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1995 Bridgeport Torq Cut 22 refurbishment and rebuild thread

swatkins

Titanium
Joined
Jul 24, 2011
Location
Navasota / Whitehall Texas
Here is my newest rebuild project. While it was born in 1995, and is by far the youngest major tool I own, I feel that in the world of modern machine tools this really is an Antique.

While there are older models of NC tools and the whole line of Bridgeport Boss CNC machines, I feel this machine is a better project to restore because it can be rebuilt and modernized to do useful work, mainly because of it's full enclosure and tool changer.

Another plus, in my mind, it the old 486x computer that handles the control part of the machine. I have lots of old computer boards, hard drives and parts that I can use if needed. I do admit that I thought my dos days were long over, glad I still remember some of the commands :)

I did a short video showing my progress..

 
Steve,
Thanks for taking the time to make the videos and telling us about your machine with your usual clear explanations .
It gives me hope that some older C.N.C. tool grinders I have looked at could be persuaded to work again given the all important right person to help with the controls .
It would be nice to be able to grind complex shapes with out having to have it done on a machine costing the more than most houses in the area where I live.

I have an 1990 era optical comparator with a( Parallel Port / Printer Port) on the Digital Read Out unit on it. to similar to your machine .
I have never used it but think read that it could be used to print out data from the measurements taken by the DRO. unit.

I was thinking yours might have been used to print out data taken with the probe attachment you mentioned you were getting to plug into the your machine .
Regards,
Jim
 
If I remember correctly, the printer is talked about in the operators manual. I THINK it was mainly for making paper copies of your programs, but it may have had other functions too.

I think when this mill was made, they expected you to do all the programming at the machine. So the only file transferring you would do is backing up your programs or sending them to another machine. One of our first machinists was an old tool and die maker. Not the fastest at making parts, but he was very good at creating fixtures and then storing and documenting the whole process. he would always have a paper copy of the programs on hand, cause you never know when a floppy is going to die, or a new machine or software might not recognize the old program so having a paper copy made it easier to recreate.

Exciting that you've got a probe on the way!!! Our new mill's going to have a work probe as well as a tool setting probe. I always thought that stuff was "too advanced" for us.... :rolleyes5::o
 
Jim that might be a use for it :)

The probe arrived today and it looks like it is good shape. The cable even fits! Just playing around with it for now but when I press F7 DIGITIZ it tells me that the program is not loaded on the machine. Included with the probe, which came out of a closed shop up north, was a single unlabeled floppy disk. I'm hoping that the software for digitizing is on that disk.

This brings up another problem people that want to keep these old machines going are going to face, lack of support tools. Right now I'm looking for an old computer just to read what is on that probe disk. I've been building and supporting computers since 1984 and luckily I have some old equipment hanging around so I handle working with the old electronics.

Soon there will not be people and easy access to repair parts to handle a rebuild like this. Unlike the good old heavy iron machines I think the tools of the future will have a very limited useful lifespan. Today there are thousands of 75 year old machines running and making useful products, I think even 40 years old NC or CNC machines will be a rarity without a total control refit.


Started working on the tool changer this afternoon. It's a pretty simple system and was in good shape until I crashed the changer :( Luckily the fix was simple and now the machine has a clean changer :)

 
Steve, this is pretty neat what you are doing with it. One suggestion which you may already be doing is to document things like putting in the jumper to run on single phase and put it in the pocket in the door of the electrical cabinet so if/when you are done with the machine the new guy can read what has been done. I also think it is worthwhile to put an explanation of why you did the jumper or whatever vs just saying "Installed jumper wire from terminal a to b".

Your mention of the people and hardware to support these old PC's is accurate. When I worked at the local university I had a mid 90's cnc panel saw that ran on DOS on a 386. In a wood environment and due to age we were going through floppy drives often. Then we lost a couple hard drives and luckily at that time the old guy in IT was a horder and kept alot of that stuff. Well, he retired and the next time the saw had a big problem in the computer it was almost impossible to fix. I tried to keep some of his extra parts when he left, but the department tossed all of it and short version is the machine got scrapped after I left because no one could or wanted to try and fix it. The machine itself was in great shape and worked awesome, but the PC died and obsoleted an expensive machine.
 
Your mention of the people and hardware to support these old PC's is accurate. When I worked at the local university I had a mid 90's cnc panel saw that ran on DOS on a 386. In a wood environment and due to age we were going through floppy drives often. Then we lost a couple hard drives and luckily at that time the old guy in IT was a horder and kept alot of that stuff. Well, he retired and the next time the saw had a big problem in the computer it was almost impossible to fix. I tried to keep some of his extra parts when he left, but the department tossed all of it and short version is the machine got scrapped after I left because no one could or wanted to try and fix it. The machine itself was in great shape and worked awesome, but the PC died and obsoleted an expensive machine.

That is sad about the machine. I guess is't like all things, a matter of economics and progress.

I'm putting notes in with the schematics with the changes I make. It would not hurt to make a tag with the changes on it in case it leaves for other places and I'm not around anymore. I plan on leaving the shop to my son but who knows when that will be and even if he would want it then. Would cost a lot to have it moved and buildings are not cheap.

BUT while I'm still kicking I'm going to have some fun with it!
 
A little more progress....

The Renishaw MP11 probe arrived yesterday. I forgot to take pictures of it but will soon. Last night I spent three hours trying to make sure it still works as the seller had no way to test it and agreed to take it back if it was DOA.

I had great hopes it would just plug in and work, no such luck. After hours of searching for how the probe works and how it is wired I gave up and went to bed, only to lie awake for two hours thinking about it :)

For those of you that don't know what I'm talking about... This machine came from the factory with wiring and programing in place to support a probe that can be mounted in the spindle then moved around the workpiece until it touches their edges and surfaces. It has an assortment of tips that can reach in all types of cavities and determine their exact size. When the tip of the probe comes into contact with a surface it sends a signal to the control telling it to stop moving and records the exact location where it touched. Sort of a fancy wiggler if you will. This fancy wiggler has wires and circuits that are now 23 years old and will need attention.

Today I started checking the pinouts on the machine / probe cord and... well I found a surprise. A picture is worth a thousand words :) Please pardon the noise level, the machine was running.. Might want to adjust the volume.

 
At-Man Unlimited on YouTube just did a series on the MP10. If you didn't come across this in your searching it may be worth checking out.

Anatomy of the Renishaw MP1 Probe - YouTube


Thanks, I've seen it and it was helpful.

The MP11 is a little different in that it does not have the on board battery and I "hope" it has much simpler circuit boards inside the body of the probe. The MP11 has two lines providing power and two lines for supplying signal and a return to control path. All the control relies on is the signal and return signal to tell it that it is touching something. When it touches it completes the path. You could run a probe with just these two wires. I'm not total sure why the unit needs the 24 volts DC provided by the other pair of wires. It does provide power for a LED on the body of the probe, the light is on until the probe touches and makes contact. Hopefully there are no electronic parts inside the body that are damaged. We will see :)
 
Thanks, I've seen it and it was helpful.

The MP11 is a little different in that it does not have the on board battery and I "hope" it has much simpler circuit boards inside the body of the probe. The MP11 has two lines providing power and two lines for supplying signal and a return to control path. All the control relies on is the signal and return signal to tell it that it is touching something. When it touches it completes the path. You could run a probe with just these two wires. I'm not total sure why the unit needs the 24 volts DC provided by the other pair of wires. It does provide power for a LED on the body of the probe, the light is on until the probe touches and makes contact. Hopefully there are no electronic parts inside the body that are damaged. We will see :)


I'm guessing that the unit needs 24v DC for the switching circuitry (aside from the aforementioned LED) on the inside. They might use a lower voltage/amperage across the contacts of the probe and still need to switch a higher voltage/current signal to whatever configuration control XYZ is using.
 
Success!

I've been off playing hookie and watching the Total Solar Eclipse from Nebraska so not much physical work being done. I took the manuals and wiring schematics with me and studied the problem. Sure was frustrating thinking I had a solution while the machine was 800 miles away...

To recap...

I bought the Renishaw MP11 on ebay for a decent price. It is a wired unit that is supposed to plug into the port on the machine spindle cover. NOT :( The man I bought the probe from did not know if it was working and had no way to test it. He assured me that I could return it if DOA so I took a chance. I was handicapped by that deal in that I really could not open up the probe and expect to receive a refund, I had to do all the testing without doing harm to the probe so that also slowed me down...

Adding to the problem was someone had cut the 4 wires leading to the probe port and taped them up inside the head. That cost me a night's work as it was the last thing I would have expected and I had no idea why it was done. Was something shorted out, fried or causing the computer to flake out? I had no idea and with some reservation I reinstalled the wires... Thank God no bang :)

The second big problem was with the probe cable. It did not have all pins inserted in the correct positions and my port on the probe head was rotated out of position so I was not sure on the pinouts. After a a nice guy took a picture of his were were able to figure out the correct pins and I thought my problems were solved... WRONG!

I finally figured out how the machine needed wiring after consulting three different wiring diagrams, two different probe manuals and assorted website posting.. I can safely say my machine is a one of a kind when it comes to wiring up the probe as nothing I have found works!

Tonight I kept at it and checked every wire back to the cabinet and reasoned out the wiring. One source of my wiring problem was a resistor that was "hidden" under the wiring block. Once I found that I changed a few wires around and it started working correctly!

Kinda loud, Please adjust your volume.


Next up on the list of repairs is a return to the X axis drive card... After working well for a week it stopped working when I was working on the probe. I don't think messing with probe killed it but I had to remove the card and replace it with the C drive card.

I had ordered a set of capacitors for the motherboard and while I was at it ordered the replacement caps for the drive card.. I'm going to replace the caps and run a repair wire to the damaged pad just for insurance, sort of a belt and suspenders thing. I need it working as I don't want to spend 800.00 to replace it and it's needed to get the 4th axis tested out..
 
Been awhile since I did any work on this machine, the flood and other work has seriously reduced the metal shop time.

Saturday I had a few moments to work on the speed change problem. It had gotten progressively worse and now I could not get the machine to go into any speed.

All my trouble shooting led me to about three things that could be wrong so I picked the obvious one, Rotary Vane Actuator (RVA), to work on first. There is a manifold on the left side of the machine and it controls everything air driven. There are two exaust mufflers and one almost always had air escaping from the system. I tracked that leak down to the RVA and after playing with the unit determined that air was leaking from side to side. Not good..

Searched around and found a company that could either supply a new one or better yet a repair kit :) Parts were 75.00 and arrived fast. Too fast as it turned out as I was busy and it just had to wait.

I have a very nice set of drawing for the machine and there was a short procedure for removing the RVA from the machine. What it didn't tell me was they were starting the procedure AFTER the motor was removed :(

Removing the motor would involve me building a jib crane for over the machine, again time I just don't have right now. Looking the situation over I found I could replace every seal with exception of a very small seal around the shaft that entered the transmission. I figured that it was worth a shot to do what I could with the motor and base of the RVA in place.

After about an hour of standing on a ladder and teasing very small seals into place I got it all back together. Another hour of figuring out where the shaft collar, with a sensor magnet embedded in it, was supposed to point to and an hour of resetting the sensors, I have a machine that loves to shift speeds!

A few pictures...

20170807_220822.jpg

Repair kit

20170917_152745_resized.jpg

Inside of the body and a picture of one of the two seals that separates the two sides of the chamber. Air enters on one side of the vane and pushes the vane, attached to the shaft, over until it's told to stop by the sensor. When the computer tells the machine to shift gears the air enters the chamber and pushes the vane back over..

20170917_152835_resized.jpg

On to the next problem ;)
 
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Me too!

Right now we are very busy working with the flooded homes and our other normal work.. When we both have time ( might not be until the February scraping class ( IF it's held, not many signups so far)) I'll invite you over and let you show me a few operating tricks :)
 
Been working on the machine a little. This will probably be the last update for a couple of months as we are working 11 hour days on a flood home and I was just cast in a new play with Rehearsals starting tomorrow :eek: I think my sleep is going to take priority over machine repair :)

After figuring out and repairing the speed change issue I'm pretty happy with the current state of the machine. I need to finish making a bracket for the flat screen monitor as I have moved it to the inside of the control station, looks better :)

I decided to hold off replacing the motherboard caps for a while. I need to make a few parts and measure them to make sure the mechanical parts are in good order and the electronics are working, leaving well enough alone for now.

The one thing I will do so is replace the caps on the A drive card. I want to get the 4th axis checked out and I need that fourth card to make that happen. The card is out of the machine and it's a simple fix unlike the motherboard caps.

Marty needed a video of the machine running to compair it to his TC 22. We have been batting problems back and forth and he is worried his x axis is making too much noise. It's very nice having someone else with the same machine to work with!

 








 
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