BLI P70 - Correcting Coupling Distance How-To

[dem34]

I'm a little surprised that MT or Rapido, with there demonstrated wizardry in casting tiny plastic parts to make up otherwise really great scale models of various passenger cars, haven't created a more refined, closer to scale, functional diaphragm. MT's heavyweights have diaphragms that are 'functional' in that they move when pressed, but they are too small to close the gap between cars, and they're too stiff to function properly even if they were in contact with each other.
Geoff

Costs, MT likes to keep their prices down as much as possible. And Rapido probably feels that most wont care and that adding it might push their prices too far. Guess its easy to just say that most people arent bothered by the lack of Diaphragms for it to be worth the cost.

[NorsemanJack]

Diaphragms are the afterthought.  Back on topic, coupling distance is the real issue.  If the coupling distance is close, the space between diaphragms is a minor issue.  If the distance is huge, I don't care what diaphragms are used; it's going to still look really stupid.  Exhibit A:  MT heavyweights.

[Lemosteam]

So I am developing multiple step/coupler pocket design that snap mounts an MT 2004 underslung coupler (screw optional) that is intended to provide a specifc dimension from coupler hood inside to the diaphragm face on the OEM surface.  I have the ability to adjust this dimension to space that and any other aftermarket diaphragms as close as possible.  Currently I am starting with this dimension at 1mm (providing a 2mm gap).

I have confidence that the 2mm gap will work on all track radii.

I plan to reduce the gap in 0.25mm increments to investigate exactly how close I can get them at various track radii and will lay these out in the days to come.

For those that only wish to improve the look of the steps individually, I now have these available here.

[OldEastRR]

Really looking forward to a photo of a KyD step set installed.

[dougnelson]

KD steps and coupler pocked in progress:

[Lemosteam]

@dougnelson , in that last shot- is the coupler snapped all the way in?

[dougnelson]

@dougnelson , in that last shot- is the coupler snapped all the way in?

No, probably not.  This was an in-progress shot.  I used MTL 1015s and they were a perfect fit including the screw hole.  The Keystone Details steps/coupler pocket are excellent!

[Lemosteam]

@dougnelson , you may find the 1015 coupler too low for other mating cars. But the 2004 coupler fits into the 1015 box. I'm glad you like them!

[dougnelson]

Coupler height seems fine. I filed the car end underside flat before I mated the steps/coupler box so the entire assembly sits a few hundredths higher.

[dougnelson]

Images of the completed car end. Final step was to add back the steam and air hose details.

[Lemosteam]

@dougnelson , that looks really nice.  I was planning on cutting out the crossbar from the brake details but i think it a$$ some needed structure under there, even if it is not proto.