Boss 5 no axis movement

[tom.jelly]

Just converted my newly acquired boss 5 over from 460 to 230. I have no idea of the history of this machine, OR HOW TO USE IT...but I was hoping someone could tell me pendant switch positions so I could at least get it to move, as I want to run it before I convert it to a modern control. As it stands the run, goto and hold lights are illuminated, limit override is OFF, e stop button is pulled out, spindle motor will run fine, but no combination of switch positions has resulted in any axis movement. moving the switches also will not extinguish the run, goto or hold lights. Any info would be greatly appreciated.
thanks
tom

[machintek]

The fact that the RUN, GO TO and HOLD are lit, seems to tell me that it has halted in its boot up. Check logic power supply, and re-seat the boards, one at a time, cleaning the edge connectors with a soft eraser.

George

[tom.jelly]

will do. I didn't touch the switches in the tape drive enclosure, do I need to do anything there?

Will report back after the contact cleaning....

thanks
t

[machintek]

Yes, in theory, you should press the reset switch after power up. I have a service bulletin from Bridgeport that the fact that these machines boot correctly when power is first turned ON is a fluke.

George

[tom.jelly]

ok, I cleaned and reseated all the boards and checked all the fuses, also removed every metal chip I could find (nothing was shorting anything). Next I powered it up and hit the reset switch in the tape drive 3x, and waddaya know, the dro reset to zero...as well as the 3 digits to the left of that. nfs and t are lit as well as x and abs- see pic. NOW I can use the xyz switch to move between axes and can hear them sing and kind of twitch, but they will not spin. Also, switching from x to y to z does not change the led on the pendant, but does twitch the correct axis. I also removed the belt guard from z, powered off the machine and spun it down about and inch- it moves freely with power off, so nothing is stuck. The servo holds it in place when the power is on. When hitting the move button I can kind of get the motor to turn in the direction its trying to go in while pushing it along pretty hard by hand at the same time, but it doesn't really want to go.

Any idea what to try next?

[machintek]

You need manuals!
Just because you moved the motion axis select switch to a different axis does not mean the display will also switch. On the keypad is where you switch the axis you want to display, or the tool number, or the TLO, line number, etc.
It sound like either all your axis have blown transistors or you have insufficient power to the drives. The maintenance manual has a excellent trouble shooting section.
Did you change the large 3 phase transformer in the back cabinet, top, from 460 to 230?

George

[tom.jelly]

I figured out about the axis change buttons after that last post (I do need manuals!) ....and yes, I changed over the transformers:
voltages off of t2:
13/14 71vac
16/15 76vac
12/11 72vac

at sx1 input side
47/16 73vac
sx2 input side
46/14 69vac
sx3 input side
45/12 71vac

sx transformers:

output side, with override light illuminated:
at sx1 output side
43/74 50vac
sx2 output side
42/74 53vac
sx3 output side
41/74 38vac

output side, with axis selector set to z:
at sx1 output side
43/74 38vac
sx2 output side
42/74 22vac
sx3 output side
41/74 71vac

output side, with axis selector set to y:
at sx1 output side
43/74 38vac
sx2 output side
42/74 84vac
sx3 output side
41/74 78vac

output side, with axis selector set to x:
at sx1 output side
43/74 38vac
sx2 output side
42/74 24vac
sx3 output side
41/74 32vac

It seems odd to me that it would be a transistor problem on ALL 3 AXES, I could see if it was one or two- do these voltages look correct? if so I'll desolder some transistors and check them....

thanks
tom

[machintek]

At T2, wires 11 to 12 (1st to 4th wires from the left) you should have 54 to 63 VAC. That is the X axis. If you have anything greater than 63 VAC you will blow the final drive transistors like a kid eating candy.

There are a LOT of postings about this!
Place the machine in X axis step, press the + button and watch the mechanical counter. As you step it the mechanical counter should move. If it goes forward and then backward, a transistor is shorted. The axis then whine but do not move (oscillation between poles of the motor).

George

[tom.jelly]

I read about the overvoltage potential for transistor damage. I got this machine from a shop where although they did see it run where THEY bought it from, they were never able to get it to run themselves and it sat for about 3 years unused. I figured at least ONE axis would work, I can only assume now that they kept swapping boards and blowing transistors board by board until they were all cooked. I can see that there have been transistor replacements done on some of the boards in the past, but all axes now exhibit the same behavior- they will go one step then stop (not the classic 3 steps foward one back, at least as far as I can tell) So although I can go thru all the transistors, I'm still going to have to correct the over voltage issue. I've rewired the machine from 460 to 230; the data plate on the t2 transformer in this machine (for 230v) says input 230v 9.04A, output 70-80v 15A.....so if I understand this correctly the transformer as originally specified by the factory for this machine puts out too high a voltage, is that correct? So to correct this overvoltage, I imagine I will need (3) 230v 3amp variacs in the line to the transformers so I can adjust the voltage; if this is correct I imagine I may as well just tear out EVERYTHING because the cost of the variacs would be most of the way to a set of Gecko drives, no?

tom

[machintek]

3 steps forward and one back may be indicative of 1 blown transistor on a axis.
You may have more.
There was a special transformer for a 208V machine.
But the 230 machine expected 230VAC. Not more.
What is your power in?
According to the maintenance manual (if my memory is correct) the normal voltage range of T2 is 54 to 63 VAC. Current is set to 8 amps DC by the ACC board but measured at the DC axis drive fuses (12, 13 and 14).
Do not attach or remove a meter to these drives trying to measure current unless the drives are off. All 4 transistors on a block must be the same.
Get a maintenance manual. It explains how the logics and drives work in great detail as well as having a good trouble shooting chapter.

George

[tom.jelly]

My power in (from a 10hp rotary phase converter) is 229/245/233; working on getting a manual for the machine. This is not a 208v transformer as it has a data plate on the transformer itself that says "230/460 in, 70-80v out", everything I've read says I need 63 v max out....do all the other t2's out there say 54 to 63 v out on the transformer data plate? will the machine automatically blow transistors with 72v at t2:11/12 if I replace them even if all I do is jog the machine with no load, not cutting? I would like to see this thing at least move before I address the voltage issue if possible, if not I will have to figure out how to reduce the input voltage to 187v to get my 76v (my at the moment highest voltage of the 3 outputs on t2) down to 62v. this seems very strange and I would have said something was wrong with t2 if it wasn't placarded 70-80v out. I'm measuring this t2 output voltage with the machine stationary I assume...I'm obvously not an electronics wiz(!) but maybe the voltage drops to the recommended range when there is a load, which I am not able to apply because the machine is not moving?

I'll order a set of transistors and manuals, do you know the value of the little diodes?

tom

[tom.jelly]

with regards to the t2 voltage issue, I was doing some more research and came across these (partial) posts:

"George thank you very much. I really don't know which Boss i have. Is there a way to find that out?
The output voltage (T2) wire 15-16 was 74VAC. I don't know why but somebody put wire 15 on the wrong output. Strange that it ever worked. So I put it back on the original place and its 64.4VAC...."

and

"Moving these motors is a matter of energy. Volts X amps equals watts. I fnow the 230 V transformer uses taps 5 and 6. What do yo have in volts AC between taps 5 and 7? If it is 63 volts or less then I would move the wires from taps 6 to taps 7."

So I tested taps 5-7 and they give 10 volts higher, approx 84 vs approx 74. I was working from and extremely poor copy of the schematic for the voltage changeover, coud you confirm that the following is the correct wiring for the primary side of t2?:

L1 to leftmost terminal 1 then jumpered to leftmost terminal 3 and center terminal 4
L2 to center terminal 1 then jumpered to center terminal 3 and rightmost terminal 4
L3 to rightmost terminal 1 then jumpered to rightmost terminal 3 and leftmost terminal 4.

I suspect the last jumpers may be out of order and should be center/center/center, middle/middle/middle, right/right/right but don't know if this would (a) cause the voltage issue or (b) cause a problem (smoke!) if I "corrected" it.

seems I know just enough to screw things up sometimes, gotta learn somehow though! outputs are 16/14/12 to the #5 taps and 15/13/11 to the 6 taps, in that order from left to right.

thanks

tom