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Author Topic: ? Big Bed Mill Retrofit  (Read 10150 times)

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Offline diygranite

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Re: ? Big Bed Mill Retrofit
« Reply #10 on: March 20, 2011, 01:30:29 AM »
Wow, glad to see there is another one of these. I do have another cabinet with the extra io too. Could you send me a picture of the photo diode part and where it is supposed to be located. Did you download your ladder logic and do you have a copy of it? I guess the only way to get it off the omron plc is with a pro16 programmer. Is that what you have? How far along are you in the retrofit? Did you continue using the servodynamic drives? The servos? Anyways thanks for the response. Hope to hear more.

Morris
Re: ? Big Bed Mill Retrofit
« Reply #11 on: March 20, 2011, 09:00:05 AM »
I kept the Servo Dynamics drives and SEM servos, but I have replaced all of the encoders.  Right now, I have the machine about 80% done.  The spindle control works fine, I have axis movement under Galil control, and all of the additional functions (coolant, tool release, master control relay, etc) are under control of the Galil + PLC. 

There is quite a bit left to do.  I have written the new PLC code for the tool changer but not tested it.  I bought a touchscreen panel that is working, but needs to be mounted and I also have a pendant to integrate.  I am also in the process of mounting limit switches for X & Y for safety and to reference the machine (limit + encoder index homing).  Will try to get a picture of the photo transistor boards today.  As I recall, it is just 2 pc boards mounted in a housing.  Like I said, very simple circuit, but it will be some work to make. 

I do have the PLC logic off of mine.  Yours is probably very close if not identical.  The main reason I changed the PLC is that it would take major programming changes to interface with the Galil as opposed to the Dynapath.  I decided that my time was better spent on a more modern, more servicable PLC.  The new PLC is a Siemens S7 series, cheap hardware and software off of ebay.  The Galil communicates things like spindle direction, coolant requests, and tool numbers to the plc which then drives relays to actually control the machine. 

Offline diygranite

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Re: ? Big Bed Mill Retrofit
« Reply #12 on: March 20, 2011, 12:24:03 PM »
I was going to leave the encoders. What are the advantages of changing the encoders? Is it index homing? Which encoders did you settle on?

The omron plc uses parallel bus to communicate with the controller (i can see that would be complicated). What does the siemans use that is easier? is it serial modbus? or is it directly from the galil board? I dont know this stuff very well. Maybe you could share this if you get it working. Need any granite countertops?

I found some pictures of similar machines last night without toolchangers. One has a picture of the original Kasahara logo which probably is difficult to find. The oter is a Vulcan. These come up so rarely so  I attached pictures.
Re: ? Big Bed Mill Retrofit
« Reply #13 on: March 20, 2011, 01:58:18 PM »
I replaced the encoders because two failed.  I found some with the same mounting pattern so they were a drop-in.  My originals were 500 line and I replaced them with 1000 line units.  My mill has .200" pitch ball screws, so this puts me at 20000 counts/inch in quadrature.

Attached are a couple of pictures of the opto sensor off of the tool changer.  The top board has the IR LEDs and the bottom board is the phototransistors.  The top and bottom housings are machined to clear the PC boards and hold everything at the right spacing.  Sorry for the poor quality on the pictures, my camera did not seem to be focusing properly.  The resistors are 390 ohm, which would be limit diode current to 60ma with 24V supply.  It has five pairs of detectors, but the far left one is not used and wasn't even connected on the PC board.     

Mike
Re: ? Big Bed Mill Retrofit
« Reply #14 on: March 20, 2011, 02:00:20 PM »
Second pic.

Mike

Offline diygranite

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Re: ? Big Bed Mill Retrofit
« Reply #15 on: March 20, 2011, 02:27:20 PM »
Thanks, I will attempt making one of these and test the system the way it is. I'll measure the slots to get the spacing right. I thought it would be something like this or switches, but could never see one. Could you say where this was mounted over the slotted disk? If facing the machine is 12:00, was it at 3:00 or 6:00? Also, do you remember the m command in the dynapath for the toolchange in case it is different than the manual (I have the dynapath manual)? Since this toolchanger wasnt used by the last owner, he didnt have other information. Thanks

Morris
Re: ? Big Bed Mill Retrofit
« Reply #16 on: March 20, 2011, 05:07:27 PM »
If you draw a line from the center of the carousel to the Z axis screw, the sensor is pretty much on that line.  There should be a couple of #8 or 10 threaded holes in the rectangular tubing where it mounted.  With the carousel locked, the sensor lines up with the notch in the wheel and will not be over any slots.  The sensor tells the next position coming around, which switches on the motor braking and the lock cylinder.  The tool number is binary with the outer most slots being the least significant digit.  With the carousel locked at position 1, the sensor will be between 1 & 2 on the wheel.  The inner slots (5th row) were not used on my machine.  I have no idea why they put them in. 

I did pull out my wiring diagram and there is another 100 ohm resistor in the supply to the LED.  I have attached it in case you don't have it.   

I know I have one bad channel on mine, so I'm just going to replace everything.  Photosensors don't do well after 25 years and I will use the matching LEDs for whatever phototransistor I pick. 

Offline diygranite

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Re: ? Big Bed Mill Retrofit
« Reply #17 on: March 20, 2011, 06:10:14 PM »
That wiring diagram will make it a lot easier. I have no wiring diagrams for the machine at all and some of the (written in) labels are faded as well. Thanks.

Morris
Re: ? Big Bed Mill Retrofit
« Reply #18 on: September 21, 2011, 08:28:44 AM »
We also have one of these machines. We need pictures of the top of the tool changer because ours is not much more than a plate with pins. We are trying to find out what the missing components might be. We would like it to be able to hold a  cat 40 tool. Does anyone have any pictures that they could post for us? Thanks

Offline diygranite

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Re: ? Big Bed Mill Retrofit
« Reply #19 on: September 21, 2011, 01:30:33 PM »
There are earlier posts in this topic with pictures. can you post pictures of what you have?

Morris