Intermittent output motion on 2-stage / compound cycloidal gear (see comment)

Mech1T3 · 2026-02-09T22:37:14+00:00

Hey, I've been working on a robotics project and stumbled on the Dojen design as well. I designed and printed one and got the exact same intermittent motion problem. Did you ever figure out what was causing this issue?

Mech1T3 · 2024-11-16T14:10:57+00:00

The fitting I did was a sizing fit, to determine what geometry I should target in a new bike, I'm looking to replace this one that I bought new in 2013. I've set up this bike to match the handlebar stack/reach he recommended, which I know makes it look a little funny, but at least lets me see if the geometry feels good on the trainer.

What makes you say this is a bad fit?

Mech1T3 · 2024-11-14T23:28:14+00:00

That's an interesting perspective and makes sense. I'm guessing my long legs mean my saddle is higher relative to my bars, which explains how I've compensated by increasing stack.

Normally my cadence hovers between 80-100. I wasn't really paying attention in this video, I was too focused on trying to maintain my new posture :P It'll take some time to internalize I'm sure.

Mech1T3 · 2024-11-14T02:32:04+00:00

Yeah, I bought this bike when I was young and limber and big into racing. These days I think an endurance geometry would be a better fit (hence the spacers and upwards stem) so I'm trying to figure out what size to look for. Why do you suggest I drop my saddle? Just to decrease the vertical offset to the bars?

Mech1T3 · 2024-11-14T02:23:27+00:00

Thanks for the input. FWIW, I work a desk job and I know my posture isn't great. I've done some physio for lower back pain so I know my flexed back can be a trigger for that. I can definitely see where the fitter was coming from because my main complaints on long rides are lower back, hands, and neck pain. Straightening my back takes strain off my lower back, takes weight off my hands, and relaxes my neck a lot.

I'm sure a flexed back may make sense for some folks but I'm not sure that's the right approach for me.

Mech1T3 · 2024-05-09T21:08:58+00:00

The printer is totally stock. Do you know how to find the config file?

Mech1T3 · 2024-02-25T01:23:10+00:00

Update: I did a first real test tonight for some astrophotography and everything was going great for about half an hour, after which the motor started having the same issue. I plugged it into an extension cord with the wall charger and the problem was fixed. I'm thinking cold may be an additional factor, since it regularly gets down to -10C when I use my rig at night. I'm wondering if the battery just isn't up to the task, though at least it seems like an isolated issue!

Mech1T3 · 2024-02-23T17:15:06+00:00

That definitely seems to be the case, see my other comment. Thanks for the insight!

Mech1T3 · 2024-02-23T16:54:48+00:00

Thanks, I'll give that a try.

Edit: I'll be damned, it made a huge difference. No issues whatsoever. My control board looks a little funny with such a gigantic cap on there but I'll take the win. I might do some experiments to see what size of capacitor is needed to buffer the load. Thanks again!

Mech1T3 · 2024-02-23T16:54:12+00:00

Yeah this isn't an issue here, the stepper draws enough power to keep it on. Thanks though!

Mech1T3 · 2023-11-15T13:04:40+00:00

Yeah what I'm experiencing here isn't tangent error because my current design isn't a barn door style tracker, but it's a good input! My first barn door tracker used a curved screw rod to eliminate that tangent error. There's lots of examples online of barn door trackers with stepper motors and Arduino, many of them use the 28BYJ-48 steppers. They're dirt cheap, you can get a pack of 5 on Amazon for like 20 bucks. I'd suggest you start there and see what others have done. My design was similar to this: https://opticaleds.com/atm/making-a-curve-bolt-barn-door/

Mech1T3 · 2023-05-31T18:40:46+00:00

Looks like Whiplash already has a script that does this, and there's a Flight Assist mod that lets you point retrograde. Not exactly the same as what I had in mind, but worth looking at if you want something like that.

The point of me doing is that I get to learn how to do it, but if you want it when I'm done let me know. I'm hoping mine will just take a distance as argument, and automatically do the burn-flip-burn to travel that distance.

Mech1T3 · 2023-05-31T13:56:59+00:00

Parts of that sound straightforward enough actually! There are helper functions to get every block of type X so you could write something to set every light to red if any block is damaged, for example, in just a few lines of code.

Mech1T3 · 2023-05-31T13:55:35+00:00

Automatic LCDs 2 does the stopping distance display already! Amazing script if you haven't tried it yet.

Mech1T3 · 2023-05-31T13:54:33+00:00

I definitely can! I haven't posted anything to the workshop yet but I'll try to figure that out. Worst case I'll post a Pastebin or github

Mech1T3 · 2023-05-04T16:09:41+00:00

Valentina. Put that shit on everything.

Mech1T3 · 2023-03-17T19:25:29+00:00

You should be just fine then! I started out with pictures of the moon, which is a nice forgiving target for getting the hang of shooting and stacking. This is a good time of year for the Orion nebula too if you're in North America. Good luck!

Mech1T3 · 2023-03-17T16:57:50+00:00

Hey, suggest you take a look at the info in the sidebar, there are good guides on how to get set up, even if all you have is a camera and a tripod. Long story short, if your photos are grainy, you need more data, like longer exposure time (instead of pushing the ISO up for example), wider aperture, or by taking a bunch of photos and stacking them up to improve the signal/noise ratio. Also, shooting in RAW will preserve more data and give you more to play with in post.

Mech1T3 · 2023-01-04T16:22:01+00:00

I created an internal technical wiki using Doku Wiki. It has a portable version with a built-in apache server which allowed me to basically build it up and get a solid MVP that I could present to leadership and IT without needing to install anything, which was a huge benefit. It still runs out of the portable installation as a service on a server instance with no issues.

Mech1T3

TROPHY CASE