Track Systems

Thanks for the site, Maniac!

I checked out their sample articles, as well, and was suprised to find that Radio Shack has come out with their own robotics erector set.

From the looks of it, most of their stuff isn’t as strong or as light (depending whether it’s the plastic or steel pieces, respectively) as the parts on lynxmotion, but they have a few neat ideas going.

I saw their Tank Tread Kit radioshack.com/product/index.jsp?productId=2131184&cp=&pg=1&y=5&kw=vex&x=10&numProdsPerPage=20&parentPage=search
And was immediately enthralled.

x12.putfile.com/1/1110343124.jpg

The treads themselves are made of plastic snap-together pieces, so there’s no need to pre-measure.

I thought that this’d be a great piece for our sumo bots.
The linking system takes out the costly trial and error of designing a whole track using CAD software.
Then, I realised that plastic treads would just slip across the ground surface.

In that light, does anyone know of a place to get this sort of tank tread, except with rubber ground contacts and an aluminum backing/gearmesh?

Tank treads provide much greater surface area than wheels do, and thus, much greater friction.

While the actual drive can be less efficient than a wheel, the added friction to the ground will probably be way more efficient in terms of pushing power.

The only real problems that treads present are tangling and gearslip.
Tangling can be prevented simply by plating the tread area over with aluminum sheetmetal.
So long as no debris comes in contact with the tread, it’ll be fine.
The second problem is harder to solve.
Since the Shack’s treads are plastic, gearslip would become a big problem when presented with the kind of torque that the planetary motors can provide.
That’s why I asked for an aluminum backing/gearmesh in my above question.

I’ll be hunting for treads online; I’ll let you guys know what I find…

edit: We’d also have trouble using the Shack’s treads because the drive gear is square. I believe that the motors on Lynxmotion all have round drive shafts.

I am aware of a place that has prototyped an elegant aluminum tracked system. I was sworn to secrecy, so I’m not going to show the images, or technical details I have here. Sorry…

Having just completed a lengthy search for just this thing a few months back, I will let you know that there are four things I came up with. This was pre Vex though…

There is a German RC toy called the Catweisel. After lots of emails I could buy them (overpriced) with no discount, if I could find someone in Germany to act as a middleman as the parent company (Conrad) will not ship to the USA. Here is a link to a forum that has an image of the bot, with an L6 arm on it. roboternetz.de/phpBB2/viewtopic.php?t=10901

There is the Kyosho Blizzard RC tracked vehicle. Gas and electric. Rumor is they are discontinued. I am still hopeful to get these and am still in the process of working with them. These are higher end than the german one. But they use a single motor and clutch system to do direct power to either side for turning and going straight. Was hoping to make a retrofit for converting to true differential drive. Here is a link to an image of the Blizzard. kyoshoamerica.com/products/30981B-EPBlizzard.asp

There is a place I found that has some promising parts, but when I tried to order 100 pairs, they melted down and said the things are made by hand, and they couldn’t make that many. They also only wanted to offer a 10% discount. The website was quite bad, but apparently it has recently been reworked… Their phone was disconnected, and it took 2 weeks to get an email answered. nelnick.com/cgi-bin/cart/nelnick.cgi?product=Tracks&cart_id=1137087339.12681

There are of course the Tamiya ones, but they are all really small, light weight, and of poor quality. There are some higher quality ones on larger tanks, but they don’t really lend themselves to robot building. They are too long and skinny for bots…

Anyway, sort of been there done that, but things are popping up all the time. Let me know what you find. Thanks!

After an endless search, I’ve given up on finding a set of treads that meets my expectations.
However, I did ask the makers at vexlabs if they had any plans for making their tank tread kit out of aluminum, with rubber soles.
I’ll let you guys know, when I get an answer.

Cheers.

There are metal track distributors. These are high quality, pretty cost prohibitive, and one size doesnt fit all yet they give you an option

backyardarmor.com/New%20Main.htm

Check out M1/Doyusha for metal with rubber pads

Have a good one

There are as many ways to make your own treads as their are distributors of premade ones. I’ve dealt with most(Tamiya, Lego, Home made) as my brother dabbles in RC tanks. These might be the best( albeit small) solution because they are a direct fit on servos, on the very powerful Solarbotics gearmotors, and on the Tamiya gearboxes. Enjoy. superdroidrobots.com/shop/item.asp?itemid=516&catid=55

oof… I’ve ordered from nelnick before. It wasn’t a pleasant experience. After a month or so and repeated requests to simply refund my money, they finally replied that the items had shipped. By the time it arrived, I had ordered and received most of the parts elsewhere, which was fortunate because only about half of the order was filled, the rest missing.

Wow, Jim!
That site is a really nice resource.

I’ve been hunting around for attachment chains, and finally found some at azusaeng.com/

Their #40 attatchment chains would be perfect bots that are 12 lbs. and up.
They’re about .5 lb’s per foot, so sumo bot’s are out of the question, really.
They’re made of stainless steel, and sell for about $7 per foot.

Maniac, nice link, too!
Those would be perfect for sumo bots.
I bet it wouldn’t be too hard, either, to mount them on any motor/servo of one’s choice.
I guess all we’d need to do is steal the gear off of a standard servo (or buy them from a servo part store) and weld it onto our motor/servo shafts.

Thanks for all the help, guys!
I think I’m going to start a 12lb. combat bot, now…
Too many evil plans, too little time.

Jim.

Gordon has some really nice treads. If you can find out where he purchased them, with your equipment, you could probably make some sprockets to go along with them. What I did for idlers for some other treads I have was to purchase 1 inch diameter wheels (hubs) and put O’rings on them.

http://www.budgetrobotics.com/shop/images/237.gif

budgetrobotics.com/shop/inde … 0&cat=119&

I bought some Nelnick treads and I really hate them. They are way too soft and just downright ugly!

Kenny

Those are some nice tracks, but you’d have to build a robot around them and not with them because they don’t come apart.

because they don’t come apart

Actually, they do. On the first pair I bought, one of them wasn’t glued very well and I noticed that it was made up of two tracks, glued together. So, I took both tracks apart and re-glued them with special rubber cement and now have 4 smaller tracks.

Kenny

I whiped up a quick design that would cost about $1200 for solid aluminum tracks with a recesed pocket to insert a 2mm thick rubber pad.

Here is the image of that design: Each link is about 1" in width.

Click image to enlarge:

img44.imageshack.us/img44/4743/tlink0ui.th.png

The two ovals on the ends of the link are for the sprocket teeth.

I meant each individual track link, their website says that each track is molded as one piece so that’s what I went on.

Are they really nice though? I heard that they come off the idlers easily. Anyone actually used them. Chime in…

We are actually looking into getting some of the conveyor system components that were used to make the robot below. This robot is around 3’ long, but they also make much smaller parts that would be better suited for a smaller robot. There are many different styles to choose from. This is a project for later this year. The tracks shown cost about $78.00 per side including the drive and idler sprockets.

I was thinking of desgining a tread system using table top conveyor.
Rexnord.com has the stuff. The SS chain that is 3.25in wide and is about 40.00 a foot it has a rubber grip pad on it as well for tracktion. It would way like 1.8lbs per foot. It just needs the houseing made and then you have a heavy duty tread system.

Hmmm… that chain is nice and wide, so you’ll get some nice grip, and should have enough surface area to get decent traction in snow…
But, at 40 dollars and 1.8 pounds, a foot, it seems rather beefy.
I suppose it would be nice for a heavy rover or battlebot, though.
There’s something to be said about having it ready to slap right onto your bot.

The only real problem is the amount of torque that we’d need to yank that chain around.
Again, we’re pretty much limited to using heavy motors/gearboxes, for that.

One could go with the expensive option of brushless outrider motors (www.maxrivers.com is a nice place for them, if you don’t happen to speak fluent German, and hate reading google translations).
But, with the chain already being at least 8 lbs (assuming that about a foot of actual ground-contacting treads will be wanted), saving maybe four or so pounds with brushless motors, instead of using car starter motors, is rather silly.
Although I say that mostly because I’d rather spend a few days converting two $30 junkyard motors, than paying more than $200 a piece for high-torque outrider kits.
Those outrider brushless kits take a while to build, themselves, anyway.
And, since we’d be throwing them into a rather high-stressed environment, I’d rather break a set of $30 motors.

All of the above is why I’m putting my Battlebot ideas on the afterburner.
I’ll get back to them when someone makes a reduction system that can handle a glow engine’s 30,000+ rpm’s.
There’ll be nothing like hearing a 12lber ROOOOOOAAAAAAAAAARRRRRRRRRRRRRRRRRRRRR!

i have found myself designing a bot using a track system, my question is if there is any sort of gain by driving the front and rear drive gears each with thier own motor (connected in seres with double the voltage)?

I don’t think there is any advantage aside from slightly increased speed and greatly increased torque. If your system has a motor on each end of the track, you now have a push and a pull moving the track around the idlers.

I guess the greatest advantage for dual motors would be the ability to use two smaller motors rather than one large motor.

I haven’t done any real research into whether two series motors would be lighter than an equivalent torque large motor, though.
I suppose that it wouldn’t as you’d be adding the weight of the motor casing twice.

Speaking of motors, if you wait a season, there’ll be a review on two different brushless robotic motor companies in the summer issue of ROBOT magazine.

Aside from possible power-weight advantages, I can’t think of any reason to have two.

If you had four, for instance, wouldn’t you’d be getting 80% of 80% of 80% of 80% (40.96% total) efficiency?
Compared to that, one motor for each side is a reasonable 64% efficiency.

check out this site -

vexlabs.com/vex-robotics-tan … -kit.shtml

same as the Radio Shack treads, but you get more for your $30.

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