I see a lot of robots have started incorporating the motors for their dr4b lift onto their towers (supports) now rather than attaching them to the mid-section. Does anyone know the advantages or disadvantages of this. I think an advantage would be that it says weight however would powering the lift from the towers require a lot more torque?
It also keeps your center of gravity slightly more near the bottom of the robot than the top (since the weight of the motors on the arm is now on the towers, and it doesn’t move upwards depending on where the arm height is), helping to not lean or tip over.
I’d still much prefer the motors in the gearbox instead of on the towers, as it puts less of a strain on them, so I can run 1:7 hi-speed on two motors and accelerate very quickly.
It is exactly the same amount of torque. If possible, I would always put the motors on the tower. The only real reason not to is if you have slop or bend in your lift (either because of high load or weak joints), or if there is no space at the bottom of your lift. Often, the best solution is to have 2 motors on the tower and 2 on the back of the lift.
We have 2 on the towers connected to the robot, and 2 on the middle section (gear box) of the lift. However, we discovered after we built this, that you can have more open space at the bottom of your robot if you put all the motors in the middle section, because you can have single-piece supports connected to the robot instead of the 2 c-channels on each side to accommodate the gears & motors on the lower part.
If you’re using a “floating tower” (basically a little piece on the side of each tower in order to hold the linkages more securely) to prevent the gearbox (midsection) from leaning, would you recommend just putting the gearing there anyway since there’s already a piece of metal in that spot? I have my two motors at the very top of my gearbox, I would think it puts the least strain on each motor there.