| Gallery, Projects and General > How do I?? |
| Einhell MTB3000 minilathe potentiometer |
| << < (4/7) > >> |
| lordedmond:
From your pic Bertie is correct It looks to me as if someone in the past as skimmed the com and rolled over the Segs Do not use a dermal as the ginding dust will embed in the copper as wear out the brushes, a well used hacksaw blade with the side kerf ground off to the grove width is the accepted tool As a ex armature/stater winder during my time that's what we used even on the big stuff we did try a air powered slitting saw and guide but the old way was better. The colour looks ok it should be a chocolate brown , one last point well two really when you have cleaned out the slots take a craft knife and gently de burr the edges , and do not use any emery cloth on the copper if you feel the need to shine it us use the glass paper the wood butchers use its th yellow stuff else it will embed the grit and wear out the brushes PDQ I hope you ran it on test on DC not AC if you did Use AC it would have got hot Good luck John knows more about the actual board than I do but I have save a few for friends Stuart |
| John Rudd:
--- Quote from: Stuart on May 04, 2015, 05:51:55 AM ---From your pic Bertie is correct It looks to me as if someone in the past as skimmed the com and rolled over the Segs Do not use a dermal as the ginding dust will embed in the copper as wear out the brushes, a well used hacksaw blade with the side kerf ground off to the grove width is the accepted tool As a ex armature/stater winder during my time that's what we used even on the big stuff we did try a air powered slitting saw and guide but the old way was better. The colour looks ok it should be a chocolate brown , one last point well two really when you have cleaned out the slots take a craft knife and gently de burr the edges , and do not use any emery cloth on the copper if you feel the need to shine it us use the glass paper the wood butchers use its th yellow stuff else it will embed the grit and wear out the brushes PDQ I hope you ran it on test on DC not AC if you did Use AC it would have got hot Good luck John knows more about the actual board than I do but I have save a few for friends Stuart --- End quote --- Good advice from Bertie and Stuart there..... As Stuart says, a group up saw blade is best for cleaning..... I also have a few spare boards of both Chinese and American flavour as a backup.....only trouble is they do need setting up to match the motor..... :scratch: so although they are a drop in replacement, there are a few tweaks need to 'tune' them...and I have the setup procedure too....if needed.. :D |
| bertie_bassett:
just had a better look at the photo, and to me it looks like the damage is isolated to that groove near the windings. looks like something has dug in at that point. iv seen similar damage from brushes that were so worn that the internal cable was poking out, thus damaging the segments. a small bit of debris could easily do the same. |
| John Rudd:
The comm doesn't look too good..... I had another look.....agreed there is a mark at the top right, but if you look further down towards the termination points, it looks like there are copper shorts between some of the segments..... If these can be cleared, the motor might be in a better state.... :scratch: |
| awemawson:
I reckon that some previous owner let the brushes wear down dangerously low, and as Bertie say got the com mangled by the wire holder. Then changed the brushes and it failed to fix the problem so got shot of it. Hence there being no apparent problem with the brushes. |
| Navigation |
| Message Index |
| Next page |
| Previous page |