Indexer Help

I’ve seen some teams with 3 inch flywheel shooters with extremely fast shooting rate (4082B’s latest WR Skills for example). I was wondering what indexer designs would make for such a fast fire rate and how do they prevent the flywheel from losing speed and firing in a straight line from long distances.

I don’t have a setup flywheel yet but our plan is to use the 606X 3600rpm direct drive powering two 3 inch flex wheel stacked on top of each other. We are trying to get our hands on weights as well.

Please let me know, thanks!

Their indexer is most likely a pneumatics driven indexer. If you are limited (like us) to not being able to use pneumatics, you can make some sort of a slip gear - puncher indexer. Below is an example of ours that uses a rack and gear slide driven by a slip gear.

If you do have pneumatics, you can do something like this that will just linearly index the discs:
Either way is effective, and it is really up to you to decide. Experiment!

For the not losing speed, that is due to the flywheel having some sort of weight, (e.g. the ones sold by VEX) that keep the inertia up so it doesn’t slow down after firing.

Hope this helps! I’d love to hear what you come up with.



Hello, there are many designs you could choose from some being better than others. It falls down into two sections pneumatic indexer or motor indexer. Motor indexers are almost always going to be faster and more consistent and faster than pneumatics, but that involves sacrificing a motor witch most teams can’t afford to do. 4082B uses a motor indexer hooked up to flexwheels and spin them in reverse to shoot. This is very good for driver controller but can be tricky for auto, This is why i recommend a liner puncher because it can be very quick or slow.
RPM drops can be tricky and take lots of trial and error, 606X 3600rpm flywheel is a great option. If you don’t have weights stacking flexwheels is a great alternative. You’re gonna need the extra weight to get up to full speed. For minimal RPM drops your gonna need a minimum squishpoint this basically means you want to be able to push the disc through the flywheel without much force. This will help with the RPM drops.


Thanks for the pictures!

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4082B uses a motor indexer hooked up to flexwheels and spin them in reverse to shoot. This is very good for driver controller but can be tricky for auto, This is why i recommend a liner puncher because it can be very quick or slow.

I’m a bit confused what you mean by this, can you clarify? How is the indexer connected to the flywheel and why would that be tricky for auto.

We are going to one more comp which is a skills only comp so we are making a 4m drivetrain, 1m intake, 1m roller, 1m flywheel, 1m indexer to maximize the amount of disks we can shoot in limited time.

Yeah, of course! If you need anything else just keep me posted.

Watching these videos will give you a better explantion than i could put in words. I would advise against doing it this way just because it can be very finicky to get right. If you have a significant amount of time go for it.

Using a 2 motor flywheel will improve your rate of fire as it reduces your rpm drop. With your motor distribution, I would recommend connecting your intake and roller using sprocket and chain which frees up an extra motor for the flywheel. A good example of this motor distribution is MENTORBUILT

The only problem with this is that if you don’t have pneumatics you need one of those motors for an indexer.

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Yes, 4m drive, 2m flywheel, 1m intake/roller, 1m indexer. If you have no pneumatics you could ratchet the indexer to also trigger expansion.

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Or just do a 1m flywheel with 1m indexer. Leaves a motor for expansion.

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We use a 1 motor flywheel and find that we have to hot swap it out after every match because of overheating which might be too resource intesive for some teams.

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Our 1m blue cart flywheel doesn’t heat up that bad.


Interesting. Is it geared to a higher rpm like 3600?


Yes, we use a Ben 606X 1:1 gear cartridge. Our flywheel is on a high strength axle that has 2 4" OD 60a flex wheels stacked on top of each other.


I’ve found that using ball bearings and grease, along with a single, lighter 3 inch flex wheel doesn’t overheat nearly as much. I used to use a 600 rpm 1:8 flywheel with a 4 inch flex wheel and it overheated all the time. As for an indexer, using a motor indexer works pretty well, leaving pneumatics for expansion.


Our school just ran out of high strentgh spacers for the 3600rpm motor. Do you know of any alternatives?

Lots of alternatives here:

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3D design 1:1 Vex VRC Motor Cartridge 3600RPM | Tinkercad is another alternative I know of, and is better than the Vex Hex version as it uses the actual teeth of the internal motor gear instead of elastic compression. But it does require a laser cutter to make the precise polycarbonate pieces needed for it.

On their brain they have a costom jelly screen, how could I do that for my brain.