Drop, Lock, or Design?

[Scottie-TX]

Go ahead tell me; "You got Waaay too much time on your hands."
Hanging on the wall and hasn't stopped in perhaps a year since I put it there clean and serviced. Why argue with success?
Well; It just ain't right. Or is it?
1. REQUIRES a pound and a half to run!
REQUIRES! and at a pound and
a half there is nearly ZERO overswing.
2. Because of this, pendulum oscillations are
inordinately wide making the pendulum swing
look more like my springwound store
regulator.
My first suspicion this eve was the pallets.
The face angles just didn't look right. Also, they were PERFECT. They were SO perfect, they were suspicious. Especially the exit pallet face. It just didn't look vertical enough - not the angle I've become accustomed to seeing.
http://static.flickr.com/45/152258544_129fa04c8c.jpg
So I yanked a couple of identical pallets from another movement and installed them. WHOOPS! After installation - SAME angle! From that I gather that the position of the slots in the anchor have led to this face angle when properly faced.
Let's try "DROP": I re-installed original pallets and established a drop a few thou above "stall". No improvement.
SO: It very probably is not pallet face angle.
It very probably is not a drop problem.
A lock adjustment problem? I now doubt that.
Why does this thing DEMAND a pound and a half when some'll run on 5oz. with VERY small oscillations?
Could it be design? Could it be this movement has these requirements by design.
I note foremost the diameter of the escape wheel. It is much larger than most I see. Probably an inch dia. at least while many others are three quarters inch or less. Smaller escape wheel meaning less travel of anchor to transit from one lock to the next? Is that correct thinking?
Do you see a larger escape wheel needing wider oscillations of the pendulum?
Whaddya think: Drop? Lock? or Design?

[Scottie-TX]

Go ahead tell me; "You got Waaay too much time on your hands."
Hanging on the wall and hasn't stopped in perhaps a year since I put it there clean and serviced. Why argue with success?
Well; It just ain't right. Or is it?
1. REQUIRES a pound and a half to run!
REQUIRES! and at a pound and
a half there is nearly ZERO overswing.
2. Because of this, pendulum oscillations are
inordinately wide making the pendulum swing
look more like my springwound store
regulator.
My first suspicion this eve was the pallets.
The face angles just didn't look right. Also, they were PERFECT. They were SO perfect, they were suspicious. Especially the exit pallet face. It just didn't look vertical enough - not the angle I've become accustomed to seeing.
http://static.flickr.com/45/152258544_129fa04c8c.jpg
So I yanked a couple of identical pallets from another movement and installed them. WHOOPS! After installation - SAME angle! From that I gather that the position of the slots in the anchor have led to this face angle when properly faced.
Let's try "DROP": I re-installed original pallets and established a drop a few thou above "stall". No improvement.
SO: It very probably is not pallet face angle.
It very probably is not a drop problem.
A lock adjustment problem? I now doubt that.
Why does this thing DEMAND a pound and a half when some'll run on 5oz. with VERY small oscillations?
Could it be design? Could it be this movement has these requirements by design.
I note foremost the diameter of the escape wheel. It is much larger than most I see. Probably an inch dia. at least while many others are three quarters inch or less. Smaller escape wheel meaning less travel of anchor to transit from one lock to the next? Is that correct thinking?
Do you see a larger escape wheel needing wider oscillations of the pendulum?
Whaddya think: Drop? Lock? or Design?

[Viennaman]

Got any more details on the clock, Scottie? Both my Viennas run on 2 1/2 pounds (one is on the original weights, the other on identical modern replacements), and they have healthy swings without being excessive. The actual diameter of the escape wheel shouldn't matter IMHO - the tooth pitch would seem the controlling factor. I take it you have not got the original weights but have used replacements determined by the spring balance mathod or whatever.

I'm used to regulators having a small swing (I assume this is a regulator from what you say), so I guess the acid tests are:

Are the ticks and tocks inordinately loud? That might suggest excess driving weight.
Does the clock stay in beat?
Does it run for the requisite time? (8 days, 31 days, whatever)
Once the pendulum is regulated, does it keep time as well as expected?
Do you have the appropriate pendulum? A bigger pendulum would require more driving weight.
How original is the clock?

[Larry]

Scottie,
Post a pic of the escapewheel too.

Larry

[Viennaman]

You can't run 'em all on 4 oz., mate! :wink:

[Ralph]

Maybe your answer is in how much impulse the escape wheel is giving. There is a lot of machine between the escape wheel and the weight. The difference can be in that part of the clock.

Ralph

[RJSoftware]

Design;

Sure a larger escape wheel would take more weight. The more teeth/diametor the less torque/impulse. More weight is needed to compensate.

(That is if rest of gears are same or produce same torque/speed ratio just before ew)

You remember those days, riding your ten speed. (you did have a ten speed way back then right? :smile:)

Remember how hard you had to peddle when the bike was stuck in higher gears like the 10th when bike was at stand still.

I know you know the arrangement is not exactly the same, but all you have to do is think along the same lines.

Gearing up.

Increase of output speed requires greater torque to input. Creates high speed output but low torque.

Conversly (Gearing down).

Decrease of output speed requires less torque of input. Creates high torque output but low speed.

Keeping in mind also that the ideal of the time train is to reduce the torque and control the speed of escape to a minute amount.

RJ

[Viennaman]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The more teeth/diametor the less torque/impulse </div></BLOCKQUOTE>

Exactly, Arjay - that's all tied up with the tooth pitch. It's a question of how far the anchor has to move the EW with each swing. The actual diameter of the wheel is not as important. It's not equivalent to the situation on a bicycle, where it's a question of velocity ratio.

Say the EW has lots of little teeth and the pendulum only has to rotate it a tiny amount with each swing. This wouldn't take nearly as much weight as the same wheel with larger teeth at a greater pitch, where the pendulum would move it a large angle with each stroke.

[RJSoftware]

Hey Viennaman;

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The actual diameter of the wheel is not as important </div></BLOCKQUOTE>

Well, I respectfully have to dis-agree. The diametor is the determining factor in torque load.

Unless your implying that the anchor size is different and adding to the torque load because it is smaller and being smaller takes more pressure to push pendulum due to leverage factors, then we agree.

The teeth are just a point of contact of the gear. Pitch as far as I know is just the angle of the teeth.

In this case pitch would effect the amount of push. I realize that different pitches would result in different torque loads but I do not think that this is as much a contributing factor as ew size.

The larger the diametor of the ew the less power is available. Compensating with more weight is required.

RJ

[Ralph]

Ouch....

The restorative force on a clock pendulum is mostly gravity and a little from the clock movement. The "little" part is there, because there is always some friction lost in the pendulum system through aerodynamics, suspension, escapement. The clock movement with it's weight, is there to move the hands and impart enough energy through the escapement to overcome the inherent frictional losses and maintain pendulum oscillations .

Ralph

[Viennaman]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Unless your implying that the anchor size is different and adding to the torque load because it is smaller and being smaller takes more pressure to push pendulum due to leverage factors, then we agree. </div></BLOCKQUOTE>

I do agree the anchor size makes a big difference, but the actual tooth size / pitch affects how much the escape wheel moves with each swing of the anchor. Shallow pitch means more teeth and less movement per swing. Greater pitch means fewer teeth and more movement. All that extra movement goes into moving the going train a further distance, with some off for imparting the impulse to the pendulum.

[RJSoftware]

Viennaman, Aha!

I see what your saying.

Swing would also be more shallow. Requiring less impulse, less torque. Requiring less weight :smile:

RJ

[Scottie-TX]

V-MAN; You're SO correct. Of the many that pass thru here, only ONE was capable at 4 oz.
Of ALL here - only THIS one DEMANDS - NEEDS a pound and a half. Inordinately loud? Definitely NOT. It produces the quantity of sound at lock that I'd associate with a pound and a half. Obviously the ring will be reduced in amplitude with reduction of power. Regulates? Yessir. No problem. In beat? Since a pound and a half is threshold power (bare minimum) - the beat sometimes exhibits disrhythmia associated with power near the threshold. At a time that was perplexing. I now DO understand that as you approach and reach minima of power - disrhythmia will commence. Now if I give it THREE pounds then all beats are normal and regular. Overswing increases by a quarter of an inch on handmade scale or an additional four degrees or more each side.
Full cycle? Yep. No problem. Now it cannot possibly run 8 days. With only a 16" interior and ten inches of weight travel - it lacks space for 8 days. However clock does run until weight reaches bottom. Also tho you can readily see that the longer (heavier) the weight - the more reduction in run time. E D I T begins here: Pendulum/bob: Stick is not original. Hardware and bob on it appear to be so. Bob is EXTREMELY light - perhaps 2oz or less. I counterweighted it a half oz yesterday to regulate it upwards a tad. VERY light, OLD, 2pc. bob.
RALPH! That - IMPULSE! Impulse has been my thinking all along. That's why my interest in the pallet face angles. That's why my interest in "impulse by design" question.
As a logical approach today RALPH - today I removed the hands. No improvement. I removed the motionworks. No improvement. I removed the anchor and tested endshake. Excellent - all. I finger tested going works for drag - friction. Seems VERY limber - agile - has a nice "coast" after removal of power. Pinions looks good. BUT RALPH! I think I found it. In fact, I'm nearly positive.
LARRY: Here's the pix. Now first is the one described here. The second I find to be the more typical.
http://static.flickr.com/49/152680835_8e19ece306.jpg
NOW! Compare that to this - the more common of Vienna designs I find. Note the thinner pallets. Note the smaller wheel. Note also the attack or approach angle of the pallets - nearer center, Top wheel 32 teeth. Lower wheel; 30 teeth.
http://static.flickr.com/44/152680833_4a796e5825.jpg
Obviously these are differing designs that accomplish the same results. But still I ask: Would you expect these differing designs would predicate differing power requirements? Advantages of one design over the other? Disadvantages?

[Scottie-TX]

Man, you guys give up easy.

[Viennaman]

Mmm... interesting. Although the EW is larger, the anchor pallets don't engage near the diameter but near the top. The "effective" diameter of the EW is therefore less, as well as the pendulum swing, and the impulse should be similar. However, the increased pallet angle seems to negate some of this - the pallets will move the EW more while engaging. That also means the weights will fall faster.

The pendulum bob may be light, but is there much weight in the anchor and pendulum rod? You say the rod is not original - could there originally have been a compensating bimetallic rod? That has considerable mass. I know they're more normally found on spring-driven clocks, but I'm just tossing ideas around.

[Bill_NY]

Scottie-In the bottom escapement, I assume the 'scape wheel is rotating counter-clockwise as we look at it. But it would not be a dead beat escapement from all appearances. I am with David on the top photo. The 'scape wheel would also have to rotate counter-clockwise to impulse the pallets, yet the wheel is designed to rotate clockwise IMHO. :confused:

Bill

[Viennaman]

Well... I have seen novelty mirror-image clocks in a few pubs, to be read in a mirror!

[Scottie-TX]

AH!
Sorry about the poor picture setup.
The essence here was showing the two differing types of deadbeats - not the minutae associated with the pictures. I could make two more operationally correct pictures but you get the idea.
Two differing anchor styles;
Two differing wheel sizes;
And the question: Between the two:
1. Would you suspect one had power requirements
different from the other ( without respect
to ancillary factors - bob/stick weight,
length, etc.) ? and
2. Benefits - advantages - disadvantages
between the two designs?
FOLLOW the V-MAN; His thinking. He's considering the question - not the position of stuff.
V-MAN: Altho stick is not original it is VERY similar to original. Typically, except in a few month-and-longer runners, these miniatures had about a 5/8" thin wooden rod. The smaller ones often had an ovate steel rod about 3/16" wide; 18" thick.

[Scottie-TX]

To bring it back on track tho, you recall the original question was why the one with the big wheel DEMANDS a pound and a half.
I MAY have found the reason.
Please study the picture of the large escape wheel - the teeth: If the picture is good enough - do you see what I see?
Again; I'm not an artist. Forgive the poor rendering:
http://static.flickr.com/47/152696567_ff05441fb0_m.jpg

[Ralph]

Scottie,

You are observing what Gazeley speaks too in his book, Watch and Clock Making and Repairing.

Page 204 in my book...

Under Graham dead-beat escapements, after extolling it, he goes on to explain about the early and late designs. The earlier one spanning 14 teeth and the later (modern) spanning 8 teeth.

On the early type, he points out that it is sensitive to motive force...as power increases, friction increases. He states that the early one runs with less power, so is more sensitive to thickening of oil which will affect it's rate.

The later type requires more power and oil changes are swamped out by the additional power , so it is affected less by oil thickening changes.

Thanks for bringing it up.

Ralph

[RJSoftware]

Scottie; Please no porno drawings allowed on this site.:biggrin:
RJ

[Scottie-TX]

WOW! Great research RALPH and, "yes." Yes, now that I read your reply I believe I also read that in one of my books. I just didn't recall but your quote jogged my memory - the only exercise I get anymore. It also explains why I have experienced that many late GB's with this large wheel design DO require more power. Now NOT a POUND more, RALPH - but indeed - more. I also find their winding drums substantially larger dia. probably to provide additional power at the expense of more rapid weight drop.
HOWSUMEVER Ralph, etalii; LAB'll confirm or refute in the near future. I am certain that MOST of the teeth on the EW are bent to an arched or radiused condition. ONE more test: When I re-assemble - if this is true I should see recoil after lock. THAT will confirm my suspicion. If the teeth are bent and cause recoil, a LOT of power will be required to compensate for the recoil. Thanks RALPH.

[Viennaman]

Also, the teeth aren't smooth- there's a "lip" on the action face. So the anchor won't smoothly push the gear round. There will be a sudden impulse "spike". If there isn't enough weight to drive it, the anchor won't have enough drive to push the EW.

[Ralph]

I don't see the arhed or radiused condition on the escape wheel. Is the pictured one, the one in question?

The one pictured looks OK to me.

Ralph

[Scottie-TX]

Indeed RALPH. Yes indeed. The large wheel. The condition is somewhat subliminal. In fact so subliminal is why I may not have noted it previously until I launched this "full court press" - a dedicated search for why it REQUIRES so much weight. But, "yes"; I'm nearly certain the problem lies in the bent teeth.

[Ralph]

Do you mean the teeth looking like they are leaning over? I think that is by design.

I notice that Britten's Watch & Clock Maker's Handbook, Dictionary and Guide goes into even more detail about deadbeat escapements, and talks about the tooth shape.

Highly recommended book.

Ralph

[Scottie-TX]

If you mean "leaning over" as in pitch angle then, "no".
If you mean leaning over as in "bent" then, "yes". Not all of them but many of them.
Logically I conclude that ALL teeth on a wheel should be identical in every respect. If there's thirty teeth and ten are different than the others, then ten are wrong or twenty are wrong.

[Scottie-TX]

"CASE CLOSED!" KaBAM!
Back together now and conjecture at least for me - is over. With every lock there occurs very pronounced recoil of the EW. THIS movement REQUIRES a pound and a half because the escape wheel needs serious attention.
However; Thanks to RALPH especially- V-MAN and others - The two design variations DO have differing properties and one DOES require more power by DESIGN! Thank y'all! 'preciate.

[Ralph]

Scottie,

Not to belabor the point and you have the EW in front of you, but the one in the picture looks OK to me. I know those wheels will give an optical illusion and can look funny. The proof is when it is running, does it escape well? does the beat sound consistant throughout the cycle of the EW?

Ralph

[Scottie-TX]

Understand RALPH and, "NO". This is not about belaboring. Not my intention to be the last reply. Far from it.
Yes, oddly; The beat is excellent. Not perfect but close to it. Yes. Escape no problem. All teeth seem to escape evenly. Those are EXACTLY the properties that would make one believe ( falsely in this case, I believe) that the EW is above question.
I envision though RALPH, that along with the power robbing recoil of a bent tooth comes also a severly reduced impulse as the pallet face meets a curved surface instead of a flat one.
DAVID C&gt; Let me see if I understand your reply. If I do - then, "yes". I do understand that an imperfect arc at the intersection of the impulse face can cause recoil. Do I understand correctly?
http://static.flickr.com/64/154373600_ea18de0d8d.jpg
If so, we agree.
However DAVID: Is that condition the ONLY one that could cause recoil? In the lower sketch I see the tooth causing recoil because it's face is not uniform as it passes from lock to overswing. Do I err in my thinking?

[Scottie-TX]

Yepperdoo! Twas my hero - da LAB!

[Scottie-TX]

Some pretty serious weights there. I could drill two holes in the bottom of each of my clocks, make a horizontal rack of pulleys, and run every clock I own with ONE of those weights. Looks like about twelve pound weights. Let's see twelve clocks; A pound per clock. Yeah. I could use one of those.

[Scottie-TX]

Well ; Funny (ha ha) you mention; That was my first reaction! They absolutely DO look like munitions. Would they work better on a clock that was shot?