The Ratcheting CVT

by Gear_Down_For_What Mar 11, 2018
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Maybe the tags could be improved? When I search for "CVT Transmission" this does not show up in my results.

I am building a lathe using steel for the bedways, and cast aluminum for the other parts. I was not looking forward to printing out nearly 50 different gears for my transmission, and am now strongly considering using this as my transmission. Thank you so much!

There are a few pieces missing from the Fusion 360 model, I'm having a hard time understanding what the planetary gearbox is actually for. It seems like you could just replace it with a shaft and it would work the same way.

i would love it if you would make an assembly video,great model but i can't quite figure out how to assembly some parts.

I remember reading about something like this in Popular Mechanics or Popular Science back in the 90's.

I believe that they referred to it as an IVT (Infinitely Variable Transmission). Taking a rotary motion, converting it to reciprocating, and then converting back in to rotary.

It always intrigued me, I have searched for it now and again on the internet since, and I finally found it. Thanks.

I was just wondering which parts that I need to make duplicates of?

FYI in the Fusion360 version that you uploaded the ratio control cap, the rack and pinion parts that changes the pushrod stroke, and the shaft that connects the two are missing.

I think I've puzzled out how it works but I'm not 100% without seeing your implementation.

By the way, what you've devised is similar (in effect at least) to some car engine tech that's popping up right now. If instead you imagine the skinny ends of you mechanism being the engine's pistons, then the current input shaft becomes the output shaft. This means you've created a variable length compression system.

Car manufacturers have been after that technology basically forever, here's one that finally made it into production: https://www.youtube.com/watch?v=79LjflIo-5I

wow this is krazy kool! great job i will so need help in how to assemble this monster. i would love to have a exact model of this in metal i have the perfect project to use it on. ps make a assembly video please! :)

Which printing material did you use for the "green machine"?

Really nice and interesting project. One small recommendation for the next Fusion project. Use different files and make an assembly. It was really difficult to figure out where is what. I wanted to change the small balls diameter and it took me awhile to find the place where you have defined it. Otherwise, create work!

You are 100% correct, this is the first situation where I have really wished that I would of done that, not doing that caused me a lot of trouble actually.

You should consider uploading your design!

You used 4.5mm BBs, I have 3mm balls that I could use for this project. Next week or so I hope I can start printing the components out.

the pins for the ratchet mechanisms are missing

okay, it took me nearly a month, but I uploaded the wrist pin part.

Your right, I’ll get them added tonight if I have time

what layer height did you design the crankshaft for? at 0.2mm the custom support material is 2 layers thick in my preview.

Hmm maybe it is just that thick then. Should work anyways.

I’ll check when I get home

Wow. Awesome thing. Awesome vid too.

Just watched the video on this what a great video