Can’t wait to see this in action in our Ontario competitions!
Also, I heard you say you’re going to speed up your drive base with a 3:1 gear ratio w/ torque motors. Can’t you just have high or turbo speed motors on the drive for that extra speed?
Lol catch 2381 @…idk yet. Our philosophy is to just…be faster than everyone else. 3:1 torque is faster than 1:1 turbo, so that means that if someone tries to play defense on us we can outspeed them and get back into a scoring position before they can (obviously they can cut us off), but it’s really up to us to out-drive, not to out-push (especially with the amount of talk about 2 traction + 2 omni).
We’re also a ball-focused bot, so being able to get places fast is super important.
Looking really good and solid! Your build quality is pretty good as well, but I have a small simple suggestion. If you are using any 6 tooth sprockets, replace them with anything but 6 tooth sprockets. They cause a lot of friction and occasionally break the chain as well.
@375X Robotics has a fair point, but it depends on where you’re using them. In our personal experience, if you get the tension ok, it isn’t too bad (link to last years robot. We used a lot of 6T sprockets on our drive with a 6m turbo drive on 4" wheels. It worked just fine unless you drove it too hard. I think it’s because you’re causing the chain to turn super sharply, so there’s more force. (it’s like you can poke yourself with a needle and your skin will break, with a pencil, maybe not).
That’s odd that you’ve had such a bad experience with these little sprockets. I have used them every year since Nothing But Net for at least one aspect of our robot (usually the drive) and never had a single chain link brake or any extra friction caused by these things.
Usually, the tension is similar to the amount you showed in your video. Occasionally, it is microscopically looser, but not by much.
For where we are currently using them, they are exactly identical (as far as I can tell) to what you have shown in your video. Surprisingly, that is the most friction-free part of our robot.
This is definitely a huge improvement over the last iteration of the design, but in my experience, low strength gears are better than high strength on the drive. This is especially true with the metal pinions, which increases friction considerably. Using low strength gears will also allow you to reduce the spacing in your drive, which is currently taking up a considerable amount of space. Also, when using chain on drives, it is best to have one continuous piece to make sure the power transfer is even, a large benefit of chained drives.
Edit: If the c channels are bending outward, that likely means the spacing is pushing out and causing friction. Noticing the extra width in the c channel, this might be the cause of the issue.
Awesome, I’ll see about LS gears (we don’t have any lying around, and the small 12T ones kept breaking last year). We tried using a full length of chain, much like anti did way back in his defense bot, but it … didn’t end very well - lots of skipping, breaking, etc. The C-channel was bending inwards originally, pinching the bearing around the shaft. I bent it back out and now the shaft is free spinning.
If it was bending inward then that means everything should be fine and adding the standoffs was all the fixing needed. I know you said you didn’t have any 18 tooth sprockets, but that would help with the chain skipping. A larger sprocket generally means the chain won’t skip. On another note, have you tried moving the c channel brace blocking the intake to about 10 holes inside the robot? This would save you a lot of trouble messing with the deployable intake and you wouldn’t lose any structural integrity.
hey @Carter quick question. I’m experimenting with different drives and I was wondering what the best way to chain a 6 wheel drive in a single loop would be? I would really appreciate it if you could help. Thanks
Full disclosure, I haven’t had a ton of experience building these, but I can give you guidance based on what I have seen. You will have two sprockets on the same axle as your wheels, and both of these will be driven by a motor. Then, you will have a motor in the middle driven by the third motor. Make sure that all the motors result in the chain spinning the same way, you should notice if it doesn’t. Also make sure that the tension on the chain is correct. Make it tight enough that the chain never skips, and make it loose enough to minimize friction. I have attached a paint document to ensure you understand what I was saying. It doesn’t look like the chain has much contact with the sprocket in the illustration, but in reality it will be fine.