CNC Bridgeport with Heidenhein control

If that is all that is wrong -- that should be easy to fix.

Good Luck, DoN.

Focus was unusually poor for your work.

Looks like servo motors, based on the one to the left of the head, so if it is more than just the monitor, you may want to go with the EMC package based on linux.

Tooling looks nice -- including a sacrifical tooling plate to protect the table.

Enjoy, DoN.

The major cost here will be your time. A lot to learn. My pure guess would be about two man months. The more equipment you can reuse the more you save and the more time you'll spend. Its easier to do a simple machine first, this one isn't it. Look in to how you do the servo drives with the Heidenhein scales and what all you'll need to interface all the I/O to your Linux box. These will be the two largest costs.

You'll end up with a machine you control from a computer keyboard - fine for hobby work. Most of my experience is with refitting a machine so its a professional job that is better than new. Costs easily run 15K to do this.

Karl

Did it not come with a controller, Iggy?

You remember when you made printouts of coordinates and then turned the handles to those positions to make shapes? That is what CNC control does, but it will do it on all 3 motors at around 1000 times per second depending on controls. The double loop, for example, is when the control gets a feedback from the motor and also gets feedback from the scales on the axis. The motor feedback is used to sense what the motor is doing, the linear scales sense the actual table position. These could be the same but if your ball screws get a tiny amount of backlash, the motor will try to make up for it.

The servo motor gets power to run forward or backward and has something to sense turning so it can be controlled, usually through a Proportional, Integral, Derivative (PID) control loop.

My system uses motor feedback to the motor amplifiers and uses encoder or scale feedback to the CNC control. So, if my position is off a move is required, my control will send out a signal to tell the drive to move the motor at a speed and direction. The amp will send power to the motor and sense the motors movement, as the position error is smaller, the controller sends a smaller signal until the motor stops at the correct position.

RogerN

Looks like a center drill to me..

I have not brought it home yet, but it does come with a controller and, if I am to believe the seller, the only thing wrong is the display that has a bad transformer (which is something weird and cannot be replaced).

i

OK, I think that I understand that. I will look for some webpage that described architecture of a CNC system. I already have all the manuals in my possession.

i

So, Karl, what would you (with your skills and all) do with this bridgeport, would you just try to restore its Interact 2 controls?

i

Heidenhain would LOVE to offer this service, but you'd better be seated for the price. Competition has driven the price way down, but I'd take a wild guess and say it is at least $15000 for a complete refit. For reliability reasons, they won't want to reuse any of the control hardware, even if it is in fine shape. So, strip it all off and replace.

There are a number of other retrofit outfits that would be cheaper, but all the turnkey retrofits are going to run over $3K, for sure. That's the Ajax, you get a box of parts and a printed manual, and a note saying "Don't call the factory, we will NOT accept your call except for broken parts. If you wanted support, you should have bought from Centroid." The Centroid control is same as the Ajax, except you pay $10K so you can call them when you run into trouble.

There are much more affordable do-it-yourself retrofit paths.

Jon

Look at linuxcnc.org, and then you need to decide how to drive the motors.

2d vs. 3D is mostly a factor of the control, not the machine itself. Anything recent (EMC2, Mach, Centroid, etc.) will be capable of full 3D contouring.

I assume your Heidenhain control had DC brush servo motors. It may have encoders on the motor, or tachometers, as well as the linear scales somebody mentioned.

Jon

It is rather unlikely the control will survive the move without some new problem coming up. The older the control, the more fragile they get, as the number of separate circuit boards and connections was much higher on the early ones. This is probably a mid-80's control at the latest, and unless you were a minicomputer hardware tech in a previous life, I don''t think you want to get involved it trying to keep it running.

I adopted a 1978-vintage Allen-Bradley CNC control in 1997 and managed to get it running, which was a HUGE ordeal, requiring disassembling the paper tapes for the executive program so i could modify it, building a "BTR" so I could dispense with paper tapes, etc. But, it had major breakdowns 3 times in 9 months, and I was getting TIRED of maintaining the DAMN thing! Your Heidenhain control is likely a bit newer, but still VERY much in the aged category now, roughly 20+ years old. So, I would strongly recommend a retrofit, too. Depending on whose servo amps are in it, they may be able to be reused, which will make the retrofit easier. Depending on the type of position encoder on the machine, these may be reused, too. With Heidenhain, there may be signal converter/interpolator boxes associated especially with linear scales that need to be kept.

There are several servo interfaces available for EMC that you can choose from (I make one kind).

Jon

Depends on the condition, how long it has been since it last ran, and whether the prints for the boards come with it. If no prints, you are in a HEAP of trouble.

My experience tells me to not bother unless all it needs is a new video monitor AFTER!!!! you get it moved to your location. If it has serious problems, it can become a total time sink.

I've had GREAT results with EMC, and would NEVER go back to the proprietary control.

Jon

You need to get into it to see what is there, and what it looks like (mouse-eaten wiring, burned parts, etc.)

First, ID the motors, and see what velocity feedback it may have there (encoder on motor, tach, etc.)

Second, ID the servo amps - just follow motor armature wires back into control cabinet, and wherever they stop should be the servo amp. Westamp and Servo Dynamics were the big players at that time, and a lot of control builders used them. Docs are still available.

See if the servo power supply needs 3-phase or can run off single.

3rd, ID the main position encoders. With a Heidenhain control, it is likely to be linear encoders on the machine table. But, Heidenhain had their own proprietary current-output scheme for encoders. Some of their encoders had very low native resolution, and the sine-wave current outputs were fed into interpolator boards to increase resolution. If so, you want to save those boards.

Once you have this info, you can start looking at interface hardware to connect to it. You can also decide whether to use the servo amps, or scrap them.

Jon

Probably not quite. it is almost certainly a servo-driven machine, not stepper. $500 with new motors? Do you know how big a Series-II is? It stands about 8 feet tall and weighs 5000 Lbs. It uses NEMA size 42 motors driving the leadscrews 1:1.

Jon

Double-loop means that there are two encoders per axis, a shaft encoder on the motor and a linear encoder on the machine table. Really, the motor encoder is used to sense velocity. I am guessing from vintage and make that your machine more likely has a tachometer on the motor, not a second encoder. The tachometer feeds velocity info back to the velocity servo amplifier, and not to the CNC control.

tachometers and rotary encoders, no linear. He apparently re-used the servo amps. Looks like a single-phase transformer, lucky!

Jon

That's good to hear. Retrofits have come a long way. I hope Iggy's retrofit is a successful one. I'm looking forward to hearing how a non-specialist makes out with it.

Jon

These machines generally used SEM Servo Motors and Bosch drives.

Wayne...

You were close. $13,000 for a model 320 control.

Invested for 30 years, it will amount for one year of my retirement.

I thikn that I should try to get this one fixed first.

i