Atlas vs Micro Trains 3 Bays

[Lemosteam]

Yes, obviously. I was appealing to @Mark5, as he may have one to share, or someone else who might.

[Lemosteam]

Hi All,

I am beginning the design of the underframe parts and have a question:

Does anybody know of a drawing or can measure the height of one of these cars to the top of rail?

I will be fiddling with ride height and I want to see if I can get it perfect, or very close with a simple mod to the bolster on the car.

[Mark5]

The overall height of the N&W cars (H11a, H11b, etc) is 12' 3".

Mark

[High Hood]

https://www.nwhs.org/archivesdb/detail.php?ID=16109

[Lemosteam]

So after measuring the car on rails, it actually sits too LOW.  The Atlas car measures a (calculated) 11'-10" off the rails, 5" (0.03" in N Scale) too low. 

I suppose I could design a 0.03" bolster spacer into the design would that be a desired feature?

Unfortunately the linked drawing is blurry to me and I cannot read any dimensions.

One thing to confirm, this would rid on 33" wheels correct?

[Mark5]

One thing to confirm, this would rid on 33" wheels correct?

I guess you missed this in reading the thread. 

These ride on 36" wheels.

Mark

[Lemosteam]

@Mark5 LOL and thanks.  Well the Atlas wheels are 33", that is why I asked, and no I did not go back and re-read.

So with the 36" FVM wheels, the car now rides at 12'-2"  Close enough.  1 scale inch low or 0.006" in N Scale.

thanks again.

[Maletrain]

@Mark5 LOL and thanks.  Well the Atlas wheels are 33", that is why I asked, and no I did not go back and re-read.

So with the 36" FVM wheels, the car now rides at 12'-2"  Close enough.  1 scale inch low or 0.006" in N Scale.

thanks again.

How much does a loaded car lose in height, compared to an empty car?

How much does an empty car lose in height as its springs age?

[nkalanaga]

"How much does a loaded car lose in height, compared to an empty car?"
Some cars used to have the "spring travel" stenciled on the car.  Would that be this number?

"How much does an empty car lose in height as its springs age?"
Probably not much, unless it's been overloaded.  If the springs "lose their spring", they should be replaced.

John, changing from 33 to 36 inch wheels, in the same trucks, will only raise the car 1.5 inches.  If the car is now 4 inches taller, there's something wrong somewhere.

Also, if the top of the car is too low, are you sure the bottom is too low, or is the side itself too short?  If the latter, raising the overall height will make the bottom of the car sit too high, which will be more noticeable than the low top.

[Lemosteam]

Nick I suspect it's the play in the axle center points from plastic axles to steel as the ewight of the caliper came down.  aslo had mu hand in there to prevent the car from tipping. 

I'm now not looking into any of that anyway/  I am not going to correct for any of that when the wheels mak it look that much better, dimensionally.

[Lemosteam]

For those interested, here is the latest status of the design.

I would prefer not to add printed brake lines, but instead provide holes for users to bend 0.010" brass wire to simulate the air lines from the reservoir to the brake cylinder.  I think printing them would make me design them flat and not so durable either.



I do intend to provide additional detail such as the brake cylinder linkage and some of the air line distribution blocks, etc. representing this image (sorry for the blurries, I enlarged in MS paint):

Anyone have a more informational image available?

[High Hood]

I have some detail shots of some modern NS hopper brake gear if you’re interested. Not exactly the same prototype, but I can dig them up if you are interested.

[Lemosteam]

Nah, this is being designed to work only with this car.  I think the image above should do.

[Mark5]

Hi John,

Not sure if these will help, but here's a few links:

https://www.nwhs.org/archivesdb/detail.php?ID=19904

https://www.nwhs.org/archivesdb/detail.php?ID=19905

https://www.nwhs.org/archivesdb/detail.php?ID=19903

Mark

[Lemosteam]

Hi Mark, thanks. Any idea what the apparatus is between the cylinder and the air tank?