I have been working on modifying our Tilter to maximize the number of cubes we can hold in our tray and properly stack. Our previous Tilter used a 1:25 gear ratio and did 8 cubes. We knew 8 cubes wasn’t enough but we also knew that it was too slow and a lower gear ratio was needed. In testing, i have tried everything from 1:15 to 3:25 and regardless of how much support, or how I build the gearbox, the gears click or skip when trying to extend it. I’m not sure what to do at this point. Structural or building advice would be great.
Down below are pictures of 1st and 2nd make of the gear box. The first one could 8 cubes and the second one could do 5.
There is too much room between the two sides. Try to go for 2 inches or less as well as screw joints. You really only need a 1:7 ratio if your motor has a torque cartridge
So the clicking or skipping is caused by the axles flexing as force is applied through them. Axles can bend due to as railgunawesome says having to span a very large gap. Tightening that gap is beneficial. Another cause of the axle bend is when your side channels become misaligned, so to avoid that I recommend increasing the bracing across the gearbox. Just a couple standoffs won’t cut it considering the force that your putting through it.
Personally, I wouldn’t use half c-channel on a tilter because you lose a lot of the strength offered by a full c-channel’s flanges. The torque on my tilter was enough to push an axle out of place and I use full size c-channel so I can only image the flexing on the structure of the tilter.
Also, the spacing on your tilter is too big. Axles bend unfortunately and they’re weakened the longer the distance they span. Try using a screw joint wherever possible. I have a 1:21 ratio and I got the gearbox to fit within 3 holes (5 holes total including the c-channel).
Lastly, this might not necessarily cause gears to skip but you have a lot of friction in your system. There are an unnecessary amount of gears . You could easily get by with 3 gears total but your range of motion will be limited.
I’d recommend a 1:7 ratio with a 100rpm motor or a 1:15 with a 200 if you don’t have 100rpm cartridges. Many teams have found success with this ratio. I can’t attest for more than 12, but 1:7 has been properly sufficient for us.
It all depends on where you connect the tilter to the tray. The higher up it is, the less torque your tilter gear box will require to push the tray forward. This just has to do with the physics and geometry of a tilter.
Thank you guys this makes a lot of sense. I have a torque cartridge in my motor but I don’t have any 84 tooth gears so I’ll have to work around that for the time being.
See Tray Torque Calculator for simulation of the torque necessary based on the geometry of your setup. It helped us to replace a 15:1 compound gearbox with a lot of clicking with a 7:1 simple, light and very reliable one, moving a 4-fold tray capable of easily scoring 12 cubes.
Since you mention no availability of 84 tooth gear (thus no way to make simple 7:1 gearbox), note that our 7:1 still has quite some margin - The motor with the red cartridge can provide up to 2.1Nm, but with our setup, we only need ~7Nm behind the gearbox according to the calculator. And indeed, while raising the full stack, device info didn’t cross much beyond 1Nm in actual testing. Thus with well designed mechanics, perhaps 11(*) cubes limit and 1:5, you should be in the game.
[*] The 12th cube is very expensive in terms of resources. It has very high leverage and thus contributes significantly to the necessary torque.
