We’re using 2 CIMs and a Mini-CIM with a 16.73:1 reduction
Two RS775’s, each powering a 50:1 Versaplanetary gearbox with a disc brake coupled inbetween the two gearboxes. A video of it can be found here: http://youtu.be/JrebWdH8x4c
mini-CIM to 20:1 versaplanetary. seems to be as fast as we want and lifts fine. will be beginning PID testing in the next day or so to see how it handles the load. Hoping to not need a break.
I can’t believe only one other person has mentioned BAG motors. In my opinion, they are the perfect choice for this application, as they have a similar free speed as the 775s and can interface perfectly with the VersaPlanetaries. Also, they aren’t fan cooled and instead have a high thermal density, meaning they won’t get wrecked as you PID loops try to hold the totes in place. They’ve been champs for us, and they weight only a fraction of a CIM or miniCIM.
The BAG motor might be ok for some lifts, but if there’s a CIM or miniCIM available, why not overpower the mechanism? speed is good…power is good…extra capacity is good…
Posting what ratios you’re using without also showing how big of a lever arm [pulley/sprocket/4-bar/etc] is involved is pretty meaningless.
We have had some issues with the chain driving the shaft skipping after it is loaded with 3+ totes, but that is a tensioning issue, not a problem with the motor. We have pulled over 100lbs of weight up with it (which is more than 6x7.6lbs (totes)+ 8.8x1 (bin)) We will be doing some actual testing with some totes once the tensioning is worked out and the chain no longer skips.
We have set up two opposing VexPro 2 speed ball shifting transmissions.
One has 2 CIM’s the other is only used as a shift on the fly ratcheting system.
It lined up so nicely putting the transmissions together…
Gear ratios of 8.33:1 and 3.6:1 on a custom 3d printed 1” diameter spool and strap guide system.
Per the JVN calculator, our low gear should move our 60” lift system fully in approximately 2 seconds with a 40lb. load and a stall load of 570lbs at 10amps. The high speed, which I doubt we will use much, runs the loaded lift at less than a second with a stall load of 250lbs at 19 amps.
It is “overkill” and so is the lift system that goes with it…
We will be adjusting speeds this week to fine tune the lift. Sure do not need to launch those totes into the stands…
Good luck to everyone this year!
We used two CIMs with a vexpro single speed double reduction with the stock (slowest) speed. Then it goes from a 22 or 18t sprocket to a 72t sprocket. I am confident that mini CIMs would be plenty powerful if you don’t have the motors to spare. This gives a ridiculous amount of torque so we can lift rather quickly compared to lifts that use smaller motors.
Edit: We don’t use a spool, a continuous loop of chain lifts the arm things and that is driven off the shaft with the 72t with 22t sprockets.
True enough. We’re driving 2" diameter sprockets with our two 12:75:1 CIMs.
What are those sprockets driving?
A belt with more 2" sprockets along the way. The total moment arm on the toughbox output shaft is 1"–the rest of the pulleys are just for direction changes.
We are running a MiniCim with a Versa Planetary that is 36:1
Robodox are using two old Bosch Van Door motors directly driving (via their included worm gearboxes) a 6" drum that has a few wraps of cord in a continuous loop lift.
- Mr. Van
I don’t know the schedule that BaneBots works to, but its probably similar to that of vex or andymark. If you go onto VEX, they sell many different gear ratios for the planetary gearboxes. Since ours is a 1:35 ratio, we used a 1:5 stage and a 1:7 stage. A great resource is the JVN mechanical systems calculator. You can choose your own gear ratios and then make educated purchases. In the linear mechanisms category, you can specify the distance to travel and the weights for approximate times.
Best of luck!
The Average Joes are using a can of spinach (aka CIM motor) on a RAW Box (AM-2372) with further reduction via Vexpro gears (30:84) to drive two 36 tooth Vexpro HTD pulleys on two 15mm wide belts, which connect to our left and right elevator carriages. Top unloaded speed is 4 seconds for a 60 inch lift, and we have lifted six totes while drawing 28 Amperes at the CIM terminals.
Or you could attach 4 BAG motors with dual-input versaplanetaries and overpower your lift with less weight (for the same amount of power) than a similar solution using CIMs or MiniCIMs.
we are using 2 cim’s that run through 76 to 1 planetary gearboxes. They have been a pain to mount but we got it mounted yesterday. Now we just need to make the elevator plate and the bracket that connects it to the fork