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Author Topic: PART CNC PART MECHANICAL  (Read 20121 times)

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Re: PART CNC PART MECHANICAL
« Reply #10 on: April 16, 2012, 02:04:47 PM »
Hood
Hope you post the results and parts required to do it.
Graham

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Re: PART CNC PART MECHANICAL
« Reply #11 on: April 16, 2012, 02:17:53 PM »
I have it working quite well in testing here with a 56u PoKeys. I have the encoder output from a servo drive connected to the pokeys and can count the encoders into a DRO in Mach. I have some VB in the reset button and when I press the button it compares the machine coordinates with the encoder reading and if it is within 0.001mm it will just bring Mach out of reset. If however the encoders and machine coords differ by more than 0.001mm then a box will pop up asking if I wish to update the machine coords from the encoder values, if I click Yes then it will and then Mach will come out of reset. I have attached an image below of the box I was talking about, I also have the encoder and machine coords displayed in that message box so I can compre before I opt to update or not.

In your situation what you would need is an encoder fitted to the disabled axis and a pokeys 56U. What you would do is home the machine at start up and zero the encoder. You would then do whatever you need to do, disable the axis and use it manually then once finished press a button on screen and it would update the machine coords in relation to the encoder counts which would then update Mach as to the position of the axis after the manual motion.
Hood

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Re: PART CNC PART MECHANICAL
« Reply #12 on: April 16, 2012, 02:20:47 PM »
BTW I would still say CNC screwcutting is much easier and much much quicker than manual screwcutting on a lathe and if your axis are already under Mach control all that is needed is a single index pulse into Mach to give Mach the spindle speed.
Hood
Re: PART CNC PART MECHANICAL
« Reply #13 on: April 17, 2012, 03:54:14 AM »
Hood
I know but being a reasonable mechanical engineer and a very poor electonic engineer I need a kit? to fit to my machine or the very least a list of parts and a wiring diagram.
Graham

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Re: PART CNC PART MECHANICAL
« Reply #14 on: April 17, 2012, 04:21:11 AM »
A slotted disc attached to the spindle, an Optek OPB 916B optical switch and a 220 Ohm resistor are all thats required. Take 5v from the BOB to the white wire on the opto, take the same 5v source to one end of the resistor and connect the other end to the red wire on the opto. Connect the Green and black wires of opto together and connect to 0v (Gnd) terminal on Bob. Take blue wire from opto and put to an input on the BOB. In Ports and Pins, Inputs set p the Index to the port and pin you have it connected to.

BTW Mach has to be licensed for threading just in case you are in demo and wonder why it doesnt work.

Hood
« Last Edit: April 17, 2012, 04:32:49 AM by Hood »
Re: PART CNC PART MECHANICAL
« Reply #15 on: April 17, 2012, 04:31:56 AM »
Hood
Fully licensed, thanks for the clear instructions.
Graham

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Re: PART CNC PART MECHANICAL
« Reply #16 on: April 17, 2012, 04:33:31 AM »
Sorry had typo, said 716B and it should be 916B have changed it in previous post.
Hood
Re: PART CNC PART MECHANICAL
« Reply #17 on: April 17, 2012, 04:49:29 AM »
Hood
A search in the internet onlyy found one UK supplier of an Optek OPB 916B optical switch and they had 4 alternatve 916B types but all out of stock!
Do you have any alternative types/suppliers
Graham

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Re: PART CNC PART MECHANICAL
« Reply #18 on: April 17, 2012, 04:56:12 AM »
RS seem to have OPB 917B which is the same just longer leg length.
Hood
Re: PART CNC PART MECHANICAL
« Reply #19 on: April 17, 2012, 07:07:47 AM »
Ordered, you may hear from me again!
MANY THANKS FOR YOUR TIME
Graham