1619, 1678, and Spindexers In General

Yes, it’s something we’ve thought about since Day 1.

This is what I was afraid of and assumed this is why you folks went up close. Your reveal video showed a behind the WOF consistent 2 pt shot.

The Wheel Of Doom sucks you in and then shows you how many ways there are to jam balls.


yes kind of dissapointing but we got to keep evolving as the season goes on .
we will keep an eye on this balls, maybe in other events thay will have more reserves but
i must say balls are getting ownd like crazy out there.


Was a majority of the damage to the balls rips and tears?

as far as i saw yes.

both. really bad condition … with holes 1…2 inch wide
teams drive over power cells … and this causes lots of damage
at least in Israel … First don’t buy enough powercells to replace damaged ones
i guess that in the USA the really damaged cells will be replaced


That’s an unknown. We may have orange and purple functional equivalents on the field by week 5

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Earlier in the thread I posted a slow motion video of our spindexer in action. It really didn’t show much detail. Here is a better view.


idk if it’s the best choice competitively, but I like 1678’s spindexer for the aesthetics. When they go to shoot and the balls are spinning around and their camera light is flashing, it really feels like party time.


Was thinking about this earlier today and wanna come back to it. I’ve heard a lot of generic statements about how spindexers jam super easily over the past year or so, but I don’t know why. More details from those who built spindexers would be appreciated.

How are they jamming? Under what circumstances? Those who got successful spindexers, what did you do to get them working?


If a ball doesn’t fully settle into its proper location fast enough and gets pushed into a static mechanical feature, it has the potential to cause a jam.

The Team Rembrandt’s YouTube channel has a bunch of great examples of different test and implantation of their “wheel of doom” spindexer prototype from last season that showcase both successes and failures.


Thank you for sharing that playlist, it’s really insightful!

It appears the only jams I can see on their prototype videos are caused by the segmentations in the spindexer, and in their videos with no segmentations the spindexer appears to work very smoothly.

In the end it seems like they went with the Spectrum-esque indexing system, despite it appearing as though their unsegmented spindexer was faster for (what appears to be) the same number of jams (0, in the videos).

If someone from 4481 sees this, I’d be very interested in hearing about why you made the decisions you did with regards to which indexing system you used, and if there were any detriments to the unsegmented spindexer system that we didn’t see in the videos.

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I should have posted this in my previous thread, but 4481 had a 2020 build thread:

Post #50 on January 20th covers their logic on not using their spindexer.


Straight money, just what I was looking for. Thanks, Sean!

Interestingly enough I was thinking about the tilted spindexer myself for the same reasons, so it’s good to see someone else thought of it as well. They said they’d be continuing development on that concept and I see a single video testing the balls rolling into a static spindexer - I wonder if any more progress has been made on that front.

On a related note, anyone have tested compression and surface speed data for spindexer “uptake” wheels?

I’m designing a prototype for a spindexer and uptake mech at the moment, and I’m currently testing at about half an inch of compression, with two Neos running a bit above 3000 rpm on 6 in. Vex omni wheels (the same two Neos are also powering a 3.25 in. Vex Omni as an accelerator wheel, ballparking at around an inch of compression).

The uptake design is based off of 1678’s, which was pretty neat, all things considered:


Here’s a gdrive folder with some robot testing from last Saturday. (Let me know if the link isn’t cooperating).

Over the past week or so, we’ve been heavily iterating on our spindexer design from way back in March and are making rapid progress. We can pretty consistently play 3 power cells (for the skills challenges) and when we have time, are working on it to get it up to 5 consistently. Some of the concepts discussed here can be seen in the videos. Feel free to ask questions as much as you want. It isn’t perfect but we’re real close to it.



My team also used a spindexer but we implemented it slightly differently than the other teams mentioned here. Our original prototype used rigid lexan flaps attached to a 3d printed hub and had five pockets so each ball had its own space. Like 4481 we found that led to a lot of jams, the balls tended to get behind or off to the side of the flaps and would get stuck between the flap and the spindexer wall or would jam up in a different compartment. The way our robot was packaged our shooter was partially supported by our spindexer floor so a spinning floor design like 148 wouldn’t work. We found that less constraints on the balls led to a better spindexer, so we added some compliance to the system. We heard about some other teams using brushes (3476 and 3538 most notably) so we gave that a try. We replaced the lexan flaps with four 4in long brushes attached to a 1x1 hub. This system was much less prone to jams. We also found that reducing the friction of the balls rubbing on the spindexer wall was important to prevent jams, we used a small amount of mineral oil on a rag to clean the sticky residue and grime off of our spindexer wall. Both of those things combined prevented jams almost entirely, and the jams that were left were present because the spindexer could only store four balls (shooter was in the way of the fifth) so putting five in the robot sometimes led to jams. For 2021 we improved the system by switching to only two brushes instead of four which gave the balls more space to fall in and had no noticeable decrease on rate of fire. We also plan to add an open hopper that feeds into the spindexer for storing that problematic fifth ball.

This was our first test, one of the flaps broke off during a jam

This is the 2021 version, Its identical to the version we competed with in 2020 but with two fewer brushes

And this is a video of how fast the 2021 version shoots


We’ve had our fair share of trouble with spindexing on 832. Our initial design jammed very frequently, and alongside our poor intake, we performed worse than we had hoped to in the shooting task at our Week1 competition.
Immediately after we went for a new design that has been doing much better for us, albeit still a bit “jammy”.

Close up shot
Distant shot
Various intake tests

We still have plenty of room for improvement, but I would still say I think we went the right direction.

It seems like a lot of your jams are a result of a lack of a barrier around your spindexer. We had similar issues with our spindexer until we added a barrier around ours using 1/32in polycarbonate. Also, we use a similar intake to you, but we also have a ramp that leads into our spindexer and also “fingers” made out of surgical tubing on the top two rollers that help to push the lemons into the spindexer. @DRandhawa posted a folder that shows some of our most recent testing that would show you the route we went to fix jams.

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