Aug 2013 31

Grasshopper Escapement

Hobbies Wood working, Clock 2

Grasshopper Escapement
Grasshopper Escapement

I'm still quite keen on making an all wood clock. I have the MLT13 Clock up on the wall in my garage and it "mostly" works. Seriously it's so close! It just wont stay ticking, and then the move caused some of the joints to swell a little so it needs work. (Humidity + Wood == Movement)

The issue with the MLT13 is that it was likely a bit more challenging than I realized and wasn't a good first clock project primarily because the escapement is fairly small. I have recut the both the escape wheel and the pallets a number of times and still not gotten it 100% correct. Either the tolerances are extremely tight or I just don't have a clue how to tune it.

It will "tick" for 5 or 6 seconds then stop with a bind in the escapement, or the escapement will spin free a couple times causing the pallets and excapement to get out of beat which throws everything off.. Either way, it's just off and I need to perfect an escapement if I am to have any hope of creating a working clock.

So to that end, my goal is to make just an escapement. A working demo that is just the "heartbeat" of a clock, with out all the extra stuff to tell time. Baby steps. This will be my minimum viable product and proof of concept, so-to-speak.

I have researched all manner of different escapements and man there are a lot of them, but I knew I wanted an escapement that didn't necessarily require a hanging pendulum. This narrowed down my list of options quite a bit and really left me with only one that I think will do the trick; The grasshopper escapement

It looks very complex but it actually isn't that bad. You can see how it moves in the gif.

I started creating the escape gear below with the intent of making a 30 tooth escape wheel just like the gif had.. Took lots of measurements, made some plans, created a jig to help make my main escape gear and sure enough! 29 teeth... Damn it! haha Math is hard!

An unfortunate mistake but not an unrecoverable one. Again this isn't supposed to be a working clock, just a working escapement.

So there ya go, the first two images are the jig and the finished glue-up without the covering wheel.

Tomorrow, I cut the various gear teeth down to size and shape them to look more like the gif.