Can a 775pro be mounted to a Banebots P60 planetary gearbox? The shaft diameter seems to work, but the 775 pro is more powerful than the RS-700 series motors traditionally mounted to the P60. I have a 256:1 P60 lying around and I’d rather not spend the money on another versa planetary.
If anyone has experience with this, any advice would be appreciated.
No experience, but there’s probably not an issue.
Does the P60 have good durable gears?
The Vex VP gearboxes handle 775pros good and they have itty bitty teeth on their gears.
Sounds like you are trying to climb. The 775pro will burn out if the motor stalls for more than a second, which will likely occur if you are not exceptionally careful in your design. I would recommend using a different motor.
No, this is for lifting our gear intake mechanism/arm, which will weigh about 10-12 lbs and travel between 0 and 140 degrees with limit switches at the ends of travel. The gearbox is being used primarily for speed reduction. Although, if the 775pro’s burn out that easily, we may have to reconsider. A pair of window motors would probably be ideal for this, but they are a pain to integrate…
However, we do plan to climb with a 775pro on a ~175:1 versaplanetary and chain reduction. All calculations show this will be fine, but we’re open to input/suggestions!
Do bag motors handle a stall better?
Much better.
Consult the “Locked Rotor Stall Test” charts for each motor on the VexPro motor test page.
Keep in mind that a BAG motor does have substantially less power than a 775 though.
You don’t have to be exceptionally careful in your design, you just need to be smart in your design and use your engineering brain. We climbed last year with 775pros and we will be climbing this year with 775pros. Use the tools that are available to you and you shouldn’t have any problem.
Last year climbing didn’t require you to dead-stop up against a plate and hold position there. I agree it is possible to climb with a 775pro, but without good design and control systems the odds of breaking one are much higher. IMO the more fault-tolerant you can make a system the better.
Make sure your design does not exceed the P60’s output shaft torque capability. Especially if your design side-loads that shaft.
You can use a 775pro in this application. You can even stall it at LOW voltages (like, 10% power) for a short time without huge issues.
However, the BB planetary… probably won’t hold up. They aren’t the strongest gearboxes, and with such a large reduction combined with such a powerful motor, it’s only a matter of time before it disintegrates unless the motor is VERY lightly loaded. I would have a backup plan ready if you go that route.
Would a VexPro versaplanetary be a better fit for the same application?
Absolutely, we use them every where we can. Never had one let us down since they came out. Need to follow Vex’s rating guide, but its easy to follow.
If you like the window motors for this, check out the seat motor that came in the kit of parts. They’ve even posted a documentdetailing simple and effective ways to interface with it, which definitely makes me like it more than the window motors!
Beware of the 10:1 reduction stages though, the tiny sun gears in them tend to fail pretty easily if you stall them.