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Recently I got a job to be a CNC setup operator. Previously, I have only had experience as an operator(load/unload parts, push green button - anything bad happens, press big red one). Luckily, they are giving me some training, but it's only SUPPOSED to last for up to 6 weeks(which I hope will be enough).

A little info: This company only has 3 machines in the cnc department, all of which are ancient. 2 of them are cnc bridgeports, and the 3rd is a 26 year old Matsuura MC-1000VS. I understand within the next year, the Matsuura will be replace with a brand new machine.

So far, the setups that I've seen there have involved taking a pre-built fixture and bolting it to the worksurface in the maching, squaring it up, and installing the tools. To get the TLO's we touch off the work surface(wherever the work instructions say where to get the Z offset from). To get our X and Y locations, we typically use an edge finder off of pins on the fixture, or a dial indicator off of a construction hole.

The only specific question I can think of is:
I know that you can use the pointed end of an edge finder to find the center of a hole, but how is this affected if the hole has a chamfer?

I don't have any other specific questions right now, but I'll take all the tips and tricks I can get from you seasoned veterans out there.

Cheers!

Hello

Bridgeports, ahhh i did my apprenticeship on them and Okuma lb-15 lathes.
Your edge finder will still pick up the centre of the hole on the chamfer provided the chamfer has been machined concentric to that hole.

I struggle to see how your setups are accurate using this method.
Best used finger dail gauge and clock up on the chamfer or hole, once this is running true then enter your x and y machine values into your work shift eg. G54 x and y.

Then MDI - G0 G28 G91 z0.0; [insert] and [cycle start].

Then Zero return X and Y. MDI - G0 G91 G28 X0.0 Y0.0; [insert] and [cycle start].

Then MDI - G0 G54 Xo.o Yo.o ; [insert] and [cycle start].

This should position the spindle exactly in the middle of that hole you clocked up on, in effect you can also check whether the chamfer is concentric to the hole.

Hope i helped dude.

I may not be describing our setups very well, but we are machining our parts typically to within +- .0005", and we are able to consistently stay within this tolerance.

Regarding finding the center of the hole, I think I understand what you describing. Next time I have a chance, I'll try this out at work. Thanks for the suggestion!

btw, any other general tips or tricks that I might be able to use?


Thanks for the help