Re: custom wheels
 

Actually we used the white wheels from the KoP but we used duct tape to change it's atributes (it looses a lot of traction but gains speed). The thing I'm trying to say is that you don't need a 3D Printer or CNC to make your custom wheels you can modify any type of wheel. It's a lot cheaper but you have the risk that it may fail so, you need to check if it functions as you want.

Re: custom wheels
 

A 3d printer sound like a pretty expensive way of making wheels. How much did yours cost?

Re: custom wheels
 

The RepRap types of printers can start around $2K, depending on material source. $3K-$4K would get you a similar printer that's been modified/built by a company. Not sure what some of the top-of-the-line desktop models run.

Material typically runs about $15/lb. Might sound like a lot, but that's a lot of material for a lot of parts.

Re: custom wheels
 

Its sounds like you need a STL or a high end additive printer to get the strength necessary for wheels. Are 3d printers material runs about 30$ a pound and it isn't very good(Bits from Bytes). Are they lighter than the equivalent milled from aluminium?

Re: custom wheels
 

The one our school is looking at costs about $20k, I'm still crossing my fingers!

Re: custom wheels
 

If you don't have an STL file, you're not getting a printed wheel. You may mean SLS, a type of 3D printer.

But strength is a matter of material, and to some extent manufacturing method. I would say that a RepRap could produce a wheel that is strong enough for FRC, if the proper parameters were used in terms of fill amount and layers at the outside. RepRap-type printers' technical name is FDM (Fused Deposition Modeling), BTW.

Lighter? YES. Take a block of PLA or ABS. Now take a block of aluminum the same size. The plastic should be lighter (unless you're Wile E. Coyote).

You may have a printer type that uses a cartridge, or a powder (SLS draws on powder with a laser). That's much more expensive, in and of itself. If your material isn't very good, it may be expired--or you might need to look into changing your source.

Re: custom wheels
 

SLS my bad. Wouldn't you be able to use less material to make a aluminium wheel than a 3d printed one potentially making it lighter?

Re: custom wheels
 

It's possible... but unlikely.

Let's say that you have 2 wheels. They're identical in form, but because one is plastic and one is aluminum, they will have different weights due to densities. Aluminum is 0.1 lb/cubic inch; ABS is 0.04 lb/cubic inch. Let's say that both wheels have about 6 cubic inches (that would be a solid 4" wheel, 1" wide, with half its material removed somehow). 0.6 lb for aluminum, 0.24 lb for plastic.

Now, ABS's strength is about half that of aluminum, give or take a bit. So, you beef up the ABS wheel a bit--say you add back 3 cubic inches (which, for a wheel, is probably all you need). Still only at 0.36 lb. Adding back the entire material gives 0.48 lb, still less than the aluminum--I've been assuming that the aluminum wheel is strong enough this whole time.

BUT! 3D printing allows you to build stuff hollow, or with support structure inside--and much of the stress is carried in the outside of whatever you're working with. So you could actually build a pretty strong wheel out of ABS, without simply adding material willy-nilly, and be pretty light into the bargain.

Re: custom wheels
 

What are COT wheels? My school has a makerbot would that be suitable?

Re: custom wheels
 

COTS parts are bought and unmodified items. COTS wheels are any wheels that you buy, so colsons, AM wheels, and Vex wheels all fall into this category.

Re: custom wheels
 

COTS = Commercial Off The Shelf

Re: custom wheels
 

COTS wheels are Commercial Off The Shelf wheels. Translation: Buy them from a vendor, who may also be the manufacturer.

A Makerbot might be suitable for printing wheels. You'd have to get more specific on size and material, though--some of the smaller Makerbots might have trouble with, say, a 6" wheel.

Re: custom wheels
 

Thanks, Since were in Canada the plastic costs a quite a bit more especially with shipping.

Re: custom wheels
 

This is what we did this year, friend of mine made these up in CAD, he even included extra aluminum on the opposite side of the valve stem for counterbalance (we used the same rims on our shooter) Our sponsor machine shop turned out 8 of them. The spinners were actually the idea of our machinist. He had too much fun making them. :p
https://www.dropbox.com/s/14cvrmahmo...314_170616.mp4

Re: custom wheels
 

Actually a RepRap printer that would be able to make a pretty decent wheel is around $500- $1000 depending on where you buy the parts and on which model you buy. That is also an un-assembled version (I'm assuming that a robotics team would be able to put it together).