The boiler details like the steam dome and sand boxes are glued to the shell.  I tried to pop one out and cracked the shell.  I wanted to save that piece, but ended up just cutting it near flush and patched the hole.  The filed and re-detailed that area.

It would be nice to get an unassembled shell.  But, I've never seen them offered before.

I placed an order for a new worm gear and bearings using the web site.

The web site shows the worm gear item and they were in-stock so I ordered it.

The next day I looked at that item again, not didn't see the bearing on the shaft so I emailed Customer Service and requested they alter the order to include the bearing.

I got a response a couple days later and a rep from that group wrote that the worm gear part doesn't include bearings and the bearing are not available.

I then replied to contact someone in product management to inquiry about how to get these.  She replied back that she can't do that and she wouldn't know who to contact anyway.  (Really?)

A couple days later a box arrived from your company.  It contained the worm gear.  To my surprise the plastic bag had three parts in it.
The worm gear on the shaft and two bearings.

However -   this part doesn't match what is on the web site.  This new one has square bearings that look similar to Athearn square bearings with an 2.0mm I.D.  The new shaft is cut down at the ends to size to fit this bearing style.   

Problem - this doesn't fit the calm shell weight that I have.

Questions - is this the newest design style that Bachmann is offering?   Are there new calm shell weights that can be ordered to match this?   Why isn't there a revision noticed on these part listings?  Why is customer service clueless about the products they are suppose to be servicing?  Why is the web site out of date on the product content/information? 

The part item for the motor says that you can purchase the motor and worm together or you can purchase the worm for just $4.00 - even that is not correct.

Is the worm gear for the version I have which has the 1mm x 4mm with  2.5mm I.D. bearings still available?

I have a 2-8-0 spectrum that has a couple of issues that need improvements.

Number 1.

The chassis assembly does not provide "free rolling" - defined as being able to have the wheels rotate as it is pushed on track separated from the motor-weight assembly.    If I apply downward pressuring and move forward/reverse the wheel can rotate.

Removing the the factory wheel wiper assembly and using just the flat piece to secure the drivers in place the wheels become "free rolling".   

The sprung drivers (2, 4) are not impacting this issue - the bottom plate eliminates much of the "spring" in those drivers anyway - to the point of making the idea of sprung drivers nearly useless.   It presses the axle back into the frame. I measurement 0.5mm of movement in the factory design. 

It appears that the wheel wiper assembly provides significant friction to the drivers to prevent free rolling which increases the force needed by the motor to turn them,  resulting in poor, slow speed, performance.

The wheel wiper assembly itself is somewhat innovative compared to what we had with brass imported models in the 1960's - 1980's.

However,  the conflicts with the rotation for "free rolling" is a huge disadvantage.

There are 8 contact wipers - while this is great for increased pickup,  using capacitors this amount is not really needed anymore.

Here are my questions -

Is the added friction and loss of "free rolling" ability a know issue to Bachmann designers in Chi-na ?   Since there are using CAD to design this they should know who to test and measure friction levels in eval simulations and prototype a new wiper design that results in 50%-80% reduction which might be enough to enable free rolling - and ultimately,  excellent slower speed performance.
Plus,  better overall wear and longer drive mechanism life.

I would also like to know if anyone has experimented with eliminating some of the wipers and did this enable free rolling?

Looking that the base plate of the wiper assembly,  there are locations that are recessed for an axle - however, this was not done on all axles - a design oversight?      The front axle has an opening to all easy lubrication - however other axles do not have this ability - another design.   A design flaw either way because once the wiper cover is attached there is not access to the openings anyway.  Again, it shows a design gaps.  Perhaps two people designing different parts and they can't speak to one another.

I don't know if the simulated brake levers play a huge part is preventing the free rolling ability.  The sound I get from the "factory" assembly is a "scrapping" sound which appears to be the metal-to-metal contact - wipers to wheel surface.

One thing that could improve the "scrapping" sound would be if the wiper blades edges had filets on the edge - since the back wheel surface is very rough (see under magnification).

Curious to hear is others have "tweaked" their models in order to get better performance.