pic: MiniCIM Versaplanetary

[AllenGregoryIV]

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[DampRobot]

So, essentially, the Mini-CIM mounts to the holes that hold the gearbox together? Also, how do you mount the CIM shaft to the pinion? I didn't know that there was a 8mm pinion available for those gearboxes.

[AllenGregoryIV]

Originally Posted by DampRobot

So, essentially, the Mini-CIM mounts to the holes that hold the gearbox together? Also, how do you mount the CIM shaft to the pinion? I didn't know that there was a 8mm pinion available for those gearboxes.

Check out the blog post for the full instructions. You don't use the holes that hold the gearbox together you use the other two holes. There isn't a pinion at all, the gearbox accepts an 8mm shaft and key.

[Kellen Hill]

Are you planning to use these on your drivetrain?

If so, what reduction are you using in the gearbox?

[Chris is me]

I really wish you had posted this two weeks ago. At one point I designed a mechanism that fed a mini-CIM through a VP and we had to redesign everything once we realized it wasn't a stock fit. I guess we should have been more creative.

Novel design nonetheless!

[AllenGregoryIV]

Originally Posted by hill

Are you planning to use these on your drivetrain?

If so, what reduction are you using in the gearbox?

No, we wouldn't risk that. We have a use for one right now and it will probably see the actual robot but it won't be on the drive train. With 6 regular CIMS allowed there is no need (unless you have a serious power need for a climbing device) to use anything but large CIMs on your drive train.

Originally Posted by Chris is me

I really wish you had posted this two weeks ago. At one point I designed a mechanism that fed a mini-CIM through a VP and we had to redesign everything once we realized it wasn't a stock fit. I guess we should have been more creative.

Novel design nonetheless!

I wish we had known as well, we didn't find it until JVN hinted at the possibility. I still can't believe VEX designed all of these features into the gearboxes and never talked about it.

[Kellen Hill]

I was thinking of putting the large CIM into the planetary. Should mount the same as a mini CIM unless I'm mistaken.

We currently have a couple old Banebot planetaries and are looking to switch them out.

[AllenGregoryIV]

Originally Posted by hill

I was thinking of putting the large CIM into the planetary. Should mount the same as a mini CIM unless I'm mistaken.

We currently have a couple old Banebot planetaries and are looking to switch them out.

Oh, yes the input would be the same but again this current setup has very little keyway profile so for heavy torque applications it might not be the best design. (This is just from FRC experience I'm not a Mechanical Engineer.)

We are using the VEXpro single speed gearboxes but I would think the VPs could work in place of the large BB gearboxes. Check the torque ratings table on the VEXpro website for guidance though non of those are for this setup as it isn't officially recommended by VEX.

The single speed gearboxes we are using are 5.33:1 so a 5:1 VP would be a suitable replacement.

[ken.3038]

Our team is going with a single wheel (8" pneumatic) with a curve. The first attempt was a CIM direct to a hub mounted on the wheel but failed. The hub egg shaped from the CIM shaft. Next we tried a belt driven shaft mounted with bearings but there is to much vibration. We have ordered 2 Versaplanetary gearboxes which one will be changed to 1:1. Mounted to a AndyMark 1/2" hex hub. The idea came from your thread with your small shooter. I shouldn't have cut the shaft with a 1:1 correct?

[AllenGregoryIV]

Originally Posted by ken.3038

Our team is going with a single wheel (8" pneumatic) with a curve. The first attempt was a CIM direct to a hub mounted on the wheel but failed. The hub egg shaped from the CIM shaft. Next we tried a belt driven shaft mounted with bearings but there is to much vibration. We have ordered 2 Versaplanetary gearboxes which one will be changed to 1:1. Mounted to a AndyMark 1/2" hex hub. The idea came from your thread with your small shooter. I shouldn't have cut the shaft with a 1:1 correct?

If you are mounting a CIM to the VP you will have to cut the shaft no matter what gear ratio. The shaft can't go all the way through the input stage, unless you did some really interesting modifications. You could use standoffs and cut the shaft less than we did.

[billbo911]

Originally Posted by AllenGregoryIV

...You could use standoffs and cut the shaft less than we did.

I believe a solid machined block might give a more secure interface than standoffs.
As you suggested, this would give both the Mini CIM and CIM the ability to interface to the VP without modification.

Are you catching this John? It would make an already great transmission even better.

[AllenGregoryIV]

Originally Posted by billbo911

I believe a solid machined block might give a more secure interface than standoffs.
As you suggested, this would give both the Mini CIM and CIM the ability to interface to the VP without modification.

Are you catching this John? It would make an already great transmission even better.

I agree with the secure interface idea. However I'm not sure you can do it without modification because the keyway on the 8mm shaft of the CIM and MiniCIM doesn't extend to the end of the shaft.