Z Offset Issue with Rear Approach Tools

[roundel325]

I'm experiencing some unexpected behavior when trying to set tool Z offsets on my gang lathe. When following the instructions in section 5.9 of the manual (make Z face skim cut, set Z Ref, measure Z offset) a Z offset value of double the Z Ref is saved for the tool. The manual says the Z offset should be 0 if the tool hasn't been moved. This only occurs if the tool is set to "rear" approach. If set to "front" approach, it behaves as expected.

Is this a bug or am I just misunderstanding something? Is there a workaround? I'm trying to setup a job that uses both front and rear approach tools.

I have made a video of this here:



Fresh report attached. I am running version 4.62.

Thanks!

[cnckeith]

taking a quick look at this...I think this was one of the bug fixes in v4.64? i don't see the same action on the beta i'm working with now. make screen shots of your wizard menus, make a copy of the cnct directory. update to v4.64 or try the new public beta.

[roundel325]

Keith -- I just upgraded to 4.64 and the issue persists. I will try to install the beta next, but if you can confirm that this is a known issue being worked on by the software guys I would feel better about moving to a beta build (which I assume is still set to time out). Thanks.

[cnckeith]

right now don't know if its known issue and haven't heard of this before and so far i can't reproduce it on the beta, please give the beta a go and report back.. fyi.. its trivial to go back to v4.64 if you don't like the beta.

[roundel325]

I installed the beta and no change. It seems odd to me that the front/rear approach parameter would have any influence on the Z offset calculation? I can imagine a way it might affect the X offset, but Z approach is always the same. Anyway, let me know what else I can send you to help you reproduce the problem.

[cnckeith]

thanks, please send me a fresh report.zip from the beta

[roundel325]

Report attached. Thanks Keith.

[cnckeith]

i am able to reproduce now, thanks for the report.zip

With Wizard set to "Gang" and "Front" the Z tool measure value is doubling..so looks like we got a sign wrong when cnc12 is adding the distance values for the tool measurement.

Wizard set to "Gang" and "Rear" is working properly.

We will have a rev9 beta out with a fix as soon as possible. thanks for finding and reporting this one.

[roundel325]

Thanks for your responsiveness! Can you explain why the wizard has a front/rear option after choosing "gang"? I always kinda wondered what I should choose. I have just as many front tools as rear and it's just a mixed bag depending on the job. Can I just change it to "rear" as a temporary fix or is that going to mess up some other behavior of my machine?

[cnckeith]

front and rear selection for gang is so cnc12 knows from which way the x offsets are being defined from in the tool lib. yes you can have gang tools that are on both sides, cnc12 just needs to know which side you decide to measure from. switch to rear is a immediate solution, just be sure to reset the tool library offsets afterwards.