Hands self tightening on Hubert herr

POWERSTROKE

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Jan 11, 2011
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50s or 60s Hubert Herr. I finished the movement and have had this problem before. It seems they all have a slightly different t set up. This movment has the larger square threaded minute canon that the square hand slips onto, then a bushing that tightens against the hand. Then you thread the conical nut onto the solid threaded shaft. When yo go and set the time, the hands are set tightening. What do I need to do in order to fix this?

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Fitzclan

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I have had this problem in the past and it drove me crazy for a while. Unfortunately I didn’t write down the remedy, but if I am not mistaken, the order is - threaded washer goes on first, then minute hand, then threaded nut.
Also, the threaded washer should be turned around with flat side against the back of the min. hand.
 

POWERSTROKE

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Can’t figure it out. The way I received was hour hand minute hand (square hole) flat bushing, small bit on the solid shaft. Too loose and the hands don’t advance. Tighten it and they become difficult to turn.
 

MuseChaser

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This is a guess, but it looks like the hand should be between the threaded washer and the nut. Those two threaded components would act like jam nuts and keep their positions without loosening or tightening or putting too much pressure on the cannon. Like I said, just a guess.....

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Willie X

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Feb 9, 2008
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Outer nut is worn and going on to far.

Needs a new nut, or you can stake the old nut to make it tighter, or you can carefully Locktite the old nut. Both hand cannons should have plenty of end play at all times. Willie X
 

POWERSTROKE

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I actually turned the outer nut backwards and it works fine.
What do you mean it’s worn? The shaft is screws onto is not tapered. Shouldn’t it either thread on or not thread on?/
This I J in
 
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JimmyOz

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Shouldn’t it either thread on or not thread on?
Yes, it should thread on, however it is only there to stop the minute cannon from walking forward, when you tighten it up against the cannon it then can't rotate. The shaft is threaded and normally stops short of the end of the minute cannon, however other clock repairers may have thought it should tighten up against the cannon as newer cuckoo's do, therefore worked to that end and stuffed it up. As Willey said just put a small amount of some sort of glue a few mm from the end of the cannon and then screw the nut on leaving the gap and it should set it in place, If you need to take it off in the future you can just turn the nut with pliers.
 

Willie X

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Yep, the threads are tapered. And yep again, the threads wear from being forced, and then the nut goes on to far, causing the problem you have there.

This has to be fixed, or it will "self tighten" itself one more time! Digg?

Willie X
 
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shutterbug

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Also be sure nothing is touching the hour cannon except the hour hand.
 

Jim Hartog

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Hello Gentlemen,

We have had this conversation several times, with some of the same participants, and all we generate is confusion. I have a loose cast plate cuckoo movement and a Herr which I took apart yesterday. Hence the photos. There are two different situations that use the double nut set up for the hands. There is confusion between the two.

One is the cast plate cuckoo movement. In the cast plate movement, the center post is fixed to the front plate. It does not move. The outer nut must not be tightened against the minute tube or the hands will not rotate and the clock will stop. The minute tube is driven by a gear on the outside of the front plate. Note where the clutch is in photo 1. Mount the hour hand, then minute hand, then inner nut, then outer nut with a space between the outer nut and minute tube. Note the two spaces. No spaces, no run. Note in the second photo that the post threads stop before the minute tube. (homemade inner nut)

DSCN0029.JPG DSCN0030.JPG

The other situation is in the Herr movements. In the Herr movements, the center post is a moving arbor. It is not fixed. It must contact the minute tube to drive the minute tube. The outer nut must be tightened against the minute tube or the hands will not turn. The center post arbor is driven by a gear on the inside of the front plate (T1). Note where the clutch is in photo 3. Mount the hour hand, then minute hand, then inner nut, then outer nut with no space (tight) between the outer nut and minute tube. There has to be a space between the minute hand and hour tube. Note in photo 4 that the outer nut contacts the minute tube. (homemade outer nut)

DSCN0027.JPG DSCN0028.JPG

So, what is causing Powerstroke's problem. I am going to suggest that the square hole in the minute hand is too loose and the inner nut is pushing the minute hand onto the hour tube causing the motion works to bind and stop the clock.

Possible solutions include: the minute hand can be replaced with one with a tighter square hole, a square hole washer can be placed behind the minute hand, or (Muse Chaser's solution) sandwich the minute hand between the inner and outer nuts. In the sandwich method, the minute hand itself then "connects" the center post to the minute arbor, but it is awkward to get "just right".

Jim
 
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POWERSTROKE

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Hi Jim. You are in fact correct that the outer nut has to push the minute cannon back or the hands will not turn I also think you may be correct that the square may be too loose? When you put a new hand on, where exactly should that rest on the square threaded minute tube? Obviously not all the way back. Thanks for the post.
 

shutterbug

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Jim - when you say minute tube, I think you mean hour tube?
 

Willie X

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Yes, Jim is correct on all points.

On a HH movement, the outermost nut has to be tight, otherwise there is no connection from the movement to the minute hand cannon.

However, both hand cannons should always have plenty of "end shake".

The minute hand shake may have a slight bit of resistance because you are moving the whole minute hand assembly, which goes through both of the plates.

Thanks Jim, Willie
 
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shutterbug

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I'm confused with "minute hand cannon" I guess.
 

Jim Hartog

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Hello all,

I did not use the word cannon since I prefer the word tube. So minute tube is minute cannon, if you like. Minute tube is the tube the minute hand is on, hour tube is the tube the hour hand is on. They are both tubes. Regulas have hour tubes but no minute "tubes".

I did proof read many times but I just did an edit to add a missing "tube" after the word "minute" in one line.

Powerstroke, yes, the minute hand should fit on the square of the minute tube but not touch the front edge of the hour tube when the inner nut is tightened. I'm thinking that when you were advancing the hand to set the time, you were rotating the inner nut which tightened the minute up against the hour tube. You would feel that as resistance to turning since you are now trying to turn the minute hand and hour hand simultaneously and it should also stop the clock. There has to be a space between the minute hand and the hour tube.

Jim
 

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