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Deckel FP1 broken shear pin. How to refit?

gotoole

Plastic
Joined
Aug 25, 2014
Location
Ireland
This Deckel is new to me and I would appreciate any help you might be able to offer me.
As the title suggests I need to replace the shear pin on my FP1. It is the older model with levers rather than dial for the gearchange.
I have searched this forum and have read as much as I can but I am still a little confused as to how to the pin and the spring clip should be fitted.. If I understand other posts correctly, the spring clip is held in with a rivet and covers the top of the shear pin, holding the shear pin in place. However on my machine, the shear pin seems to be holding the clip in place. The shear pin seems to fit through a hole in the spring clip holding in place. The spring clip itself seems to be broken. I also found a very small pin/rivet at the broken end of the spring clip. Not sure where this went but I assume it was to hold down the end of the spring. I feel that the arrangement on mine is incorrect.

I attach a photo of what I found and also a rough diagram of what I understand the arrangement on my machine is.
I would be grateful for any help getting this sorted. I have ordered the correct shear pins, spring clip and rivet from Franz Singer on Ebay.
Thanks for reading
diagram_shearpin.jpgMetalStrip_P2051203.jpg
 
What i can see in your photo looks incorrect.
The clip is riveted to the outer collar using what we herein the states call a"drive screw"
Looks like a rivet that has the shank knurled. the knurl provides a press fit when the drive screw is hammered into the proper sized hole....
these are the sort of thing used often to attach name plates on machines etc...
At any rate the clip free end should bear on the head of the shear pin when the pin is properly installed.
The free end of the clip should have its end formed into a cylinder ...the riveted end is flat.

The outer collar has a through hole in it . One end of which is larger than the other.
The shear pin is to be fitted into the smaller hole so that it engages the hole in the inner shaft to make the coupling.

The large hole is there to make removal of a broken pin easier...it is not there to receive the head of the pin.....

The shot is from an FP3 parts manual, but it shows the arrangement...

attachment.php


If the pin and clip are installed correctly, the free end of the clip should point opposite the direction of rotation for the feed drive shaft, that is it should trail the rotation direction.

Cheers Ross
 
I agree with what Ross has written.

Your hand-drawn diagram has an important mistake. It is missing the SECOND HOLE on the outside diameter of the outside (yellow) part. Search for this hole in your machine BEFORE you take action. There is one hole for the rivet that holds down the spring, and one hole for the shear pin. I believe that the second hole may be hidden underneath the spring. Use a mirror or dental pick and check for this. If so, THIS is the hole into which the shear pin is inserted. The hole that you have identified in your drawing, which currently has a "pin" in it in your drawing, is the rivet pin hole/rivet for holding down the spring.

Alternatively your spring/shear-pin was installed by someone who did not know what they were doing. If that's the case, remove it and replace it correctly. You can easily make your own rivet on a lathe (knurl the end). You can make your own shear pins from free cutting steel, or buy them online from Singer, 10 Abscherstifte mit Feder fur Deckel Frasmaschine FP1 FP2 FP3 /L | eBay shows what it all looks like, 5 Abscherstifte ohne Feder fur Deckel Frasmaschine FP1 FP2 FP3 /L | eBay are the naked pins.
 
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Thank you both for the replies.
I will look again for another hole under the spring. But in fact I think the pin has been fitted incorrectly on my machine.
Too dark now to have a look but I will examine again in the morning. I will try to remove the pin (or rivit0 and broken clip.
 
Thanks Erik,
I would love a manual.
My daughter is fluent in German so the language should not be a problem.
Do you need my address/email address?

Thanks again
Gerard
 
Just an update.
I checked for another hole and of course it was there under the broken spring. The diagram was therefore incorrect. As you both pointed out, what I identified as the pin was in fact the rivet. The undated diagram is herediagram_shearpin_correct.jpg

I retrieved the top of the pin and found what I think is the sheared end of the pin. It is an incorrect size, being only 2.1mm diameter. Photograph here shows the broken shear pin, the broken spring clip ( 3 mm and 2.5mm drill bits for comparison).P2071213Shearpinbroken.jpg

There is still some of the rivet in the ring. I assume this will needs to be drilled out.
 
There is still some of the rivet in the ring. I assume this will needs to be drilled out.

Glad you sorted it out. This is not high-tech/precision stuff. Just drill out the rivet, and make or buy a new spring. If you search the PM archives or look in the manual you will find a description of the correct steel to use for the new shear pin and the dimensions.
 
Thanks ballen.
I have ordered the correct spring, rivet and shear pins from Franz Singer. They should arrive Friday. I will use them as patterns and make some myself.
Obviously it was fitted with the incorrect size pin (2.1 mm instead of 3 mm) so the pin was probably lose in the shaft.

Erik has offered a copy of the 1938 manual and that will be an enormous help.
 
Pin should be slightly underside so as to not be tight in the drilling..Believe the correct dimension is 2.95mm.....
Length is important so as not to bridge the outer sleeve and put the inner shaft in double shear....
Pin length should be at 12.5mm long under the head of the pin.

Cheers Ross
 








 
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