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Deckel Aktiv Feed Problem

sneebot

Stainless
Joined
May 14, 2001
Location
Massachusetts
I've been trying to sort through getting the DC feed drive hooked up for an Aktiv machine (FP3). I've got the feed drive engaging (turning on)- the feeds will work but the run opposite the direction they are supposed to (when moving mechanical engagement levers). BUT they move in the correct direction when the rapid feed is engaged. There are a couple of relevant diagrams (below)-- any suggestions for what to look for?


D1.jpgD2.jpg
 
When the feed motor runs, does it work properly but just in the wrong direction ?

There are a few setting pots on the electronic boards of the DC drive.
Been a looooong time since I did investigate in that departement and I wouldn't be able to tell you exactly why, but I wouldn't be surprised if the solution of your problem was here.
 
Tien,
Yes the drive powers the feed motor in the wrong direction for normal feeds; BUT the correct direction for rapid. Something is obviously switched around in the normal feed wiring chain, but I haven't been able to figure it out yet.

I've played with the adjustment pots a bit- they do not change directionality just the speed.

a question about engaging the feeds:
-Turning on the feed motor requires pressing two buttons
-After the feed motor is turned on, the feed levers can be engaged
-At this point the machine will start feeding-- is this correct or should the feeds require both mechanical lever engagement and then pressing the feed button on the console?
 
Matt:
When engaging the feed going in the correct direction, does it start immediately, or does it pause, perhaps nudge in the correct direction before then running in reverse?
Is this a new problem, or is this machine new to you and has never run correctly since you have owned it?
Cheers Ross
 
When engaging the feed going in the correct direction, does it start immediately, or does it pause, perhaps nudge in the correct direction before then running in reverse?
Once the feed motor is engaged (started) via the console the feed will start (in reverse) immediately after one of the mechanical feed levers is engaged.

Is this a new problem, or is this machine new to you and has never run correctly since you have owned it?
This machine had the feed drive replaced by the previous owner- not with a swap in replacement but a full on different drive where they redid a bunch of the wiring. The replacement drive did not have rapids or creep functionality and it was underpowered. I found an original drive and have been trying to get the wiring back to stock. It's almost there-- but not quite. So the answer to this is no, it has never run correctly while I've owned it.
 
Had a somewhat simular problem on a Ferrari once Turned out the wires of the tacho were reversed

Peter

nope, same problem when I switch the Tach wires--- the same in that feed direction is incorrect. There is a change in that the feed motor is in super rapid mode when the feed motor is engaged (feed motor is spinning very fast).
 
I would try to swap both motor and the tach now

If I do troubleshooting on this system I connect everything directly to the drive
Also a 10K potmeter for speedcontrole
That way the motor rotates one direction half the stroke of the pot and the the reverse direction the other half of the potmeter
In the middle of the stroke the motor stands still
The additional potmeters in the system make it turn one direction

Peter
 
I would try to swap both motor and the tach now

If I do troubleshooting on this system I connect everything directly to the drive
Also a 10K potmeter for speedcontrole
That way the motor rotates one direction half the stroke of the pot and the the reverse direction the other half of the potmeter
In the middle of the stroke the motor stands still
The additional potmeters in the system make it turn one direction

Peter

I just did that (reversed both Tach and motor connections). This results in correct feed direction but the rapids now will not work at all. When I press the rapid button the feeds stop.

I do have a 10K pot in the console.
 
I found this in an old post by Don:

I wonder if Deckel ever produced a service manual that tells folks these little secrets... like how best to adjust the various pots on the A1B and A2B ? I noticed for example I could get the DC to drive backwards (allbeit very weakly) if I adjust one pot in particular wrong. They are at least labeled. The large pots on A2B give no clue what they are actually for.

That was in this thread:
1980 Deckel FP3, power feed seems "weak" in Z up

I have not played with the pots on the A1B (DC Drive). The feeds do seem slow (weak?) compared to what I would expect.
 
I found one problem-- a broken trace on the A2B PCB. Repairing this resulted in the feeds advancing in the correct direction.

Now, Rapids do not work. The speed pot on the console does not effect the speed of the motor. Does not seem to want to lift the Z axis up.
 
Hi Matt,

I found one problem-- a broken trace on the A2B PCB.

Are you sure it was broken and not deliberately cut? Many printed circuit boards (PCB) have modifications done at the factory which involve cutting traces. Sometimes this is because there was an error in the PCB, and sometimes it's just part of the configuration process for a particular machine or set of components.
 
To determin if it is the drive or something els I would connect a 10K pot directly to terminals 5-6 and 7 and see what it does
That way you bypass a lott of potentialy faulty parts
Like explained before speed should go from max CW to stop to max CCW

If it works fine then the problem is not in the drive If it does not work correctly I would check al the terminals input to start with
I found that if the tacho and motor + and - are out of sync it does crasy things like randomly pick a direction and overspeeding

Peter
 
Hi Matt,



Are you sure it was broken and not deliberately cut? Many printed circuit boards (PCB) have modifications done at the factory which involve cutting traces. Sometimes this is because there was an error in the PCB, and sometimes it's just part of the configuration process for a particular machine or set of components.

Definitely deliberate- previous owner made a number of modifications to install their 'new drive'. I found it while tracing through the electrical schematic and the PCB vs schematic connections did not match.
 
To determin if it is the drive or something els I would connect a 10K pot directly to terminals 5-6 and 7 and see what it does
That way you bypass a lott of potentialy faulty parts
Like explained before speed should go from max CW to stop to max CCW

If it works fine then the problem is not in the drive If it does not work correctly I would check al the terminals input to start with
I found that if the tacho and motor + and - are out of sync it does crasy things like randomly pick a direction and overspeeding

Peter

Peter, thanks for the explanation. I will try this-- it may take me a day or two.
 
To determin if it is the drive or something els I would connect a 10K pot directly to terminals 5-6 and 7 and see what it does
That way you bypass a lott of potentialy faulty parts
Like explained before speed should go from max CW to stop to max CCW

If it works fine then the problem is not in the drive If it does not work correctly I would check al the terminals input to start with
I found that if the tacho and motor + and - are out of sync it does crasy things like randomly pick a direction and overspeeding

Peter

Peter,
I tried this today. When I connect a 10K pot directly to terminals 4/5/6 the feed motor will start CW, go to zero and then turn CCW. It is not symmetric- the motor will turn faster CCW and there is more of an adjustment window CCW, whereas CW there is very little adjustment. I've not tried to play with the pots on the drive to see if I can adjust/ balance this.
 
Oke So basicly it works I do not know much about electronics but the function of the pot is to split voltage
So it generates a input ranging from +10 volt to - 10volts That was told to me at least
Normally I send it out for repair to the OEM for 250 euro But in your situation I would try to turn the pots near terminal 5
Do you have a diagram ??
Peter
 
Oke So basicly it works I do not know much about electronics but the function of the pot is to split voltage
So it generates a input ranging from +10 volt to - 10volts

But the reversing of the drive with the pot directly connected is not the normal behavior of the system so the voltages must be modified (0-10V?) by the A2B PCB?

I played with the pots on the drive a bit and got it more balanced. Now I need to dig into the A2B PCB (with the three trim pots) I believe this must be where the problem is.

I do have the schematics.
 
I know A2B is for adjusting the stopping of the motor exactly to the position dictated by the TNC 111 or 113
That is discribed in the manual
I do not know if it also contains the pots you need But if you look that up you can at least rule out some pots

Peter
 








 
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