Key stock for axles and drivers?

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Glenn Brooks
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Key stock for axles and drivers?

Post by Glenn Brooks »

Hello all,

Anybody have experience securing drivers on axles using keystock? In the same manner as a go kart wheel- slip fit on a 1” axles, 1/4” keystock to lock down to the axle? How did it work for you??

Thinking about modifying a set of trucks so I could have the capability to convert from 12” gauge to 15” gauge at so,e,point, by taking off the wheels and reversing a 1 1/2” spacer on each side of the axle. Only way this could work, I think, is with keystock and maybe locktite on the shaft.

Now this loco is more like a light duty ROW yard goat, or trolley, not a heavy HP mainline freight hauler. So loads on the drive chain would be fairly light.

Wondering if anyone has experience doing this, and what the results are??? More importantly, are there reasons why this wouldn’t be suitable?

Thanks much!

Glenn
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Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
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Steggy
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Re: Key stock for axles and drivers?

Post by Steggy »

Glenn Brooks wrote: Mon Sep 28, 2020 1:15 am Hello all,

Anybody have experience securing drivers on axles using keystock? In the same manner as a go kart wheel- slip fit on a 1” axles, 1/4” keystock to lock down to the axle? How did it work for you??

Thinking about modifying a set of trucks so I could have the capability to convert from 12” gauge to 15” gauge at so,e,point, by taking off the wheels and reversing a 1 1/2” spacer on each side of the axle. Only way this could work, I think, is with keystock and maybe locktite on the shaft.

Now this loco is more like a light duty ROW yard goat, or trolley, not a heavy HP mainline freight hauler. So loads on the drive chain would be fairly light.

Wondering if anyone has experience doing this, and what the results are??? More importantly, are there reasons why this wouldn’t be suitable?

Thanks much!

Glenn
The drivers on my F-unit are keyed to the axles, but are also a press fit, as I have no need to routinely pull the wheels.

On a set of Backyard Rail trucks I converted from timing belt to roller chain drive the wheels are keyed to the axles and are removable. However, the fit between the wheel bore and axle is essentially zero clearance, with a capscrew and hardened washer retaining the wheel against a shoulder on the axle. If there is any clearance between the wheel and axle, cyclic loading will eventually cause the wheel's bore to start wallowing out, resulting in wobbly wheels.

I don't see Loctite helping you in this situation.
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Erskine Tramway
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Re: Key stock for axles and drivers?

Post by Erskine Tramway »

Hi Glenn...

I'm using keyway cut bar stock, and keys, on my 7-1/2" gauge 'Lister'. I have tubing spacers that go between the wheels, and set screws on the wheels. After I get the frame all put together, I'll measure and cut sleeves to fit between the wheels and bearings.
2-19-15 wheelsets.jpg
Colin Edmondson, in England makes kits for little locos that are re-gaugeable from 7-1/4" to 10-1/4" gauges. The wheel/axle fit would have to be what we used to call a 'push fit', so that they would slide, but not be 'sloppy', to prevent the problems that BDD pointed out.

That's my 2-cents, for what it's worth.

Mike
Former Locomotive Engineer and Designer, Sandley Light Railway Equipment Works, Inc. and Riverside & Great Northern Railway 1962-77
BN RR Locomotive Engineer 1977-2014, Retired
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ChipsAhoy
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Re: Key stock for axles and drivers?

Post by ChipsAhoy »

Glenn:
On my speeder I use a key and spacer that sounds like what you are looking at. And I can change spacers to change guage. But, my axle is threaded on the end with a locknut. The axle is still a tight fit and I have to use a puller to get the wheels off. Now, that being said, the nut looks ok on a speeder, dunno what your machine will look like with a nut hanging out there.
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Dick_Morris
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Re: Key stock for axles and drivers?

Post by Dick_Morris »

What about a hub permanently fixed (Loctite or pressed and keyed) to the axle with the wheels and spacers bolted to the hub with about four bolts through the wheel and spacer and threaded into the hub? Wheels and spacers to be a slide fit on the axle. Swap the spacers from one side of the wheel to the other when you want to change gauge.
Glenn Brooks
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Re: Key stock for axles and drivers?

Post by Glenn Brooks »

Wow, some great ideas here!

BDD, yep, had figured on set screws and likely a light press fit, as you describe. Glad to hear this has worked for you.

Mike, your spacers are exactly what I have in mind, seems like the right solution for this. I suspect the OD needs to be fairly heavy - with some fair bit of bearing surface between the wheel and the hub. Something thicker than schedule 80 pipe, which we used to use on go kart axles.

Scotty, a nut on the end of an axle wouldn’t look out of place at all. In fact all my old mining wheels were all held on to axles on the original mining cars, with your method. As this loco is sort of a free lance steam punk center cab electric, don’t think it wouldn’t look out of place at all. Might even give it more ‘character’.

Dick, I like your hub idea as well. Actually, some of our old commercial go kart track karts were built with your suggested configuration. 4 bolts holding a split rim together - with a fixed hub on the axle. Same principle with a removable spacer, and fixed distance inner hub. Genius, man! Thinking hard about this design...

Iam contemplating switching from 12” to 15” gauge if we are successfull in in developing a local, grand scale, live steam club track. So want to have the option readily available to regauge down the road, without having to do a complete tear down of the loco Iam just now working on.

So feeling much more confident one of these methods will work.

Thanks much, everyone!

Glenn
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Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
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Erskine Tramway
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Re: Key stock for axles and drivers?

Post by Erskine Tramway »

Glenn Brooks wrote: Tue Sep 29, 2020 12:12 am Wow, some great ideas here!

Mike, your spacers are exactly what I have in mind, seems like the right solution for this. I suspect the OD needs to be fairly heavy - with some fair bit of bearing surface between the wheel and the hub. Something thicker than schedule 80 pipe, which we used to use on go kart axles.

Thanks much, everyone!

Glenn
Hi Glenn...

I went out and measured my sleeves. They are 1-1/4" OD, 1" bore, mechanical tube. They are partly there to space the wheels, and partly to stiffen the 1" axles outside the wheels.

Mike
Former Locomotive Engineer and Designer, Sandley Light Railway Equipment Works, Inc. and Riverside & Great Northern Railway 1962-77
BN RR Locomotive Engineer 1977-2014, Retired
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Steggy
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Re: Key stock for axles and drivers?

Post by Steggy »

Glenn Brooks wrote: Tue Sep 29, 2020 12:12 am Wow, some great ideas here!

BDD, yep, had figured on set screws and likely a light press fit, as you describe. Glad to hear this has worked for you.
Attached are some pics of the BYR truck I reworked to roller chain drive. Note the "field-removable" wheels. Removing the capscrew and washer allows the wheel to be pulled from the axle using a mallet or dead-blow hammer.

Modified BYR Truck w.Removable Wheels
Modified BYR Truck w.Removable Wheels
Wheel Retention
Wheel Retention
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Glenn Brooks
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Re: Key stock for axles and drivers?

Post by Glenn Brooks »

BDD, thanks, very cool. Looks like your upper sprocket gear is attached to the motor output shaft? And is your second sprocket gear acting as an idler gear - as in attached to a swing arm, for swiveling, to take up slack?

I do have two 24v electric motors that look like they would fit your design pretty well. still need to drop the trucks to take a closer look at what I have...

Glenn
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Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

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Steggy
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Re: Key stock for axles and drivers?

Post by Steggy »

Glenn Brooks wrote: Tue Sep 29, 2020 1:31 pm BDD, thanks, very cool. Looks like your upper sprocket gear is attached to the motor output shaft?
Correct. It's an off-the-shelf sprocket.
And is your second sprocket gear acting as an idler gear - as in attached to a swing arm, for swiveling, to take up slack?
Also correct, and the idler is also an off-the-shelf part.

Attached are some more photos.

Wheelset w/Sprocket & Chain
Wheelset w/Sprocket & Chain
Above is a view of one of the wheelsets installed in the truck frame.

Old & New Wheelsets
Old & New Wheelsets
Above is the new wheelset (right) and old BYR wheelset. Part of this exercise was to increase the reduction between the traction motor and the wheels. I used an 18 tooth, sprocket on each axle and a 14 tooth sprocket on the motor. The roller chain is ANSI 40.

New Wheelset Assembly Drawing
New Wheelset Assembly Drawing
Above is the new wheelset assembly drawing.
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tetramachine
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Re: Key stock for axles and drivers?

Post by tetramachine »

Glenn, Setscrews are used to hold the wheel to the axle, Not in lieu of a broached keyway and key to transmit the power.
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rkcarguy
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Re: Key stock for axles and drivers?

Post by rkcarguy »

Glenn,
I'm late to the party on this one, but my racing go kart has hubs that allow the rear track width to be set by sliding them in and out on the axle. They utilize a pinch bolt and 2-3 set screws on top of the key. I have never had one move except the one time I got put into the wall at ~50mph at the end of the straight. Using the kart hubs probably wouldn't work because of the weird 3 stud/bolt design for kart wheels, but making your own hubs the same way or modifying some purchased ones with a pinch bolt should work well.
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