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I cannot seem to find the specs for our schools 1981 vintage wells index CNC machine that we are in the process of rebuilding for use with geckodrives. It is a wells index 800 series with a BEI brand encoder, does anyone know anything about the specs on these machines or where i can find them?
thanks in advance
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Did you contact Wells Index, they are still in business.
There are other threads on this forum about Wells Index CNC retrofits. I converted mine to gecko with Mach3 a hear ago and posted almost all the details in a thread here somewhere just search for my user name "boilerbots".
hey there, what model do you have boilerbots?
also, do you know of a good way to tell what the motor size is?
You can ask Wells Index. Mine had steppers. I got the motor specs from them. They are not as powerful for their size as newer motors but they are pretty good. They ran your machine for many years and should continue to work. They main problem is that they are most likely designed for a fairly high operating voltage. The voltage of a motor and how high you can drive to that voltage will only effect the top end speed, so this may not be a problem. If you have the Bandit controller you can build new power supplies from the parts in that cabinet.Originally Posted by GtownHigh
Here is the thread: Wells Index conversion
Read it and ask question over there.
GTownHigh,
I am so happy to find someone else trying to update a Wells Index machine. Hang in there.
My friends and I are trying to update a 1979, Wells Index 833 with ElectroCraft E723 servo motors. We have decided to disassemble the existing tachometers since they don't work with modern controllers and mount an AMT103-V tach on the end of the shaft. We are hoping to use the existing power supply with High Power UHU controller and Mach 3. We've gotten one motor to work using the G-Code in Mach 3. That's as far as we've gotten so far.
We're trying to keep the cost under $1,000. We're at ~$200 per controller and $30 per motor so far.
We tried to get the specs on our motors for months. We failed.
Hello Bob. Your motor power supply or driver boards may give you an indication of what voltage and amperage your servos need. The voltages may be listed on the boards and a current limit might be marked on the driver somewhere. You can measure the supply output voltage with a meter of course. 45 or 90 Volts at 6 to 15 Amps would be my guess. There are a couple of solutions if you have drivers that need +/- 10 analog input, and you want to reuse them, but I would consider going to a PWM output controller with PWM input amps, and replace the resolvers and tachometers with rotary incremental encoders. I use Pico Amps on my HNC lathe:
Pico Systems : PWM Servo Amplifier [PWM] - $125.00
I use the Pico controller, but Mesa has one, the 7i43P, that is less expensive:
anything i/o
You can reuse your motor supply.
I try to go cheap on the encoders by using USDigital disks and sensors and build my own encoder housings.
This should get you axes working. Good luck. Keep us informed.
--
Kirk Wallace
Kirk Wallace's Machine Shop
E45 Pine Mountain Lake Airport Webcam
California, USA
Thank you Kirk,
What I need most is information on how each part of the system goes together. I'm a mechanical engineer and elect is a second language for me.
When I was looking for information I found lots on the development of the UHU and HP UHU controller in CNCZONE. I assumed that if I got in trouble there were people out there who could help me. I have already built and tested three of the EMBEDDEDTRONICS units and felt that I understood how they work. That is why I chose the HP UHU.
I was hoping to show GtownHigh an alternate, maybe cheaper, route. It sounds like you're way ahead of me.
Bob
Hello Bob,
I was just trying to present an alternative too, but I happened to be biased.I left out most of the details to keep the message brief, but I don't mind elaborating on what I have done so far with CNC conversions. There are a lot of options and much of what you should know, I think will depend on what you are trying to do and what resources you have. My guess is that if you are building a UHU system, you either want primarily a learning experience, or you are trying to save money. To confess, I have drunk the EMC2 cool-aid and that is my bias, but I also I believe that learning and having fun are more important.
My HNC lathe has a servo system, so it is configured close to what I would recommend for your mill:
Conversion of Hardinge HNC Lathe to EMC
I am active on the EMC2 mailing list LinuxCNC.org - Home, click on "where to ask for help", plus there are people on CNCzone using EMC2. Getting help at any level should not be a problem, as long as you don't mind getting your hands dirty. Sharing pictures and details from your project will help too.There is a lot I don't know, but I am happy to share my opinions.
--
Kirk Wallace
Kirk Wallace's Machine Shop
E45 Pine Mountain Lake Airport Webcam
California, USA
Hello Kirk,
I inherited Mach3 from a friend who changed his mind on building a router so I never looked into EMC2. Looks good and it's free. That's nice.
We have already gone with the HP UHU controller. I have looked for a CNC Group here in San Diego for guidance. I didn't find one so I went with what I could learn from CNCZone. It's been an adventure.
Bob
If you don't mind, I'll go into why I personally would not put a UHU on my short list. It's not that there is anything wrong with it, other than it is a step direction controller/driver, as are most other common hobby drivers. A step/dir controller driver basically makes your servos look like steppers to your CNC software. With step/dir the servo feedback goes to the step/dir box and it decides how to maintain or correct the path following. The tuning of this feedback system is controlled and tuned in the step/dir box as a separate process through a software app or jumpers and potentiometers. EMC2 has the controller bit built in and the driver part is all you need. With an EMC2 PWM servo system the encoder feed back goes back to EMC2, so tuning is done with EMC2 and you have full access to add or modify features if you want. This allows for things like using encoders on the axis motors and linear scales on the slides. Each encoder can have a PID loop, or you can use the scales for P and the motor encoders for I, or whatever. EMC2 gives you access to just about any feature you would want through a meter display or digital oscilloscope display. EMC2 can control step/dir drivers with a stepper configuration file, but it would be kind of a waste. There is nothing wrong with Mach or most other programs, but you will be using your servos as steppers and will need to stay with the configurations offered. For most hobby CNC's that should work okay, but for me, I like the power and freedom that EMC2 offers. It will be more technically demanding, so if that isn't your thing, it might not be a good choice, but you can get on the EMC2 mail list and ask if anyone has converted a machine like yours, then privately ask how they like it.
--
Kirk Wallace
Kirk Wallace's Machine Shop
E45 Pine Mountain Lake Airport Webcam
California, USA
Wow,
That was the information I was looking for when I first began. We have the hardware now.I'm still looking for a local group, a class or a book that can give me the insights on what to choose and why on updating this machine.
I am going to take your advise on joining the EMC2 group.
Thank you
Bob
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