2-rail steam locomotive conversion techniques - a place to share ideas

I like where you are going with this. I hope this turns out to be fruitful.

I was waiting for someone with a big lathe to chime in.  You really need collets to do a good job, always remembering that the average 3 jaw chuck is not accurate enough for model train wheels.

Just to broad-brush it,  Joe used Leadloy - a free-machining steel - and he pressed a partially machined tire on the driver center before final machining.  I was never talented enough to make jigs for such machining, although I have done tool post grinding to true up some really out-of-round wheels.  Generally the insulation will yield under the pressure of a cutting tool, and the accompanying heat.  Joe is a talented machinist.

I make my tires out of iron pipe, when I can get it in the proper diameter.  I wouldn't dream of making tires from solid - takes way too long and wastes material.  I chuck the pipe up in the three jaw, then mark it so if I have to take it out before the first tire is complete, I can put it back in the same location.  I machine the tire, flange, and inner diameter, then take a cutoff bit to partially form the back side.  At that point, I take a file to the flange, and round it off a bit.  Then I polish it with sand paper.

Driver axles are always center-drilled around here.  I do that next, along with any machining that must be done with a driver that is still affixed to the axle.  For the Williams drivers, we machined quite a bit of material off the back side, since tinplate drivers are a lot thicker than scale drivers.  And of course, when starting with a tinplate driver, you cut the old tire off, and make the diameter compatible with the tires you have machined.  The insulated side needs clearance for the insulating paper.

Pressing tires is easy - you need a press of some sort, and for me the Harbor Freight cast iron drill press works.  The fit should be tight, but not so tight that you cannot easily press the center into the tire.   The insulated side uses Loctite-saturated paper of appropriate thickness, and that is even easier to press - often finger pressure will do.  A really tight fit will shear the paper, and result in an out-of-round finished product.

More later - open to questions.

Boy this is outstanding information, so thank you Bob!  I have access to collets, and have some experience with toolpost grinding as well.  I see the key decision point regarding pressing a partially machined tire onto the wheel, and considering heat buildup at the last step ruining the insulator.  I'll have to figure out which way to go on this.

There are a few disparate projects i have in the queue.  One is to work with a set of Scullin disc drivers.  For a 3 rail blind set example, it seems that I would have to completely remove the outer material down to where the ridge line ends, and then turn a new tire out of pipe which would include a 2-rail flange, for an interference fit (0.001" with the wheel plus insulator OD?).  I see fish paper sheeting comes in a variety of thicknesses, is there one in particular which is good for O-scale?  Also, do you default to the green Locktite for these kinds of applications?

Lastly I would guess I need to also figure out proper electrical insulation of the rods, such as providing plastic inserts to the wheels and/or at the cylinders.

Thanks again!

The advantage of rim insulation is that you do not have to insulate rods.

I never used fish paper - my machining can approximate .001 if I am really careful - I do press fits more by feel.  If you can hold it that close consistently yours will be perfect.

Yes, blue or green Loctite - 602, or "shaft" Loctite.

I just use those post cards that come in the mail at election time.  Make them bigger, then trim after the loctite sets.

Of course you machine the old tire off, but also you will need to machine the backside of tinplate wheels - they are way too thick.  Tires should be a max .172" thick.  Third Rail uses .158, and there was a move to standardize at .145, which is too skinny for my track.

Just posting here so I get notifications of updates for now.  I have a Weaver Brass G1 in 3R that I want to covert to an 800 series CNJ version in 2R.  The detail modification side is fairly simple, but learning techniques on making the wheels scale is very interesting to me.  I also have other locomotives I'd like to convert as well. 

I have a Unimat lathe I got as a gift, but most of the collets got destroyed when my last house flooded in 2016.  Finding parts is going to be interesting to get that up and running.  It came with almost all the accessories one could imagine.

Unimat is too small, unless you got one of the larger bench models.  The 6" Atlas is too small.  Actually, the early 12" Atlas was too small as well.  If you get one of the later 12" models with flat ways, that might work.

I got my 9" South Bend for $600 with full collets, taper attachment, huge toolpost grinder, and several chucks.  Bargains are out there.

Unless you like to do the machining work, why not just obtain 2 rail models.     Usually the 2 rail models are closer to scale then the 3 rail versions.    They tend to be better starting points for most projects.

I can understand that the accomplishment and machine work can be a lot fun.

That's my hobby - building things.  Right now it is a ten-wheeler, a P-5 SP Pacific, and a Taylorcraft L-2 wing.

@prrjim posted:

Unless you like to do the machining work, why not just obtain 2 rail models.   

Sort of presumes that the 2 rail models actually exist.

I tried to say that if the building things is your hobby focus that is fine.    I enjoy building things, but I don't have the tools or skills to do real machining work.

I was trying to say that generally speaking, there have been more specific 2 rail models made than 3 rail.    The imported brass steamers have been aimed at getting more and more road/prototype specific over the  years.    These models have historically been hand assembled with simple jigs and fixtures allowing small runs of as few as 50  units.     Brass fabrication lends itself to this sort of assembly.    The markets are quite small for many unique locomotives, say the Suncook Valley mogul from Connecticut is an example.    There are probably very few people who would be interested in a mass producted model of that loco.

3 Rail locos are aimed a much bigger market and therefore can focus on larger runs.     However the economics of the doing the larger runs in competition means they have to mass-produce - ie with automation.    They make molds or dies for diecast or injection molding and do runs of 100s or 1000s.   they have to have big numbers to pay for the tooling within the price range they have to sell.    This means they make many many units that are identical.     they often change the paint scheme but that is generally all the unique detailing they do.     Hence a given model, say 4-6-0, is generally the same regardless of road name and regardless of differences in the prototypes, including to the level of such things as boiler shape and length, and driver size.    

My opinion is that 2 rail models will generally be a better starting point for a scale project.   I'm sure there are exceptions.    And of course the cost could be important.    If you are a scratch builder, then that is a step farther and neither is a starting point for you - ie you want to build from scratch.

Here are a couple reasons - I am personally charmed by the inaccurate Lionel B6 switcher.  Cannot buy that in brass; did not come in 2-rail.

I got a Lionel FEF as a present from a customer.  Its details put the USH model to shame, so rather than dump it I 2-railed it.  I did use USH drivers.

That is a relatively inexpensive solution if you do not have a lathe - drivers pop up on the used market often, and go for around $25-$30 an axle.  Still requires metal work, but mot of it can be done with a $60 HF drill press.

@bob2 posted:

The advantage of rim insulation is that you do not have to insulate rods.

I never used fish paper - my machining can approximate .001 if I am really careful - I do press fits more by feel.  If you can hold it that close consistently yours will be perfect.

Yes, blue or green Loctite - 602, or "shaft" Loctite.

I just use those post cards that come in the mail at election time.  Make them bigger, then trim after the loctite sets.

Of course you machine the old tire off, but also you will need to machine the backside of tinplate wheels - they are way too thick.  Tires should be a max .172" thick.  Third Rail uses .158, and there was a move to standardize at .145, which is too skinny for my track.

Outstanding, and thank you so much.  This is exactly the kind of information I was looking for - practical information.  I had sketched up a drawing to hang over my machine for reference based on the recommended O-scale standards, but perhaps I should increase the tire width from 0.145" to at least 0.158" to improve operations.  My track is a mixture of ME and Atlas, and a mixture of codes from mainline to sidings.  Do you also try to induce some tread taper as well?

Also, does anyone have tips on accomplishing the fillet and inner/outer flange radii?

With regards to prrjim's questions about starting with a 2-rail model instead of 3-rail, one of the primary reasons for me would be prototype specific.  I model eastern roads, and after years of watching the oscaleyardsale, looking at local shows, web vendors and search filters on eBay it gets frustrating waiting for a vintage brass model which is not likely to arrive.  Meanwhile there are many fine 3-rail offerings now, and with the fancy proprietary electronics being the weak link they can be had for a bargain in a no-op condition.  I think the phrase 'doorstop model' might take on an additional meaning for me over the next 10-20 years, to include 3-rail scale models which don't work anymore (I don't predict some the feature-laden electronics are going to age well).  Personally my patience to sit behind the computer screen waiting/searching is wearing thin, and I'd rather spend the time working with my hands to resurrect/kitbash some of these diamonds in the rough.  Electronics are a specialty of mine, so if I can increase my drivetrain skills I should be all set.

Every once in awhile I am lucky to score a fine 2R brass model on my want list, which only requires some minimal work to correct the aesthetics and operations.  Those are great days!  I was very fortunate to obtain a brass Niagara which must have been dropped on its head from a decent height, and that only required a minimal amount of enjoyable work to repair.  Interestingly I used Lionel as a parts resource from their 3R Niagara.

@GG1 4877 posted:

Just posting here so I get notifications of updates for now.  I have a Weaver Brass G1 in 3R that I want to covert to an 800 series CNJ version in 2R.  The detail modification side is fairly simple, but learning techniques on making the wheels scale is very interesting to me.  I also have other locomotives I'd like to convert as well.

I have a Unimat lathe I got as a gift, but most of the collets got destroyed when my last house flooded in 2016.  Finding parts is going to be interesting to get that up and running.  It came with almost all the accessories one could imagine.

I don't really have the room for the equipment I'd need but I'd like to follow this topic too.  On the Weaver engine the  ones I have allow you to remove the wheels and axles from the bottom.  I've converted two of them by changing to 2 rail drivers.  The drivers aren't common but they do show up on the forum and on auctions sites at least a few times a year.  It wasn't that hard to remove the old drivers, pull the wheels, then install the new drivers with the Weaver bearings.

Yes on the taper.  It is slight, but all wheelsets have it.  You just set the compound rest for a couple degrees and cut.

The radius between tread and flange is not necessary, but if you grind your tool to the proper round nose, it is automatic.  The flange itself can be rounded with a clean file, using appropriate care.

Leave about a thosandth for polishing.  Use wet-or-dry sandpaper and some oil to get a mirror finish.  Looks good and slows corrosion dramatically.

Let's see some photos of your lathes?

@bob2 posted:

Here are a couple reasons - I am personally charmed by the inaccurate Lionel B6 switcher.  Cannot buy that in brass; did not come in 2-rail.

I got a Lionel FEF as a present from a customer.  Its details put the USH model to shame, so rather than dump it I 2-railed it.  I did use USH drivers.

That is a relatively inexpensive solution if you do not have a lathe - drivers pop up on the used market often, and go for around $25-$30 an axle.  Still requires metal work, but mot of it can be done with a $60 HF drill press.

Good info, Bob!

Here is my 11' Sheldon.  Please be aware that among my many failings is the tendency to not clean up after every job.  I should change that - they tried to teach me in high school.

And here is a 12' Atlas - the older style.  I am going to suggest that this is not a good lathe at all - if you must go Atlas, get the more modern version.  Still, there is enough cast iron in there to enable you to cut steel pipe if you want.  Not sure what kinds of collets will fit - this one got sold rather rapidly on Craigs List.

Nobody else owns a decent-sized lathe?  Here is the 9"South Bend.  I sort of cut the tailstock out of the picture - my mind was elsewhere, on a Taylorcraft wing rib stitch project to the left of the camera.  I regard the South Bend as the epitome of lathes - one of the most beautiful machines ever created, and able to reproduce itself.

Very cool, thanks for sharing your setups.  Work is a bear this week, but I will post some lathe pics this weekend.

@bob2 posted:

Nobody else owns a decent-sized lathe?  Here is the 9"South Bend.

Owning is one thing; having a place for it is something else. Not everyone has space in an hanger for their shop.

You want to carry that 9" South Bend down the steps into my basement for me, where there's no space for it as well?

Bob2

Nice photos. You've posted many great pics of your trains, but this is the first time I can recall actually seeing your work area. I wouldn't mind seeing more! Looks like some HO scale stuff lurking there above the lathe...

Mark in Oregon

It is.  It was all in a box for a half-century.  Much happier having it out.  Each piece has been duplicated in either O Scale or 17/64 Scale, except the Ulrich Gons.

Martin - my point is that if you cannot own at least a 9" South Bend or the equivalent, you are not going to be machining locomotive drivers.  Surely you have a garage?  That is where my 11" Sheldon is - right in front of the Beemer, along with a mill and large drill press.  But not everybody desires a big lathe or wants to machine drivers.

Interesting topic!

Bob, you really are an expert. Thanks for that polisihing tip - I'll try that, too.

I do more and more conversions of OW5 wheels to Proto:48 but I also made some completely new tires using solid ledloy steel on my sherline lathe. These were for the blind tires on a Sunset 4-12-2 that I wanted flanged.

The old tires come off by cutting them with a hand saw, the very last bit of the tire is then broken by inserting a screw driver into the slit and give it a firm twist - that tire comes off so easy.

I am using fish paper with great success, by the way. It's easy to work with, I glue it in place with a tiny bit of CA and then move the raw tire over it and soak the gap with locktite. It's real thin and absorbs the liquid.

First I wanted to buy a much bigger lathe but then realized that you really work small pieces in O scale. Should I need more tires I am hiring a professional metal craftsman. That person already made 12 raw tires for a 3-rail conversion of an early Sunset Challenger.

And here are some pics of my own work:

Wow...that is some really nice looking work!

Mark in Oregon

No doubt, ....very nice Sarah!...that’s some talent!..

Pat

Leadloy is the solution - really easy to cut.  Even then, I would not have guessed that a Sherline was up to the job.

Sarah uses Joe Feohrkolb's idea - machine the final contours after pressing the tire blank on.  I am not that good - I can make a very light cut if I have to, but the heat expands the tire, and then it slips off.  I have followed Sarah's efforts, and am impressed!  Maybe she is a surgeon in real life - precision like that is a real skill.

Hmmm... I think that finishing a wheel contour is where the precision of the Sherline really shines. Matthew Forsyth taught me how to use a lathe and make these conversions. To achieve a press fit on the engineer's side drivers the ability to do real light cuts is essential. On the fireperson's side no pressing is needed, just a loose fit to allow the fishpaper to stay where it should. The green loctite is nasty and extremely strong, no problem to turn the tire.

I am bot yet too good in grinding the cutting tools and cheat a bit by using carbide reversing plates. That costs some extra bugs but you know...

We'll here's one of my conversions, A Sunset Pennsy E6. The lead truck wheels, were also turned from scratch, with turned Acetal rod for insulation. I wonted the right contours on the lead  wheels. The trialing truck uses the original wheels with the flanges machined back to 2 rail specs and insulated as the lead truck. I cut of the tyres on the drivers, just as Sarah did, and turned new ones on my Sheraton lath ( manufactured in Melbourne ), looks just like Bob's South Bend, funny that! ( the South Bend was a much coped design )  I swopped a small Unimat to get it, and the guy through in shipping form Melbourne to Adelaide South Australia, no cash changed hands. I thought it was a great deal, and couldn't believe my luck. Iv'e since lowered the front cylinders, as the 3 rail version has them to heigh. The whole thing was winged from what I could remember from school in my youth, I still have a-lot to learn. O! I also added ball bearings to the driver axels, and some to the gearbox.  cTr... ( Choose the Right )

This is a Pecos River Brass Santa Fe Baby Hudson, converted as above. This one came with badly smashed cab that needed to be straitened and re-soldered.   cTr...( Choose the Right )

Gee whiz...there are some real artists here...

Mark in Oregon

Great to see the handiwork of the forumites, some real talent there!

When I was a student I had picked up one of the Harbor Freight/Central Machinery 3.5" mini-lathes, which has been real nice for cutting small pins and such for custom electrical work.  Since then these things seem to have really climbed in price, so might not be a good deal anymore.  Here is a picture of it, and just behind it you can see a small cast tabletop press, and next to it is a makeshift floorstanding bottle-jack press:

Recently I inherited a well-loved 6" Craftsman-badged Atlas lathe.  I am hoping to use this from now on, and may sell the mini-lathe.  Here it is sitting on a homemade bench, and I've added a revolution counter for wire winding operations and a small OD grinder for surface work:

Lastly I do have access to my father's 7" lathe.  This is an imported unit (Birmingham/Taiwan), but is high quality and quite affordable on the used market (for what it is).  It has an interesting feature worth sharing in that a section of the bed can be removed to increase the swing for operations such as turning brake rotors.  It's probably overkill for scale work, and like I mentioned I hope to use the above Craftsman/Atlas from now on since it's in my shop. 

Here in Ohio there are two big used machinery brokers, HGR and McKean, and both are great sources for affordable equipment.  For example, non-digital display Bridgeport mills regularly go for under $1K.  Of course moving them home requires summoning the ingenuity of the ancient Egyptians!

I found some other pics that might be off interest .   cTr...( Choose the Right )

And this was my first attempt at two railing. I machined from scratch all the tender wheels, lead truck and rear truck wheels. The drivers where USH but the tyres were worn out, and needed replacing. I guess when you're feeling brave, you just have to attempt these things. I really need to finish this one.   cTr...( Choose the Right )

Hello, I hope this is not off topic, but would any of the experienced forum members (Steven, Sarah, others... ) be willing to take on a conversion for me?  It seems that Joe F. is retired - he doesn't respond to email or phone.  I have a Lionel Century Club NYC Niagara and desperately want it 2-railed.  I can do everything myself except the driving wheels.  I guess I am chicken - I have a Logan 10" lathe with all the bells and whistles but could never do the work myself.  Alternatively, could you point me to someone who does this as a business like Joe did?

My last resort is to cannibalize an older KTM Niagara for the mechanism.  That would be a shame.

Thanks, John

Shame, but cheaper and better.  As far as I know, nobody will touch this stuff for less than $125/axle.  I have a leftover set of T1 drivers (PRR) at $80/axle, beautifully done.  Nobody wants to pay that much.

I really wouldn't be much help, as I assume you are in US and I am in Australia. I would say take courage and have a try thou. The best thing is to start with a few simple turning projects, and get some confidence, and work up to it.      cTr... ( Choose the Right )

Mr. Bloy: Really fine work.  Have you models of any Austrialian railways?  If so, would you please post here?

Thank you,

Joseph Toth Jr.

Joseph   I dont have any Australian models, when I started In model railroading, there seemed to be two choices, British or American. The truth is bigger has always been better for me, and US prototypes had that. Its different now, there are some great models avaliable in HO, of Aussi trains. Its tempting, steam runs in my home town most holidays, and some weekends. Its around $30.00 for a rid down the coast, and back.       cTr....( Choose the Right )

I have a Lionel L2a Mohawk converted some years ago by Joe Foehrkolb.  Beautiful job.  I put DCC in it and it is one of the best running engines on my pike.  I would gladly pay $100/axle to have the Niagara drivers converted.  Picture shows that they do come out of the frame.

Joe - are you still out there?  Anyone PM me if interested.

John