gear shifting

I am thinking of making a transmission for this years game. After prototyping for a bit a started to wonder if there was a way to make the shift from one gear to another smoother. Is it possible for a smooth shift when the gears are stationary or is it best when the gears are rotating? Or can we have both? :confused::confused:

If you’re doing a mesh shifting design, where the gears physically move in and out of mesh with one another, putting a bevelled edge on the shifting gears can help smooth out the process. Generally, shifting this way is smoothest while the gears are in motion.

I see… is it possible for it to shift smoothly while they are not in motion but stationary, will beveled gears help?

Take two gears and push them together.

If the teeth hit it won’t work. Without motion it will only work some of the time. Beveling should increase the chance of a correct mesh but will not insure it.

I think you’re looking for something like this:

or this:

Thanks for the replies guys, it helped. :slight_smile:

There literally could not be a better time for Kyle to plug his lathed gears. Unfortunately, his dropbox link seems to have expired XD

Speaking of bevel gears I had these on my transmission :smiley:

What would be the best way to bevel the gears, other than lathe?

You need a way to rotate the gear evenly and have a way for an external tool to be able to remove material at a given angle.

In a perfect world the lathe is the perfect tool for the job. You spin the gear, you lock the tool that’s going to remove the material into the rail and off you go. That would be Plan A

Plan B: Put the gear in a drill press. Create a cutting tool (medium grit carbide sand paper at a 22 degree angle. Align the cutting tool so it does the outer 1/4 of the gear, drill press on at low speed, press lightly into the sandpaper, Will require cleanup

Plan C: Chuck the gear into a fixed Dremel tool Create a cutting tool (medium grit carbide sand paper at a 22 degree angle.) Slide the tool into the rotating gear removing the material. Cleanup

Plan D: Chuck the gear into a fixed but rotatable holder. Carbide wheel on the dremel. Create a fixture that allows you to slide the Dremel to the fixed gear so it cuts at a 22 degree angle. You will need to hand rotate the gear for each flute.

Plan E: Mount gear on a long shaft, securely so it won’t turn. Use very sharp buck knife to slow shave away excess material (Bonus, this can be done in your back yard)

Plan F: Contact the original poster and ask how much for 4 gears? Consider it a win, you support their team, and you did not loose a finger like in Plan E: :rolleyes:

Plan G: Ask IFI / JVN to supply these as custom parts

Plan H: Get a lathe, figure out how to cut the gears, offer here to make them for teams and pay for/ for some of the costs of the lathe from the profits. Hey, at $1-2 per gear over the cost of the gear, I’ll take a stack and then they are ready in my box of stuff.

Foster’s Plan A would be your best bet, but you could also put the gear on a mill, use a chamfer tool, and run a circle path around the gear. If you walked in to a local machine shop, explained your cause and a little bit of what VRC is, and then presented the lathe and/or mill option, they more than likely they would be more than willing to help you out.

In fact we used a hard way to bevel the gears——all handmade:P.

You must know the Technic Gear 20 Tooth Double Bevel from LOGO:D right?

We use sandpaper to rub the first bevel(of course vise set gears and must rub them evenly ) and cut the second bevel with graver.

BTW double bevel is really easy for gear shifting and handmade is cheap =-=,
But it’s really a hard job.


Here is a link to our reveal thread which talks a lot about our transmission for our drive:

Our setup was specifically designed to be super smooth and as small as possible. Instead of shifting sideways where you might require beveling gears (as noted) we just pushed ours together using a double acting piston on both sides. The force that is on our drive isn’t nearly enough to force the gears apart and the piston is plenty strong. The set up also slims down the horizontal space, but adds vertical space. Our transmission has improved significantly from the video shown, but it gives you the idea anyways.

Thanks for the replies, I will make sure to explore my options.