Replacement Athearn Bombardier BiLevel Trucks, aka making the train roll

[ryan_wilkerson]

What about using neolube?

[CNR5529]

I did try neolube, but it didnt help in this case. We tried some better graphite lube and it made things better, but I'll let Craig speak to that.

Pete, I dont have any Amfleet cars, so can't compare. But stand by, I have a solution in mind that will very much reduce the contact surface area, and that people will still be able to do at home with minimal effort.

[craigolio1]

Neither Fredrick nor I have those trucks on hand. If anyone has one they would be willing to disassemble and document please feel free to post the results.

Keep in mind while this isn't a holy cow result it's by no means a failure. I'm still looking forward to seeing how many cars my F59 can pull as there was improvement.

My goal here isn't to get a magic carpet. It's to get a train that moves. This isn't the subject of the post but while installing the decoder I've noticed there is room in the loco for some weight so I'm looking at some options there. Combining the two may result in a much better train.

Craig

[peteski]

Neither Fredrick nor I have those trucks on hand. If anyone has one they would be willing to disassemble and document please feel free to post the results.

I have these Karo trucks (and cars) and I have even posted some truck photos (it might have been back on the A-board). What I was asking for is not to see the truck's construction (I know it well) but how the those truck's rolling characteristics compare to your trucks. It would be good to see how the Kato Amfleet compares when rolled down the same slope you tried your cars on.

[craigolio1]

Indeed. I see what you mean now.

How about this. You weigh your Amfleet car and I'll weigh mine. I'll send you the parameters of my ramp which will be very easy for you to duplicate. We match up the weights and perform the same test and compare how far the cars roll. Do maybe three tests and average the results.

Would you be willing to do this?

Craig

[peteski]

Indeed. I see what you mean now.

How about this. You weigh your Amfleet car and I'll weigh mine. I'll send you the parameters of my ramp which will be very easy for you to duplicate. We match up the weights and perform the same test and compare how far the cars roll. Do maybe three tests and average the results.

Would you be willing to do this?

Craig

That sounds reasonable but with the amount of projects waiting to be completed (and lack of space for a decent length ramp) I will decline the challenge (at least for now).  But I am curious about the results.  Do you possibly know any modelers around your area (or in your country  ) who own Kato Amfleet cars?  Maybe they could lend you one for testing?  I'll be even willing to go as far as reimbursing you for buying one Amfleet car on your next model train order.  That way you could own one for testing and for evaluating the truck's construction. 

[Lemosteam]

Ok.  So conceptually the idea here is to reduce the amount of surface contact for friction reduction.  Been mulling this...

I have a couple thoughts on this.

Metal rides well against FUD/FXD.  Not as slippery as delrin, but hard like metal on glass.

What if you designed the snaps back down to the axle diameter +0.3 mm on the radius.  Then to keep the axle centered you added a cone around the OD of the snap radius with a small, like 0.3mm wide, flat on top with that flat having about 0.7mm gap to the back of the wheel on each side.  This would allow 1.4mm of lateral side play.



When the wheel does make contact, iut will only be on one side and the surface area is minimized to the 0.3mm flat on top of the cone.  The axle shaft would have only a line contact at the top of the axle to the ID of the snap pocket for the length that the sideframe there is thick. 

Note- all printing artifacts would have to be cleaned from the snap pockets.

[C855B]

Tossing another idea into the ring - micro ball bearings have fascinated me since I was disassembling servo motor gearheads back in the '60s. Here's a supplier of super-miniature ball bearings. Have no idea of cost, but if you want a truly free-rolling solution, here you go.

[CNR5529]

@Lemosteam, I have an idea that incorporates some of the elements that you described.  However I believe I can further reduce the contact area. That said, I am waiting for the final test on if Craig's loco can haul all the modified cars before starting revision 2. I believe he is almost done with the conversions. My second idea also gets rid of the bushings, in favour of materials most of us have on hand. The lateral boss is also part of that plan.

@C855B we did look into this, but enough bearings for an 8 car train was close to 700$... 

[peteski]

Tossing another idea into the ring - micro ball bearings have fascinated me since I was disassembling servo motor gearheads back in the '60s. Here's a supplier of super-miniature ball bearings. Have no idea of cost, but if you want a truly free-rolling solution, here you go.

IIRC @mmagliaro experimented with using (inexpensive) micro ball bearings in his scratchbuilt loco but abandoned that idea. One of the problems was very poor electrical conductivity. Yes, you can install wheel wipers but that increases friction . . .

[C855B]

In looking around I was able to get that down to $15 an axle, but... yeah, I see what you mean. Too bad.

[craigolio1]

I have finished the conversions. It took some time to sort out how to get wires run to the powered trucks on the cab car but I solved that last night. I need to revisit the alignment of the bushings as some cars roll very well and others not so much. Just need to find some time that's not at 0300 in the morning. I have less patience then. Haha.

I'll post photos soon.

Craig.

[craigolio1]

I tried using a drilled out MT king pin to attach the trucks but drilling out the truck frame damaged it so I needed a way to do it with out modifying the truck. I found some styrene tube that fit the hole in the truck perfectly. I flared the end with heat to create a flange and then filed under the flange a little so that once  installed, the truck could rock.

Then I drilled out the frame. The rod was a tight friction fit but I still wanted to have a locking device so I found a larger styrene tube and sliced through the side, creating a clamp that slides on from inside the car. I beveled the end of the tube to make it easier to slip the clamp on.

34awg wires fit through no problem. Larger wires would too.



I soldered the wires onto the bushings prior to assembly and then built the trucks, inserted the tubes and fed the wires through.

 





Once the trucks were mounted on the frame I slipped the clamps on over the ends and it was done. Between the friction of the tube in the frame and the clamp they are  held in very strongly.

At the end in the photo I've removed seating to make room for electronics. At the other end I made the tube long enough that the clamp sits just above the seats.

I'll probably put some kapton tape under the trucks to keep the wires flat. But you can't see them as is unless you really get down and look.
Craig

[CNR5529]

This weekend is the Brampton Model Railway show (now also known as the Greater Toronto Trainshow). Craig and I will be conducting tests with his newly retrofitted BiLevel consist on 300+ ft of the Ntrak Roadshow layout. If any Railwire members are in the Toronto area this weekend, come by and say hi!

[craigolio1]

Well it wasn't the success I'd hoped it would be, but I would still call the experiment a success because we improved on the performance of the original design. I think there's more that can be done but we're headed in the right direction.

This link shows my seven car trainset on the N-Trak Roadshow's layout at the Brampton train show (thanks guys for inviting me. I had a great time and enjoyed meeting all of you!).
 

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Modifications:

The cab car has a TCS function decoder wired for track pick up via 34awg magnet wire to each of the 8 bushings. The loco had a Digitrax decoder. Aside from the decoders and the addition of LED lighting, I also upgraded the entire trainset to Microtrains True Scale long shank couplers. The couplers have whiskers trimmed to allow the freedom to swing side to side in the draft gear, and the two coupler halves are fused together since the whiskers are no longer there to keep them together. I did this because the couplers are very stiff in the boxes and I was afraid it would cause the cars to push outward in the turns and put additional pressure on the trucks. Finally, I moved the couplers in a little to allow for closer coupling. These couplers don't have a slinky effect and can there for be closer together and work more reliably in pushing mode.

Observations related to the modified train's performance:

We started with a train of 8 modified cars. Fredrick has one too. It pulled no problem for the most part but did struggle a little through some of the sections of the layout.  Then we added a single Unmodified car and that brought things to a halt. Literally. It was slow on a straight and then stalled in the first curve. Fredrick made a good point in that the addition of that one car was like adding another four modified cars. We removed the unmodified car, and Fredrick's modified car so that just my 7 car set was running. The train ran fine with no problems related to the trucks. I wish I'd filmed it but the highlight was watching the train negotiate snaking through a three track cross over from the inside most to the outside most track.

Observations not related to the performance of the trucks... and struggles.

Even though Fredrick carefully calculated where I should mount the couplers, with my ham hands (and I think might need glasses) I mounted the couplers so that some of the cars were too close together, and the diaphragms fouled in some of the turns. This caused the train to slow or derail. Moving from the inside track to the outside track helped this.

Due to some issues with connector tracks on the N-Trak modules I had some uncoupling issues. This was brutal as due to my modifications and the close coupling, it was a real test of patience to couple these cars.

I'll be switching the train to 1015s, at least until testing is complete, as the True Scale couplers are just complicating things.

The decoder in the cab car needs keep alive capacitors big time, but, the power pick up experiment was a success.

Conclusion:

Good:

We basically doubled the useable train length.

Non friction adding power pick up proof of concept was a success. And my cars didn't catch fire or melt.....  yet.

Bad:

We wanted to get to 10 cars so the GO transit guys can be happy too. I would say the reliable limit is 7.

Assembly needs to be done PRECISELY. A deviation as little as a few .001" has a noticeable effect on the rolling capabilities and tuning is difficult once assembled as it's hard to move the bushings around once clamped in.

Recommended improvements:

Fredrick made a kick a$$ assembly fixture. It made assembling the wheel sets in gauge very easy and quick. The issue is getting the bushing to seat in the best spot when snapping them in.  This is where I spent literally HOURS messing with the bushings.  I feel like a set of shims could help here, or possibly an improved version of the truck could include a slot for the bushing to seat in so it self located the same way every time.

That's it for now.

Fredrick, @CNR5529,  you did an absolutely outstanding job on the truck. It looks 1000 times better and performs 100% better. Hopefully we can find a way to make that 200% better.

Craig

PS: Fredrick I'm still pissed off that my Dinner Train was a complete fail so if you feel I've embellished at all in an effort to have SOME success from the day please add any corrections. Folks Fredrick has no feelings. Only computations and hypothesis.

PPS: That was supposed to be a joke either in case Fredrick has feelings and is insulted, or in case I'm right, and he had to be told it was a joke.