Hey CD,
We got some wheels in our FIRST choice. Does anyone have in-match experience with the 4" diameter .5" Hex AndyMark stealth wheels? How did they perform? How long did they last?
These are the wheels if anyone is wondering: http://www.andymark.com/mobile/Product.aspx?id=39576
I believe the primary/intended use for them is FTC
with a 1/2" hex and that bolt pattern? it’s for FRC as well.
To answer the OP’s question: I have not experience with this 4" wheel, but I have used their 6" wheel in the past and have no complaints.
We have the 8 inch version and it had mediocre traction the wedge are rough top tread is a lot better.
I’ve handled them and the tread reminds me of the harder compound kit wheels that were around before 2012. Those wheels were ok at best, I would go with anything else for frc drivetrain.
We sometimes used them on our practice bot because they were cheaper and didn’t wear as fast as our blue nitrile wheels. The tread is quite hard but the grip is fair (it’s a lot like the old grey tread sky way wheels). After a while they would wear and leave the tread with a powdery feeling which reduced their traction significantly. I probably would not use them in competition unless you couldn’t afford anything else. Vex’s new hex Colson are a better option
There are no 6 or 8 inch “stealth wheels”. Those products simply don’t exist.
There is the 6in. “2008 FIRST Wheel” and the 8in. “2010 8” FIRST Wheel" (https://www.andymark.com/product-p/am-0144.htm and https://www.andymark.com/product-p/am-0420.htm respectively)
With that out of the way our team did use the hex bore stealth wheel a bit in testing and found that they were not very grippy. They were adequately strong to support an FRC robot and very light and cheap but otherwise not worth it. We found they didn’t mark up the tile in our school much so that is pretty great for a demo bot. They also didn’t wear down very much but then again we didn’t do much testing. They’re pretty hard so we’d expect them to last a while.
The new vex hex bore colson wheels look like a pretty great replacement. At $9.99 the Colson Performa (4" x 0.875", 1/2" Hex bore) wheels would drop in pretty much anywhere the stealth wheels would and will provide much more traction (colsons are great) and are also nonmarking and last a long time, but are heavier and more expensive. (http://www.vexrobotics.com/vexpro/motion/wheels-and-hubs/colsonperforma.html)
These may work on some FRC applications like intakes or object manipulation but I would not use them on a drive. The 4" high grip wheels are the same price and we have used them successfully for years.
The plastic hub can’t handle the torque of a frc drivetrain without adding an aluminum hub. I think they’d work well for other things like pickups and shooters.
Says who? Most other AndyMark wheels have plastic hubs, and they have spokes. The inside of the stealth wheels is solid plastic.
I’ve broken more plastic Andymark wheel spokes than I care to talk about.
But the stealth wheels in question don’t have spokes.
They have hidden spokes. That’s why they are stealth wheels.
My team hasn’t ever broken a spoked Andy Mark wheel, though I don’t doubt you folks who say you have. AM has been around for a decade and their products improve annually. I would have no fear of using the stealth wheels for just about anything FRC; they are among the latest products and will be high quality.
They are VERY light for their diameter.
I think they have a good fit in FRC for intake applications (5136 used them last year) due to their very low weight, low price and reasonable grip.
If you need more grip, screwing/riveting on some roughtop is solid too. The wheel is so cheap even if it is just a hub in that application.
TL,DR; I like 'em.
I like 'em, too.
Adam, how would you compare the AndyMark Stealth 4" (AM-2647) vs. the recently introduced VexPro Colson 4" (217-4049)? To me, the Colson looks a little better for CoF and hub material/structure. The Stealth costs less, is about 8% lighter and has a sprocket mounting pattern. Overall, I like the Stealth as an intake component, but would prefer the Colson in a drivetrain. Do you agree?
I have used 4" colsons for the past two years. They provide good traction, great wear at a reasonable cost. I am interested to try the new hex version by vex soon.
1756 used them last year, robot was sitting first practice day with cracked hubs
Yeah I think these wheels are not meant for a FRC drive, maybe an intake, but I believe they are more intended for FTC use.
Hi CD
Thanks to everyone who posted their experiences with the Stealth Wheels last season!
I was the main designer on that wheel and I wanted to share a bit of our design intent. We set out to create a really competitive FTC wheel (see the 8mm version here) and at the same time create a wheel that could be used all over an FRC robot; for intakes, drive trains, shooters, internal conveyors, roller claws, etc). We have seen and heard from teams that a main drive train gearbox can round out the internal hex on the wheels, but this can be solved by adding a hex hub (here) to the wheel.
A few quick pros and cons to using the wheel in a drive train:
Cons
-Lack of a 3D tread prevents mechanical engagement with carpeting (lowers total traction)
-May need to add a hub to prevent round-outs
Pros
-A stiff sidewall edge helps to prevent the wheel from sliding sideways (like when getting pushed by a defender)
-Like stated earlier, the wheel is inexpensive
-The wheel is easy for us to make so its easy for us to keep them in stock
-The 6 hole pattern in the wheel’s center body means it works with all the AM sprockets, hubs, and other components.
Let me know if you have any questions
Thanks
Danny