Ride Height

[bbussey]

... Seriously though in this age of printing and self-design, I wish MT would share non-proprietary, basic step file models of their critical parts: boxes, lids, coupler halves, etc., or even just an envelope package of each coupler, especially the Z.  It would allow for perfect design of mating cars with respect to the coupler height from the top of rail and proper fitment of the couplers to the car, as designed.

It's easy enough to reverse-engineer those components with digital calipers and dimensions documentation available on their website.  A necessary step for designing models with body-mounted couplers that are compatible with Micro-Trains products.

[rail_nut]

peteski and milw156 are right about everything is based on TOR (top of rail). Seeing your gauges and comments about flange height included but not considered I think your cars end up not meeting the heights allowed by the plates and will be low. Car builders have to also consider the second part of the clearance diagram which is car width based on car length and truck centers.  Having done this exercise in real car design I am missing something. Cars meeting a certain plate do not necessarily fill the plate, just don't exceed it, and some cars actually listed as meeting a plate exceed it by small amounts in specific locations. Not shown in the plate but in real cars truck design including wheels, suspension and movements are also considered.

[squirrelhunter]

Ok, so basically you are not worried about how the cars look like viewed from the side (whether they are sitting too high or low in the trucks), but just how tall they are.

If the car side is actually to scale and not vertically compressed then if the roofline is at the right height, it seems to me that the side sill will also end up in the correct place?

(And I'm not including MTL's various vertically compressed boxcars in this, I personally don't have any because of that issue)

[peteski]

If the car side is actually to scale and not vertically compressed then if the roofline is at the right height, it seems to me that the side sill will also end up in the correct place?

Well, not necessarily. Many N scale cars have excessive daylight between the underframe/side-sill and the ground/rail due to the truck design.  Modelers lower the ride height by changing the trucks or reducing the height of the bolster.  For them the important visual difference is how low the car settles over the truck, not the overall height.

The MTL cars which are vertically compressed are perfect example what was done in N scale for the overall height to be correct:  MTL vertically compressed the car because it was designed to ride too high over the trucks.

[randgust]

Whatever you try, it's still worth it.     Same carbody, before and after, on an MT 40', this one has the floor pushed up inside the carbody:



Link:  http://www.randgust.com/mtlower2.jpg

Just as worth it on gons and flats:   This with a full bolster replacement.



link:  http://www.randgust.com/MTdropgon2.jpg

And I'm not getting into the coupler height issues at all because I retained the original trucks.   I very much use magnetic uncoupling and truck mounts are still preferred for me on that keeping the coupler aligned and proper height.

[milw156]

Whatever you try, it's still worth it.     Same carbody, before and after, on an MT 40', this one has the floor pushed up inside the carbody:

Just as worth it on gons and flats:   This with a full bolster replacement.


so do you mill something off of the top of the floor, or modify the carbody? Picture of the bottom of the gon?
TIA

link:  http://www.randgust.com/MTdropgon2.jpg

And I'm not getting into the coupler height issues at all because I retained the original trucks.   I very much use magnetic uncoupling and truck mounts are still preferred for me on that keeping the coupler aligned and proper height.

[dandopinski]

Another indicator of ride height is the foot stirrup. Look at prototype pictures to see where the bottom of the stirrup is in relation to the journal boxes on the trucks.

[randgust]

I have a reputation for 'just doing it' to see what will work, paying no attention to anybody, and this is another classic case.... 



Link:  http://www.randgust.com/MTdropgon1.jpg

Yeah, hacksaw off the original bolsters and put a styrene one in there....glue to the plastic car body on a flat or gon.  Heresy.

Another benefit, at least for me, is dropping the car height also makes the pizza-cutter flanges about invisible.    The current wheels work well for me but when I was doing this the low-profile wheels were a failure, stringlining off on a heavy train as soon as the flanges scuffed up.

[amato1969]

Love it @randgust , simple and straightforward.

  Frank

[milw156]

Thanx, that is not what I was picturing. Picture worth 5000 words!

[Maletrain]

To me, the height of the box cars is not bothersome. I guess I am used to seeing photos of transition era trains with box cars of all sorts of heights mingled together in trains.  Only trains with a batch of single type cars, like stock or reefers, seem strange to me if the tops don't match.

On the other hand, the relationship of the bottoms and the floors of the cars with respect to freight platforms and the height of stirrups above the tie tops do catch my eye.   

[Sokramiketes]

It's easy enough to reverse-engineer those components with digital calipers and dimensions documentation available on their website.  A necessary step for designing models with body-mounted couplers that are compatible with Micro-Trains products.

And yet there are so many cars produced that get it wrong!  My hunch is that no one takes into account the varying location of the wheel sets in the side frames.  Given the needle point axles, I'm not sure all wheels ride at the centerline of the truck, but rather ride up higher, causing interference with the underbody. 

[peteski]

And yet there is are so many cars produced that get it wrong!  My hunch is that no one takes into account the varying location of the wheel sets in the side frames.  Given the needle point axles, I'm not sure all wheels ride at the centerline of the truck, but rather ride up higher, causing interference with the underbody.

While the vertical range of the axle end's location in the bearing cup is fairly small, that is a valid point. While MTL doesn't have that problem, trucks which have loose axles (from other manufacturers) will have the truck frame raiding lower than it should be.