Two N Scale Turbo Trains, 50 Years Apart

[peteski]

Yes, funny hos projects seem to get more and more complicated while we are working on them. I have the same "problem".

Why reinvent the wheel (pun intended) and make yourself extra work when Kato stocks their wheelsets in both 36" and 33" sizes? Pointy axles and each side already insulated. About a one US$ per axle.

Their currently offered passenger car wheelsets have nice looking narrow tread and lower-profile flanges.  Nice wheels.

A project I'm working on involves a similar conversion. Hint: I just buy Kato passenger trucks and utilize their wheelsets *AND* the dimpled metal bearings for converting other trucks.  I will eventually post a write-up(probably 2 years from now). 

[Dwight in Toronto]

Thanks Peter.  Good idea - the Kato passenger car wheelsets sound like that would/should be the way to go.  Having gotten caught up in the challenge, I guess tunnel vision takes over and I was trying to get by with whatever I might have at hand. 

But I should just order a few passenger car trucks and be done with it.  Maybe I can scavenge a truck from one of my SP Daylight coaches, and then replace it when the spares arrive.  Time to visit the Kato parts inventory.

[peteski]

Thanks Peter.  Good idea - the Kato passenger car wheelsets sound like that would/should be the way to go.  Having gotten caught up in the challenge, I guess tunnel vision takes over and I was trying to get by with whatever I might have at hand. 

But I should just order a few passenger car trucks and be done with it.  Maybe I can scavenge a truck from one of my SP Daylight coaches, and then replace it when the spares arrive.  Time to visit the Kato parts inventory.

I recently ordered several trucks and wheelsets from Kato.  They have very good selection in stock.  Remember,  if you order any of the 3-axle trucks, the middle axle is a "dummy". Well, the wheelset is same as the other two, but it rides in plastic cups. Only the outer axles are set up for electric pickup.

[Dwight in Toronto]

Good to know - thank you.

I was looking over the various parts, wondering what else I could include to make the shipping cost more worthwhile.  I was thinking 4 sets of conductive 2-axle passenger car trucks, a packet of motor brushes/springs/caps, maybe some wheels, maybe a coreless motor, and a set of those tiny GS4/FEF linkage-retaining rivets/pins (the latter was out of stock).  Before I could order, she-who-must-be-obeyed needed my help, so I abandoned the ‘basket’.

But hey …. look what I just found hanging on my workbench pegboard!  I forgot that this came as a 2-pack, and I had only used one of them.  Back to the drawing board!

[peteski]

Good find Dwight!
For deepening the dimples in the sideframes I use 60^o  1/8" diameter tungsten carbide single-flute countersink, but I know lemosteam uses a ball-shaped dental burrs.

[Dwight in Toronto]

Trying to form a single axle powered bogie from that Kato passenger truck would require serious surgery.  Instead, I decided to first try adapting the Kato wheels to one of the old Bachmann single axle trucks. 

Surprisingly, I managed to bend and twist two of those copper wipers that I salvaged from the little ESU assembly (shown 2 pics earlier/above), and inserted them into the bogie such that the dimples actually lined up with the original axle depressions.  I had to dremel a shallow channel into the inside faces on each side of the truck so as to recess the copper wipers, and thereby provide the Kato axle points with sufficient space to properly seat and freely spin.  I then folded over the excess copper on each outside edge of the bogie to serve as a solder pad for the black & red track power wires, and used a drop of epoxy to hold the wiper in place:




While the epoxy set up, I did a complete tear-down, clean-out, lube job and rebuild of the Bachmann power cab mechanism, and then let it bench-run for 20 minutes or so on DC.

[Dwight in Toronto]

Having turned my attention to the power cab, I started preparing the shell to accept the single axle bogie with the track power pickup.

I ended up carving out the old bulkhead just as I had done with the coaches, and then removed the floor from the entire back half of the cab.  I fashioned a new bulkhead using styrene, and glued it to the rear of the floor section:



What I’m thinking here is to fabricate a removable module, that will facilitate servicing down the road.  I see this module accomodating, say, a pc board that serves as a junction point for soldering track power and motor wiring, and perhaps a decoder later on.  Pins and sockets could terminate here, enabling the module to be separated from the shell (ie - no wires tethered to headlight led’s, motor, track leads etc).

In my mind’s eye, I see this module sliding into the shell from the rear.  Have to give some thought to how to keep it in place!

[Dwight in Toronto]

Well, I conjured up an idea that just might work for securing the “electronics module” within the power cab shell.

Here’s hoping that the following picture is worth a bunch of words:




First, I plan to glue the two steel weights together (these were originally sitting on two yellow pins, one of which can be seen on the floor segment).   I will then affix them to the roof in the back half of the cab using cushy foam-backed double-sided tape (tape not shown).

As it turns out, those two pins on the floor perfectly accodate 3/8” Evergreen tubing, which I used to make two standoffs.  The flat length of 0.04” styrene sheet is the same dimensions as the steel weights, and will get glued to the top of the standoffs.  Finally, I’ll attach the piece of 3M peel-&-stick fridge magnet to the top of the styrene sheet.

My hope is that the entire module will then “thunk” into position when the fridge magnet gets attracted to the steel weights up in the roof.

My first trials were with two small rare earth magnets, but the attractive force was far too strong.  I think that the fridge magnet material should be just about right.

[wm3798]

There's some Yahoo selling a whole case of the Bachmann coaches on ebay right now.  12 cars in original packaging, all PC, no power cars at all.  His price is absurd, but if parts donors you need, there they are!
Lee

[peteski]

I would recommend placing any weights as low in the car as possible.  Placing them up in the roof moves the center of gravity up. That might make the model tippy and wobbly.  Low center of gravity makes the model  stable, especially an articulated Talgo-type car, which doesn't really have stable wheelbase

I'm a also curious why you ran the bogie pickup strips diagonally?  Why not just straight up the sideframe?

[Dwight in Toronto]

Lee - thanks for the lead on additional Turbo coaches.  I’m hoping that I won’t need them, but good to know, as these are kinda rare.  I was curious to see the “absurd” pricing, but couldn’t find the eBay listing (although a “new unopened” complete set has been on the site for ages now, at a lofty asking price of $800+ Cdn !).

Pete - thanks as always for the input.  The weights are already fixed within the ceiling level of the coach, and I don’t think that it will impact stability.  I finished cobbling together the “module”, and amused myself with not only how nicely the magnetic strip adheres to the steel weights, but how silky smooth it slides back & forth, into and out of the shell.  It’s really quite slick, if I do say so myself!  I’ll post pics soon.

Regarding the bogie pickup strips …
Note that there are two tiny open spaces on each sideframe of the truck (which are only there to suggest or highlight that a crude representation of a bogie suspension spring is centred in the sideframe casting).   On a whim, I tried slipping one of those pickup strips through one of those tiny side holes, and was surprised that it not only fit, but that it could be angled down in such a way that the dimple on the strip centred precisely on the axle dimple in the truck.  Other than using the dremel to chamfer a slight recess for the strip, no other alteration was required on the bogie.  It was as if it was meant to be, so I was happy to accept, and roll with, divine intervention!

I’ve still got a ways to go to actually facilitate getting power to the cab itself.  And should anything go south in this regard, I’ve always got the Kato passenger truck to fall back on. 
It’s all experimentation!

[Point353]

I was curious to see the “absurd” pricing, but couldn’t find the eBay listing (although a “new unopened” complete set has been on the site for ages now, at a lofty asking price of $800+ Cdn !).

Link for a dozen TurboTrain coaches: https://www.ebay.com/itm/365136825728

[Dwight in Toronto]

Thank you @Point353 for the link.  Gotta wonder how someone acquired a whole box of coaches!

There was another listing offering a full set (2 cabs + 3 coaches) “for parts or repair”, at a much more reasonable $50 US.  I’m going to keep a casual eye on these, just out of curiosity. 

[Dwight in Toronto]

As a further testament to just how helpful TRW can be, I was recently sent a PM offering me four additional Turbo coaches (which had apparently seen better days and were just sitting idle gathering dust), just in case I might need spare shells and bogies.  This really is a great group.

I’ve made some progress on the slide-out electronics module:



I made up a pc board and used foam-backed 3M double sided tape to adhere it to the floor.  In anticipation of eventually adding a decoder, I pre-installed two smd 8200 ohm resistors for headlight LEDs.  I also soldered in angled pins, and will use mating connectors from the chassis for the red, black, orange, gray, blue and white wires.  In this way, the module can be slid out and the two plugs from the mechanism can be disconnected for servicing/maintenance.

Side note - even the smallest connectors/plugs-&-sockets I’ve been able to find don’t really jive with N scale “diminutiveness”.  I would love to hear what other folks use.

I also forged ahead with the powered single axle truck:



Here, you can see that I’ve mounted two springs as per the previous approach.  But this time I used phosphor bronze springs, soldered red and black wires on the ends, pulled the wires through the bulkhead, and soldered them to the track power pads on the pc board. 

On the bogie itself, I scavenged two more copper wheel wipers from one of those little ESU devices, and epoxied them to the bogie as backstops for the springs.  In the pic, I just have to bend the wings down, then solder them to the copper pads previously affixed to each side of the truck.  In this way, I’m relying on the springs to convey the track power from the Kato wheels to the pc board on the slide-out module.  The alternative was to use decoder wire, hard-soldered to the truck pads, and feed the wire through a hole in the bulkhead.  I thought with that approach, the wires could mess up the bogie-centering action.  Also, by using spring contact, the bogie is easily removable for servicing.

Now to try to pull it all together!

[Dwight in Toronto]

So far, so good … I completed the soldering on the bogie, soldered the motor wires to a socket, plugged the socket into the track power pins in the electronics module, and clipped DC leads onto the Kato wheels.

This short 30 second video shows that the single axle truck is successfully conveying power to the old Bachmann motor.  It’s satisfying and rewarding to see that all the bits, pieces & scratch building are actually playing nice together!

It will soon be time to conduct an on-track DC test.

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