How do I orient spindle after encoder replacement? Torq Cut 22

[vettespeed]

I just replaced a failing spindle encoder on a 1995 Bridgeport Torq Cut 22. As I expected might happen, when I orient the spindle with a M19 it is no longer in the correct location for a tool change. I'm assuming there might be a parameter change required to get the spindle orientation back to where it needs to be? Or is it simply rotating the pulley/belt a few notches to the correct location. I've scoured the operating manual and also the parameters trying to find what I'm looking for and just cant seem to find out how to do it, anyone out there know the proper procedure and possibly which parameter it might be? This machine has the 7500 RPM BT40 spindle although I cant tell you if it's a Parvex motor or not. I notice there are different parameters for the Parvex motor. I don't know what Parvex means or whether or not my machine has that. Thanks, Mike. vettespeed68@hotmail.com.

[machintek]

In the same screen where you turn the drives on, one of your choices is TOOLCHANGER.
Under that menu you can LOAD or HOME the tool changer and another key says PASSWORD.
Press that key. The password is PASSWORD in capital letters.
Under this menu press 1 which says START setup.
The head goes to the tool change position and the spindle orients.
here you have a menu that allows you to jog the spindle using the jog knob and save the orient. It also allows you to jog the head up and down and save the tool change height.
You acn also use the jog + and - keys to bump the tool changer toward and away from the spindle to see how the fingers go onto the tool and if your orient is close.
When you save, the value actually goes into the parameter file (bmdcprms.sys).
The Parvex motor is a lot stronger and bigger than the SEM. If you look at your Z axis, you may see the label for it. It was an factory recall/upgrade that we were required to do along with a redesigned wire feed to the saddle.
I hope you got a Heidenhain encoder for the spindle. It will last a lot longer than the cheap replacement I got from Hardinge the last time I ordered one. It did not even work. Also I hope you have the correct paramters for it. There were 2 different resolutions that are in current use with these machines. If you command a spindle speed and it is wrong, then you know you need to change the parameters. Or if your spindle times out (not up to speed in time). The control expects the spindle speed to be within 20% of command or it will not do a feed rate of an axis.
I also check spindle balance (S0M03). If the spindle drifts at 2 RPM or more, it will bomb out in the middle of a tool change. Drift is adjusted at the Yaskawa spindle drive. I also check spindle speed. If it is off a little bit, I can get it to match command by adjusting parameter 71 in the bmdcprms. But this usually upsets the balance which will need adjustment again.

George

[One of Many]

I have had similar issues with one TC22. If you look in the book somewhere it shows the spindle to encoder ratio of some odd value. Seems to me it was 1.3:1 something.

I ended up placing a mark on the belt and the encoder wheel as a reference. Then changed the sync a few positions at a time until I got it realigned.

You may be able to go into the maintenance page and monitor the bit for spindle orientation, but if you are in the wrong sync of the ratio, it still may be a crap shoot!

DC

[vettespeed]

George (machintek),
Thanks for the info, that was a perfect explanation that worked flawless. I did indeed get a Heidedhein encoder, I believe it is an exact replacement as the one that I removed, it was a rebuilt unit from BPTparts.com, Hardinge didn't even have a unit to offer me. As you mentioned, the spindle speed is off a little. It shows it being slow by about 20 RPM at max (S7500) and progressively less as you slow down. Should I bother trying to fix this and what do you mean when you say adjusting parameter 71 upsets the balance? How long do these encoders usually last? Records show this is now at least the 4th encoder this machine has seen, possibly more? Thanks again for the info, you got me up and running. Mike.

[machintek]

I believe the encoder life depends on the belt tension and the RPMs used. This is a timing belt and the tension does not need to be great. Running all day at 6K or 8K can decrease the life of the encoder. The 10K versions had a bearing housing to take the load and vibration of the pulley with a coupling to the encoder. I am sure your encoder pulley is not balanced and has some mass that can (like an unbalanced tire) create accelerated failure at elevated RPMs.

George

[One of Many]

Thanks for that description George.

I take it that procedure to work the same on a VMC1000?

We just sent the spindle out for new bearings for 10k and a CAT change to a BT. I'll give this a try when it returns.

Do you know if when converting a spindle from 6k to 10K RPM, if there was a pulley change on both the spindle and motor? Are those pulleys off the shelf available and where?

What about upgrading the encoder mount to add the bearing housing etc.?

DC

[machintek]

WOW!
The procedure is the same for a VMC1000 as long as it has the Dx32 control.
A while back, I had a VMC1000 fall off a fork lift somewhere in transit. It was a 10K machine. So Bridgeport sent in what they had, a 6K machine (December of 1996).
To convert it to 10K required a special spindle with ceramic bearings, a special Siemens spindle motor, special encoder set up as mentioned, special pulleys and belts to drive the spindle. And of course, the parameters changed.

This set up is not for roughing steel, and do not crash it as the bearings will not take it. We also had a lot of difficulty with accel and decel of the spindle especially when rigid tapping. Coolant would deposit on the two small spindle drive belts and they would slip. So the belts would be tightened. Eventually after a couple of go arounds at this, this caused the spindle motor to start tilting as it was mounted on a plastic sheet to insulate the head from heat. That is another story. About 1993, I installed a VMC with a Heidenhain control that would not fly cut a large aluminum plate flat (with no steps). I could tram in the head square to the table but it was not stable. Turned out the heat from the spindle motor went into the head and it grew more at the top, hence it went out of square. I suggested a sandwich of steel and silicone glass. They supplied plastic. But the results were good, at least with a poly V belt. There might be better belt technology 10 years later. Research it.

George

[One of Many]

George,

Ha! I had a similar situation in my Field Service days. Only it was a 175ton 8' press brake that fell off a train at 50+mph going around a corner. It was resurrected from a scrap yard and returned to service somewhat bent although removed from the OEM books. My customer found a way to "straighten it up" by welding it to a steel structural support post in their building after mounting the press to the foundation. I was not allowed to even do service on it since I worked for the OEM.....can you say "175tons of Liability risk"?

I digressssss,

Well, this is a CIB machine, but it should still be DX32 dispite the CIB I/O.

This machine does have Siemems AC drives, although the spindle motor itself may not be. We have been working with EMI, but they never mentioned any other changes so far.

Yes, the bearings will be ceramic and no we will not be doing steel. Now that you mention it, this will be a specific purpose machine for decking taper plates of aluminum on a forth axis vac chuck. We already have one machine up an running for this application, but it came in with the 10K spindle, parameter limited to 8500 for our fly cutting purposes. Tram could be a problem and we will look into that.

Thanks for the heads up!

DC

[machintek]

The machine I mentioned above was at Fort Walton Machine in Florida. That was when I met Bart Stater of EMI for the first time. He was there trying to tune the machine movements better and we found the "slinky" type couplings in it between the motors and the ball screws instead of the lovejoy couplings.
Yes, the motor is siemens. Yes the same procedure applies for the orient and tool change height settings.
I know what Bridgeport required me to change. Maybe some of it was over kill or maybe there are different ways of achieving the same goal.

George