pic: Team 3266 Sheet Metal Drivetrain

[BurkeHalderman]

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[BBray_T1296]

This looks really cool.

Hope to see pics once it is built

[Jared]

Looks cool! How are the pulleys attached to the colsons and how thick is the sheet metal?

[BBray_T1296]

My guess is that the pulleys are attached to the Colsons with this

[Oblarg]

Looks nice.

How are you handling the Colsons on dead axles? What size Colsons are you using? What pulleys are you using?

[BBray_T1296]

Originally Posted by Oblarg

How are you handling the Colsons on dead axles?

My guess is this

[BurkeHalderman]

Originally Posted by Jared

Looks cool! How are the pulleys attached to the colsons and how thick is the sheet metal?

We are using pulley stock and turning the end down to make our own pulley/hub that will press-fit into the Colson wheel. All the sheet metal is .100" aluminum.

Originally Posted by Oblarg

How are you handling the Colsons on dead axles? What size Colsons are you using? What pulleys are you using?

The Colson wheels are the standard 4" diameter, 1.5" width. The pulleys press-fitted into the wheels are 28 tooth, 5mm pitch, GT2 profile pulleys, and the ones on the output shafts are 20 tooth.

You can see here the full wheel assembly with the hub, wheel and 3/8" flanged bearings, and on the right is the pulley hub that is machined from pulley stock.

[Oblarg]

Nice, I like that custom pulley design. Slick. No flanges?

Re: pulley stock, where do you buy yours? I bought some recently, and was dismayed at how expensive it is.

[MetalJacket]

Looks great!
One question for you though - how do you plan to mount bumpers? I have been practicing with sheet metal drive bases (my team plans to use one on a competition robot for the first time this year ) and I like the idea of having the flanges of the outermost panels bent outward but I'm not entirely sure how to mount bumpers securely.

[BurkeHalderman]

Originally Posted by Oblarg

No flanges?

Re: pulley stock, where do you buy yours? I bought some recently, and was dismayed at how expensive it is.

We buy all our pulleys, pulley stock, and belts from SDP-SI. I agree the pulley stock is really expensive. At $60 for a 200mm bar I questioned if it was worth the cost to make our own hubs. Although the price drops a lot per bar the more you buy, which helps justify spending that kind of money.

Originally Posted by MetalJacket

One question for you though - how do you plan to mount bumpers?

I haven't put to much thought into mounting bumpers on this frame since it's just an offseason prototype, but I think what we'll do is something similar to 148's 2011 bumper system; put 1" hex standoffs in the corners and then use a uni-body bumper frame and bolt it to those hex standoffs. I'll CAD this and post a picture of it.

Here is a front view of the bumper frame and hex mount:

[Chris Endres]

You loss a bunch of strength when you don't have the belly pan under the CIMs. try to fit the CIMs so the belly pan isn't cut out. Anyways, great job, looks like a good start to a great bot.

[AdamHeard]

Originally Posted by BurkeHalderman

We buy all our pulleys, pulley stock, and belts from SDP-SI. I agree the pulley stock is really expensive. At $60 for a 200mm bar I questioned if it was worth the cost to make our own hubs. Although the price drops a lot per bar the more you buy, which helps justify spending that kind of money.



I haven't put to much thought into mounting bumpers on this frame since it's just an offseason prototype, but I think what we'll do is something similar to 148's 2011 bumper system; put 1" hex standoffs in the corners and then use a uni-body bumper frame and bolt it to those hex standoffs. I'll CAD this and post a picture of it.

Here is a front view of the bumper frame and hex mount:

$60 for an entire drives worth of pulleys isn't crazy at all.