Stephenson's Rocket

[Brian Rupnow]

My current idea is a bit more exotic.--Has more parts, but is "easier?" to fabricate because I don't have to turn the ends of the square spokes to fit into round holes. I have reduced the number of spokes from 12 to 10, and they are all located by the machined red hub (the red hub is shown  both "in place" and copied to the right hand side of the assembly so you can see what it looks like by itself). The red hub, although it looks complex, is all just basic rotary table work using a 3/16" end-mill cutting 3/16" deep. The spokes can lay in their appropriate slots and be Loctited in place, and the outer ends of the spokes can be tig welded to the outer rim.

[Brian Rupnow]

Regardless of what I do with the inner hub and spokes, the outer rim will not change. Next step will be to mount the material for the outer rim on my lathe and machine two outer rims from it. Because of the very real possibility of heat distortion from welding changing things a bit, I will make the rim about 1/16" greater than the drawing calls for, and about 1/16" wider than the drawing calls for. This will allow me to make clean up passes after all of the welding is completed.

[BillTodd]

I don't mind a bit of 4 jaw set-up, but doing it repeatedly 24 times is a bit too much.

Set up a square collet ?  or If you have one a small round ER collet will usually grab a square fairly well by the corners (in the spring relief cuts).

[Brian Rupnow]

I don't have any collets of any kind. I may look into buying some.--thank you for the suggestion.

[Brian Rupnow]

This hub seems to be the most complex part of the drive wheel assemblies. I was going to begin by machining the outer rims first, but I've had a change of heart, and this is what I will be making today.

[BillTodd]

Harold Hall has this suggestion:

<a href="https://www.youtube.com/watch?v=jEQDgFcFN1c" target="_blank">http://www.youtube.com/watch?v=jEQDgFcFN1c</a>

[Brian Rupnow]

Here we have the hub, reamed to a 0.75" bore, and stock 1.25" o.d. mounted in the rotary table, and a slot 0.188" deep cut with a 3/16" endmill. One picture shows the cut slot, the second picture shows a piece of the 3/16" square key material tapped into place for a trial fit. I have found out two things. #1---My 3/16" endmill is painfully dull, and #2 that my shoulder wants to quit about half way thru taking 0.005" depth of cut. Next trick will be to index the rotary table 36 degrees and do it over again.

[Brian Rupnow]

Things got a lot easier when I switched to a carbide endmill and was able to take 0.010" depth of cut. This is the hub which has not been cut to finished length yet, but has one spoke setting in place to show how it's going to work.

[crueby]

Should work out well, watching along....   

[Brian Rupnow]

These shots show the two piece center hub and one spoke. I'm happy with it so far. It will require a bit of touch up with a file before final assembly, but so far--so good.

[Brian Rupnow]

Things are going to stop for a while now. My lathe quit working last night about 6:00 o'clock.  I was half way thru a cut, turning at 400 rpm with a 0.015" depth of cut , in automatic feed mode. The lathe just stopped. No grind, no clunk, just stopped dead as if the power supply had died. I have checked the fuses and that is really all I can check. I'm afraid I may have to take my lathe to BusyBee in Toronto and have their technicians fix whatever went wrong.

[tghs]

fault light?,, I find many of these machines use cheap plug and spade connectors,, when my mill was faulting I replaced the power cord to machine connectors with better ones,, never a fault again,, I used to work for biotech company that provided machines that had to run,, service people would respond 24/7 to get the unit back up and running,, the phone in check list started with #1 have you checked all the electrical connectors and fuses,, # 2 go back and really check all the connectors and fuses, #3 did you use a meter?  one of techs drove 3 hours one way in the wee hours to change a fuse that was claimed to have been checked,, (the machines were provided with a very well stocked spare parts box) good luck..

[Brian Rupnow]

It's amazing what one old guy can do when he has some plywood, some metal rollers, and a cherry-picker engine hoist. The lathe came out of my shop, thru my office, into the main garage and onto my truck. It is now in Concord where the Busy-Bee main Ontario center is. i just got home and eat supper.

[Art K]

Brian,
I don't envy you your day, sounds busy. Loading up lathe and all. My last weekend ended up in a similar manner. Flicked on the computer on switch, heard a popping sound reminiscent of the power supply blowing on the previous computer. Talked to my nephew the resident computer expert... well that is if you consider a 3 hour drive away resident. he said try a new atx style power supply, if that works you're good if not it's the 3 hour drive to drop it off so he can fix it, again. At least I didn't need a cherry picker to lift the computer into my trunk, or boot if you are elsewhere in the world.
Art

[Brian Rupnow]

Aarghhh Billy--I think there's a wheel in sight!!! Got my lathe troubles sorted and just finished the first outer rim. Lookin' good so far. Mighty scary stuff parting off at that diameter.