Thread: Grasshopper Escapement

Attached is some information on making a grasshopper escapement. Hope this helps you out.

Terrific!
Thanks. This is just what I was after.
cheers
rosco

Rosco there is also information at this site http://www.bealltool.com/clockforum/index.php

Rhys

Thanks to you too Rhys.
cheers
rosco

Rosco

I want to see pics after you get it made.

Good luck

Tim

Well here ya go troops! Thanks for your inputs.
It works a treat. This is the top of the clock that I am designing. I wanted to test it before I made the whole clock. Its all running on small bearings.
cheers
rosco

p.s. the reason for the chopped off bit was because I thought it was going to get in the way, until I worked out how to 'trim' it.

There is a nut hanging on the back of it being used as a weight

Rosco I like your work. It certainly makes more sense of the grasshopper seeing it in large form like that rather than trying to study prints or books. I trust the clock you are designing will be on the forum in the near future.

Rhys

Rosco, If you Google WIKIPEIDIA Grasshopper escapement you will find some great reading about the grasshopper and its limitations.
I done a lot of research a couple of years ago hoping to fit one to one of the wooden geared clocks that I have made, keeping constant power to it has to be overcome.
look forward seeing you clock with the grasshopper
regards nine fingers.

Thanks Nine fingers for the heads-up. That sounds like fun to build.
We'll see how we go.
cheers
rosco

Thanks for the input Nine Fingers.
Here's my idea for a "maintaining power"
Actually, you can maintain power while winding just by adding pressure with your finger to the main gear.
But thats no fun is it?

I think this should work...
The explanation following is in relation to the left picture. The right picture is simply to help you understand the mechanism.
There are 3 main parts to this picture, the blue is the pulley for the power drive string and rewinder string. It has a ratchet on it to ' connect' it to the black/grey wheel which has teeth on its circumference. That wheel in turn is connected to the brown wheen by springs. The brown wheel will be connected to the main gear putting power through to the grasshopper.

The idea is that the blue string is pulling down with the weight drive on the end of it, turning the blue part clockwise. The ratchet is transferring the drive to the black/grey wheel clockwise and that drive is transferred to the brown wheel through the springs....(have I just repeated myself?)
The springs are 'storing' power. So when the mechanism is being rewound and drive is stopped. initially the springs will pull the black/grey wheel anticlockwise till the yellow part which is connected to the chassis of the clock stops it from turning... this will happen in an instant. Once that is done, the spings will maintain power into the brown wheel and keep the drive in a clockwise direction, until the rewinding is finnished and the weight drive is reinstated.

Does that make sense?
What do you think?

cheers
rosco

Well, its looking good in some ways...I am having a trouble that I hope someone might be able to help me out with.
I 'borrowed' the pendulum from another clock that I made, because I wanted to see the grasshopper work. The good news is that it wors like a dream, I am very happy. The bad news is that the period of the pendulum is different!?!?!?!
The clock that the pendulum was 'borrowed' from is a Graham Escapement.
The bob on the pendumum hasn't moved...
I measured 73 swings over 60 seconds.

Does anyone have any ideas?

cheers
rosco

Rosco

Sounds like you need to make a longer pendulum. Lowering the bob slows it down so you can try that or make a longer pendulum assembly.

Good Luck
Tim

Originally Posted by roscopeeko

Well, its looking good in some ways...I am having a trouble that I hope someone might be able to help me out with.
I 'borrowed' the pendulum from another clock that I made, because I wanted to see the grasshopper work. The good news is that it wors like a dream, I am very happy. The bad news is that the period of the pendulum is different!?!?!?!
The clock that the pendulum was 'borrowed' from is a Graham Escapement.
The bob on the pendumum hasn't moved...
I measured 73 swings over 60 seconds.

Does anyone have any ideas?

cheers
rosco

Any chance of getting your CAD files . I would love to play with one.