How to diagnose rapid traverse on an FP2?

Hi,

I am taking the afternoon off today to go look at an FP2 an hour away. One thing I know about it is that the rapid traverse either does not work at all or it is very slow. I had a hard time getting any more details than that.

I have never even seen an FP2 live, but I have had an FP1 for a couple of years, so I have some familiarity with Deckel.

My question is, what could I do to figure out quickly what is the likely cause of the rapid traverse issue. Where should I look? I assume there is a shear pin as in the FP1 but might there be two different shear pins on the FP2? One for milling feeds and one for rapid traverse? As I understand it, the milling power feed otherwise works as expected, but perhaps I misunderstood that.

In summary, any hint as to what to look at in terms of defective rapid traverse or any other generic inspections clues specific to a Deckel FP2 will be welcome. And, might I say,... the sooner the better.

Thanks in advance for any and all suggestions,

Jacques

jariou said:

My question is, what could I do to figure out quickly what is the likely cause of the rapid traverse issue. Where should I look? I assume there is a shear pin as in the FP1 but might there be two different shear pins on the FP2? One for milling feeds and one for rapid traverse?

Click to expand...

There's only one shear pin in the FP2, and if it shears it should disable both drive and rapid feeds. It's easy to get at, just open the door and you'll see it down there. From what I understand it's the same arrangement as the FP1.

I've never dug into this on my FP2, but I found some great photos in this thread. It looks like it's simply wet clutch pack that grabs on the output shaft, where the clutch press is dogged into the feed gearbox's output gear whenever the clutch is released.

There isn't a whole lot to go wrong there other than a worn down clutch pack, clutch lever trouble or broken gearing. The last seems unlikely, as I'd imagine the clutch would slip before the gears give up.

While I was in a blind panic when I crashed my FP2 and sheared the pin, I do seem to remember that there was sufficient drag in the input shaft that at least some of the feeds would move. The rapids are geared much higher, so that would not necessarily move under those circumstances.

Fingers crossed for you - happy hunting!

As for any general inspection advice (I'm clearly not an expert), I think you'd be fairly well set having used an FP1 before.
One thing that took me by surprise with my FP2 was that in addition to the gib lock at the back of the ram, there's a caphead screw at the front of the ram that also locks the Y axis.
When I got the mill, this was snugged up some, and the Y-axis dragged a fair bit. Only when I loosened it up did I get a real sense of how much the Y-axis gib was in need of adjustment, as the vertical milling head would move 10thou or so side to side.

Think most likely that the sear pin has failed.
As "sigurasg" points out often there is enough residual drag in the failed pin to move an axis under power feed....But not enough to move the axis at rapid (higher drag)

Simple test is to engage the power feed and hold the associated hand wheel....If you can stall the feed by hand then the shear pin is the culprit....
Additional issues could be worn "shift fork" that engages the rapid feed clutch pack...If worn enough i believe that you will not
get full pressure on the pack and full rapid will not occur.

Cheers Ross

Thanks to Sigusrag and to Ross.

The feeds worked flawlessly, actually a very good positive feel. The rapids were essentially unreliable, dong nothing one second and suddenly racing the next depending how much pression you put on the "stick". Probably a clutch issue.


It's a bit of a basket case. A 1 phase Harborfreight motor, no switch, no electric cabinet, no vertical spindle. Plus when I tried to change speed, the control dial stayed in my hand.

I'm familiar with the different FP1 models, in particular the two pairs of levers versus the two dials to set speeds and feds, but I know next to nothing about the FP2.

My FP1 has the two dials and this FP2 also had two similar dials to set speeds and feeds. What does that mean in terms of generations of FP2's? Is it a somewhat recent version? An older one?

If it had the vertical head, I probably would have snatched it immediately. But right now, I'm in limbo, leaning on passing.

Jacques

The rapid feed is done by a multi plate clutch that is kept open via spring action.
To engage you have to apply enough pressure to stop the clutches from slipping...need to overcome the spring and the clutch pack.
A normal setup will go from no feed (a neutral point in the lever travel) to some feed to full on rapid when enough pressure is
applied to the lever.....

Could be dirty or gummy or dry....If its working at all then its likely fine, just needs some TLC......Cleaning or fresh oil....

Is the motor exposed out the rear of the machine, or is it under the main casting and enclosed in the machine base?
Are the shift dials for feed and speed made as concentric dials (a knob in the center of the dial) or is the selector made with a large dial and a smaller disc crank below the dial that you rotate to make the large dial move?

No vertical head, could substitute the precision boring head and still have vertical capacity......The precision boring heads do appear from time to time....

Cheers Ross

Thanks Ross,

The motor is sitting outside the main casting, like on my FP1.

The shift dials for feed and speed are made as concentric dials, again, essentially as the FP1 I have. The knobs are slightly different, but there are no apparent disc crank you talk about.

I wonder how often and at what price do precision boring heads come up!

Jacques

jariou said:

I wonder how often and at what price do precision boring heads come up!

Click to expand...

If you are willing to endure the hassle of international shipping, you can buy one in Germany fairly easily. These ones are expensive, I have seen them frequently for around 7-800 Euro. Not sure if the second link is for an FP1 or 2, would have to check model number and don't have time now.

Vertikalfraskopf mit SK 40 Aufnahme fur Deckel FP2 Frasmaschine | eBay

Feinbohrkopf Typ 2021 fur Deckel Frasmaschine | eBay

ballen said:

. Not sure if the second link is for an FP1 or 2, would have to check model number and don't have time now.

Click to expand...

Precision boring heads only go with the FP2 (its a gear thing)...there is no FP1 version. Only adaptable on the FP1 by using the rather rare (=expensive) FP1 riser.

Cheers Ross

Like Ross wrote...

The rapid feed is not an on-off thing.

Pulling the lever a little make the feed stop.

Pulling more give some feed.

And firm pulling give full rapid speed.

At least on my FP2 - it works very nicely.

Cheers
Erik

So, what happened?

Did you discover it's really ok or....?

AlfaGTA said:

Think most likely that the sear pin has failed.
As "sigurasg" points out often there is enough residual drag in the failed pin to move an axis under power feed....But not enough to move the axis at rapid (higher drag)

Simple test is to engage the power feed and hold the associated hand wheel....If you can stall the feed by hand then the shear pin is the culprit....
Additional issues could be worn "shift fork" that engages the rapid feed clutch pack...If worn enough i believe that you will not
get full pressure on the pack and full rapid will not occur.

Cheers Ross

Click to expand...

Hi,
my FP2 has a sheared pin, I have only just got it the machine. How do you remove the old pin?
I have rotated the shaft until I see the end of the pin and tried tapping it out but no luck.Does the retaining clip come out or does it just come away from the pin?

There is some confusion with the way the pin is installed,perhaps the previous owner got it wrong.
Pins should have a head at one end.
The pin should be installed in the small hole of the outer sleeve, and retained by the clip.
The large hole (opposite) is there to make removal of a shorn pin easier.
Swing the clip clear and use a small drift through the large hole to drive the broken pin out.
Be sure to make the replacement from dead soft mild steel. Do not use a nail.

Cheers Ross