Simulation of Denison double 3-arm gravity escapement

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BillM
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Re: Simulation of Denison double 3-arm gravity escapement

Post by BillM »

Art

As I look at the simulation it is still not quite right.  The spin of the vanes should be much faster.  Any increase in the rpm results in either failure or erratic behavior.  Too high of a driving rpm and collisions are missed or the arms do not get released properly.

I think some of my problem lies with fine tuning the placement of the vanes, stops and pendulum.

I will soon have access again to a real gravity escapement that will help me with the redesign.  Keep posted...I do not give up easily.

Bill

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ArtF
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Re: Simulation of Denison double 3-arm gravity escapement

Post by ArtF »

Bill:

  It may be granulation, where the motion is not fine in time slice enough to properly react
to the hits on either side. If I redo the kinetics Ill have to look deeper into ray tracing to
capture those intersection events of fine proportion.

Good job with what you have though...

Art
Jerrywi
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Re: Simulation of Denison double 3-arm gravity escapement

Post by Jerrywi »

Good Morning Bill, Art,
I was going through the forum this morning and came across your post and remembered that many,many years ago I build a clock made completely out of paper. It uses, I believe, is the same escapement as you are describing. It doesn't use a spring but rather a small paper box that I filled with sand (as a weight) . when the pendulum pushed the left arm out and released one leg of the (Star wheel) I believe that's the term the instructions used to described the escapement wheel) the weighted side would return the leg.   

My intentions where to dig the paper clock out of the catacombs and duplicate it using wood and recreating it using Gearotic Motions. (that hasn't happened yet, LOL)  I thought this would be of interest to you.

Thanks for letting me share
Jerry

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ArtF
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Re: Simulation of Denison double 3-arm gravity escapement

Post by ArtF »

Very nice.. from paper yet...

art
BillM
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Re: Simulation of Denison double 3-arm gravity escapement

Post by BillM »

Jerry

Thanks for sharing the info about the paper clock.  The escapement that the paper clock uses is similar to the model that I created using Augie's vector processor.  I don't know if you had a chance to download and run the model...it does not use any springs.  The model is being designed based upon a GIF simulation that I found on the internet.

I think you should dig into the catacombs and recover your paper clock.  You have an ideal situation where you have the actual gears of a running clock that can be modeled using Gearotic Motions.  I think such an effort to learn Gearotics will be worth the effort.  A while ago I used Gearotics to model/document the entire main train of a tower clock that I have access to.

The particular gravity escapement is not modeled in Gearotics but you do have the original that you can measure and make wood equivalents.

Modeling the escapement using the vector processor is a challenge.  Getting the timing correct between the vanes that lock the arm relative to the pins that lift the arms is a problem that I'm currently working on.

Thanks again for sharing your photos.

Bill
Jerrywi
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Re: Simulation of Denison double 3-arm gravity escapement

Post by Jerrywi »

Bill,
Thanks for the words of encouragement. I admit the project is long over due.
I reviewed your model in augie and it looks great. I'm no where close to having the skills or abilities of designing a project by scratch.
My intention was to take the plans from the paper clock and scan them into a dxf format  then import them into CamBam software to produce  the framing
then use gearotic to produce  G-code for the gears since I have the gear info at hand. 
Let me know how your model is coming. I always appreciate someone that can take a thought or idea and turn it into a working model
Thanks again
Jerry
BillM
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Re: Simulation of Denison double 3-arm gravity escapement

Post by BillM »

Jerry

Keep at it and don't be afraid to experiment with Gearotics, Vexx, and Augie (especially the vector processor's simulation capability).

I did refine the gravity escapement simulation to the point that it was running with a regular beat and ran for a 1/2 hour.  I then decided to stress the vector processor more by combining my motion works simulation with the gravity escapement model.  The combined model is posted as a new topic.

Bill
Jerrywi
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Re: Simulation of Denison double 3-arm gravity escapement

Post by Jerrywi »

Thanks Bill, I ran your model again and it's amazing
Great work
Jerry
John T
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Re: Simulation of Denison double 3-arm gravity escapement

Post by John T »

Hi Guys,
I have done what you guys are talking about.  I had the original paper clock so I was able to reverse engineer the unit.  The gravity escapement is not exactly the same as the one  you posted here - but it does work as a gravity escapement without any springs.  I you are interested in my experience you can read about it here

http://jtwoodenclocks.com/peace-tower.html

John
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BillM
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Re: Simulation of Denison double 3-arm gravity escapement

Post by BillM »

John

I checked out your website.  Quite an impressive collection of clocks and figits.  It looks like you have a lot of fun dreaming up and creating those machines.

I like the way you reverse engineered the Paper Peace Clock model. As far as the gears, did you use Gearotics to reverse engineer the various gears/gear ratios?

I am quite impressed with the capabilities  of Gearotics.  A while ago I used Gearotics to build a model of an 1860's E Howard Tower Clock. I had the chance to actually measure each of the gears in the clock and then used Gearotics to model the actual clock.

Bill


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Re: Simulation of Denison double 3-arm gravity escapement

Post by John T »

I do have other programs for gear design, but Gearotics is the only one used for the tower clock  I still keep and use a Gearotic 1.0 to make and design ?imaginary? gears. Otherwise it?s current gearotics all the way.
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