Backlash

All info relating to the Denford Novamill CNC Milling machines

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JohnHaine
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Posts: 51
Joined: Mon 21 Nov , 2011 12:12 pm
Hardware/Software: My Novamill, bought in Nov 11 without electronics, is now up and running under Mach3 with a home-build control box. I'm very pleased with the machine, only project so far is correcting a cheap small machine vice originally bought for a vertical slide to use on the machine - not a right-angle in it when bought!

Backlash

Post by JohnHaine » Fri 11 Jan , 2013 19:12 pm

Having had a couple of unexpected small tolerance issues, and being a newbie to CNC milling, I realised that backlash could be the problem. I measured the backlash at 0.03 mm on X and Y, and about 0.02 mm on Z. Are these of the order to be expected on the Novamill please? I have switched compensation on in Mach3 and it seems to have improved matters.

John.

angel-tech
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Re: Backlash

Post by angel-tech » Fri 11 Jan , 2013 22:30 pm

check the angular contact bearings on each axis, they may need adjusting.

JohnHaine
CNC Apprentice
CNC Apprentice
Posts: 51
Joined: Mon 21 Nov , 2011 12:12 pm
Hardware/Software: My Novamill, bought in Nov 11 without electronics, is now up and running under Mach3 with a home-build control box. I'm very pleased with the machine, only project so far is correcting a cheap small machine vice originally bought for a vertical slide to use on the machine - not a right-angle in it when bought!

Re: Backlash

Post by JohnHaine » Mon 21 Jan , 2013 12:01 pm

Thanks, worth a try. But presumably the ballscrews aren't perfect anyway, do you know what the spec is for them, or what might be achievable on the Novamill please?

John.

angel-tech
CNC Guru
CNC Guru
Posts: 525
Joined: Tue 14 Nov , 2006 12:12 pm
Hardware/Software: .....
4 Quatros
3 Oracs
2 Easiturn atc
12 station lathe atc
Mach 3
Location: Quatroland

Re: Backlash

Post by angel-tech » Mon 21 Jan , 2013 12:25 pm

the ballscrews are ground and have double ballnuts, so they should have zero backlash. I've not seen one yet with bad screws, and i've seen quite a few.

JohnHaine
CNC Apprentice
CNC Apprentice
Posts: 51
Joined: Mon 21 Nov , 2011 12:12 pm
Hardware/Software: My Novamill, bought in Nov 11 without electronics, is now up and running under Mach3 with a home-build control box. I'm very pleased with the machine, only project so far is correcting a cheap small machine vice originally bought for a vertical slide to use on the machine - not a right-angle in it when bought!

Re: Backlash

Post by JohnHaine » Mon 28 Jan , 2013 12:22 pm

That's encouraging! I will check the thrust bearings and gibs.

Thanks, John.

njlwilliamson
Posts: 9
Joined: Wed 18 May , 2011 9:12 am

Re: Backlash

Post by njlwilliamson » Mon 15 Apr , 2013 16:56 pm

Hi,

Did you manage to eliminate the backlash? I have about the same on mine. I tried adjusting the thrust bearings and gibs but it is still about 0.02mm on all axis.

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