Re: New AndyMark Product Game Hint???
 

Ok, so does anyone have any recommendations for shooter wheels that aren't $30 each? Are Colsons the best cheap alternative?

We used 4" kop wheels last year on our shooter, were only $6.00 each if I remember right

Re: New AndyMark Product Game Hint???
 

Any tips on how to adapt them for hex shaft?

Re: New AndyMark Product Game Hint???
 

I think the bore is 1", in the past we just made an aluminum hub that was .001 or so oversize and just pressed it in. You can probably take a colson hub or versahub and shave it down to size if you don't want to make a hub from scratch.

Re: New AndyMark Product Game Hint???
 

At a certain point you'll have to spend some money with some game objects.

Colsons worked for us in 2016, but in many other years didn't work nearly as well as more expensive options.

Considering the base price per axis in terms of speed control and motor, $30 per wheel really isn't that bad.

Re: New AndyMark Product Game Hint???
 

Man, what's the point of teaser videos if nobody looks closely at them. :yikes:

Re: New AndyMark Product Game Hint???
 

Yes, if you already know the wheel is going to do the job as expected.

$30/ea for trial and error can get expensive.

Re: New AndyMark Product Game Hint???
 

Depends on what you are shooting. I saw some pretty good shooters made from $5 AM stealth wheels this year.

Re: New AndyMark Product Game Hint???
 

Are you referring to this wheel in the AndyMark teaser? That hex bore looks pretty small. Is that a wheel AndyMark just had laying around, or do you think that's an upcoming product?

Re: New AndyMark Product Game Hint???
 

Hm... What's that plastic bit in the middle of the wheel? I hope it has some way to interface with a hex shaft nicely.

Re: New AndyMark Product Game Hint???
 

It looks to me like a .375 or even .25" hex bore.

Re: New AndyMark Product Game Hint???
 

Looks like it is the FTC bolt pattern so probably 6mm round or D bore with 6-32 bolts on a 16mm bolt circle. Most likely compatible with the new AM Nubs: http://www.andymark.com/AndyMark-Nub-p/am-nub.htm

Re: New AndyMark Product Game Hint???
 

I think you are right. That is likely an 8 mm (5/16") hex bore, so a nub would pilot in it.

Re: New AndyMark Product Game Hint???
 

Doesn't look like there's a nice way to adapt this to hex though :/

Re: New AndyMark Product Game Hint???
 

What "this" are you referring to?

I was looking at the hex bore in the white plastic hub. It appears to be 8 mm or 5/16" across the flats. If so, it will pilot on a nub's 8 mm boss. It also seems to have the 16 mm circle pattern of four holes that would suit a #6 screw.

So you could drive the wheel using 6 mm shaft through a nub, or you could drive it directly using 8 mm (5/16") hex shaft.

Or were you thinking about 3/8" hex?

Re: New AndyMark Product Game Hint???
 

Definitely not enough meat in the center to be able broach out to 1/2inch hex. The holes on the 16mm bolt circle would also clash with the points of the shaft.

Surely if you need to adapt it to use it, you might as well just make a hub from scratch.

Re: New AndyMark Product Game Hint???
 

It looks like there should be enough clearance to broach it.

Re: New AndyMark Product Game Hint???
 

It would end up looking like this if you tried to broach it to 1/2inch hex.

Re: New AndyMark Product Game Hint???
 

That would work just fine.

Re: New AndyMark Product Game Hint???
 

Definitely half inch.

Re: New AndyMark Product Game Hint???
 

Woah.... might want to resize that, or make it a link...

Re: New AndyMark Product Game Hint???
 

Checked with our engineers--we goofed on that. Updated CAD will go out next week.

Re: New AndyMark Product Game Hint???
 

Engineers are available on Christmas Eve? Jeez!

Re: New AndyMark Product Game Hint???
 

Come on... We know they didn't goof. They over designed. :D :D :D

Re: New AndyMark Product Game Hint???
 

There is a very old principle of engineering at work here:

When the print does not match the part, change the print. The part is always right.

Re: New AndyMark Product Game Hint???
 

As builts.

Re: New AndyMark Product Game Hint???
 

Yikes! These are already gone.

Any idea when they'll be back in stock?

Re: New AndyMark Product Game Hint???
 

Is there something in the FRC teaser we have all been missing? Something in the AM twitter "teaser"? Is this whole discussion of shooters useless because there's something obvious we're missing?

Re: New AndyMark Product Game Hint???
 

Nah, I was just referring to the wheel that looked very similar to the McMaster sure-grip wheels that were the topic of conversation at the time.

Re: New AndyMark Product Game Hint???
 

(somewhat off-topic: )

Or at my company, if the drawing doesn't match the CAD, change the drawing as CAD is master (unless the marketing department tosses back one's plans to make said part because "the CAD is wrong" :mad: ).

Sadly in manufacturing as supplier (in my case, to Toyota), that old principle doesn't fly for parts being sold to a customer. If you're not meeting the spec, too bad, no good. We've had to toss hundreds of trial parts over changed drawings and related sillyness... but they're the customer, and they're always (usually) right.

Re: New AndyMark Product Game Hint???
 

Engineers? Where?!

;)

Re: New AndyMark Product Game Hint???
 

Thank goodness there are people in this world who refuse to let physics and calculus ruin a good story.

Re: New AndyMark Product Game Hint???
 

Thank goodness there are people in this world who refuse to let 2" wheels have all the fun.

http://www.andymark.com/product-p/am-3480_60.htm
http://www.andymark.com/product-p/am-3480_50.htm

(CAD coming soon on the website--we were too excited to let these sit on the shelf.)

Re: New AndyMark Product Game Hint???
 

Re: New AndyMark Product Game Hint???
 

I'd buy that for $8 :D

Thank you AndyMark for another great COTS product!

Re: New AndyMark Product Game Hint???
 

We had good success with Delrin hubs in our shooter wheels this year. Went with around 0.004" over size press, some may have been more like 6 >_>. We have a big arbor press and I may have gotten a little carried away with the interference #SorryNotSorry.

Re: New AndyMark Product Game Hint???
 

http://www.banebots.com/category/WHEELSHUBS.html

Much lower durometer than Colson wheels, but not as compliant as the teardrop rollers from McMaster. Prices range from $2.50-$5.00ea (not counting hubs, which are only necessary for applications other than 0.500hex). 4 durometer options and numerous size options.

Re: New AndyMark Product Game Hint???
 

Hope that you will have enough stock of all four of the wheels.

Re: New AndyMark Product Game Hint???
 

Beyond the 2" sizing, this one has a black color option too! ;)

Re: New AndyMark Product Game Hint???
 

*redesigns robot to match color scheme*

Re: New AndyMark Product Game Hint???
 

Keeping stock for plastic molded AndyMark products is not a problem. Our mold shop is about 5 miles away, and they provide fast service. We don't have to keep gobs in stock, due to quick production runs.

We may run out of stock for a molded item for a few days, but it's always back in stock soon.

This is reason #3480 we don't buy molded parts from distant lands.

Sincerely,
Andy B.

Re: New AndyMark Product Game Hint???
 

Fun fact, at size 12 single spaced Times New Roman with 1 inch margins, you can get ~46 lines on a page so the AndyMark handbook for buying molded parts must be at least 76 pages assuming each reason is at least a single line.

I'm guessing Andy uses that handbook to keep his desk level. ;)

Re: New AndyMark Product Game Hint???
 

/r/theydidthemath

Also, the entire AndyMark employee handbook is only 15 pages. (I just checked.) Aside from FIRST's game manuals, I can't think of any company-guiding documentation that comes in at 50+ pages. ;)

Also, you think Baker can't build a level desk?

Re: New AndyMark Product Game Hint???
 

LOL. Now people are going to be looking at that desk for teasers. :)

Baker can't use you to defend his honor! He better provide a video using a NavX to show how level that desk is without a stack of paperwork under those wheels!

Re: New AndyMark Product Game Hint???
 

Marshall, don't spit into the wind. Even I can cut and drill pieces off site for an outdoor workbench to be used from a boardwalk and have it come out level at the right altitude (and be more solid than the boardwalk). Baker's so got an indoor desk that it's not funny.

Re: New AndyMark Product Game Hint???
 

That desk has wheels and is clearly meant to be rolled outdoors into the rain. #WaterGameConfirmed

At this point I'm just trying to see how absurd I can make this thread prior to kickoff. I'm waiting on Nate to drop a memey gif in here next.

Re: New AndyMark Product Game Hint???
 

We are rating the 2 inch wheels at 6000 RPM, or "don't go any faster than direct drive off a Mini CIM" below that speed it will not significantly expand (~1mm) but above that speed it becomes unstable and different parts expand at different rates. Interestingly, even at ludicrous speeds (+10,000 RPM) the hex will stay aligned if nothing touches it. When subjected to hard impacts at any speed the hex will slip (game piece, compression, and RPM dependent) but for the application it is designed for, that isn't really a problem. Even if it were used as an FTC shooter wheel for this years game it would probably function pretty well since the balls are light and only have to go a few feet. I can also say with confidence that it will not explode below 6000 RPM. I am unable to do any damage to it by hand, and it took putting pins between the spokes and stretching it by mechanical means so that the pins were over 13 inches apart before it tore.

Also, they are back in stock, so BUY BUY BUY!

Or one of our even newer 4" compliant wheels rated to Over 9000 RPM :D
Also an expansion vs RPM table should be up on the site soon (along with more stock :P )

Re: New AndyMark Product Game Hint???
 

Citation, while the page is being updated.

Headline GIF:

Re: New AndyMark Product Game Hint???
 

That number seems DANGEROUSLY high to tell general case to team's at large.

With compression and a high number of shots, I'd be very concerned running at that number.

Re: New AndyMark Product Game Hint???
 

What is on the paper that says product teaser?

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: