Rolling Along

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I've got a couple projects in mind that need wheels-- bigger than I want to hack out of solid, so I thought I'd play around making a few wheels and try a few things along the way.

The first wheels should to be around 3.5" in diameter. So, off to find something for rims. A little 3" pipe would be nice since that runs 3.5" OD, but I've not got any stashed away... except this rusty old piece of what's probably some sort of historical oil drilling pipe. And it's rusty. Really rusty and pitted. Been outside for many years. But, half the fun of making stuff is finding material inside other material, so we'll see how this goes. Hack off a bit with the bandsaw and throw it in the electrolytic de-ruster.

Overnight in the de-rusting tank and it's still rusted and ugly, but at least most of the loose rust is gone and most of the red rust converted to the softer black sort (if not, there would be clouds of rust-dust from the lathe, as is now it dusts very little) so on to the lathe to see how deep we have to go to get under the rust.

Hey, there is some metal down there.

A few things of note in the pic--

- The lathe ways are completely covered so no loose rust gets anywhere important. Paper is good because you can chuck it when it gets full of chips and it won't get wrapped badly around the chuck if it gets caught. Paper is bad because it can catch fire if you hit it with hot chips. Don't do that.
- I'm using a ratty brazed carbide roughing tool and taking light cuts towards the headstock with slow automatic feed @ 70 RPM. There's too much overhang and not enough grip for much else.

And on to clean out the insides (this bit was a threaded coupler, so I have to take out the threads):

All cleaned up and ready to whack off a couple inch-wide rims

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Way more effort than going to the pipeyard for some 3" pipe, but a lot more entertaining finding good material inside some rusty trash.

Next up; hubs and spokes.

 

[cfellows]

Looks Good. How does that de-rusting gizmo work?

Chuck

 

[shred]

Looks Good. How does that de-rusting gizmo work?

Chuck

The de-ruster is great, especially on surface rust. Sometimes I can't believe the part that comes out is the one that went in.

Searching on 'electrolytic rust removal' should get a bunch of hits, but in a nutshell, it's a bucket full of water with a little washing soda mixed in (baking soda doesn't work as well, but will do in a pinch). Connect up a few sacrificial iron electrodes (I use rebar; uncoated steel also works, galvanized makes a green mess, stainless makes toxic goo) around the outside, and suspend the rusty part in the middle of the bucket. Connect a 12V battery charger up so the - lead goes to the rusty part and the + lead goes to the iron electrodes (keep the clips out of the water). Turn it on about 4 amps (actual current varies with electrode surface area, charger, part size and so on) and pretty soon clouds of tiny bubbles are coming off the part-- some rust gets converted back to metal or black iron oxide, and most gets knocked off. After an hour or two, fish out the part, wipe it down and put it back if needed. Clean the electrodes as well, since they'll be covered in rusty goo like everything else in the tank.

Do this all outdoors.

Here's a larger picture of the setup--

 

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Now that we're done with the rusty stuff; on to the hub.

I made the hub from 12L14 steel and used my round profile tool to auto-generate some decorative fillets while I was making the part dimensions.

Then over to the vertical RT to drill through and counterbore 1/4" every 60 degrees (it's not necessary to use a RT for this; collet blocks, spindex or indexer would work fine. Starting with hex stock would also work)

Part off on the bandsaw

Turned around back in the lathe to clean up the sawn end and make the outside hub. Cut-up soda can in chuck jaws to protect the finish on the spigot.

Finished hub in a rim. All we need now is spokes to connect them.

 

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Here are the spokes. This time I'm going with round brass spokes.

If you look carefully you'll notice the hub is threaded, while the spokes are not. Running design change.

I was going to thread the spokes in and set their total length (somewhat critical to fit the rim) off the bottom of the counterbore, but a little experimenting showed the 1/4" brass rod press-fit in the counterbore well and I didn't need to fiddle around threading the spokes and trying to get the length minus thread just right.

Pressing in the remaining spokes.

To fit the rim reasonably concentric, I made a little centering jig-- it's a round plate with a 1/4" pin in the center and a step at the outside edge the same size as the ID of the rims. You'll notice I've gone ahead and soldered the spokes into the hub as well.

Here's the whole mess in the jig ready to solder, showing how it works. The hub and rim are held concentric and the little gaps at the ends of the spokes are filled with solder. The size of the step determines the offset of the center hub. If you wanted to get really fancy, you could turn the spokes to the exact fit, but solder covers enough gaps there's not much need for that much fiddling around.

Originally I was going to silver-solder everything, but an experiment early on showed my torch really didn't have the power and the gap between the rim and the spokes was difficult to get the silver solder to flow into, so I dropped back to soft-soldering. Darn soft solder really doesn't behave as nicely as silver solder and I have a number of globs and splats to clean up later. I plan to paint them in the end, so I can hide any little flaws that way

Here's one ready for cleanup. There's some more cosmetics to be done to them later, so I'm not too worried about them looking perfect yet, and I'll probably bore out the hub when I fit them to the axles to eliminate the last bit of wobble.

The second one took about a quarter the time, even re-making the hub.

They're not quite perfect, but they'll do the job fine.


View attachment WheelDwg.dxf