LEGO Pendulum clock with grasshopper escapement
12,348
Published 2021-10-24
As described in my previous video, the escapement pallets would wear out over time. This didn't bother me that much, replacing them as they wore out was not a problem, and the parts lasting around a year cost less than a single cent each. However, I realized that this wear was likely the largest source of inaccuracy of the clock. As the pallets wore down, the characteristics of the clock would change, requiring a different effective length of the pendulum.
I wanted to fix this, so I've replaced the escapement with a design inspired by @davidziemkiewicz1350's grasshopper ( • grasshopper/anchor, another variant ) and Kei Abe's pendulum suspension ( • A prototype of an accurate LEGO pendu... .
I think this escapement is probably one of the easier escapements to replicate, and certainly the easiest of my designs. It uses few parts and relies very little on exactly positioning parts with clutch power, which can be annoying to set up.
A small change I've made since the video was posted is to use the rubber liftarms with 2 axle holes as the parts the escapement pallets fall onto. This makes the clock almost completely silent!
All Comments (21)
-
So clean! Great design. Interesting that elasticity of the pallet axles provides sufficient space for recoil. Much simpler than moving pallet stops.
-
Great design and fun build. I especially like the improved grasshopper design. I confess to redesigning the winding system. The links kept failing for me. So, I removed the whole mechanism. I have replaced your winding system with a differential gear using the same axle point. The diff is prevented from taking power away from the drive train by use of a catch/stop which hangs freely from the existing axle which holds the two 12t bevel gears which connect with the caterpillar mechanism. I was concerned any torque/friction caused by the force of the diff on the catch/stop would affect the power of the drive train. It does not! If I knew how to post photos in comments it would make this description much easier.
-
Awesome improvement! After I switched to a grasshopper escapement I lengthened the pendulum and made appropriate changes to the gear train so that the escapement wheel could double as a seconds hand. On your clock you could probably get a 4-5 day autonomy.
-
The sound is so gentle and mesmerizing!
-
Wonderful, after sourcing everything and then getting my parents to search through my childhood Lego to find and out of production bevel gear everything is up and running. I had to add some wire braces to keep the frame “true” & now running for 52 hours and keeping good time. Thank you for these great plans.
-
This design is so clean and easy to reproduce!
-
Well, I built your design. At first I hung it on the wall while I waited for weight washers to come. Pulling on the chain it didn't want to go. I think because the wall is uneven and it just caused things to bend somehow. So I had to make a flat board to it to sit on and level that. Still was kind of finnicky so I sprayed some PTFE lube on it. Now it's just up to tuning the pendulum arm length. I have steel axles coming from the UK. I bought some 0.001" PTFE sheet, and I just think it's too thin to even manipulate to get in there between the axle and beam. I went with solid pieces on the pendulum so I could hear something from it. This is awesome. Thank you for sharing!
-
The sound it makes is so soothing I love it. I think I'll copy that one.
-
This is amazing! I built one of your previous designs and couldn't get it to run, mostly because it was the first clock I had ever built. Now I'll update the design and give it another try! Thank you for the update!
-
This is superb! I’m subscribed and the disappointment is worth it!
-
Nicely done.
-
It may be even more accurate if you add a pendulum clutch between the escapement and the pendulum, so the they aren't connected on the same axle. This is what is what "real" mechanical pendulum clocks have.
-
Very nice!
-
Me subscribing right as he says don't subscribe. Great videos! Can't wait to build one myself!
-
the best way to start a clock video is at the beginning. :) KEvron
-
Sorry I couldn't the clock to work using this updated escapement. Not sure how Dillon gets it to run for 3 days. I changed the gearing so that it goes a couple of hours before rewinding. Then used an escapement design by Berel Levy. That's much easier to fine tune. https://www.youtube.com/watch?v=QTZ8OrSvuVw
-
Awesome instructions. Thank you so much. For step 20 I'm think of using an axel that I push though to the other side and use two more 4185 wheels and a rubber band for a little less friction rather than sanding a harder to find part.
-
Could you post a video how to fix common problems if it doesn't work?
-
How does the grasshopper escapement work reliably? I attempted to make one very similar to yours and it seems to untune itself if it works at all.
-
I’d love to have instructions on how to build my own piece. Please let me know if you are planing to publish or sell instruction manuals. Cheers!
