$ Door Credenza- Help With Shut-Off-HELP

[need4art]

Yes, Back on the Credenza. When I took this apart (years ago )I took all the springs off the shut-brake unit to have polished and plated. I used the Victor 4-7 that I have as a model to try to figure out which springs went where, and it don't work and I have played around with it a bit. When I get it to hold the platter in place, if I release it, it springs back like it should, but will not hook up again when I try to pull it back in place. Something must not be set up correctly. Any Ideas?

Brake, shut-off

IMG_0965.jpg (80.71 KiB) Viewed 911 times

Do the pictures look OK?
Abe

Brake, shut-off

IMG_0965.jpg (80.71 KiB) Viewed 911 times

[Inigo]

I don't know... The HMV version I'm familiar with its slightly different. The HMV operates the trigger leg by friction and has less springs.
Maybe there's a video on yt explaining the performance of this brake.... Who knows!

[need4art]

One can only Hope!

[barnettrp21122]

Could it simply be that your tone arm is not positioned to the far right when you release the brake to start the turntable spinning? What I call the fork should be positioned to the right.
The knife blade needs to clear the ratchet (to the left) before the released brake will stay in the locked position.
Your springs look correct. Hope this helps!
Bob

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[JerryVan]

Since you state that you got this replated, I'm wondering if everything still moves freely. Sometimes the plating process reduces necessary clearances and can cause binding. It's essential that everything can move without the least friction.

[Inigo]

As I've seen in hmv brakes, only the parts seen with the turntable in place are played or gilded, not the mechanisms, i.e. the fork and the handle.

[need4art]

With a bit of help-thx Bob, I did the following: to out the entire unit, cleaned and used some fine valve lapping compound on all pivot points, cleaned and relubed, swapped the spring from the fork (much stouter) for the one on the "knife" and bingo it works.

One thing that I have not figured out is that the rod that goes into the fork does not stay in place. It is threaded so if I spin it out to add to its length it works as it should-but that rod is really loose. It does not appear to have a method of locking it in place. So I'm thinking very small washers in brass would work as spacers and then I could retighten. Thoughts?

Abe

[barnettrp21122]

Abe:
I'm glad you've gotten it working. Your idea adding washers might do the trick, and would be easy to undo if it doesn't.
Have you looked to see if the fork is parallel to the motor board and not bent a bit downward? Perhaps you could bend it upwards slightly at the pivot point without it being too obvious. You've already found that any adjustments are better made with the brake assembly removed from the motor board. Hope this helps!
bob

[Inigo]

I've read herein, just days ago, that the rod must have a fixing nut in the upper part, that you screw against the tonearm, to fix the rod in place, once it's length is adjusted...