Spindle speed change problems Deckel FP2NC

Hi all,

So my deckel is just brought back from the dead.
(It had problems electronic problems in some cards) I have never used this machine before so I dont know how/when this problem started.

The problem is when I push the spindle start button (Left or right with or without spindle brake on doesnt matter) I hear the spindle brake goes on and off like every second. I removed cover for gearchange solenoid/motors I see that all three motors trying to put gears in so all this seems fine!?
I removed the backcover of the spindle motor and can see the spindle brake moves but the motor is not Rocking/moving at all!
In the big electrical cabinett I see that Relay K10 and K1 is pulling/releasing after each other every second or so and K3 is pulled constanly.

If I use a stick to force the motor slightly in any direction during the machines attemt to put the gears in. I can eventually get the spindle to start and this works at all different speeds and in both directions. Ones the spindle starts at a selected speed, it starts directly the next time I hit the start button again.

I thought relay K3 was the problem with poor contact. My voltage meter wasn`t fast enough to measure the voltage passing over K3. But Resistance check showed some varius ohms up to about 120ohm so I took it apart.

All contact surfaces looked good but I cleaned them anyway and put it back together, measured resistance and it was more or less nothing. Back in the machine again but still same result.
I also measured the 3 big resistors, they all was 56 ohms.


Thanks to Ross "AlfaGTA" explanation in this thread below I got a understanding how this system should work:

https://www.practicalmachinist.com/...ene-mills/deckel-fp-nc-spindle-speeds-295614/

I also copy/paste Ross writing here below:

The wiring diagram you post is for the first generation FP-NC's.
Your evaluation is correct. The main drive motor is a two speed 3 phase induction motor....
What gives all the spindle speeds is a conventional (more or less) gear box, with sliding gears to change the ratios.
Shifting is accomplished by using the main motor to "rock" the spindle while the gears are moved by small DC motors moving the three shift forks.
Position of the forks and thus the gears is controlled by micro switches being actuated by cams to tell the control when the selected gear is engaged.

The rock of the spindle is accomplished by dropping the motor voltage using large resistors (r1,2 & 3 in your print) , switched on (K3) for shifting.

Sequence goes like this ...Once the speed is selected (note only specific speeds can be programmed..not variable due to the gear transmission) the
motors to move the shift forks are energized, at teh same time the motor brake is released and the main drive motor is turned on (low voltage via resistors) for an instant.
The sequence repeats for 3 cycles about once every second. Then the motor (main) is reversed and the cycles are repeated, all teh while the shift motors are powered and trying to move to the programmed
rotational position.....
There is another reversal of the main motor and a final three short power pulses to the main motor.....If the gears don't engage at this point the machine faults....
The motor/brake/reversal cycles will stop as soon as the shift switches indicate that the selected speed has been reached...
On my FP4NC this usually takes takes about 2-4 motor/brake engagements...(3-5 seconds)

Its a complex system but it works pretty well if the main motor relay contacts are in good shape. Owing to the low voltage used on shifting, any burned or pitted contacts will affect teh motors ability to rotate and thus
make shifting slow and unreliable....
Cheers Ross


Here is a picture from my orange book of the motor schematic:

If the system is designed to rock/move the spindle in both directions during gear change? Doesnt relay K2 need to be pulled next after the K1 has been pulled and released? But still, my spindle isn`t rocking/moving at all even if just K1 and K3 is on.

Any thoughts/experience?

Best regards
Henrik

Hi Henrik

Have you checked that all 3phases are there?

I just had a similar problem before shipping cards back out, it turned out that my big air compressor had killed the fuse on 1 phase, so the Deckel only had 2 phases.
Control still worked, but spindle brake and motor gear flipping didn't.
Took me a while to figure that out, lol.

Spindle brake is electric (not hydraulic, as I incorrectly assumed once), you should be able to turn the motor if spindle brake is disengaged, the white button below spindle stop button.
Remove the belt cover on the back, like 5 screws, than you can easily turn the motor with hands.

If spindle motor brake works (ie is disengaged), the motor should do a couple of jolt in both directions, until the gears are engaged.

Hi "deadmahodude",

Yes all 3 phases are there!
The spindle brake disengages when I push the white button below spindle stop button. And then I can turn the spindle motor by hand. That is what I do when I trying to change speeds and the machine wont do that. But still, during the start attempt the spindle brake keeps going on and of by Relay no 10. But Relay no 1 passing current through relay no 3 and the resistors doesnt seem to move the spindle at all.

However when the machine or me gets the gear to mesh, the spindle starts perfectly in both directions. So I doubt there is any fault in relay no 1 or no 2. But during the rocking movements (wich my machine lacks)shouldnt relay no 2 also be pulled after relay no 1 done its pull? That does not happen!

Best regards
Henrik

As far as I understand the schematic:

Q3: Main switch, not interesting.
K1/K2: phase flip relays, flips 1phase on the motor so that the motor spins left and right.
K4/5/6: full or half speed selection on the motor.
K5 on: 1U/1V/1W: delta/dreieck in series, half speed, 1500rpm
K4&K6 on: double star, doppel-stern, full speed, 3000rpm
Page 2, here:
https://ueba.elkonet.de/multimedia/...bare_Schleifringläufer_Motoren-p-20023300.pdf
K3 over resistors: motor jolt for gear change, K1/K2 phase flip relays for left/right flip.
K4/5/6 should be open during gear change.

If spindle works in both directions, K1/K2 phase flip relays are likely fine. If half/full speed works, K4/5/6 are fine as well.
Then it's likely a problem with K3 or burnt resistor.

Can you perhaps try to override relay #10, so spindle brake is permanently disengaged and see if gear shifting works then, then you know that it's not a problem with spindle brake engaging when it shouldn't.

Unfortunately my electrical cabinet is currently burried behind the machine, because I need every space available as I'll hopefully get my new (old) CNC-lathe soon. Perhaps someone else can make a short youtube movie with relays/NPP console LEDs switching/blinking during gear change.

Do not assume that just because the motor runs fine in forward/reverse or low speed that the issue is not with those relays....
If the voltage is reduced at all by resistance in the relays the dropping resistors will be enough to keep the motor from jogging.....

Clean the contacts of all the relays involved in the jog circuit....(K1 & K2)
Cheers Ross

Hi "deadmahodude" and Ross,

I did not see that it is a double speed motor.
(My electronics skills are limited)But thanks for your explanation there "deadmahodude".

And Ross, good tip I will start open and clean K1 and K2 maybe tommorrow?

Best regards
henrik

Hello,

I think you where right, Ross.
I took relay K1 out from the cabinett and measured the resistance.

The middle connectors was hard to get any contact at all from!
Below is the K1 relay, Connact points of the middle one totally gone!

So I guess thats the smoking bandit.

I will check K2 also, it might be in the same bad shape.
And hopefully there are still new ones to be found in the market.

Thanks for your help!

Best regards Henrik

Ebay has everything. You need 3phase NO (normally open) relay, with 24VDC signal voltage.
Ebay germany search:
https://www.ebay.de/sch/i.html?_fro...itleDesc=0&_osacat=0&_odkw=24v+schütz+3phasen

The small auxiliary contacts on either side are not connected to anything?
Then this relay might work just fine:
Klockner Moeller DIL 0 M-G Leistungsschutz 24V DC gebraucht | eBay

Be sure to get one with "Hutschiene" mounting, so you can just clip it into the existing "Hutschiene".

Fingers crossed, looks to be the issue......Shifting on these machines is never great.....But if the relays are good shifting can be relatively reliable.
One of those things where if the machine is used often the shifting seems to get better....
On my FP4NC which pretty much runs every day, i only have a failure to shift once or twice a year.....If you can't find a sutible replacement on e-bay i am sure Singer or FPS in Germany could supply a direct replacement,
at higher cost of course....

Cheers Ross

Hi,

Well I ended up not buying any original new or used relay. I sort of stopped looking when I saw the prices for a used one.

To get a sort of standard relay from a local warehouse!. Its hard for me to figure out if they work the same way.
Because these relays are quite advanced with 4 more contactors (for those blue control wires) working simultaniously with the larger 3 each contactors.

So I turned down a copper bar to the size of the original contactpoints and riveted that one on the bad copperlead.
Maybe it will work as a permanent repair.. will see . (there are at least for now good contact)

I opened up K2 relay as well and it was fine just minor polishing.

Put them back in the electrical cabinett and....
of course the same result.

The spindle did not turn.
Found all 3 phases named 1U 1V 1 W at the motor. Tried to measure the voltage during its attemt to turn the spindle. The voltage where coming up but since my meter isnt so fast and the period of the K1 relay is pulled is like a fraction of a second i get like various AC voltage up to 20 volt or so.
I removed the spindle drive belt so motor was disconnected to the gearbox.
Started the spindle again and now I could kind of see some sort of micro twist attemts of the motor but more looking like its was trying to move and returned back.
I could feel that the brake did not completely release the spindle during its attemt to get the gears in. If I push spindle stop button and push the brake release button then the spindle is completely released.
Brake unit:

Then I removed the spindle brake unit and had it laying on top of the motor but still connected at the wires.
Started gear change again and now the spindle moves very nice with small hits of crankpulses with a small torque.

I found this thread from Ross,
FP2NC brake motor brake adjustment?

I dissasembled the brake/clutch unit and cleaned it put it back adjusted it to 0,8mm and still same result.

I polished the "screw/nuts" (the ones that the laminated pole disc guides on) to make sure that the laminated pole disc wasnt catching on those "screw/nuts".

Then I put everything back again and started the spindle again,
During the sequence when K10 (brake relay) pulls, I kept my finger on that override extension rod for K10 relay and let it stay for like a micro second more. Then the spindle starts directly and did so everytime on all speed selections when I let the duration of K10 be pulled longer than the machine do by itself.

So I think the best/easiest? solution to this would be to figure out how to trigger that relay to stay pulled for a half second longer or so. Maybe build a Capacitor circuit to keep it energised a little longer.

But for now I got it working by removal of 2 smaller springs of those 7 installed on that brake unit and it works everytime.

But the spindle is slower to stop but only noticeable at higher speeds.
This will wear my brake down faster I guess, but at least now I can change speeds.

And my machine never pulls relay K2 during its gearchange there for motor only put turn hits in one direction. Does your machines realy pull K2 during gearchange? Then I have another fault wich is not realy a problem if it starts anyway.

But I am happy that I can start playing with it now (except for my dirty X-scale wich will be my next step)

Best regards
Henrik

I parted out a total of 3 Deckel NC machines and kept all the nick-nack. So if ever needed, I can give you such relay (used and unchecked) for the effort of finding, boxing and shipping. I never had a bad relay myself, but falsely suspect them serveral times.

BTW I recently had a bad NEA card. It would not send a signal to operate 1 gear change motor.
You may want to check that you actually get the signals you need from the NEA.

There is a DIP-Switch on NPP90 that defines how long K3 is pulled to jolt spindle for gear meshing. It's called "Kusa", no idea what that means.

According to orange book:
NPP90 S1.8 closed: 380ms on K3 to turn spindle for gear mesh
NPP90 S1.8 open: 320ms on K3 to turn spindle for gear mesh
I'd try that one first.

On X50 LEDs in electrical cabinet, you can see if spindle is in left (X50/2) or right(X50/1) turn mode.
X50/3 is spindle gear mesh pulse on K3
X50/6 is spindle brake release

Just had another look at NEA90 I/O card schematics, PIA1 controls switching transistors, PIA2 has the LEDs connected to it, LEDs are connected to output side of switching transistors.

So if a transistor is fried (shorted), then the related LED should be on continuously. Also, since PIAII is monitoring the outputs, it's likely that there will be some sort of error on display.

KUSA-Schaltung – Wikipedia

Kurzschlussläufersanftanlauf-Schaltung

The name says it all.

Just magnet'ed a webcam down in my electrical cabinet to see the LEDs blink during gear change operation.
https://youtu.be/JmgAZcG4dcs?t=25
Interestingly, X50/3 spindle motor resistor relay seems to be always on during gear mesh cycle, spindle turn rate is controlled by short release of spindle brake, X50/6.

Hi "deadmahodude"

My NPP90 S1.8 was set to OPEN.
I changed it now to CLOSED. maybe that extra milliseconds is all I need?
I havent put back the removed springs yet, since I got my X-scale removed and want to finish that first.
But I tried gearshifting with this new setting now and it works so I´will keep that dip switch Closed.

Thanks for your tip!

Best regards
Henrik

One additional note:
There is a capacitor ? (black plastic rectangular case with two wire leads ) connected across the brake relay contacts.....Have had trouble with the brake on shifting with this connected.
(Sorry, don't have my orange book here to give the specifics)
If the change in motor pulse time does not resolve your shifting issues, try disconnecting one of the leads to the black box...

Cheers Ross

AlfaGTA said:

There is a capacitor ? (black plastic rectangular case with two wire leads ) connected across the brake relay contacts..

Click to expand...

More likely that is Metal Oxide Varistor (MOV) or a diode. They are there to suppress the spark/arc across the relay contacts that would otherwise result when the coil is de-energized: the collapse of the magnetic field inside causes a big voltage spike. A typically solution for DC coils is to put a diode across the contacts, which is reverse biased (no current flow) under normal conditions. When the coil is disconnected, the voltage spike (called "back EMF") is in the reverse direction and will flow through the diode, preventing the relay contacts from burning. An MOV has a similar function. So if it is a diode or MOV rather than a capacitor, removing it is not a good idea.

Might be a bad idea, but you could not prove it by me in this case......my FP4NC had shifting issues with a sluggish brake (if memory serves).....replaced the device and the issue persisted....
Removed it perhaps 8-10 years back, cured the brake issues and has had no ill effects as far as i can tell...Brake works fine and gearbox shifts well

Cheers Ross

Braking power is a function of these springs On many motorbrakes you can get different springs to get different braking power
Perhaps those springs were replaced at some time with wrong ones

Peter

Been a while since had that apart but pretty sure the brake/spring tension is adjustable to some extent.