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triac not machining properly. loosing steps??

Posted: Sat 19 Mar , 2016 17:42 pm
by toby1995
hi everyone.

a newbie to using triac cnc mills.
I've come across an issue on my triac when machining circular toolpaths. it machines circles out of round weather its external or internal. it will randomly leave notches in the machine finish were it has dug into the material. I've checked the programs are correct. has anybody else had this problem? if so how is it sorted? its becoming more than annoying now

thanks in advance for replies
toby

Re: triac not machining properly. loosing steps??

Posted: Mon 21 Mar , 2016 10:50 am
by Martin
What software are you using?

Re: triac not machining properly. loosing steps??

Posted: Mon 21 Mar , 2016 21:11 pm
by toby1995
denford vr milling v5 software with bobcad v28 mill

Re: triac not machining properly. loosing steps??

Posted: Tue 22 Mar , 2016 10:54 am
by Martin
Have you updated to the latest version of VRMilling?

VRMilling 5.63

http://website.denford.ltd.uk/index.php ... -downloads

Re: triac not machining properly. loosing steps??

Posted: Thu 24 Mar , 2016 0:39 am
by toby1995
no i haven't i have 5.62 will update and see if it helps. also just for future reference is there a good place to get parts for triac machines?

Re: triac not machining properly. loosing steps??

Posted: Thu 24 Mar , 2016 10:30 am
by Martin
I don't think the software will make a difference if you are on 5.62.

What about backlash? Can you post a photo of the circle it machines?

Re: triac not machining properly. loosing steps??

Posted: Thu 24 Mar , 2016 12:35 pm
by toby1995
it only seems to be on a certain point on the traverse of the x axis. if i use the far left of the table for machining it does fine, if i use the other side of the table it doesn't like machining circular paths and when facing it leaves lines as if it needs tramming. but this is only on one half of the x axis so I'm not sure what to do here, its getting me quite concerned. as theres only so much you can do with a gib strip when it seems your sideways are unevenly worn
i will upload some photos shortly today

Re: triac not machining properly. loosing steps??

Posted: Thu 24 Mar , 2016 12:39 pm
by toby1995
and I've checked for backlash. all good there I'm only getting between 0.008 and 0.01 backlash and have coded in the backlash value in VR milling to compensate. and wrote a figure of "10" to correspond with how many microns of backlash there is. in Fanuc control systems this is the correct way, is VR milling the same? as its Fanuc based

Re: triac not machining properly. loosing steps??

Posted: Thu 24 Mar , 2016 17:04 pm
by Martin
VR Milling does not compensate for backlash even though you can input the figures.

It could be a broken wire which shows up when you have the bed in certain positions. I would jog the bed to where you think it is bad & wiggle the wire. Listen for the stepper motor changing pitch.

Re: triac not machining properly. loosing steps??

Posted: Sun 27 Mar , 2016 14:55 pm
by toby1995
no change in pitch and wires seem to be connected okay with no breaks. is it possible its the electronics in the main cabinet of machine? like the drive boards?

Re: triac not machining properly. loosing steps??

Posted: Sun 27 Mar , 2016 22:55 pm
by toby1995
i tried some engraving today and it came out double lined after i retuned for a clean up pass at the same depth. one line was clearly cut atleast 0.8 mm from were it last cut. i only get this with the x axis. i will try to post up some photos asap

Re: triac not machining properly. loosing steps??

Posted: Wed 30 Mar , 2016 17:53 pm
by toby1995
machine is sorted now. turned out to be a worn stepper motor. the machine is cutting smoothly and accurately now. thanks for the advice :)

Re: triac not machining properly. loosing steps??

Posted: Mon 18 Apr , 2016 14:31 pm
by toby1995
is there likely to be an updated version of vr milling software that actually compensates for backlash? i don't see any point in being able to just input the figures for the software to do nothing with that information.

Re: triac not machining properly. loosing steps??

Posted: Wed 20 Apr , 2016 9:32 am
by Martin
I am not aware of any plans to use the backlash facility. I agree it should not be present if it is not active. I will have a word with our IT.

Re: triac not machining properly. loosing steps??

Posted: Thu 21 Apr , 2016 13:24 pm
by toby1995
thankyou martin, would be a lot of help!

Re: triac not machining properly. loosing steps??

Posted: Mon 13 Jun , 2016 14:06 pm
by toby1995
hi martin is there any more news regarding the backlash facility in vr milling? I'm having to draw my round parts out of round on my cam in order for the machine to machine it correctly lol

Re: triac not machining properly. loosing steps??

Posted: Mon 13 Jun , 2016 14:57 pm
by Martin
I don't think we have any plans to insert Compensation at any point.