Ron, one more Acela question...

[daniel_leavitt2000]

I have cobbled together a few more train sets. One will be a second full 8 car set with a first class turned 180 degrees until I can find an end business car. Another will run as a six or seven car train until I can find an additional business and end business cars. The third will be used to supply cars and parts for the first two. This is in addition to the full, correct 8 car train I purchased when it came out.

Now that I had a chance to look at the running gear a bit, I noticed that other than the gear cut outs in the underside of the side frame part, the power truck and dummy trucks are exactly the same. This it's important because the power trucks have inboard electrical pickup while the dummies have needlepoint pickups. Even more interesting in that both pickups transfer power to exactly the same point in the cars: Meaning it should just be a master of swapping the power truck wheels with needlepoint equivalents and using a set of needlepoint wheel wipers from an unpowered car. Have you tried this? What were the results?

[u18b]

Hi Daniel,

There are really two "locomotives" in this set.

There are two dummy locomotives. 
And then there is the powered Cafe car.

I assume your question is about the powered cafe car.

I never found a way to change axles on the cafe car.  I gave quite a bit of thought to how I might reduce the friction in the cafe car, but never found a way.

On the dummy locomotives, I did replace the axles with Kato E8 axles, once I trimmed the gears off of them.

If you place new axles in the power car, be sure and post what you did so we can see.

I'm kind-of thinking you are correct.  But it never occurred to me to swap powered trucks with unpowered trucks-- and then powering the unpowered truck by adding gears and all the rest. 
And the reason it didn't occur to me is because I didn't have a supply of extra parts.

I think this is a great idea if it works.

[brill27mcb]

If you are aiming to have truly correct-looking train consists, you will also need to turn a few cars around 180 degrees. Even the Amtrak floor/seating plans in the original brochure are wrong. Take a good look at the arrangement of the A/C "bumps" on the roof of each car in side-on photos of the prototype. On each car one is closer to its car end than the other one is, and their orientation varies along the length of the train. The lavatories are also arranged to be at the opposite end on some adjacent cars. To fix this on the models, I removed the triangular cover plates that contain the hook-and-bar couplers, holding the whole assembly together with my fingers while swapping it end-for-end on the cars that needed to be reversed.

Rich K.

[peteski]

Daniel, I have converted my Acela's power trucks to axle-end cup pickup, but it was a major pain because the metal axle is a single piece.  I had to split it into 2 pieces.  One of these days I'll try to write an article on how I did that (I wish that I documented it as I was doing the conversion).   I have to dig out my Acela ant look at how I did it - I don't recall the details.

I have no idea why Bachmann didn't just use the axle-cups pickup on that truck in the first place (as you say, they already used that system on the dummy trucks).  Instead they totally redesigned the power truck with those sucky inboard pickups.

[daniel_leavitt2000]

Ha ha... I knew it wouldn't be this easy.

Gear towers are the same: check
Powered Side frames can be swapped out with dummy side frames: check
Powered friction bearing contacts can be swapped for non-powered end cap bearings: check
Powered wheels can be swapped with dummy wheels: DOH!

So I took a look at the powered wheels. Like Pete said, they use some sort of weird sandwich where one wheel is connected to a long metal axle. An insulating geared axle is then pressed onto the metal one. Finally the opposite wheel is press fit to the insulating geared axle. Lord knows why they did this. This is unlike any of their other models, where both wheels simply plug into an insulating axle.

This also makes conversion to end bearings very difficult: you can not simply plug in Kato or Bachmann end bearing wheels. So I went to the part box to find an insulating axle with matching teeth. No such luck. The teeth are a different size than Kato, so nothing from their massive parts store will work. This also excludes LL and Atlas as they all use the same tooth size.

I have a sizable parts box of retired Bachmann engines, but I have a feeling this tooth/gear size is specific to this model as it is the only one to have 36" powered wheels. I don't feel brave enough to start chopping the insulating gears on the model until I have replacement parts if something goes wrong. More to come...

[u18b]

Like I said.   When I did that project years ago, I spent a LOT of time trying to figure out how to make a low friction Cafe truck.

And I couldn't figure it out.  Peter was more imaginative than I.

Looking forward to seeing what you do.

[daniel_leavitt2000]

I think Pete is on the right track. Right now my idea is to pull the wheels and metal axle from the insulating axle and replace them with Kato 36" wheels. I think if I turn the insulating axle 180' it should fit the Kato axle halves and line up with the gears.

Now, any ideas where I can find low profile blackened 36" wheels with traction tires?

[u18b]

Are traction tires needed with changing out all the wheels?

I replaced ALL other wheels (except for the Cafe car) with Kato wheelsets since the needle point was longer.   This reduced friction in the whole set dramatically.

[daniel_leavitt2000]

I did the same with my first set. A non TT equipped Café was able to pull the 5 car train set, but not the 8 car full train. It would slip on curves and stall on 1% grades.

I am looking at Kato Japan parts. There are 36" wheels for their various Shinkansen trains, but these are all bright silver wheels and the flange is a bit bigger than I would like.

[peteski]

I still haven't dug out my set but I'm now remembering more of what I did.  You are right Daniel, I have never seen this kind of arrangement in the past and I also have to ask why did Bachmann do this considering that they had a perfectly good outside axle bearing systme already designed for the dummy cars?!  One will never know.

I suspect that one of the reasons was that the fit on the dummy trucks was too sloppy for proper meshing of the gears.  I pressed the dummy trucks half axles out a bit to tighten things up (Ron simply replaced the wheel sets).  But the Bachmann wheels have a very wide tread which sometimes shorts out on Peco electrofrogs.  I might eventually replace them with Katos.

The 1-piece metal axle in the powered trucks is a royal pain when wanting to convert them to axle-end bearings.  What I did is sort fo silly (but it works).  I cut a short piece of the axle end on the side with insulated wheels. Then I pushed it back into the insulating insert but I also sandwiched a tiny styrene disk to prevent the stub axle from contacting the other axle. I then made some phosphor bronze wire pickups on that side to rub against the  still-insulated wheel. That way I had power pickup from all 4 wheels and the axle was now split so it wasn't shoring between the side bearing plates.  I have to get the Acela out to take some photos.  I also recall tightening the very sloppy gear train with some washers made from brass tubing.

[u18b]

I never tried to pull an 8 car train.

Are the shells interchangeable?  Can you run two powered units and swap shells with something so as to still remain prototypical in consist?

[peteski]

I dug out the power car and pop the truck out. Now I see that my modification was even more complicated that I remembered.  I also can't find any drawings of how I did it (I do remember making sketches when I did the work - but where are they now?). I'll try to take some pictures of the truck (assembled and dissembled) tomorrow.

There are lots of issues with updating the trucks. Wheel sets from other manufactures use 1mm axles - Acela for some strange reason uses 1.2mm axles!  The gears are also different (more coarse teeth than most other modern models).  I'm just thinking that maybe some gears from the old Life-Like or Model Power locos would work here... I couldn't find any viable solutions other than heavily modifying the original Bachmann parts.

[peteski]

Here is how I modified the power trucks for axle-end bearings.  For each power truck I needed a sacrificial wheel set from a "dummy" truck (from a free-rolling car). I only needed the half-axles.

I took the geared wheel set apart.  I used an arbor press to push the axle out of the wheel set. I had to do the same to get the half-axles from the plain wheel sets from the "dummy" truck.  I also used the arbor press to push the shortened axles back into the wheels.  I super-glued the longer axle into the new muff (as the fit wasn't tight enough).  But there is no need to glue the short axle into its muff.  Revisiting what I did, I could have simply made a new outer muff out of metal for the short axle (purple item in the drawing) and not use the extra wipers, but I didn't. 

Here is a diagram of the wheelset modifications.



Modified wheelsets.


In the body of the truck, all the gears were free to move laterally along the metal axles. That sometimes caused them to bind and jam. I used 2 brass washers on both sides of the worm wheel. Then I made sleeves from thin-wall brass tube to restrain movement of the idler spur gears.  I also enlarged the openings which originally served as bearings for the wheels.


Here are the wipers needed for the side of the truck with insulated wheel.  They are made from 2 pieces of 0.008" phosphor bronze wire crimped in a short piece of thin-wall brass tube. They are soldered to the stock pickup/bearing from a dummy truck, then bent to shape to properly contact the sleeve on the back of the wheel.


Assembled truck. This photo shows how the wipers contact the wheel. This does not add much friction.


Bottom of the truck. I slightly enlarged the long gear openings to prevent the edges of the opening from interfering with the gear teeth.


The improvement was quite drastic. The truck now rolls very smoothly and with little resistance.

[u18b]

Wow.  Fantastic. 

2 thumbs up.

[daniel_leavitt2000]

Wow, that is very, very involved.

I wonder if I can replace all gearing with Kato parts. This would eliminate the gear slop and wheel problems.