A new solution to re-wheeling Tri-ang diesel locomotives for modern track?

[Ken-362318]

 

Hello again.

In my post on 11 November 2023, subject “Reprofiling Tri-ang diesel locomotive”, I discussed my adventures trying to reprofile those super-hard knurled wheels fitted to R.55 and other locomotives using Tri-ang’s version of the North American “Blomberg” power bogie (“truck”).

Although that method does work, it is, perhaps, and not really surprisingly, fiddly and very, very time consuming, somewhat dangerous and chews through a lot of diamond edged files.  Thank you “threelink” for your suggestion about annealing the wheels, which had never occurred to me, but I haven’t tried it because even if I can soften the steel (I do have an oxy acetylene kit) it is really all too hard and there must be a better way.

There is a better way! 

Inspiration came when I purchased an A-B-A single ended diesel set (R.55, R.57 and R.58) in almost as-new condition.  Unlike the excellent similar set I bought from Dave Angell, this R.55 had a MkI power bogie, which I had never seen in the flesh before.

The bodies were covered in dust and grime and the power bogie looked like it had not run for many, many years.  The oil felt pads on the X.04 motor’s shaft had dried stiff and the motor’ commutator was all black and gooey.  I did a complete strip-down and clean (I gave my new ultrasonic cleaner its first workout!), I replaced the carbon brushes and fitted a spare “Neo” magnet I had as an experiment, even though the original magnet was still one of the strongest I have encountered and so, surprisingly, didn’t need re-magnetising.

The three units cleaned-up beautifully and after fitting new decals on the A units they all look as good a new.  I was surprisingly very impressed with the power bogie, which I initially thought of as quaint and archaic, but it is powerful and very smooth with an interesting “diesel growl” (on top of the usual knurled wheel noise), probably due to the extra gear.  The MkI power bogie is beautifully engineered and I expect, with proper, routine maintenance, will still be running smoothly in another 65 years.

I bought the set very cheaply with the intention of sprucing-it up and re-selling it, but after the dirt and grime were removed, the bodies all turned out to be in such excellent condition that I decided to keep them all for my (ever growing) collection …. and that is when the matter of the re-wheeling raised its very, very ugly head.

I am using modern PECO code 100 track and I have several double slips and three-way points (switches/turnouts) which are very fussy about what wheels they like.

Unlike “normal” Code 100 points, the double slips have slightly higher rail chairs and so even the diesel wheels with the medium depth flanges bounce across the tops of some of the rail chairs, so only the shallow flange wheels will work at all.  However, as with all Tri-ang wheels, the back-to-back spacing on all three versions of those wheels is too tight for modern track and all are so wide that they can short out non-electro frog points when traversing the frog, causing a stall.  To add insult to injury, the wheel flanges are thick and can jam in the gap between the rail and the check rail on the minimum radius points I use in yards and sidings. These problems are, of course, well known to those who want to run early Tri-ang on modern track and there are a lot of posts and blogs discussing various fixes for diesel wheels, most of which involve turning-down the flange depth and thinning the wheels, which is more easily done for steam locomotive driving wheels which are either made wholly of zamak (or similar), in the case of the solid pre-1959 (approx.) wheels, or the later see-through wheels with zamak centers and a mild steel rims (for Magnadhesion), than for the super hard diesel wheels.

I have bought several wheel sets with shallow flanges, but I need so many, both of the larger diameter for the R.55s and other Transcontinental diesels as well as the smaller diameter for the various locomotives fitted with smaller wheels (R.751, R.357, R.555, R.156. R.158, R.352 and so on), that it is just too expensive and no longer a viable alternative (especially as international postage from the UK can cost two or three times the cost of the items ... an ebay seller once wanted to charge me AUD $85 to post a 4mm body retain screw selling for $2 from the UK .... seriously?  Naturally, I did not buy it).

What to do about my new R.55's deep flange wheels …. 

I was fitting Hornby R 8218 disk wheels to the non-powered bogies (using the method in my post of 24 July 2023, subject: “Re-wheeling Tri-ang R.54 loco bogie and pony truck”), when it occurred to me that perhaps I could simply drill out the centres of those or similar wheels and fit them to the original Tri-ang axles.  I had a few Evemodel 48" HP0287 geared driving wheels (which are the same diameter as the Hornby R 8218, but have a slightly wider wheel tread and a slightly deeper flange) and so I used them for this experiment in case it didn't work because I didn't want to waste the Hornby wheels.  It worked a treat!  It is fast, simple and relatively cheap.  In future, I will use the Hornby R 8218 disk wheels to be consistent with the non-powered bogie and may retrofit a set to this model later.

The only catch is that you must be very, very exact and drill not only at the dead centre of the wheel but also absolutely at a right angle to the back of the wheel or the hole will be eccentric and/or at a slight angle and the bogie will wobble (as is the case with some new Dapol wheels I bought to re-wheel Tri-ang wagons with needle point axles; so far, all of the dozens of new Hornby and Evemodel wheels I have bought in various styles and sizes have all been perfect).

I recently bought a Ryobi Hobby Station and I thought that would be ideal.  Wrong!  I used that for my first attempt and I made a jig out of wood to hold the wheel flat and in the correct position.  It was a total failure because the Ryobi Hobby Station is not a precision tool.  The rotary tool is only fastened to the stand at the bottom and so it flexes the instant the drill bit engages the wheel and so the flexing caused the hole to be drilled ever so slightly too big resulting in a loose fit of the wheel on the axle instead of the interference fit that is required. 

Then I remembered my Proxxon hobby lathe .... duh! ..... which is currently in offsite storage with most of my OO/HO and O scale collection during the bushfire season because I live in a heavily forested area in the mountains of southern Tasmania and fire is a very real annual threat. 

The lathe did a perfect job!  A few seconds per wheel ... sorted.

If you do not have or have access to a lathe, I expect that you could use a proper, purpose-built drill press, but you would need to centre and hold the wheel very carefully and precisely.  I expect a jig could be made from wood that could be clamped or bolted to the bed of the drill press.

Before drilling the new wheels, I removed the old wheels using a puller (I have several and I found that my North West Short Line “The Puller” was the most suitable).  The benefit of using a puller is that it will leave the plastic insulating bush on the axle and it can be reused.  If the wheel is a tad loose on the bush, a drop of super glue should secure it (LokTite takes too long to dry).  Alternatively, press a new plastic bush into the wheel.

I used a 1/8” drill bit for the non-insulated wheel and a 3/16” drill bit for the insulated wheel.  I bought new drill bits to ensure that they were sharp.  Both the Evemodel and Hornby wheels are plated brass, so they cut easily.  Check that the wheel is spinning true before engaging the drill bit.  Use gentle but consistent pressure and let the tool do the work. 

When the holes were drilled, I brushed them to remove the swarf and I then lay them face down on the bench.  I introduced one end of an axle to the hole in the non-insulated wheel (it should be a smooth, even, slightly tight fit) and when satisfied the axle was square with the wheel, I GENTLY tapped the axle with a tack hammer until the spline on the axle engaged the wheel and then onwards until the end of the axle was flush with the face of the wheel.  I then repeated the process at the other end of the axle with the insulated wheel.

Both the Hornby and Evemodel wheels are much thinner and slightly smaller (by approx. 1.05mm in diameter) than the original Tri-ang wheels, so even when both axle ends are flush with the wheel faces, the back-to-back spacing will still be slightly too big.  To correct that I sat the wheelset face down on the bench and placed 3/16” socket, which fits over the axle, so that it was resting squarely on the wheel.  I GENTLY tapped the socket until the axle protruded from the wheel about 1mm and then turned the wheelset over and repeated the process on the other end until the back-to-back spacing was correct.  If the wheel is tapped too far down the axle, the spacing can be adjusted using the puller, half a twist at a time, checking each time with the NMRA standards gauge until the wheel set is properly in gauge.  The wheels spin true without any wobble.  They may look skewed in the following photo but that is only camera distortion.  They are actually square on the axles. 

 

As with all things, one gets better with practice.  The total process only takes a few minutes.

 

The following pictures show the new wheels fitted to the power bogie.

I now fit a 1cm length of 2.5mm ID brass tube as an axle sleeve to wheelsets on all my non-powered locomotive bogies and steam locomotive tenders for additional electrical pick-up.  The tube is an almost perfect fit for the diameter of the Hornby axles.  I solder a wire to each sleeve before fitting it to the axle and pass the wire through to the motor.  I have found that tube sleeves have less drag than either a wheel wiper/spring or axle wiper, especially when LIGHTLY lubricated with graphite, which is also electrically conductive …. Caution: graphite is VERY messy.  I found that both Kadee “Greas-em” and hardware store graphite powder for padlocks, etc, work well.  The former is easier to use, having a very small hole at the end of the tube, but the latter, although harder to apply, is vastly, vastly cheaper for about eight times the quantity.

I use a two pin PC micro-plug to connect the axle sleeves to the power bogie to enable an easy disconnect if the power bogie needs to be removed for service (the soldering in the photo above is less neat than I would like; it was very good the first time but I had forgotten to pass the wires through the hole in the rivet before soldering, which is important because the plug is too big to pass through that hole and so I had to unsolder and re-solder after passing the wires through the rivet and, naturally, I couldn't get it as neat the second time!).  The wires are thin enough that they do not put any sideways force on either the powered or non-powered bogies.

 

I also fitted a directional LED headlamp (with “headlamp sleeve” X.5271 to prevent light leakage) while I was at it.

I am very, very happy with the end result.  The locomotive glides smoothly through the double slip as if it were on a piece of straight track and, with the extra electrical pickups, I don’t expect it will ever stall on the points.

 

I will use Hornby R 8096 disc wheels for the power bogies with smaller wheels.  Evemodel HP0187 38" driving wheels could also be used instead of Hornby R.8096. 

Drilling and fitting the new driving wheels, cutting and fitting the brass axles sleeves and fitting the wheels to the non-powered bogie took just under an hour all-up on my first attempt.  The costs were the Hornby wheels sets and a few cents for Evergreen styrene tube (for the non-powered bogie wheel axles bearings), a few more cents for brass tube and around 50c for the micro plus and socket.  The Kadee Greas-em I’ve had for over thirty years, but a new tube costs around AUD$15.  

So, if you want to run vintage Tri-ang diesels on modern track, perhaps this might be the solution for you too.

Happy modelling!

 

[Rana Temporia]

Excellent solution. I have a MK 1 powerbogie with the smooth wheels from a scrap Dock Shunter in it. I retained the original axles with the brass gears though as the plastic ones uses on later models either disintegrate or come loose on the splines on the axles. The smooth ones used to be easy to find but I think everyone is looking for them now, same as the smooth DMU wheels.  

[ColinB]

Brilliant suggestions, trouble is my lathe is too big and wheels are not the easiest things to hold in a 3 jaw chuck.

[What About The Bee]

Hi Colin

Perhaps a jig could be turned in the lathe.  A shallow depression sized to the OD of the flange.  Mount the wheel into the depression, backside of wheel towards the lathe head.  A simple screw down clamp would hold the wheel in the depression. 

Voila!  The wheel concentric to the lathe's axis of revolution.  Held perpendicular.  Ready for accurate boring.

Bee

[Ken-362318]

I forgot to mention that if you use my method for replacing original Tri-ang sleeved wheels in open axle boxes with needle point modern metal wheels of whatever size and style you require, (be they for Transcontinental freight cars, Transcontinental or BR passenger coaches, four wheel good wagons, locomotive/EMU/DMU/NSW "red rattler" bogies or pony trucks) as per my post of 24 July 2023, (subject: “Re-wheeling Tri-ang R.54 loco bogie and pony truck”), you can easily lubricate the new wheels by inserting a hypodermic oiler into the ends of the 2.5mm Evergreen styrene tube "bearings" inserted into the open axle boxes that hold the new wheels in place, as per the following photos of the R.55 in this post.

Happy modelling and long live Tri-ang trains!

[Ken-362318]

Further to my previous posts, I went to fit Hornby R 8096 12.6mm wheels (approx. 38") to the non-powered bogie of a Tri-ang R. 450 NSW "Red Rattler" power car trailing bogie to provide additional electrical pick-ups, but I had forgotten that, unlike the Hornby R 8218 14.1mm (approx. 41") wheels I use for Transcontinental locos, the R 8096 wheels have BOTH wheels insulated from the axle, so conductive paint is needed to electrically connect one wheel on each axle to the axle (unless you want to go to the trouble of drilling out some brass rod and then turning it down to replace the plastic insulating sleeve!).

Also, depending on the batch, some Hornby 8096 wheels (with a more silvery appearance) have a spline on the axle that prevents the brass tube sleeve sliding over the axle.  Others (which have a more gunmetal appearance) do not have a spline, so those are the best ones to use for additional pickups.  Pot-luck which ones you get when you buy through the post.   Two more packets arrived in the mail today and both were all the splined variety (perhaps the splined versions are an upgrade to resist wheels sliding out of gauge along the axle?).

I bought some conductive paint in hypodermic syringe applicators on ebay some time ago and used it for the first time last night and the photo shows the result.  When dry, it works perfectly BUT it is very, very expensive for the minute quantity provided and is VERY gluggy and hard to apply neatly (I used the end of a paperclip in the end, but it was still very fiddly).  As with all such paints, it will not be electrically conductive until it is thoroughly dry (overnight).

So I went out today on the hunt for a better solution and bought some Kemo conductive lacquer from JayCar electronics (also available on ebay).  Aside from the exceptionally noxious fumes (outdoor use only, if you buy it), the lacquer was just too thin and separated over the edges of the plastic bush even after multiple coats, resulting in there being no electrical continuity between axle and wheel.   The photo shows a (non-splined) wheel and axle after five coats of the lacquer. 

 

JayCar also sell electrically conductive marking pens (cheaper than on ebay), but they were out of stock.  I'll buy one when when available again and report back.

Happy Modelling!

[Going Spare]

An interesting comment regarding the wheelsets in pack R8218 versus R8096 because I had hitherto thought all wheelsets in R8xxx retail packs were double-insulated and only more specialised wheelsets such as those for the lit Pullman coaches (spares pack X9096) are insulated on one side only so as to permit track electrical pick-up for the lights.

[Ken-362318]

Well, as usual, things turned out to be a bit more complicated that I first thought!

I forgot to mention in my original post that the axles on very early R.55 locomotives had a hole drilled in the end of the axle on the non-insulated side that was splayed, like a rivet, to hold the wheel on the axle without a spline.  After cleaning the burr from the end of the axles, a slightly smaller hole may have to be drilled in the wheel for a good interference fit and as I have plenty of the later wheelsets with the axles splined at both ends, I haven't needed, as yet, to try and re-wheel these very early wheelsets.     

In the process of re-wheeling my Tri-ang diesels I have discovered that there can be a slight but significant variation in original Tri-ang axle diameters, so if one drills a ("standard") 1/8" hole in the non-insulated wheels and a ("standard") 3/16" hole in the insulated wheels, they will fit some axles perfectly while others will be a slightly loose fit.  Drat!!   I also had one set of axles where the spline on the insulated side had worn off (or was never manufactured properly in the first place).  These axles were churned out by millions, so minor variations will inevitably creep in for a variety of reasons, including due to machine tool wear over time.

Despite using a digital caliper and a small bore gauge to calculate the drill size required on a case by case basis, I have found it best to drill a slightly smaller hole than calculated, test fit, and drill up if required.  I advise against attempting to use a hand-held file to make holes bigger because, for most people, the result will not be accurate enough for a good interference fit.

On the non-insulated side, 1/8" = 3.175mm, so I have found that a 3.15mm hole, or, in a worst case, a 3.1mm hole works if the "standard" of 1/8" is too big.   

On the insulated side, one solution if the wheel is a good but slight loose fit, is to apply a tiny, even smear of Gorilla 5 minute epoxy glue (or any other two part epoxy recommended for a strong bond between metal and plastic ... not all do, it seems) around the outside of the insulating bush (part S. 5065).

However, the better solution is, I think, still to drill a slightly smaller hole in the wheel.  3/16" = 4.78mm, so I have found a 4.75mm, or, in a worst case, a 4.7mm hole works for the insulated side if the "standard" of 3/16" is too big.

Alternatively, those with a 3D printer can produce custom insulating bushes designed to the correct thickness to fit any axle while maintaining a constant hole size in the wheel.  I haven't tried this yet with me Ender 3, S1 Plus, but I will do as some stage.  Sam's Trains posted a YouTube video in which Sam successfully designed and then 3D printed some replacement bushes. 

Of course, axles can always be turned down in a lathe if the wheel hole is a tad too small, but I am trying to avoid that if I can .... so far, so good ... 20 locos to go!

I have also started converting my locomotives with the newer, faux, 6 wheel bogies.  Again, I am using Hornby's excellent R 8096 plain disc wheels.

On models with needle-point axles in the non-powered bogie, R 8096 wheels are a direct, albeit slightly loose fit, replacement.  On models with rounded-ended axles and sleeved wheels, R 8096 wheels, if removed from their axles with the tiny plastic bush still in place, can be press-fitted to the original round-ended axles, but be sure to adjust the gauge using your standards gauge of choice (I use an NMRA standards gauge for both my HO/OO and O scale models).  On some wheels sets, a small fillet of super glue around the inside join of the axle and wheel may be required to assist in maintaining gauge (such a fillet can be seen in the right hand wheelset in the photo below).

On models with factory fitted wipers for additional electrical pick-ups, the plastic insulated wheel can be replaced, as a push fit, by a single R 8096 wheel with its insulating bush still in place, as outlined above.

On any of these models, additional electrical pick-ups, or replacement electrical pick-ups, can be fitted using the brass tube sleeve method I mentioned in an earlier post.

The following photo shows shows additional pick-up wheels from two R. 357s with a single R 8096 wheel on the insulated side of each one (on the right in each case), fitted to replace the original Tri-ang plastic wheel.  A needle point axle is on the left and round-ended axle on the right. 

 

The following photo shows R. 357 driving wheels: Tri-ang original on the left and fitted with R 8096 wheels on the right.

       

For these driving wheel axles, 1/8" is too big a hole for the wheels to fit snugly on the axles and I found that, for one axle, a 3mm hole was the correct size while, on another, 2.95mm was the correct size.  I also found that test drilling a hole in plastic ( I used a rigid plastic window spacer), sounds good in theory, but is unreliable because even rigid plastic is ever so slightly elastic and allows a snug fit that will be a tad too tight in metal.  Using a piece of scrap metal (say an old hinge, blind bracket or shelf bracket that is at least 5mm thick is a better choice for a test hole. 

The following photo show an R.357 with R 8096 wheels fitted to all wheels except the electrical pick-up wheels on the non-powered bogie, which are the Tri-ang originals.  Although made of steel, in my opinion they were good enough and close enough to the thickness of the R 8096 wheels to avoid needing to replace them and either drill out a bigger hole, or, use as is and have to apply conductive paint to electrically joint the replacement wheel to the axle.  All wheel sets have been gauged using an NMRA standards gauge.

This locomotive has been fully serviced and (as it seems is always required with these power bogies) needed new shaft bearings.  I also fitted a neo magnet rather than re-magnetise original magnet that had lost most of its magnetism even though, from the slight wear on the motor brushes, this loco has seem little use.  The loco would not start when I bought it, but now runs very quietly and smoothly and glides through the double slip and three way point on my test track without any bumps, jolts or hesitation.  A great result (even better because I picked-up this loco, which has a body in as-new condition, plus 5 BR wagons from an op-shop the other day for next to nothing).   

Happy modelling!

 

Edited February 29 by Ken-362318