Re: New AndyMark Product Game Hint???
 

A product teaser.

In all seriousness though it looks kindof like someone took apart a motor and spread it out.

Re: New AndyMark Product Game Hint???
 

We tested them pretty thoroughly with old FTC balls, including a 1" practice golf ball that has basically zero squish of its own, and the engineers derated it to a number they were confident in. Obviously, anyone running any crazy-high-speed system should inspect those wheels early and often.

Nathan did the actual testing, and he may be able to provide more detail.

A product that we want to tease. ;)

Re: New AndyMark Product Game Hint???
 

And on the back of the paper is the 2018 water game field element CAD drawing.... come on, we know... :)

Re: New AndyMark Product Game Hint???
 

As of right now the site still shows 9001 RPM.

What is pretty thoroughly? 1000 shots? 10000?

I know some of the teams running the fairlane teardrop wheels in 2013 replaced them a few times over the season due to tears propagating.

Re: New AndyMark Product Game Hint???
 

My only comment with the "9001" rating is that carrying things to that amount of significant figures implies strong confidence in that specific number. While I certainly get the "over 9000" meme, many FIRST mentors (especially those over the age of 35 or so) aren't going to, and may interpret that 9001 figure to be a more scientifically approached limit given the specificity to 4 sig figs.

Re: New AndyMark Product Game Hint???
 

Has any one tried 3d printing there own wheel of this type? I have a spool of a flexible material I have been wanting to try out.
https://ninjatek.com/products/filaments/ninjaflex/

Re: New AndyMark Product Game Hint???
 

You are assuming that the zeroes are not significant figures already. Zeros can be significant.

Tell a machinist to make a part with a dimension of 1.00000" and see how hard they hit you. Whereas 1.00" and they won't bat an eye.

Re: New AndyMark Product Game Hint???
 

Oh, I agree. But these aren't zeroes beyond the decimal point. The zeroes in "9000" could be significant, or they could be placeholders for the proper unit value. However, the zeroes in "9001" are definitely significant.

Re: New AndyMark Product Game Hint???
 

My simple minded calculation of stress on the 4" wheel in question:

The wheel's outer section ("rim") is about 5 mm thick, 25 mm wide, and 320 mm long. Its volume is about 40 cc. Assume its density is about 1.5 g/cc so its mass is about 60 gram or 0.13 lb.

At 9000 rev/min, the "rim" has ~4400g centripetal acceleration, or ~570 lb. centripetal load. This stress acts on the spokes and is divided equally among them, at least until the wheel loses symmetry by deforming. So each spoke takes one-eleventh of the centripetal load, or 52 lb. That spoke stress is born by the same cross-section as the rim, or about 0.2 square inch, so the material must withstand ~ 260 PSI.

Neoprene yields somewhere above 500 PSI. How much higher? Probably depends on the durometer.

Please, will a real mechanical engineer check this for me? I know it ignores stress-rise in corners, for example. Those will be more significant for the AM design than for the tear-drop spoke flex-grip rollers we've bought from McMaster-Carr.

Re: New AndyMark Product Game Hint???
 

It looks like this, but it doesn't seem to have been altered from its current version.

Re: New AndyMark Product Game Hint???
 

Good to know my shooter wheel will still function as long as nothing touches it. :rolleyes: ;)

Re: New AndyMark Product Game Hint???
 

How does it perform at bench grinder speeds?

Re: New AndyMark Product Game Hint???
 

There it is! :cool: :cool:

Re: New AndyMark Product Game Hint???
 

Children, please stop teasing the products. They might bite you ;)

Re: New AndyMark Product Game Hint???
 

Well. West Coast Products may be propagating the rumors with their 2017 release. There are a lot of roller and conveyor parts :yikes: