For the last while I have been using Gearotic Motion to design gear, gear trains and now escapements
I have had some experience with Grasshopper escapements as this one in from Clayton Boyer’s Swoopy design
There are many variables to work with and the first task is to select a layout that “looks” like it should work and is buildable.
The default that Gearotic Motion produces is a little different from Clayton Boyers, and doesn’t have as many variables for adjusted.
Essentially there are three moving components to the grasshopper and they are the entry pallet, the exit pallet and the pivoting frame works.
The first bench test is with only one gear to test the layout and poisitons. This took a couple of trails but this layout looks like it will be OK
A very simple drive drum was constructed so that each wheel could be the “driver” as it was added.
With three gears in th train the last one is the hour wheel.
The fourth wheel has a 12:1 ratio which means two revolutions per day. So this is a workable train.
The original design calls for one more 12:1 reduction which would mean two revolutions per week. This last gear has been added but only as follower.
With the long pallets it was a challenge to keep everything loose and stable at the same time. A double pivoting frame was the solution.
At this stasgethe pendulum is directly attached to the pivoting frame and has a 12º arc giving a really energetic swing
The drive drum is 7” in diameter and the wights will travel about 42 inches in 24 hours.
The frame isn’t the prettiest I’ve made but it is rock solid.
I’ve left lots of room between the plates just to be sure there is no problem with crowding.
With the easily changable drive pulley I was able to do lots of alternative testing of the drive train.
I simply could not get used to the 12º pendulum arc - to I employed a verge and mounted the pendulum 3 inches above the escape arbor and with a 3/4” verge reduced the swing to 6º
The pendulum is as long as the case will permit - nearly 60” and is weighted. Still I cannot get the desired one second pendulum. It beats 50 seconds to the minute.
The Face of the clock is 12” with 12 spokes and numerals for the 3, 6, 9, and 12. The time train is an Aaron Dodd Crane type with the daisy and tri.
The complete (at least for now) clock with the full drive train installed.
The Great wheel at the bottom is 1” thick with and mates with a 2” pinion.
This clock is a "qualified" success. The movement works as it should but since it is "butt" ugly it has since been relogated to the fireplace.