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Need help installing new shear pin in FP1


Cast Iron
Jan 20, 2008
Cary, NC
Hi all,
I got a Deckel FP1 4 or 5 years ago and I just broke the shear pin for the feed in a moment of inattention. When I got the mill, the shear pin was already broken. I was able to replace it then and turn a couple of spares with the correct dimensions. So, I know where to look and what to do (in principle), but something is stomping me this time.

When I did it the first time, I don't recall how I was able to align the pin hole on the outside shaft with the one on the inside shaft so that I could insert the pin fully. I don't recall having any difficulty with it. But this time, these two shafts seem to be spinning together even though the pin is in fact broken and I removed the largest part of it.

I don't have feeds. I doubt I broke some other internal component. I am quite confident that the only issue is the broken pin. But I am at a loss as to how to move the two hafts relative to each other.

So, what is the procedure to move the external shaft in relation to the internal one so I can align the holes and insert the pin fully? Do I engage the feed and turn the spindle by hand? I tried that while putting a drive punch in the outside shaft pin hole to hold it back from spinning and it never felt like I could really hold it back. I'm wondering if the shearing did not
raise a burr or a chip that is caught between the two shafts and causing them to turn together. One of the reason I think this might be the case is that I have not recovered the shorter piece of the pin. But then again, since I can't see any through hole, that part might just be caught inside the inner shaft pin hole.

I would appreciate any suggestion as to what to try, where to look.

Thanks in advance for any help.

I have an older 2 lever machine. To get the inner and outer shafts to align, WITH POWER OFF, I engage up/down feed lever, and then rotate gearing with the black handwheel, above the motor. If not aligned, rotate the up/down handwheel while feed lever is engaged. The pin is installed in the smaller of the two outer holes. Then swing the spring clip over it. Do not install pin through the larger diameter hole. That is used to remove broken stub. If you install head of pin in larger hole, you will shear pins quite quickly. I've done it. Pin should be 2.95mm dia x 12.5mm long, under head of pin.
Thanks Irontoys, That's pretty much what expected. I'll take the time and be a bit more attentive tonight or later this week. I could swear the two shafts kept moving together.

Maybe you can answer this though. Which of the outer or inner shaft is the driven one by the pin? I'm realizing now that it is probably the inner one.

Thanks for your help.