[skullworks]

I just got the wiring in to my Roto-master motor type phase converter for my (1991) KM3P.

As luck has it the legs were out of phase so the motor ran backwards... no big deal right, - Wrong!

The speed adjustment motor started turning to set the spindle @ 2000rpm - going the wrong way and went way beyond the normal scale before it was shut down.

Now I need to know how to get things back in sync without blowing the head up.

I can start the spindle in manual and use the over-ride momentary switch to adjust speed but - if you don't use the over-ride the speed control tries crank the speed up well past 4000 and only stops when it binds.

The belts in the head are less than 18 months old, and have had very few hours on them thanks to the economy. So at least those should still be in good shape.

I'm not sure if I need to swap wires for the speed adjustment motor or what at this point. I spent about 6 hours going over the all the different machine manuals and there is lots of great info there, just nothing which applies to my issue short of how to tear down the head completely.

It seems the limits were ignored because while it "thought" it was turning the speed down towards the lower limit while it was really approaching and passing the upper limit.

I'm sure I'll have other issues to work out since the move. Last time I ran a Max II KM3 was about 2000 or 2001. This machine has the Max32 with the 3D option - so many updates and improvements, its going to take a bit to get fluid with it again.

I also have 4 matched 30 pin simms to install in the 4 empty sockets.

And I guess I should also check all the motor brushes too. - This is beginning to feel like WORK!

[bloke]

Just pull out the Voltak speed control card. That way, it won't try tearing off on it's own. Or just swap two input phases to the machine before you start it.
If I remember correctly, you will still have the ability to jog the speed with the card removed.

[skullworks]

The Electrician did swap the input phases so that the main spindle motor turns correctly.

So I can pull the Voltac speed control card then jog the spindle around so that the Min/Max limits are on the proper side of the switches? Then replace the card?

I will be out to the shop again on Wed. and hope to get that sorted so I can move on to other problems.

Anybody have an idea where I could get the original spanner for U200 AF75 series Collet chuck nut... Also looking for the AF38 nut spanner too - but I am prepared to just make one from some O1 tool steel.

I know I could just order an off the shelf hook spanner for the AF75 - but I really liked the full contact area of the Universal OEM wrench.

I have 4 Universal 200 Kwik-Switch spindle release spanners and none for the collet chuck - go figure.

[bloke]

Swapping the phases to your spindle motor was the wrong thing to do. The motor that changes the speed is three phase also. This is why it goes off in the wrong direction to find it's speed.
Put the phases to the spindle motor back as they were and swap two input phases to the machine.

[skullworks]

My bad, I failed to state how the phase was changed.

Swapping the phases to your spindle motor was the wrong thing to do. The motor that changes the speed is three phase also. This is why it goes off in the wrong direction to find it's speed.
Put the phases to the spindle motor back as they were and swap two input phases to the machine.

No wiring in the cabinets was touched. The electrician swapped the leads on the phase converter's output terminal block. So as you say both motors should be turning the correct direction ( now ).

When the machine was first fired up the spindle rotated backwards - and also the speed control motor started turning backwards trying to set 2000 RPM but due to the phase shift it was heading the wrong way, and I think it went past the limits ( not sure, didn't have the face cover off at that time. ).

What I'm wondering is if the speed dial limit switches may be fooling the control into thinking its somewhere far different and its attempting to get back to where it thinks it should be. Only problem is it can't get there from here going the direction its chosen.

Once I get it back in the ball park I will still have to use a laser tach to fine calibrate the spindle since the motor was removed briefly during moving into its final spot. None of the wiring was disturbed, the motor was just secured to the side of the head to get the machine through a low door way.

[skullworks]

In Manual mode. ( KM3p )

If you want to start the spindle it wants you to be in High gear and once the spindle is turning the speed control tries to set the RPM to 2000 rpm.

Question How does the speed control know what speed it is at when started, and how does it know its reached 2000 rpm. I'm wondering if I have a failure in the feedback circuit.

Right now - I could start the machine with it all ready at 2000 rpm at the speed adjustment motor would just run the spped up until it sheared the roll pin on the adjusting chain.

This is old school methods - use a mechanical device to adjust spindle speed instead of a VFD and software. I'd love to gut the head and run a 5hp inverter rated motor direct retaining only the High/Low gear select. But I don't think there is a way to incorporate that with the Hurco Max32 system.

I bought this machine back in August, and its been an adventure trying to get it running again. I ran programs on it while it was still under power at the sellers location so I know the machine was working prior to the move.

I almost went with a BMC20 - but was not sure it would have fit. - I know getting power would have been a big problem.

[bloke]

The sensor for the speed control card is under the head. Take off the front cover over the Z ballscrew, undo the three nuts that hold thehead to the ram casting and lift the head up. You'll see an 8mm proximity sensor - that's the one.
It could be also that your voltak card is out of adjustment.

[Hurco1]

Did you check rotation when you werein high gear or low gear? When your in back gear (low) the spindle motor runs reverse to get the spindle running clockwise.

Always do your rotation check in High gear!

[skullworks]

A few posts back I told that during a test the speed adjusting motor wound things up so tight it bent the roll pin which attaches the chain to the front dial shaft which is rotated by the worm gear. The worm gear shaft is where the speed adjustment crank would go on a Bridgeport type mill, however unique to the KM3"P" model this is driven by a small 3 phase motor to crank the vari-drive.

The mill is about 30 miles from my home. Recently we have had a staff shortage due to a few people quitting, both with and without notice, so I have been working 60+ hour 7 day weeks. It has not allowed time to get back to fixing the mill.

Well I got a few hours free on Friday and we were able to get the head back together some. The roll pin was replaced, but the incident when it sheared has left us with a new problem.

That last runaway blew something. Now we can not get the servo's to power up.

I checked the fuses in the left side "Magnetics" cabinet and all appear good. Machine control boots up without errors.

Select Manual mode, and press Power and you trigger the ice cube relay on the relay board in front of the power conditioner in the right side control cabinet. The relay won't stay on. "Reset Servos" does nothing.

This mill has the Black "Hurco" servo amps and the Power LED showns green on each of them. The LED on the Voltac card is green. I'm kinda stumped now. I have not had a chance to dig out the proper manual and go thru the official trouble shooting list again, (did that when it happened).

I'm ready to hire an expert - if I could find one. I fear most anyone I were to hire would have never seen this type of speed control. The KM3P is kinda unique with its programmable spindle speed for a vari-drive mill 19 years old. Add to that that the system was upgraded to the Max32 control and I have a somewhat unique little B@$TARD.

Ideas or advice welcome.

[Hurco1]

Sounds like you're nearing the end of your rope.

The Hurco distributor in that area is Foothills. I don't have any direct dealings with them but they are certified by the factory (may not mean much! depends of the service tech!) Have no clue where you are in relation to them but if you want someone to look at it, here they are.

Foothills Machinery Sales
6855 West 116th Avenue
Broomfield, CO 80020
(303) 466-3777

[skullworks]

Yes I knew Foothills had taken on the Hurco line a few years back. I met Dick K. over 20 years ago, not sure if he is still running the outfit.

I will give it one more go myself. I need to get the factory service dept on the phone to see about getting some replacement floppys for the offline programming suite. We have all the manuals and the floppy dust jackets but the actual floppies are missing.

One of the biggist factors in choosing this exact machine was all the extra software options that had been added as well as the complete Max32 upgrade. The amount of included tooling was another.

Originally I was searching for a dead control KM3 with working servos/amps that I could retrofit with EMC2 because I was looking to add a 4th axis, and trying to do that with the Ultimax control would be a prohibitively expensive hemorrhoid.

I still have one eye open looking for another KM3 to follow through with the original plan. Having machines with tooling and some parts in common just makes more sense. Kondia made a good base machine, I really like the quality of the iron - I just wished they would have chromed the ways.

[Jim Caudill]

Does anyone know whether the 8mm proximity sensor is PNP or NPN? I need to buy one, and there are no markings other than the insulator over the sensor is green in color. Since the voltage going to the sensor is 15vdc, I am assuming the 10-30vdc sensors will work. A Turck or other brand part number would be great. The only numbers I can find in my Hurco documentation is "4PRS" for this sensor.

Any help would be greatly appreciated.

[bloke]

I think the sensor you need is a Pepperl & Fuchs NBB1.5-8GM50-E2

[Jim Caudill]

I ordered from a company in Georgia called "Automation Direct". Their part number is AE1-AP-1A and cost $18.50 plus shipping. They indicate the part is made in Italy and is in-stock for immediate shipment.


Here are some equivalent part numbers:
Turck - Bi 1.5-EG08-AP6X catalog #S4602240
Omron - E2E-X1R5F1-N (SS)
Pepperl & Fuchs - NBB1.5-8GM50-E2
Sick Optic - IM08-01B5PS-ZW1
Siemens - 3RG40 11-0AG05 (SS)

This is a 3khz switching, PNP, NO, 10 to 30vdc, stainless steel, inductive sensor, 8mm in diameter, 40mm long, with a potted 2 meter long 3-wire cable.

It also has a signal LED in the base which will not be visible once installed.

The Turck sensor from my supplier was $92.76 plus shipping and a 1 week wait.

PLC direct wanted around $93 for the sensor also.

[skullworks]

Well after applying the shotgun approach the spindle "sync" issue appears resolved.

The Upper head was removed and cleaned out, fine chips and other grit removed from the prox switch which reads the speed gear. Prox switch wiring checked and all connections tight. Fresh fuses all over. Re-seated Voltac card. So now it reads and sets spindle speeds ok.... Well Not exactly.

We have not been able to get the spindle below 730 rpm (RPM read by laser tach) in high gear. You can keep on the over-ride to crank that chain but it does not have an effect on actual spindle rpm and will either pop the roll pin or blow the overload on the spindle speed motor contactor.

Over-ride towards Max Rpm will allow speeds over 4400rpm. Adjustment of the pivot stud in the top of the head has some effect at top speed and no effect at min high gear speed.

We pulled the spindle motor and checked all the motor mounted Vari-drive parts and verified the function once that unit was re assembled. - Side note: There was a huge buildup of crud in the fan housing, about a 1/2" thick layer. Cleaning all this out dramatically improved air flow.

Both belts were swapped out just over 40hrs ago by the Hobbs meter.

Is it possible that the wrong upper belt was installed? Could a belt that is too short cause this higher than normal speed?

Machine is usable provided you don't program any speeds between 800-450 or lower than 100.

A new issue just popped up also. When you start the spindle you get a glitch movevement on the Z axis servo motoer - enough to alarm out the machine... "Motion error detected on Z axis."

Also - when running a little air cutting trial the Z axis kept flashing Z axis OVERLOAD on the horizontal load bar graph randomly... This is seen when the Z axis is stationary or moving.

[bloke]

Sounds like your chain is wrapped the wrong way round the shaft, me old mucker!
And your speed changer motor is phased wrongly.

[skullworks]

Sounds like your chain is wrapped the wrong way round the shaft, me old mucker!
And your speed changer motor is phased wrongly.

I don't understand your conclusion. The chain is wrapped per the manuals. Actual speeds follow the movement of the speed indicator wheel - which would ( I think ) be backwards if the chain was wrapped the wrong direction.

The Voltac control of the speed setting motor goes right to the programmed speed +/- about 8RPM.

The problem now is that the lowest speed you can reach in High Gear is 730, while I can get up to 4400 at the top end of the scale. Its almost like the fixed speed motor is going too fast. ( that I have not checked yet)

When it was at 730rpm the motor pulley was full open and the belt about touching the center. Belt position on the spindle side was about 4mm from the edge of the pulley. On another non speed controlled KM3 that belt actually comes outside the pulley edges by about 1-1.5mm.

Now that the speed control circuit electrics have been sorted it will go right to the programmed speed with out and hunting. Its just that if I ask for a speed below 730 but above 499 it will try to get there but will pop the roll pin or trip the overload because mechanically you can't get there it seems.

[bloke]

Looking back, it was the part in your post where you said it was snapping the pin and tripping out that made me think that. I once had to correct a machine where the fella who owned it had stripped it and re-built it with the chain on wrong.
It should have a 37-10-850 belt in it

[skullworks]

This Friday I'll be checking the belt and shooting some vid of the Overload I get on the Z axis display as well as the servo "jump" which often causes a motion error when the spindle is started.

Still sorting out little issues that might have greater implications.

All this time we have only cut air and we will have had the machine a year come August.

[Hurco1]

Never really thought about a short drive belt causing RPM error but yes, I believe it would RPM trouble as would a narrower belt.

Just to clarify, the main power belt in the vari-speed head is a taper sided belt. The angle of the taper somewaht matches the taper of the pulleys. If the belt is worn (I know. 40 HRs by the Hobb meter) or the belt is short, you will have trouble getting to both extremes in both ranges.

Did you mention if you did a spline bushing job on this?

I try to get the goodyear Eagle replacement belt (sorry don't have the numbers for it. All my KM stuff is at home and I'm stuck in Boston of all the damn places!) you can try to get a new belt from Hurco or give the parts department a call and see if they can sort out an OEM number for you.