brocot drop adjustment

disciple_dan

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I have my first Brocot on the test stand running strong. I have a damaged EW that I'm working to repair or replace. I have a lot of drop on the entrance side and I'm not sure how to correct it. I can never remember if you close the exit or the entrance or vice versa. I always have to look that up. I think it's close the exit. I check again.
So how do you do that. Or how do you move the anchor close or away? It doesn't seem to have adjustments.
Thanks, Danny
 

wow

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I have my first Brocot on the test stand running strong. I have a damaged EW that I'm working to repair or replace. I have a lot of drop on the entrance side and I'm not sure how to correct it. I can never remember if you close the exit or the entrance or vice versa. I always have to look that up. I think it's close the exit. I check again.
So how do you do that. Or how do you move the anchor close or away? It doesn't seem to have adjustments.
Thanks, Danny
Dan, I would get the escape wheel right first. Adjustments are very critical. There should be almost no slop in the escape wheel arbor pivots, especially the front one. Playing with the anchors can get you in trouble fast. Get the EW right and then post a video and let us see what is happening. Good luck.
 

MuseChaser

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I have my first Brocot on the test stand running strong. I have a damaged EW that I'm working to repair or replace. I have a lot of drop on the entrance side and I'm not sure how to correct it. I can never remember if you close the exit or the entrance or vice versa. I always have to look that up. I think it's close the exit. I check again.
So how do you do that. Or how do you move the anchor close or away? It doesn't seem to have adjustments.
Thanks, Danny
Danny,

RC REALLY helped clear all that up for me with a wonderfully succinct and clear explanation here during a thread drift I caused in a discussion of an Ingraham cracked pinion gear ...

Drop and Pallet adjustment

If you continue reading through that thread, you'll find some more helpful discussions and comments by RC, Shutterbug, and maybe even me.

What Will above said undoubtedly applies, though.. no point in messing with the pallets until you get the escape wheel pivot holes squared away...... well... not "squared," but you know what I mean... ;)
 
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R. Croswell

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I have my first Brocot on the test stand running strong. I have a damaged EW that I'm working to repair or replace. I have a lot of drop on the entrance side and I'm not sure how to correct it. I can never remember if you close the exit or the entrance or vice versa. I always have to look that up. I think it's close the exit. I check again.
So how do you do that. Or how do you move the anchor close or away? It doesn't seem to have adjustments.
Thanks, Danny
I agree with WOW, if you are working on a damaged EW, get that right first. There really is no such thing as "closing" the exit pallet or "closing" the entrance pallet. You can adjust the distance between the pallets. reducing the distance between the pallets is "closing the pallets" but it does not close one anymore than the other. When you say "drop on the entrance", we need to be clear if you mean drop off of the entrance pallet (typically referred to as entrance drop), or do you mean drop on to the entrance pallet (the distance the released tooth travels to contact the entrance pallet)?

Even on a good day Brocot escapements can be finicky; if you have one that is running strong and reliably I would think twice before messing with it even if the drops are not perfectly equal.

RC
 

disciple_dan

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Ok, this EW is fine. I was thinking of another clock that has what appears to be a Brocot EW and it's in bad shape. The wheel in this video is fine. It's just the drop I'm wanting help with.
When I say drop I mean the distance the tooth travels before landing on the pallet. Entrance drop, is that correct?
I think I may need to turn the pallet just a bit so that the tooth lands more on the apex of the entrance pallet. You probably can't see that in this video.
I just need to know how to shorten the drop Thanks, Danny

 

Willie X

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dd,

I would lower the pallet arbor a bit. That should make it better.

Willie X
 

Willie X

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That's a good question. Can't see anything very clearly in the vid but that upper bracket might be movable? If not you may be able to bend the pallet arms downward a bit, one at a time and very small movements. That will have the same effect as lowering the pallets but will also put them closer together too. :oops:

So, slightly moving the pallet arbor pivot downward would be much preferred. This all depends on how the clock is made and they are made in many different ways.

I agree with wow too, especially if that puppy will run for 10 days ...

Willie X
 

disciple_dan

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Thanks for the help, Willie. So, on a deadbeat escapement, if you shorten the distance between the pallets doesn't it decrease the drop on the exit pallet? Or is it the entrance? I can never remember that. I'm going to get that straight.
Anyway, If I move the EW arbor center and the pallet arbor center closer will that decrease the drop on the entrance pallet?
The bridge for the pallet arbor is hinged on one side and has a stabilizing pin on the other. It's not set up to be adjusted though. Check out these pics. The pendulum is hanging plumb.
20210505_210023.jpg 20210505_210145.jpg 20210505_210213.jpg
 

disciple_dan

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Do I need to turn the entrance pallet a little to get the teeth to have more lock on the apex of that pallet? In pic 2 the pendulum is in the middle of its arch. Would that be causing a little recoil?
I wound it completely and will see how many days it will run.
Thanks, Danny
 

Willie X

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Escapements need to be "close" but "perfect" is quite rare. :)

Two things that may help you: Every tick should cause exactly the same degree of rotation of the escape-wheel. And (on your clock) every tooth should drop onto the pallet a little short of the high point. When all is well, the overswing will carry each tooth a little past the high point.

Some of this can be seen with the clock running but is best viewed by watching the escapement while slowly moving the crutch back and forth.

For the best action, the flat side of each pallet should be radial to the escape-wheel, or close to it.

Willie X
 

disciple_dan

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For the best action, the flat side of each pallet should be radial to the escape-wheel, or close to it.
I set the flats of the pallets with a razor blade to be in line with the center of the EW arbor. I did file the pallets by hand so they are a little less than perfect. I'll check them again. I still think I need to decrease the drop on that side though. It's pretty large.
Thanks, Danny
 

JeffG

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Hi Dan!
As usual I agree with Willie X. It looks to me that your EW arbor and anchor arbor need to be a bit closer together so that the EW teeth drop onto the pallets at (or just shy of) the roundest part of the pallets- or the tangential point? (I did not do well at Trigonometry) As Mr Croswell clarified in a previous thread drop is actually the tooth falling off of the pallets.
A very helpful tool that I've found for such issues is the "slo-mo" setting on iPhone cameras. Super helpful for looking at drops and balance wheel rotation.
 

shutterbug

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Also bear in mind that the pallet shape can cause an early release off the flat edge. You might be able to adjust the pallet a little so the flat edge is further away. Tiny adjustments.
 

disciple_dan

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Yeah, I'm looking for a way to move the center. There are no adjusting points built-in.
I think either way you look at the drop (falling off/falling on) will work as long as you're consistent and you get it equal on both pallets. Steve Conover has a very detailed explanation of drop in one of his books.
I'm doing the experiment that WOW suggested of winding it to see how long it will run. If it runs far past its run then I could probably let it run.
 

disciple_dan

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Ok, So, I turned the entrance pallet just a little bit. It seems to have helped a bunch. Check out this vid.
I also slightly adjusted the beat.
 
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disciple_dan

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I think I made a boo-boo. When I bushed the backside of the EW which is actually in the front plate, I put the oil sink facing the arbor. Now, I think the EW, as it turns in its bearing, works toward the bushing and enters into that oil sink and binds up.
Have any of you guys had a similar incident? I think I need to tap the bushing out and turn it the other way.
Thanks, Danny
 

Willie X

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Normally, reversing a bushing has no ill effect. That pivot may be bent, or to tight, or no relief/chamfer for a radius at the root of the pivot. Willie X
 

disciple_dan

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So, that first Brocot that looked good, sounded good, was good, went bad. I've lost all power. I just cannot imagine what is going on. If you read my last post you know about the backward bushing. I turned it around and it hasn't worked since. I thought I had bent a pivot on the EW but I put it in the lathe and it was ok. I'm going to take the EW out and try to make it stall without it. That will eliminate the EW as the problem but I think it might be.
Hopefully in the meantime, one of you brilliant people will come up with a cause.
Thanks, Danny
 

disciple_dan

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Willie, I'm making money on your experience. I need to send you some sort of compensation. All of you actually.
I'm not sure now if it was a tight hole or the gnarled pivot shoulder but I addressed both and it is running at full speed again. I think it was more the gnarley arbor.
Thank you, Thank you, Thank you, have a Happy Day, Danny
 

disciple_dan

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I'm wanting to get this clock back to the owner. While it seems to be running and keeping good time but it has some kind of irregular beat.
Let me know what you see.
Thanks, Danny
 

Willie X

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There is a slight irregularity there, it's also slightly out of beat.

I would wind it up and run it for 10 days (as is) before taking it back.

Willie X
 
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shutterbug

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It's going in and out of beat, which probably points to the EW wheel either being out of round or there is some irregularity in the teeth. Check them for hooked points. You might have to pull a couple of them straight again.
 

JeffG

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Escapements need to be "close" but "perfect" is quite rare. :)

For the best action, the flat side of each pallet should be radial to the escape-wheel, or close to it.

Willie X
In the never-ending quest to be more perfect, at what point in the anchor's swing should the flat side of the pallet be radial to the EW arbor?
 

disciple_dan

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In the last video I did, the clock had run down for one week. It looks and sounds a little off. In this video, I have made no adjustments but only a full wind.
How does it look and sound now?
I think it sounds much better. You can't hear that irregularity as much. I believe it was Willie X who testified that you can tell a lot about a clock when you have a low amplitude. When I'm testing a clock on my test stand I always by giving it a very slight push ( just enough to get the tic, no overswing) and listen close. If it is at all out of beat it will be evident. If it's a strong runner it will pick up speed, if not, it will stop.
Thank you for your time, Danny
 

Willie X

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Yes, at low amplitude, escapement errors become more apparent. But, if it keeps a reasonable rate and runs 10 days, it's probably close enough. :). Willie X
 

disciple_dan

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After I wound this clock I tweaked the beat and what a difference it made. I'll see if it sounds that good in 10 days.
Thanks for all the help, Danny
 

disciple_dan

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This clock is in its 15th day running and striking. The strike is very weak and it has lost 18 minutes. It is obviously overpowered. That kind of explains why it was so worn and I had to bush nearly every bearing.
It's going home tomorrow. I'm going to instruct the owner to not wind it fully but just until it gives good resistants.
I really appreciate all the great instruction I was given here to help me with my first Brocot escapement.
Thanks again and God bless you all, Danny
 

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