Our team is looking to possibly use the new AndyMark tread system, due to the vast amount of obstacles, anyone have any thoughts? Pros/Cons? Thanks!
Another question, does any other site sell any kind of tread or kit? We would rather not have to wait 2-3 weeks to get a kit and also would rather mod the KOP chassis to take treads.
Edit: one other question, what would be a good wheel for treads?
That was one of our mentors’ first thoughts. They’re very expensive ($170 a side for simple two-wheel-per-side), and we’ve found that most of the uses we’ve thought of would be covered with 4WD and a large clearance. I’ll edit when we do some deeper analysis, but at least one other team is thinking about them.
Treads are great for crossing rough terrain, but do not have great maneuverability.if your strategy is to mainly cross defenses then they would be a good idea but if your aim is to focus on boulders then other types of wheels would be better eg. 4/6 wheel tank
The AM treads are quite expensive
First thing that came up when “Tank Treads” was searched was this and the general response was an “lol nah” so we are gonna try and make a cheapish one (buy some treads, get some wheels to go with, mod the KOP to use it) the issue is, we are not sure of what would be good wheels and how we would go about modding the KOP Chassis (which also depends on the design we go with)
Y’all should ask 1619 for advice on this. They have a near-perfect history with tank tread, and have a list of suppliers.
I’ll volunteer their webpage for starters.
This is great. Thanks for posting this. (And thanks to that team for their info/experience!)
Hey everyone,
This is what we use…
Part Number: 5994K9
I would like to add that a sponsor helps us to order through McMaster Carr. Our parts usually ship same day and we pick them up the following day.
Have you had any issues because those are not timing belts? Seems like they might slip.
Something my team did was buy just the tread and the wheels. Therefore we can customize how many rollers we have. Plus we wont have to wait 2-3 weeks for the tread since the site stated that only the full modules would take that long, while the tread doesn’t have that time constraint. Another thought is using belts that you would regularly use on belt driven systems (wouldn’t suggest that). Another idea is use custom conveyor belts from McMastercarr.
Good Luck.
Possibly. They do sell some belts that you can customize to your needs.
Hey just wanted to say thanks for everyone’s help posting this.
How would you cut down the width of the belt from http://www.mcmaster.com/#rough-top-belts/=10m5v49 to fit on the gears in the KOP kit though, cuz I’m guessing straight out cutting them would tear it to shreads. Is there a special tool or can you request a specialized order?
We cut the blue nitrile rough top with tin shears. They work really well. As for splicing the tread, we were considering threading the two ends together with very thin wire. This would be the first time we are using blue nitrile for belt/tread material, so, we are still experimenting with different ways to splice it.
Some folks on our team are batting around the concept as well. Don’t know if its the best choice, but we are in agreement that if there ever was a game where they could be useful, this is it.
Other than looking at previous FRC robots, I would encourage anyone looking at crawler tracks to check out real world designs. There are many VERY different concepts in use in various industries. They all have specific strengths and weaknesses. Earthmoving equipment and large cranes have very different designs…and as a hint, crawler cranes are actually the ones designed to be more maneuverable and smooth.
Military and classic “tank” tracks are another ball of wax from anything in construction. Construction equipment actually rides on small rollers in the middle of a crawler “side frame” and roll smoothly by keeping the roller spacing different from the track pad spacing. As such, they have no suspension. Tanks do have suspension and killer obstacle-climbing ability, but that introduces all kinds of track tension issues. There are many different ways that military designers keep a nice, bouncy track system that doesn’t want to jump off the idlers and sprockets.
And, of course, for FRC, you want to crawl all over those obstacles but also not have a robot that’s bouncing and leaning all over the place.
Very interesting stuff…
Alligatorclips can be used to connect tread together.
We’ve already ordered the Andymark ones, they’re a bit expensive but basically deal with the entire Outer Works problem for us. The only foreseeable problem is using them with bumpers, which he haven’t figured out, anyone have any ideas?
We are doing Rhino too… as far as I can tell you would need 4 corner bumpers minimum they all could be fairly small corner ones. 8" and 8" (5" tall)
Mounting them to ends of Rhino track (between 4-12" off floor) could be done assuming body is smaller than drive base, but you have to plan for tread and angled ramps and obstacles.
So basically angle brackets of track, some support (and mount with 1.5 inch play up or down from center.
No matter what you do the bumper will cross the horizontal plane of the tracks themselves IMO.
Or go up… with a larger body than track footprint. So the structure makes the outer corners (at least 4) anywhere from a foot to 4 inches off floor.
If larger which is more likely I think then it has to be on body corners with top of bumper placed at no more than 12" level, but you could make you body larger than the drive base and not mess with the treads as much. Depending on how wide and long you make it.
The treads are 9.498" at max height , bumpers have 12" max height 4" min height and are 5" tall.
So if you make the track itself an outer corner, or your body (above track) an outer corner is your choice. Definitely an important choice .
I’m a derp and can’t find the edit button, but we just had a PDR and we decided to go with the am-3322 tread module. We’ll test it out on a simple bot base, and if it doesn’t go well, we’re going to replace the tread rollers with 8" or 10" wheels and use the same frame. The real wheel v. tread debate was manueverability vs clearance, and we chose clearance.
EDIT: just found the edit button, but it’s not appearing on my original comment. Not as stupid as I thought.