i didn't take the table completely off to remove the x saddle to access/examine that split nut. could the use prior to tightening the bolt have damaged the split nut so its now out of spec? the exploded diagram (further up this thread a few times) might show this bolt as part #69, but its in the wrong place on the diagram, and doesn't really show what it connects to.

I also remember a really good thread on here about someone who basically eliminated the backlash on this type of machine using annular contact bearings and more expertise than me - but i cant find it. anyone remember that one?

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