Weekend Update 1/18/26

[jpf94]

Would this be low enough to be used on slugs?   Great work so far!

A U18B with a small fuel tank and lots of air under the frame may be a reality in N scale. I made a frame to hold an 8x16 coreless motor and Bachmann truck and worm assembly. The bottom photo shows how much room is available to add DCC and weight. There's still room above the motor to reduce the frame height even more. This is proof of concept at the moment, there's a lot more tweaking to be done, both on the frame and the shell.

I have FB-2 trucks from a B23/30-7 that will be used on the final model.

[CR4100]

Would this be low enough to be used on slugs?   Great work so far!

I measure 16.4mm from the railhead to top of the frame. I'd be more worried about weight, the entire thing weighs 19g.

EDIT: This same concept could also be used to make a longer frame for something like a GP40PH-2 or GP40TC by using longer drive shafts.

[Lemosteam]

I measure 16.4mm from the railhead to top of the frame. I'd be more worried about weight, the entire thing weighs 19g.

EDIT: This same concept could also be used to make a longer frame for something like a GP40PH-2 or GP40TC by using longer drive shafts.

Suggestion, make a negative of each frame half, in cad add some slight draft from the deepest plane up to the opening, fill the holes, BD PRINT THE TWO MOLDS Melt and pour safe metal (bismuth or pewter) into the mold and let cool, belt sand or machine the cooled side.  Drill the holes and add an MT washer between the halves, use nylon 1-72 screws and BOOM, your 19g just went to XXg.

[CR4100]

Casting the frame sounds like a great idea to add even more weight.

I was planning to cast a large weight to go in the space in the long hood and a separate weight for the cab, similar to the old plastic frame Life Like locos.

[Iain]

A U18B with a small fuel tank and lots of air under the frame may be a reality in N scale. I made a frame to hold an 8x16 coreless motor and Bachmann truck and worm assembly. The bottom photo shows how much room is available to add DCC and weight. There's still room above the motor to reduce the frame height even more. This is proof of concept at the moment, there's a lot more tweaking to be done, both on the frame and the shell.

I have FB-2 trucks from a B23/30-7 that will be used on the final model.

okay, this design unlocks a bunch of projects.

[Lemosteam]

Casting the frame sounds like a great idea to add even more weight.

I was planning to cast a large weight to go in the space in the long hood and a separate weight for the cab, similar to the old plastic frame Life Like locos.

I have experimented with casting directly into printed resin molds. Surprisingly, the mold stood up to the heat really well.  I imagine they might even be better if the molds were 200F before pour.

Since printing the molds is inexpensive, you can mess with shrinkage to get them in the proper range for fitment.

That chassis would be a pulling monster, and yes, the added weights would only add to that, provided they are electrically isolated.

[Doc Frankenfield]

@Doc Frankenfield,

Have you actually laid out this track plan with real track yet?  I think you may have fallen into the trap that everyone of us has done a time or two.  I don’t think you’ve allowed enough room for your turnouts in your drawings, which may make it a challenge to build the plan to your satisfaction.
....Yes, cork is laid out and turnouts are temporarily placed. the layout plan evolved a bit with this process as did the scenery and overall design.

[nkalanaga]

Going back to the ConCor gons:  They're too short, but I just measured mine, and it seems that they're actuallv too SMALL.  Across the top they're only a bit over 9 scale feet, while most 50 ft gons were 10 to 10.5.  If these were scaled-up to 10 ft wide, they'd be the same length as the BLMA and Bluford cars.