I'm intending to purchase a large 2nd hand CNC milling machine in the not too distant future (bridgeport interact or similar) so I was wondering if I could get some pointers here so I dont get ripped off.
Whether it be at an auction or private seller, these things are normally sold as seen and is up to the buyer to discover any faults when viewing before parting with any money.
As far as the electronics go, I dont care about the condition of them as I intend to replace the servos and drivers with new stuff anyway. Its just the mechanical gubbins that are more of a mystery to me.
I know backlash on the axes is a big issue and perhaps my single biggest concern. So how does one go about testing for backlash in a scientific manor other than trying to move the table? Is there a way of measuring it without acutally running the machine ? Also if the machine is running, is there a better/alternative test I could do and how would be the best way to go about it ?
Is there anything else I should be overly concerned about other than backlash ? Ovbiously I can check the general condiditon of the machine just by looking, but are there any other specifics ?
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Dom
http://www.ukrobotics.com/projects |