The Beall Clock Forum

General => The Grasshopper escapement => Topic started by: ub52 on May 14, 2011, 06:15:58 PM

Title: Problems with new design using a grasshopper escapement.
Post by: ub52 on May 14, 2011, 06:15:58 PM
Hi All,

I'm designing a clock and have it layed out using a grasshopper escapement, designed from the documents found here. The problem I'm having is that it seems to require an exorbitant amount of weight to run. I realize that there are many variables which can effect this. I've been through the time train which free wheels quite easily under weight(approx 8lbs.) with the escapement disengaged. Once I engage the escapement it runs for about 30 seconds and then stops.

Some other relevant aspects of the design are that I'm trying to use a compound pendulum. I think this has compounded the problem, ha ha ha. Also the pallet arbor is below the pendulum pivot about 1.5 inches and the crutch extends below another few inches. I was thinking this would lessen the required pendulum arc, however, it seems to have made little difference. I've loaded up as much as 20 lbs. of weight and it still stops after about 20-30 secs.

I can upload some pics if it helps, but right now I'm looking for where I can improve power to the train.

Thanks,
ub52
Title: Re: Problems with new design using a grasshopper escapement.
Post by: David J. Goodyear on November 29, 2011, 05:59:42 AM
How long is your compound pendulum?  Is it a dumbell or a continious body?  There are many issues with compound pendulums.  Where the crutch lever engages the pendulum rod is definitely one of them.  Are you still investigating this.  If so post a reply to this message.  i will get back to you with some more information in this post.

David