Rob L
Aluminum
- Joined
- Nov 5, 2019
- Location
- Staffordshire, UK
Hello all,
I'm having some problems with my Emco Turn 325 which are leaving me scratching my head, hopefully someone here will have a better idea of the cause and be able to point me in the right direction of what I need to check and test. Any help will be very much appreciated, age got the better of the turret encoder in my CHNC just before christmas so I've started 2020 with both of my CNC lathes out of action
Anyway, the problem is I am currently trying to run a pretty simple alu part but with quite a tight tolerance, three tool program of turning tool, grooving tool and parting off tool.
I am finding that I will get two parts off where the OD will be within tolerance and within a few of microns of eachother but then the third part will drop in diameter by around 0.02mm, if I adjust the offset for the turning tool by that amount I'll get another two parts then the OD drops again.
The part length isn't moving by any real measurable amount and more confusingly the OD of the groove on every part that I've made (good and scrap) has remained within 0.01mm of the first one which is the level of repeatability I've grown to expect from this lathe.
I should say user error on my part came in prior to this problem and the machine suffered what seemed to be a fairly minor tool crash which broke the M2.5 insert screw and pushed the insert out of the holder, however I checked the turret alignment after that and it seems to be within the spec that is in the manual. I've also swapped to an un-crashed holder so I'm fairly sure that isn't the problem.
I've also checked for movement on the turret plate/hirth coupling, placing an indicator on a tool and trying to rotate the tool plate doesn't show any movement, the only movement I can find is a little backlash in the X-axis but I would have thought if that were the problem it'd affect all the tools, not just one.
Next thing I want to try is moving the turning tool into another position and running again and also checking the condition of the X-Axis toothed drive belt but past that I'm a bit stumped.
I'm having some problems with my Emco Turn 325 which are leaving me scratching my head, hopefully someone here will have a better idea of the cause and be able to point me in the right direction of what I need to check and test. Any help will be very much appreciated, age got the better of the turret encoder in my CHNC just before christmas so I've started 2020 with both of my CNC lathes out of action
Anyway, the problem is I am currently trying to run a pretty simple alu part but with quite a tight tolerance, three tool program of turning tool, grooving tool and parting off tool.
I am finding that I will get two parts off where the OD will be within tolerance and within a few of microns of eachother but then the third part will drop in diameter by around 0.02mm, if I adjust the offset for the turning tool by that amount I'll get another two parts then the OD drops again.
The part length isn't moving by any real measurable amount and more confusingly the OD of the groove on every part that I've made (good and scrap) has remained within 0.01mm of the first one which is the level of repeatability I've grown to expect from this lathe.
I should say user error on my part came in prior to this problem and the machine suffered what seemed to be a fairly minor tool crash which broke the M2.5 insert screw and pushed the insert out of the holder, however I checked the turret alignment after that and it seems to be within the spec that is in the manual. I've also swapped to an un-crashed holder so I'm fairly sure that isn't the problem.
I've also checked for movement on the turret plate/hirth coupling, placing an indicator on a tool and trying to rotate the tool plate doesn't show any movement, the only movement I can find is a little backlash in the X-axis but I would have thought if that were the problem it'd affect all the tools, not just one.
Next thing I want to try is moving the turning tool into another position and running again and also checking the condition of the X-Axis toothed drive belt but past that I'm a bit stumped.
