custom wheels

[Tow]

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.

[mman1506]

Originally Posted by Wiifi

We almost made our own wheels this year, unfortunately we had to return our 3D printer before we could finish them. Some advantages would be that you can make the wheels any size you would like as long as they remain within the constraints of the 3D printer. You can also change the structure of the wheel potentially saving weight.

When designing a wheel you would need a CAD software compatible with your 3D printer as well as some tread to attach to the wheel once they have finished printing. If I have some time later tonight I will upload an image of our CADed wheels.

Cost wise, you have a pretty large start-up fee. A 3D printer can cost you more then an entire team's budget for one year.

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

[EricH]

Originally Posted by mman1506

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

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.

[mman1506]

Originally Posted by EricH

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.

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?

[ehochstein]

Originally Posted by EricH

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.

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

[EricH]

Originally Posted by mman1506

Its sounds like you need a STL or a high end additive printer to get the strength necessary for 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.

Are 3d printers material runs about 30$ a pound and it isn't very good. Are they lighter than the equivalent milled from aluminium?

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.

[mman1506]

Originally Posted by EricH

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.

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?

[EricH]

Originally Posted by mman1506

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?

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.

[1683cadder]

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

[MichaelBick]

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.

[dcarr]

Originally Posted by 1683cadder

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

COTS = Commercial Off The Shelf

Originally Posted by FRC Manual

“Commercial, Off-The-Shelf” COMPONENT or MECHANISM, in its unaltered, unmodified state. A COTS item must be a standard (i.e. not custom order) part commonly available from the VENDOR, available from a non-Team source, and available to all Teams for purchase.

[EricH]

Originally Posted by 1683cadder

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

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.

[mman1506]

Originally Posted by EricH

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.

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

[Mr. Rogers]

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.
https://www.dropbox.com/s/14cvrmahmo...314_170616.mp4

[Tmaxxrox97]

Originally Posted by EricH

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.

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).