Torque problems with tray lift

I have a tray lift with a worm gear gearbox with a ratio of 36:1. I had the motor set to green, where it worked fine, but was too slow. Then I changed it to blue, and it was the right speed, but has trouble with torque when there is some weight on it. Also, when the program has the motor set to red, when the motor is actually blue, it moves much faster and I’m not sure why. Attached video: https://drive.google.com/file/d/1_pCOagy1G4g5IXvLB8ZNmdeHnsN3ddzI/view?usp=sharing

(this is blue motor programmed to be red motor)

edit: when the blue motor is programmed to blue, it goes real slow and has little/no torque. I assume can check the programmed motor color by looking at the motor in the devices menu. I have a tester program that changes the color depending on the port.

basically you don’t want to tell your code that a motor is one color, when it really is a different color.
if you attach close pictures of your lift, especially your gearbox, we can tell you what is wrong with it, if you don’t have enough torque it’s likely a mechanical issue.

2 Likes

Is the video working?

My experience is that worm gear boxes like to skip when under load

1 Like

just now saw the video. didn’t notice it right away.
I haven’t seen tilters done like this before, it makes sense, very compact. There may be a lot of friction in the gearbox though. try going back to a green motor cartridge, and make sure you’re telling your code to run it at 100% speed.
if that still fails, you likely have a lot of friction. since the worm gears are screws, and the hs 36t gear has straight teeth, I can imaging the two gears won’t be meshing perfectly. however there are gears designed to mesh well with worm gears. they are a bit smaller than 36t gears (I forget the tooth number) and they have slightly slanted teeth.

1 Like

I’m thinking about zip tying a spacer on the axle to somewhere in the gearbox, to keep the gears meshed. This is the easiest fix for gear skipping,

yeah don’t do that. will create very high friction.

your best bet is to just use a normal gear ratio. try 1:7 100 rpm.

I’m just using Motor1.spin(forward) for the programming. I designed the gearbox in mind with the bars in the shape of a parrallelogram, but I saw some videos and decided that having the bars being diagonal when the tray is fully up at 90 degrees was the best option. The parrallelogram requires 45 deg of movement for a full extension, and the diagonal requires 135 deg of movement for a full extension.

The motors for the testing program are right, I checked in the program. So in the video the blue motor is set to red in the programming, do you know why it would be moving slowly if it is set to blue as it should?

if you just tell it
motor1.spin(forward) then you aren’t specifying speed. idk if that makes a difference, but try:
motor1.spin(directionType::fwd,100,velocityUnits::pct);

1 Like

Ok, I set motor1.setVelocity.(100,percent); before the code, and it totally helped with the speed, but the torque for the blue motor is still not quite enough. I’d say its at 90% of where it should be.

I think reason it goes slower is that the program is always telling the motor to spin at 100 rpm no matter the cartridge. When you have it set as a blue cartridge in the program it goes at 1/6(100rpm/600rpm) the max speed in order to achieve the 100 rpm it was told to go. Once you set it as a red cartridge it goes at full speed.

I ended up fixing that by setting velocity. Do you know if I can use:

TrayLift.setMaxTorque(120,percent);

to overclock the torque on the motor?? I have as much compressed air as I need if it overheats I will try to build a makeshift heatsink or some remedy."

edit: it’s not giving me an error in my code