Composite drive wheels

[Functional Artist]

I have been looking for some narrow(er) "keyed" (6") "drive" rims (~3" wide)
...but, most of the (6") rims that I've found are (~5") wide (~$19.00 ea.)
https://www.bmikarts.com/6-x-4-12-Steel-Rim-1-Bore_p_5402.html

Then, I was thinkin'
...maybe I can just add hubs to those composite rims from Surplus Center (~$7.00 ea.)
...would even be lower cost & lighter weight
https://www.surpluscenter.com/Wheel...0-6-Carlisle-Wheel-Tire-Assembly-1-116259.axd


Lookin' into it a bit, the "hub hole" of these composite rims is (~1 5/8")
…& a hub for a 1" axle is to big (~1 3/4" OD)
…but, the hub for a 3/4" axle seems like it will work (~1 1/2")

* Just happen to have a differential with 3/4" axle shafts

So, I rounded up some 3/4" hubs (from a Craftsman riding lawn mower)
…& then, cut 'em out of the (way too huge) rims

Now, we gotta get 'em installed into the composite rims

I'm gettin' 'em ground down to the hubs (removing the excess material)

Questions:
1.) Would an epoxy work to bond these hubs into these rims?
…if so, recommendations on types or kinds of epoxy

2.) Should the hubs be "shiny" clean metal or painted?

3.) How long do ya think they will last?

Thanks, fellas

 

[Texan]

Looks iffy, but you are a pretty crafty guy. We use a few epoxies at my job, and we try to get the surfaces as clean as possible for the best adhesion.

 

[anickode]

It really depends on what type of plastic the wheels are made of. Polyethylene products for example, are basically unglueable.

I'd bet they're probably a Nylon or PAG (glass fiber reinforced nylon). An epoxy made for plastics should work. I wouldn't rely solely on the bond strength to transmit torque however. I would go inside the bore with a saw blade and make a series of shallow radial cuts (like splines) to allow a mechanical interface between the epoxy and wheel. Do the same on the outside of the hub sleeve, either cutting into it with a grinder, or by adding some beads of weld along the length of it.

That's your best bet, IMO. Only thing better I could think of would be to machine some thicker hub sleeves, cut shallow splines into the outside of it, heat it up, and press it straight into the bore of the wheel, melting the plastic and fusing them together. But that is a lot more complicated, and would probably cost more than sourcing the proper wheels in the first place.

 

[Functional Artist]

exothermic reaction

Been doin' some grindin' & shapin"
…& a little research

"Epoxy glue is a synthetic mixture of a resin or epoxy polymer and a hardener used to attach or join a variety of the same or different surfaces together with a strong, durable and resilient thermosetting bond that can withstand extreme stress and environmental conditions"

"Epoxies are created by polymerizing a mixture of two starting compounds, the resin and the hardener. When resin is mixed with a specified catalyst, curing is initiated. Curing is the process by which molecular chains react at chemically active sites, resulting in an exothermic reaction."

Think Ima gonna try some of this stuff

JB Weld Clear Weld

•ClearWeld is a quick setting, multipurpose two part epoxy that provides a strong and lasting bond on most surfaces including tile, most plastics, ceramic, glass, wood and metal
•ClearWeld is designed to cure with a clear, transparent bond when used at thicknesses of less than 15 mil
•ClearWeld has a 1:1 mixing ratio, sets in 5 minutes and cures in 1 hour
•With a tensile strength of 4400 PSI, ClearWeld sets to a hard, permanent bond

 

[Functional Artist]

Directions say:

1.) prep by roughening both surfaces (#40 sand paper)
2.) clean 'em with degreaser (alcohol)
3.) thoroughly mix equal amounts of epoxy (A) & (B)

 

[Functional Artist]

Before, I mixed the epoxy, I drilled a 3/4" hole (@ 90*) in a piece of plywood
…& then, inserted a piece of 3/4" axle shaft
(to use as a centering/squaring/mounting/gluing/epoxying stand)

After, mixing the epoxy, I slathered a heavy layer of it onto the outside of the metal hub & then, slide it into the 3/4" shaft
…then, carefully set the composite rim down onto/over the hub
…then, drizzled some of the remaining epoxy down into the gap (~1/16") between the hub & rim
…& then, weighted the rim down to keep 'er from moving while the epoxy cured

 

[ezcome-ezgo]

The outcome of this must be posted here. The world is waiting...

 

[Functional Artist]

Well, that's the first one
…& it seems like a pretty solid bond to me

On the second one, Ima gonna add try-n-add some "splines" to the hub & rim
...like "anickode" suggested

I just wanted to see how the first one, would turn out...first

 

[Functional Artist]

Spacer Ring

The original plan was to make & use a "temporary spacer ring"
...as a "removable" centering/alignment spacer, between the hub & rim

I put it on the bottom side
…& left it protruding out ~1/8"

The plan was to only apply the epoxy to the top side
…& let it "set" (~5min.)

Then, flip the rim over
...remove the "spacer ring"
…& then, drizzle in some of the epoxy, to bond the other side.

Here's what actually happened

1.) the epoxy "drained" all of the way down/thru the rim
…& "glued" the now-permanent "spacer ring" in place

2.) also, when I flipped the rim over to drizzle some more of the epoxy into the other side
...the rest of the epoxy had already "set up" in the pan

Well, it didn't go "according to plan"
...but, it got the job done

 

[Functional Artist]

Been cuttin' some splines
...inner & outies

Made a new centering spacer
...this one will be permanent too

Then, masked/covered the rim to protect it from any "excess/mess"

 

[Functional Artist]

Sorry for the delay, I had to get some more epoxy

This centering spacer is made of a bit thicker material
…so, it fit's over both the hub & inside of the rim, pretty tightly

After givin' everything a good cleanin'/de-greasin', I applied some epoxy onto the hub
…slid the centering ring on
…then, slathered a thick layer over the whole thing
…& finally, slid it into the rim

It took a bit of effort to slide 'er in
...but, she fit's nice-n-snug
…& is very well centered

Had to align the hub, within the rim, so that ~3/8" was stickin' out on each side (just like the other rim)
...then, drizzled some of the epoxy into the "gap" & around the hub, on both sides

*While the epoxy was still "runny", I also "sealed up" the back side of the first rim by drizzling some of the remaining epoxy around it

Boom! (2) composite drive wheels

 

[Dingocat]

Now the test: do they hold up? or if one fails which is it

 

[ezcome-ezgo]

I'll bet you a haircut one of them will fail.

 

[Functional Artist]

I'll bet you a haircut one of them will fail.

Oh, ye of little faith

It's just an experiment to see
A.) if I could do it
B.) & if so, how long they would last
C.) data: if/when one of them fail (or both) I/we'll know, for sure "what, where, when, why & how"

* These rims are actually made/sold for/as wheelbarrow wheels
...but, low cost/light weight ...hmmm
…& I'm always re-purposing stuff


I have tested these rims on, the front of, the Torsk kart, Damien & also, the Atom kart
...with NO ISSUES what so ever (just installed "proper" bearings)


My initial concerned was, if they could handle all of the dynamic loading that can be applied by the front of a kart
...but, they seem to handle it pretty well (so far anyways)


So, now we are gonna find out if/how well they hold up to the dynamic loading applied by the rear of a kart
...plus, we'll "throw in" the torque applied by an electric motor too

* Stay tuned, there's more to come