A gravity escapement

BillM
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A gravity escapement

Post by BillM »

Art

I’ve tried to recreate my Augie vector processor model of a Denison double three-legged gravity escapement.

Attached is a zip file of one of my many attempts. It does seem to run at least on my computer. I’m wondering if it will run on your computers. Don’t be fooled by my version number of the model. I had dozens of failed tries varying many of the parameters that I asked about in different topic.

I’m not completely satisfied with the model. I think the motor force needed to run the model, with gravity =9800mm/sec^2, seems to be excessive.

An interesting feature is that all shafts and objects have their positions locked. I thought somewhere in your videos you said objects would not collide if they had their positions locked.

It was a challenge getting parts properly aligned. The left & right arms were particularly troublesome.

I pre-positioned the right arm so the model could self-start. The Augie model required the user to pull the pendulum to one side or other to start the mode.

Enjoy the model. I do hope to continue testing variations of the model.

Bill
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A_Denison_V03.zip
Denison double three-legged gravity escapement
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ArtF
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Re: A gravity escapement

Post by ArtF »

Awesome Bill:

Ill check it out

Art
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Re: A gravity escapement

Post by ArtF »

Bill:

I have to say that works extraordinarily well. Force in this case is kind of questionable about
how much a unit is, so I wouldn't worry about a force number. I think it works really well, and slowed down
it shows it doing as one would expect.
I have been working on collisions and such so one of the upgrades may have made the locks OK logically,
but it is situational, so if it seems to be not colliding, its worth keeping the old rule in mind.

Ill keep working on making positioning easier..

Inspiring work..

Art
BillM
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Re: A gravity escapement

Post by BillM »

Art

I think I started my victory lap too soon.

I've started looking at the model in slow motion and have discovered that it happens to run but not in a true Denison gravity escapement fashion.

There is a fine balance between the pins on the drive disk lifting an arm and the vane locking the arm to wait for release by the pendulum.

The vanes are never locking the arms. I was able to see this running at .1 simulation speed. I verified this non locking by turning off collisions for the pins on the left and right arms. The escapement still ran. I guess I may have stumbled upon the right combination of pendulum period relative to the lifting pins on the driver disk.

Back to the drawing board.

Bill
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Re: A gravity escapement

Post by ArtF »

Bill:

I agree, for me the pins seem out of sync. Shouldn't the left be pegged while at rest stopping the motor until the right comes in and unpegs it..

I can see I need a better way to re-orient that motor driver..

Ill keep playing,

Art
BillM
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Re: A gravity escapement

Post by BillM »

Art

I'm redesigning the escapement. I'm laying out the drive wheel pins on a tighter. When I built the model, I fused together the drive disk to the two vanes. I will set up the new drive system to allow for adjustment of the phase of the vanes relative to the pins.

One unfortunate feature is the inability to fuse the pins to the drive wheel. When I twist the drive wheel through an angle, the pins stay still and have to be deleted and recreated. My next version will probably fuse the two vanes since they have to be 120degrees.

I've noticed that during a simulation extra pins (interpreted by the software as shafts) I've placed on objects rotate as the simulation runs. I can prevent this by locking the added shafts to the object.

Aligning pieces is a challenge when viewing things on different levels. I've also noticed this in Fusion 360 that has 2D views. Adding the 2D view capability to Ticker will not be as much of a game changer.

Bill
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Re: A gravity escapement

Post by ArtF »

Bill:

Yes, I think I need to make the orient also move the pins..of coarse that would mean everything attached to those pins ( if something was..)

Your close, I can see that, but I do see there must be an easier way for placement on planes and such..

Art
Hessel Oosten
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Re: A gravity escapement

Post by Hessel Oosten »

Art, Bill,

Stupid me...

I don't see where to open the file in Ticker.
Don't see a menu where I can choose "Open".

Dropping it "by mouse" in the program gives the usual "+" sign, but nothing happened either.

Hessel
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Re: A gravity escapement

Post by ArtF »

Hessel:

Sorry, my bad, its the icon in the top left corner, it opens the system menu.

Art
Hessel Oosten
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Re: A gravity escapement

Post by Hessel Oosten »

Art,

I still don't see it.
So really stupid me.

Hessel
Ticker where to open.png
BillM
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Re: A gravity escapement

Post by BillM »

Hessel

Just to be certain, the current version of Ticker is 1.13B.

BillM
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Re: A gravity escapement

Post by ArtF »

Hessel:

Sorry, yes, that version is very old. If you have upgraded, the problem is that you are running an old "ticker.exe" in your main folder.
Update your shortcut to point to the one in the /TickerKinetics/ folder of Gearotic.

Art
Hessel Oosten
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Re: A gravity escapement

Post by Hessel Oosten »

Art,

Found the solution:

For some unclear reason, I had 2 installations on my PC, on C:\ in the root and on E:\ in Program Files X86.

The shortcut was directing me to the wrong install.

Sorry for the unnecessary workload..., keeping us away from milling, turning and printing ... :eh:

Hessel
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Re: A gravity escapement

Post by ArtF »

Hessel:

Never a problem. :)

Art
BillM
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Re: A gravity escapement

Post by BillM »

Art

When version 2.0 Beta goes online, I may try experimenting with the gravity escapement again. The following website has a simulation explaining the phases of a gravity escapement: https://www.bmumford.com/clocks/courthouse/escapement/ My Augie vector processor gravity escapement model that I created a while ago used that simulation as a starting point.

The problem I've run into is the "Lock" step of the escapement sequence. The arm that should be briefly locked simply slides down the vane and is in the wrong position to assist the motion of the pendulum. I'm not sure if this is simply a friction adjustment or I have to modify the vanes with a step near their ends to block the arm from sliding during the lock phase.

My interest in the Denison double three-legged gravity escapement is two-fold: Big Ben's escapement is this type of escapement; I also have access to a gravity escapement that's in the Clock & Navigation instruments shop at Mystic Seaport Museum.

I've also located a book that describes the gravity escapement on Google Books: The Watch & Clock Makers' Handbook, Dictionary and Guide
By Frederick James Britten · 1896. I'll have to study this book some more before I get back to my gravity escapement model.

Bill Michael
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