Replacement Athearn Bombardier BiLevel Trucks, aka making the train roll

[CNR5529]

@Lemosteam I like that idea! We'll see how initial tests fair, but that would be pretty easy to implement going forward.

Also, while waiting to meet up with Craig, I got some paint down.

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And a side by side with stock trucks:

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[peteski]

Looks good. Too bad you didn't show a side by side comparison of the truck's sides. The top view doesn't seem all that exciting.

[CNR5529]

If a side view is what you want, then just ask! 

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To be honnest, I didn't post this view earlier because I find the detail didn't pop as well as the closeup did. Stuff like the longitudinal dampers, traction rods, casting core holes, tread and disc brake units and some of the more hidden details like the elastomeric sidebearers are hard to see in the photographs. The real point of the top view though is to show that the bolster is the proprer width. To me a major flaw in the looks of the Athearn truck is that all the secondary suspension components are flush with the wheels (the truck is too narrow).  The top view illustrates how this truck looks more appropriate. Consider this photo of the West coast express BiLevel truck.

http://www.canadianrailwayobservations.com/RESTRICTED/2016/October2016/via.htm scoll down a bit.

Also for full disclosure on prototypical accuracy, I did not include the lateral rods and dampers as they would have interfered with the truck rotation...

[peteski]

Thanks - they look good from the side too.

[CNR5529]

Thanks! Only one thing left to test...

[craigolio1]

One thing indeed.

The bushings came in the mail a while back and I haven't lost them.
I have my drill press all ready to go. 
The decoders in the loco and cab car should be done tomorrow.
I'm picking up my MT True Scale couplers on my way home after I pick up the trucks from you.

I'm hoping to post a video of a simple test of two cars, one equipped with the new trucks, and the other stock, rolling down a pair of inclined tracks, on Monday night.

Following that I'll work on the rest of the fleet and then we'll get some footage of a train, hopefully being pulled effortlessly by one loco.  I only have seven cars but I understand three or four are about the limit as they are now.

Craig
 

[CNR5529]

Well, I can now confirm two things:

- Conversion is literally a snap! The bushings snap nicely in their seats, with just enough pressure to hold them firmly from moving, but not so much that the FXD frame would be at risk of cracking. Using the assembly jig made quick work of prepping the wheelsets.

- Even with just one truck converted, with no time spent optimizing the bushing positioning and no use of any lubricant, there is a noted reduction in rolling resistance.

The rest of the trucks have been handed off to Craig for installation in his test consist, so he will be able to report back soon with more objective findings. Until then, here are more progress photos.

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[RBrodzinsky]

Now I am starting to get excited. After not being able to pull 6 cars up a slight grade, I put my cab conversion on hold, awaiting these results.

Any estimates on costs for these new trucks and bushings?

[delamaize]

This is making me regret selling my Sounder consist I had, Since that was one of the reasons I sold it....

[CNR5529]

Any estimates on costs for these new trucks and bushings?

Cant say just yet what the final price will be, because there may be a few alterations to the CAD model based on our testing, which would change the price a bit (so far there is one minor change to address). That said, there will be some savings for both the bushings and the trucks when purchasing in larger quantities. The bushings are 4-5$ per 20 pack (8 needed per car) depending on how many packages you order, and the trucks are in the neighborhood of 4-6$ per truck IIRC. That will include the wheelset assembly/drill jig as well. Once we are done with the testing and modifications (and the project is actually deemed successful), I will be able to formally release these at Shapeways.

Thanks for the interest!

This is making me regret selling my Sounder consist I had, Since that was one of the reasons I sold it....

Too bad, Sounder is one of the more stylish BiLevel paint jobs...

[Scottl]

Those look great!

[craigolio1]

I was able to get a six car consist converted last night. I still have 1 car left but it will require modification in order to run the wires through the kingpin for power pick up.

The result. It definitely rolls better that the original. Not nearly as much as I had hoped. I have a video but can't figure out how to post it. What it shows is two parallel 6 foot runs of flex track. One end is elevated about 4" and gradually slopes down so that second piece of track is flat.

When the two cars are released at the same time, the car with bushings accelerates faster and rolls farther making it right to the end of the 6 ft run. The original car fell short about two car lengths.

So it's no Microtrains truck. But it's an improvement for sure. You can really feel the difference when pushing the cars with a finger. The original feels like all its brakes are stuck on. The new one feels like half its brakes are stuck, haha.

I tried lubricating one set of bushings with graphite spray. It may have made a little difference but I didn't have the chance to properly test it. I'm also going to try some ceramic wax I have for my triathlon bike chain.

http://www.finishlineusa.com/products/chain-lubricants/ceramic-wax-lube

The biggest thing with the trucks are assembly. You really have to make sure that everything is in there just right otherwise something might rub. The disc brake hanger for example,  I unknowingly bent it in on one truck and it actually works like a brake! Amazing. And not good!

All and all I'm still optimistic but I thought results would be better.  The real proof will be when I can test the train on a layout in a few weeks time.

I'll post more after I can experiment with lube.

Craig

[peteski]

The results are what I expected.  I mentioned making the bearing sleeves narrower to decrease the contact area (and friction) between the bearing and the axle. If the bearings were made very thin that would be ideal.

Do you happen to own one of the Kato Amfleet cars (or a pair of the Amfleet trucks)?  It would be interesting to see how your design compares to the Amfleet truck design.

[CNR5529]

I mentioned making the bearing sleeves narrower to decrease the contact area (and friction) between the bearing and the axle. If the bearings were made very thin that would be ideal.

So when Craig picked up the trucks for testing, he left some spare bushings to experiment with. I was able to test the effect of adding different types of lubricants, and ended the night by carefully cutting the bushings in half with a wire saw to test the effect of reduced surface area, as you had previously mentioned. The bushings are now roughly 1/3rd of their original thickness (0.5mm / .020"), but this only marginally increased the distance traveled compared to the full width bushing. It was way tougher to ensure proper alignment, and in the end provided very little reward.

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The results are what I expected. 

The car does roll better than a stock Athearn car and looks better too, so all in all it is a step in the right direction. That said, there is still room for improvement. I do have another idea I want to try (inline with what @Loren Perry described on page 1), but it is going to take a bit of time to get it worked out. Craig also has some interesting lubricants that might help, so I am looking forward to the next round of experiments.

If it was an easy problem to solve, someone would have already solved it! 

[peteski]

Thanks for this info. So, one possible modification to  the design has been verified as a solution with diminishing returns. I'm still curious how your trucks compare to the Kato Amfleet trucks which to me are as close to the ideal design as possible (thin axles and narrow bearings).  But Kato also puts a dab of grease in each bearing - I'm not sure if that really makes things better.