Is there a way to insulate wheels from 3 rail rolling stock to operate on 2 rail?

Maybe, maybe not. Take one of the trucks put it on a test track piece and run DC. See what happens. Seems silly, but if you're prepared to cut the power it might be simplest way. It's what I'de do and I still have all ten fingers.

Ron

Chris...It's the same as HO...one side must be insulated...you will have to change the wheel sets......or go to a plastic axle...joe

Thanks Joe.  I thought it might be something like that.

Chris...you might try early MPC wheels...they were plastic.....

The hard way is to find a nylon or plastic bushing with the same Inside diameter as the axle.    Then pull the wheels on one side, and bore out them out to the OD of the bushing.    Reinstall the now insulated wheels on the axle.  

Remember to keep all the  insulated wheels on one side  or you will get a short in the trucks.

@prrjim posted:

The hard way is to find a nylon or plastic bushing with the same Inside diameter as the axle.    Then pull the wheels on one side, and bore out them out to the OD of the bushing.    Reinstall the now insulated wheels on the axle.  

Remember to keep all the  insulated wheels on one side  or you will get a short in the trucks.

You beat me to it....that was going to be my suggestion....it’d be the most appropriate direction, although with a difficultly level......I’ve done this years ago Chris, .....Ace hardware used to ( not sure if they do anymore) had a drawer full of short nylon spacers that were perfect for this job....I converted some 3 rail axle sets for a two rail guy....now, I had to turn down the flanges, and bore for an insulator, and of course, I did it on a lathe, but with a good drill press, and a way to clamp the wheel on the press table, you could achieve the same results....machinist’s secret tip: always start with a smaller bit than what you measured....sneak up on the sizing...😉

Pat

I'd be looking for some already insulated wheels.  MTH has lots of insulated wheels as they offer their 3/2 switchable locomotives and tenders.  The wheel sets from many tenders are likely to be the right size for rolling stock.

Plastic wheel sets would be my last try, they suck!

Don't think I am endorsing this technique but two railers many years ago used diamond wire in a coping saw  to cut a circle half way around the wheel they then filled that gap with epoxy after it cured they cut the rest of the way around and filled it with epoxy.  If you don't mind the time, it works.  I did it once on a dummy Lionel F3 B unit that was enough.  BTW if you really are a gluten for punishment  search ebay for "Diamond Cutting Wire Saw Blade"    I Don't believe we are supposed to actually post links on the bay.                j

@gunrunnerjohn posted:

I'd be looking for some already insulated wheels.  MTH has lots of insulated wheels as they offer their 3/2 switchable locomotives and tenders.  The wheel sets from many tenders are likely to be the right size for rolling stock.

Plastic wheel sets would be my last try, they suck!

Please John, tell us what you really think!  

Mark in (very smoky) Oregon

Maybe I'll try and see if I can get some insulated wheels from MTH while I still can!     Thanks for all the suggestions guys.   Chris.

A popular method with our British friends is the split axle. A tight-fitting fibre or plastic sleeve fits over the axle, keeping the correct back-to-back track gauge measurement. A short piece is cut from the centre of the axle and all pieces epoxied together. You now have an axle with the two sides isolated from each other. I think the old Carlisle & Finch axles were done similarly but with wood - our antique experts will know better than me. 

@Firewood posted:

A popular method with our British friends is the split axle. A tight-fitting fibre or plastic sleeve fits over the axle, keeping the correct back-to-back track gauge measurement. A short piece is cut from the centre of the axle and all pieces epoxied together. You now have an axle with the two sides isolated from each other. I think the old Carlisle & Finch axles were done similarly but with wood - our antique experts will know better than me. 

Good idea, you do have to make sure that the trucks have plastic bearings or also insulate the two sides of the trucks using a similar method.

I speak from experience, having converted over 100 cars of various manufacturers from 3 rail to 2 rail:

Replacing the wheelsets and using the same trucks is the easiest and most durable solution.

If the coaches use 33" wheels: 

       Intermountain (IM) wheel sets should drop like in, as dkdkrd said. Scale City designs has the IM wheelsets as well

      You can also use MTH wheelsets, as GRG said, but they are more expensive (almost 3-4 times) and harder to find

If you want to use 36" wheels your options are  

     Precision Scale: Check eBay

    NWSL:  Go to their website:  https://nwsl.com/collections/o-scale

All of these wheelsets works fine with most MTH, Lionel and Weaver cars. Atlas cars have a different axle length. Your only option there is NWSL

Lionel sells two rail wheelsets that are insulated and meant to use the same truck.  I just picked up a set for a PRR N5b but haven't installed them yet.  Looks pretty straight forwards.  They are 33" wheels, but probably are the same size as what the Hogwarts set came with.  The conversion kit also comes with truck bolsters for both Lionel scale freight cars and a separate set for Lionscale cars.  

@dkdkrd posted:

You might be able to use Intermountain's 4-pack of insulated O-scale wheel sets, Walthers sku #85-20050, currently in stock. 

They're a rather popular item at our LHS.  Folks who belong to a local O-scale club buy these to re-equip plastic-wheel trucks or convert trucks with old tin-plate wheels (e.g., All-Nation, Walthers, etc., kit trucks with deep flanged wheels...old kit-built cars from secondary market purchases).   They scale at 33" diameter.  Unfortunately, I/M doesn't offer the same in 36" wheels.  It's rather strange....amazing, in fact...that I/M still provides these....they've been out of the O scale market re they're excellent O scale car kits for quite some time now.

Haven't tried the use of these wheels myself.   Wrong direction of conversion for my needs.

FWIW, always.

KD

They are very nice and add a lot of weight to the car; they appear to be a drop-in replacement for Athearn axles (with a rather short, pointed end) so they don't really fit into a lot of other brands of trucks without modification. They're also a bit "shiny" so painting is often called for. FWIW.

And yes, it's a shame they don't offer a 36" version...

Mark in (still very smoky) Oregon

Based on the following parameters -- you are using 3R track;  your Lionel cars are illuminated [ and thus have centre rail roller pickups, etc ] -- I would suggest you might take advantage of that, and run a connecting wire from a coach, via a plug/socket, to the loco and thus power it from the centre rail;  both leads to the loco wheels can be connected for the return.  This way you have coach lighting -- although perhaps you were planning on a separate feed [ with appropriate xformer isolation, blah blah... ] to the centre rail for fixed voltage for the car lighting -- and wouldn't have to modify the car wheelsets or make any other major mechanical mods.

SZ