Rhino Track and R402

Rhino Track Drive Module

Question about bumper rule R402. BUMPERS must stay low. BUMPERS must be located entirely within the BUMPER ZONE, which is the volume contained between the floor and a virtual horizontal plane 7½ in. (~19 cm) above the floor in reference to the ROBOT standing normally on a flat floor. BUMPERS do not have to be parallel to the floor.

We’re looking at using the Rhino Track Drive that we used in 2016 for stronghold. I am worried about the height of the front of the track, being about 9" from the floor to the top of the track. Does this interfere with Rule 402? Or can we modify the bumpers to be lower, and the track to be above the bumper plane?

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IANARI (Robot Inspector), but the way I read the rule, your Bumpers must be mounted so that the top is no more than 7.5" from the floor. From what you say, this would cover most of the slanting part of the Rhino Track treads.

Also remember that the Tracks cannot define your Frame Perimeter - that must be made from solid stationary parts. So there must be some frame in front of and behind the Tracks.

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We do have the bumper kit from Andymark that we plan on mounting to the corners of the tracks, and have made a subframe to enclose most of the track. I was just worried that the front bumpers, kinda like the picture below, would be too high. But if we can mount them lower, that will hopefully work.
image

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Have you considered the design tradeoffs in using the Rhino Tracks for this game vs using a more standard WCD or even the kitbot? Unlike 2016 (even then it wasn’t really the best solution) there is very little “terrain” for you to drive over. Plenty of videos have been posted showing a variety of WCD, and kitbot drivetrains driving over the charge station and cable protector.

Consider that this game is a cycling game where being fast and nimble will be advantageous. These are two qualities that the Rhino tracks do not really have. I would strongly recommend your team considers all of the design tradeoffs being made in choosing Rhino Tracks over a more standard wheeled drivetrain.

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Writing a concurring opinion here:

I don’t know that a Rhino is any more or less capable for this game than the AM14U5.

But that brings up the question: why not run an AM14U5? Unless this is a “clean out the fridge” build, I don’t see the upside.

Yes the bumpers are too high as pictured. Making Rino bots confirm to the rules was a major headache in 2016. The AndyMark kit looks to do a good job to defining the frame perimeter which is the second issue with the Rino tracks.

This kit will satisfy the frame perimeter rules that the Rhino Track does not otherwise meet, by putting a solid frame element in front of the tracks. However, you still have the bumper height problem and that will not be so easily solved. You could try to add an vertical extension (some kind of mounting plate) to the mounting flanges on the front part of the kit where it attaches to the Rhine Track frame to lower the whole thing so that it’s top is at the 7 1/2" maximum for bumpers. That would allow you to conform to bumper rules that require bumpers to have a solid frame element behind them by putting the top of the bumpers even with the kit’s frame top. Having the tracks project upwards past this is not a problem for the bumper rules, as long as they are behind the added frame elements.

All that said, while you can adapt this combination to conform to current bumper rules, I have to agree with the other commenters who have been asking why you would want to use a tracked drive base for a game like this that has no real obstacles. It won’t give you any advantage for most of the game and doesn’t really help that much over other drive bases when attempting the Charging Station either, since it’s not actually difficult to get up on that thing (balancing on it may be a different question, but tracks aren’t likely to make that any easier either.) Maybe you want to keep saving this base for a future game that has more in the way of field obstacles and go with something better suited to the current scenario.

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You are forgetting all the top heavy robots that are going to be on their side…

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Keep in mind that the frame perimeter rules and the bumper height rules impact each other. R101 tells you that the frame perimeter is “contained within the BUMPER ZONE and established while in the ROBOT’S STARTING CONFIGURATION, that is comprised of fixed, non-articulated structural elements of the ROBOT”. If the mounting bracket is above the bumper zone, it DOES NOT define the frame perimeter.

You need a structure at the proper height to define the perimeter and to mount your bumpers to. Honestly, the Rhino Track’s leave a fair bit to be desired in this area. You’ll likely need to find a way to mount additional structure below the tracks in order to meet the bumper and frame perimeter rules.

Seeing as normal drive trains (kitbot, WCD, swerve, etc) can drive everywhere just fine this year, I wouldn’t take on something like the Rhino Tracks that increase scrub and make turning more difficult with no real benefit.

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I believe the Raptor Drive is an upgrade to the original Rhino Drive that addresses the bumper issues (among many other concerns).

I appreciate the replies. I tried to inform my team of these concerns on day 1, but with letting them read the comments. They’ve agreed to change some of their ideas! :joy:

And thus my pointing out to the OP that they had to put in some kind of bracket or other extension to lower the outside parts of the mounting kit (i.e., the artificial frame perimeter) to get their top down to bumper zone height. Without that, as I noted, they don’t have a solid (fixed, non-articulated) structural element behind the bumpers. I was trying to answer their question by telling them how to do exactly what you’re talking about. I was also, like you, questioning why they’d bother to try to make the Rhino Track work when there are better solutions readily available.

Rhino Track / Raptor Track has repeatedly failed us, specifically in 2016 worlds (I’ll write this one off since revisions have been made since then) and in 2019 DCMP. I wouldn’t recommend them to a team.

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