393 HS mode

Our robot uses 4 393’s for the drive. It is direct/chain drive. I’m debating whether or not to change the 4 393’s to High speed mode. We are planning on lifting a max of 5 sacks. Would you recommend it? What is the max weight the 4 393’s at high speed mode can push?

My team just switched to the High Speed setting on the 393s for our base. We were able to eaisily push around 5 sacks today on our practice field. So I would reccomend them they should also have plenty of torque to hold 5 sacks in your lift as long as your robot doesnt weigh 20 pounds.

Thanks! I just weighed the robot. It weighs around 14.4 pounds. Did you have any complications with HS mode.

Sorry, I just have to jump in here. My current robot weighs 19 pounds without any sacks, and the drive never burns. It weighs well over 20 pounds carrying sacks. 4 393’s on speed mode. :stuck_out_tongue:

With a 14 pound robot, you definitely shouldn’t burn. Just be careful that your chassis is constructed correctly to avoid excess friction. Take the shafts out of the motors and check the wheels spin freely. Its also worth lubricating the drive bearings (remember that the rules state that lubricant must be used in extreme moderation). If the drive is built correctly you can get away with 4 393’s on speed, even with a much heavier robot. However, you should avoid pushing battles AT ALL COSTS. If your driver/s enjoy ramming full pace into other robots, I would stick with torque motors :p.

Also, for your driver control code, consider programming the motors so they accelerate towards the joystick value instead of jumping straight to it. This means that the motors receive less current while they aren’t actually moving, so they overheat less. An unnoticeable amount of acceleration can make a real difference to overheating, and also protects the gears in the motor. I took the “ramp” off my robots drive for one match, and managed to break the gears in one of the motors. This has been discussed to death on these forums, so let me know if you don’t understand and I can find you some relevant threads :).

Totally agree with this. Last year our robot also weighed over 20 pounds, and we were perfectly fine, except if we got pushed or had to push, our drive died. 1.6:1 should be fine

You were exactly right! In the Chula Vista tournament today, we lost the semifinals but not bad for the only middle school! We’re thinking of making it a 6-motor drive. Do you think externally gearing the motors at 1:2 for speed with the motors at the regular configuration will stall? Or, should we just keep the 6-motor drive at HS mode with no external speed gearing?

Our team has been extremely successful using a 6-wheel, 6-HS 393 drivetrain with the motors directly connected to the wheels, with 4" wheels.

Do the six wheels eat sacks?

I’ll try to post a video this afternoon.

I’m sorry for not having a video today; I was too busy working on squishy PID software stuff at today’s meeting. However, I did have more time to play with our drivetrain, and even with our fairly heavy 4-bar arm and intake and 5-6 sacks, it had no problems with stalling or climbing over sacks. I’ll try to start a thread discussing the robot tomorrow. (I have another meeting.)

Thanks. After the tournament, we just want it more reliable.