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1980 Deckel FP3, power feed seems "weak" in Z up

Milacron

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I forget the DC vari drive feedrate scale numbers, but for Z screw to start turning to move the table up, the vari knob on the panel needs to be at least halfway speed. Been a while since I'd had a late DC drive Deckel but was thinking even near the slowest feed rate that Z should still move up. Axis clamp is loose....so what is more likely....

1. Z ways need lube ?

2. Z gibs too tight ?

3. DC power feed got "weak" somehow ? Any "torque" adjustments to that drive possible ? Beyond the halfway point Z will more up same speed as it moves down...and the rapid works fine as well. But below half feedrate Z just sits there in "up" mode. Machine works perfectly otherwise.

Re 1 &2, I have yet to install the Z handwheel to see how it feels turning the screw by hand. I have yet to install that handwheel as I must first relocate the electrical box from the pallet both pieces came mounted to, to make room for it. But seeing as it turns fine at faster speeds and rapid, I'm inclined to think something up with the DC drive. Any ideas ?
 
inclined to think something up with the DC drive. Any ideas ?

Even the (old) analog ones self-monitor, trip into an alarm condition if/as/when.

But they can be 'blind' sometimes.

I'd put a 'scope on it to see if it is making use of both sides of all phases. 6 to 24 pulses if 3-P power, given it will (or is MEANT TO) utilize both sides of the incoming sine-wave [1].

Quick and easy test if you have the scope. FIXING it - if even that is wot it be - is another story.

'Sight unseen' and I don't even have a schematic on-disk, but ..

Next would be to see if the control input is per OEM. A PO with bespoke needs may have wanted to intentionally slow down Z movement and/or reduce the available crunching torque, and have altered the control for that axis. That need not be done on the drive PCB.

Bill

[1] For bog-standard DC motors with SCR-class DC Drives. Servos and steppers are on separate planets.
 
After reading the manual in English last night, now I wonder about a 4th possibility... there is an adjustment for the stop drag below the long joystick....purpose to adjust a brake when in Z down mode....wonder if someone got over zealous on that adjustment, might it be a drag on "up" as well ?
 
After reading the manual in English last night, now I wonder about a 4th possibility... there is an adjustment for the stop drag below the long joystick....purpose to adjust a brake when in Z down mode....wonder if someone got over zealous on that adjustment, might it be a drag on "up" as well ?

As said, I dunno SQRT-FA about Deckels, nor even what race of DC Drives or controller you have in-hand. But that IS the sort of thing I was suspecting as a field mod, rather than factory.

(Eurotherm)Parker-SSD 514's, to name one, provide trimpots on-PCB for all that.. and/then/also bring out bypass terminals so over-rides can be easily implemented for bespoke 'situationally aware' ramp-times on braking/accel, current-limits, rotational zero-RPM and its zone-width, braking trigger/NOT, etc., etc. And the 514C are old-school ANALOG, yet.

Drive PCB may be blameless here. You might simply have a remote open/shorted wire, wonky pin in a connector, soggy or deteriorated switch, potentiometer, or relay that is a player in the selector logic for up/down 'personality' or such.

Bill
 
Messed with the machine more today and realized it should have been obvious to me, to simply grab any axis handwheel to check the torque from the drive. So, it's not just the Z but the DC is weak in all axis...even at 5" minute I can easily stop the handwheel from rotating on X or Y axis as well. Curiously the "rapid" function works fine...but at normal milling speeds DC is weak.

Input voltage to DC drive is as it should be (380 volts) but the schematics do not mention output voltages (which seems amazingly lame) and the Siemens DC motor nameplate is nearly impossible to read.

Here's what the drive is....something totally obscure of course... Labod DC Drive GN 2 DZ 24 175 12 4Q 12 A GN2 GN2DZ | eBay

Assuming 240/175 refers to the DC voltage outputs, any modern equivalent to this ?

(even though the Labod is 380 VAC input, 230 VAC input would be ok via bypassing the 230/380 transformer)
 
Messed with the machine more today and realized it should have been obvious to me, to simply grab any axis handwheel to check the torque from the drive. So, it's not just the Z but the DC is weak in all axis...even at 5" minute I can easily stop the handwheel from rotating on X or Y axis as well. Curiously the "rapid" function works fine...but at normal milling speeds DC is weak.

Input voltage to DC drive is as it should be (380 volts) but the schematics do not mention output voltages (which seems amazingly lame) and the Siemens DC motor nameplate is nearly impossible to read.

Here's what the drive is....something totally obscure of course... Labod DC Drive GN 2 DZ 24 175 12 4Q 12 A GN2 GN2DZ | eBay

Assuming 240/175 refers to the DC voltage outputs, any modern equivalent to this ?

(even though the Labod is 380 VAC input, 230 VAC input would be ok via bypassing the 230/380 transformer)

Try this link:

http://www.unitek-online.de/en/produkte/thyristor/classic_q2.html

Two more links. The maker was Reta-Labod Antriebstechnik GmbH. Lebod is still making CNC controls 'in general'. Dunno if they still make this unit..

LABOD electronic GmbH & Co - Home

Spares MAY still be in one or more supply chains:

Reta-Labod Antriebstechnik GmbH Products | Lektronix

Not totally sure it is obsolete, but if not, it is probably pricey. Repair services are often twice the price of a NOS/NIB drive, outright. Onesie labour vs automated production line thing.

I'll try to search a manual for it tonight.

No fear... a (Eurotherm)/Parker-SSD 514C 4Q regenerative series might be the still-stocked equivalent.

Providing they are lying about 'servo' motor in the same way they are lying about '2 phase center point' (Singe-phase 240, AKA 120-0-120 is more likely).

You WILL need all 380 VAC on the input side AND NOT just 240 VAC. Otherwise, you'll be limited to approx 60% power.

AKA 'weak'.

Need all the info you can sess-out on the motor(s).

If the motors are vanilla shunt-family DC, wound, not PM, AND ALL axis have the issue but 'rapid' works?

The field regulator / supply may be buggered.

More after I've had my sushi ration...


Bill
 
If the motors are vanilla shunt-family DC, wound, not PM, AND ALL axis have the issue but 'rapid' works?

The field regulator / supply may be buggered.

More after I've had my sushi ration...


Bill

Don't think there is any field regulation on these....Pretty sure feed motor is Basic PM motor. W/.4 brush armature....Not positive but think it has feedback via tachometer....so it should compensate for load.
Motor runs in one direction only so tach output is 0/+. Guessing tach is not sampled or a factor when running rapid.
Cheers Ross
 
Don't think there is any field regulation on these....Pretty sure feed motor is Basic PM motor. W/.4 brush armature....Not positive but think it has feedback via tachometer....so it should compensate for load.
Motor runs in one direction only so tach output is 0/+. Guessing tach is not sampled or a factor when running rapid.
Cheers Ross

Good news, actually, if so. Onboard/option card field regulators are pretty much absent from any of the affordable 4Q DC Drives under ~ 10 HP. Even so, those as have 'em are near-as-dammit 3-P ONLY.

Which might then point back to a sensor/control fault.

Just back from supper - haven't read the manual for this one yet, saw it was IR-sensing for regulation - haven't yet delved into tacho optioning.

More as it unfolds...

OK... The nanuals - hope they are the correct ones - are under the imprimatur of "Unitek Industrie Elektronic GmbH"

Unit is modular. Basic 'power' side is dumb as a box of rocks. Manual "E-Q2.pdf" starts off clear enuf.

Smarts are on another module. Manual "E_REG.pdf" covers those.

Field Regulation option - if present - is covered in manual "E-F2.pdf"


Bill
 
Time for my second contribution to a forum i have gotten alot out of.

I own the dreaded FP3A, the unloved child on an overzealous German electrical engineer and a proper Deckel, with the over complicated but still useful 2102 control.

My Deckel shares the same servo drive as the Aktivs and later manual Deckels.


Im sure many of you have seen this site before.

Deckel FP2A, FP3A, FP4A

The fourth manual, "Deckel FP3A schema elec part 2", contains the schematic for the drive, starting on page 27 if you are electrically inclined. Im pretty sure all components are still available if your keen, it shares more in common with a vintage audio amp than anything digital and can be rebuilt. Its a permanent magnet DC servo, with resolver feedback.

If you look at the wiring diagram on page 11 it will tell you something about the power requirements. On the FP3A power comes from the Phase to Phase voltage through a transformer, creating a centre tapped 240VAC(480VAC phase to phase) so as to make about plus-minus 175 DC for the servo motor, hence 240-175. Dont know if this applies as Australia is effectively European voltage, there may be differences especially with the one-way feed direction.

Neil
 
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The fourth manual, "Deckel FP3A schema elec part 2", contains the schematic for the drive, starting on page 27 if you are electrically inclined. Im pretty sure all components are still available if your keen, it shares more in common with a vintage audio amp than anything digital and can be rebuilt.
Actually, Neil .. it has a good deal in common with the Mark 42 Radar Gun Director that aimed 120 mm Ack Ack tube artillery, WWII, then became MIM-14A NiKE-Hercules (Improved) Fire Direction Control Computer (analog).

Push-pull-parallel 6V6 thermionic valve servo amps, and in Quadrature at the radar servos, IIRC (been a few years, arredy..) but very similar concept and function.

My recent experience with 'vanilla' DC Drives is not germane, so I am off to other pursuits.

Boss?

If it isn't sumthin' simple, that Rockwell Automation LeKtroniX site might have a rebuilt drop-in replacement.

Upgrade/conversion I'd leave to a retiree/hobblyist

Bill
 
Time for my second contribution to a forum i have gotten alot out of.

I own the dreaded FP3A, the unloved child on an overzealous German electrical engineer and a proper Deckel, with the over complicated but still useful 2102 control.

My Deckel shares the same servo drive as the Aktivs and later manual Deckels.


Im sure many of you have seen this site before.

Deckel FP2A, FP3A, FP4A

The fourth manual, "Deckel FP3A schema elec part 2", contains the schematic for the drive, starting on page 27 if you are electrically inclined. Im pretty sure all components are still available if your keen, it shares more in common with a vintage audio amp than anything digital and can be rebuilt. Its a permanent magnet DC servo, with resolver feedback.

If you look at the wiring diagram on page 11 it will tell you something about the power requirements. On the FP3A power comes from the Phase to Phase voltage through a transformer, creating a centre tapped 240VAC(480VAC phase to phase) so as to make about plus-minus 175 DC for the servo motor, hence 240-175. Dont know if this applies as Australia is effectively European voltage, there may be differences especially with the one-way feed direction.

Neil
Yes, that's it...starts at the 26th drawing with detailed schematics at the 27th drawing....I have that already...came with machine.. but the web scan is more clear...mine is more like a copy of a fax of a fax, print quality....this is much easier to read, thanks. Will check capacitors tomorrow and the motor tach. Checked motor brushes today and they look good..
 
Will check capacitors tomorrow and the motor tach. Checked motor brushes today and they look good..

"Your mission , if..."

MAY lead you into transistor replacement. Suitable ones can be found.

Reminder that in that era, production-batch matching was wanted as often as not. I honestly do NOT know if that is still the case, or if process and QA improvement have reduced/elimnated the need.

Went over to digital IC's long-since and no longer much had to care about discretes.

Message is do them in pairs if you have to replace them at all.

Same again with anything else in a balanced array. Might not affect the operation of the machine. Could reduce stress on other aged components.

Bill
 
Maybe I found the problem....one of the 10uF 25 volt electrolytic caps is bad on the front Labod board (upper left corner).....not just weak, but infinite resistance via ESR @100kHz, bad) Nearby identical cap is perfect, as new reading. Both compared removed from PCB also...same result. Same deal with conventional ohm readings...good one acts like it should, bad one goes to infinite resistance within 2 seconds.

However I know from experience smaller caps like that are not always the smoking gun...but could be. Difficult for me to compare real circuit to schematic but the offending cap is either C14 or C15 on the drawing....my bets on C15.

Maddening that Radio Shack is out of business as this is one of the few components they probably would have had in the store. Closest I can come looking a scrap boards from other machines is 100 uF at 25 volts.

Seeing as I am now dying of curiosity if that was the whole problem, would a brief substitution of a good 100uF for the bad 10uF be too risky to other components ?
 
Maybe I found the problem....one of the 10uF 25 volt electrolytic caps is bad on the front Labod board (upper left corner).....not just weak, but infinite resistance via ESR @100kHz, bad) Nearby identical cap is perfect, as new reading. Both compared removed from PCB also...same result. Same deal with conventional ohm readings...good one acts like it should, bad one goes to infinite resistance within 2 seconds.

However I know from experience smaller caps like that are not always the smoking gun...but could be. Difficult for me to compare real circuit to schematic but the offending cap is either C14 or C15 on the drawing....my bets on C15.

Maddening that Radio Shack is out of business as this is one of the few components they probably would have had in the store. Closest I can come looking a scrap boards from other machines is 100 uF at 25 volts.

Seeing as I am now dying of curiosity if that was the whole problem, would a brief substitution of a good 100uF for the bad 10uF be too risky to other components ?

The PCB - or more than one - 'dying' of (your) curiosity - AKA 'impatience' - is the more likely possibility. A full order of magnitude greater capacitance looks much akin to a dead-short, briefly.

Prolly don't have even ten different cap values in the whole system. Why not tally those, then hit one of the 'usual suspects' with a bulk order and refresh yer 'Hell box' [1]?

Other needfuls will present themselves in due course, 'electronic age' as it is w/r middle-aged machinery. IOW - it will get worse before it gets better, all-manual machine-tools having largely passed from dealer channels and broad - or 'well funded' - customer interest.

Bill

[1] Could prolly STOCK several Radio-Slack outlets. Five 60-dawer Akro-Mills alone 'ere. And enough other 'new junk' to fill two more. MOST OF IT shelf-aged beyond trustworthy use as far as caps go. So.. 'with care'.
 
The PCB - or more than one - 'dying' of (your) curiosity - AKA 'impatience' - is the more likely possibility.

Prolly don't have even ten different cap values in the whole system. Why not tally those, then hit one of the 'usual suspects' with a bulk order and refresh yer 'Hell box'?

Other needfuls will present themselves in due course, 'electronic age' as it is w/r middle-aged machinery.

Bill
Besides the maddening aspects of defunct Radio Shack is the fact that I had a drawer full of misc caps, resistors, etc from old shop and after moving, now can't find the box. The search for same was fruitful however as in the process I found something else I had been looking for way more valuable.
 








 
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