Truck bolsters and draft gear sizes....

[10KPete]

It's me again, the greenhorn.

I've been all over IBLS and Google and anywhere else I could think of but no joy.

I would like to find out about any standards (!!) that might exist, for 7 1/2" ga. 2 1/2" scale, truck bolster heights and configurations. Is there any interchangeability at all?

I wouldn't think so, but does 1 1/2" scale share coupler sizes with 2 1/2" scale?

I see some nice couplers for sale and wonder if they all fit a standard socket size. IBLS gives a coupler height but no socket information.

Also, can anyone steer me to some typical size information on 3 foot narrow gauge freight truck dimensions for axle spacing, wheel sizes, bolster height, etc.??

And freight car sizes typical for small 3 foot narrow gauge railroads.

Thank you again,

Pete

[Glenn Brooks]

There's a lot of experienced people here to offer comments and suggestions, but I'll throw in one approach for you. Generally, I think it is safe to say the two scales you mention are not compatible. Couplers for 1.5" scale will be smaller than 2 1/2" scale, And potentially at a different height if your wheels are also scaled to 2 1/2" versus 1.5". So they will be mismatched if you try to couple up to another different scale car.

Now having said that, you have the option of standardizing YOUR equipment to the club or track standard you normally operate at, regardless of scale. Thus you could build 2 1/2" equipment, BUT install 1.5" scale couplers such that your equipment is compatable with other rolling stock at your 1.5" club. Might not 'look' scale correct, but will work just fine. Or build out to 2 1/2" for couplers and cars and just not worry about coupling to other 1.5" cars.

Cheers! It's all in fun anyway.

Glenn

[10KPete]

There's a lot of experienced people here to offer comments and suggestions, but I'll throw in one approach for you. Generally, I think it is safe to say the two scales you mention are not compatible. Couplers for 1.5" scale will be smaller than 2 1/2" scale, And potentially at a different height if your wheels are also scaled to 2 1/2" versus 1.5". So they will be mismatched if you try to couple up to another different scale car.

Now having said that, you have the option of standardizing YOUR equipment to the club or track standard you normally operate at, regardless of scale. Thus you could build 2 1/2" equipment, BUT install 1.5" scale couplers such that your equipment is compatable with other rolling stock at your 1.5" club. Might not 'look' scale correct, but will work just fine. Or build out to 2 1/2" for couplers and cars and just not worry about coupling to other 1.5" cars.

Cheers! It's all in fun anyway.

Glenn

Thanks Glenn,

I had thought that I could have draft gear at two heights on the back of the riding car to accommodate both sizes and heights of cars. But while I want to have equipment that looks good, I'll sacrifice a little authenticity for practicality!!

Pete

[10 Wheeler Rob]

I remember reading some where that someone built cars with two coupler pockets one at height and size for 2 1/2 scale and a lower pocket for 1 1/2 inch scale. This allowed easy change to interface with both scales.

Rob

[makinsmoke]

Hi Pete,
The Rio Grande used "idler cars" in the yards where they had both standard and narrow gauge equipment and rails, including segments of three rail.

The idler cars had a standard gauge coupler on one end and a narrow gauge coupler on the other end, mounted so that the couplers were centered on the gauge rails being used. In the three rail yards, the narrow gauge rail was always on one side of the track no matter where in the yard, meaning the third rail was on the "west" side, or "south" side.

What that meant was the standard gauge coupler was centered on the car and on the other end the narrow gauge was offset to one side. Hope this makes sense.

How this applies to you is build what you want, but either mount a coupler on one end of a regular car to connect to everybody else's equipment or build an "idler" car with the same coupler set up but used specifically when you want to connect to anyone else.

When running alone or on your own track you just drop the idler car.

Take care,
Brian

[makinsmoke]

As far as truck specs check out Branchline
Products pages:

http://branchlineproducts.com/catalog.html

[Harlock]

OK here's the rundown on 2 1/2" scale coupler stuff:

The standard centerline coupler height is 5.42", which is ~2 1/2" scale of 26" prototype coupler height, which was used by most of the Colorado lines.

The shank height on most of the solid shank 2 1/2" couplers I've run into is 1 1/2. I use a 1 1/2" tall by 3" wide steel rectangle tube that runs the length of most of my cars and provides the pocket on each end. The Fascia is built up over that to look prototypical, whether a purchased cast surround or built up with wood.

There is no coupler geometry standard, just as there is no coupler standard that 1 1/2" scale manufacturers adhere to, unfortunately. MOST of them work with each other, but not all. For 1 1/2", Railroad Supply long ago put out a nice coupler spec from GGLS with full dimensions in an early handbook, which LALS later reproduced in one of their publications as well. But that's about as far as it got.

That being said, they can all be made to work with each other but sometimes you will need to grind a knuckle if one is too fat. There is actually quite a bit of geometry that goes into making a good working coupler that doesn't pop open by itself or is very hard to release or binds prematurely.

For your own train, purchase matching couplers from one vendor. I use RMI 2 1/2" couplers as the price is reasonable. Tom Artzburger also has some nice short shank couplers that go into a matching pin pocket for your loco.

I absolutely do not recommend standardizing on 1 1/2" scale couplers for your large scale train. Especially since if you are building a MEG it will actually be even larger than 2 1/2" scale. It looks funny and causes difficulties making dropped coupler pockets at the ends while accomodating 2 1/2" scale trucks under the car. If you use 2 1/2" scale standards the couplers will look on the small side but reasonable (like 3/4 AAR couplers used by some NG railroads) and you will be compatible with the large variety of 2 1/2" scale equipment out there.

For 1 1/2" scale compatibility, pick one car that will adapt to 1 1/2" scale, and weld a 0.75" X 3" pocket underneath the 2 1/2" scale pocket and it should come out to ~4 7/16 height needed for 1 1/2" scale couplers. Then you can switch the couplers out. Or make a special 1 1/2" coupler with a drop shank to go in the 2 1/2" pocket.

Regarding trucks, the 2 1/2" Pacific Coast RR style arch bar freight trucks made by Steve Easlon that I use under all my cars put the 1 1/2" X 3" rectangle tube at the correct 5.42" centerline height for the 2 1/2" couplers at the ends.

Here are some photos of one my car builds: http://www.chaski.org/homemachinist/vie ... 95#p301795

Sometimes we do prototypical undersides with all wood construction but only for the very fine scale replicas. Those have individual pockets at the ends. The rest are as appears in the photos in the link above.

-M

[10KPete]

As far as truck specs check out Branchline
Products pages:

http://branchlineproducts.com/catalog.html

Excellent! Thank you. I downloaded the truck drawing.

Pete

[10KPete]

Mike,
I do not intend to 'mix' scales; that way lies disaster. Been there with other things.

RMI looks to be a good source, however their web site does not have pictures of half of their 2 1/2" couplers. I messaged them to see if they could provide pics and info.

Other 2 1/2" stuff isn't exactly everywhere. I find a few things here and there. I can't find the truck guys you mention for example. I found that Super Scale has proper glad hands and sill cocks but man they're proud of them!

So, any sources you can supply links to will be greatly appreciated! I'm starting from almost zero here....

Thanks,
Pete

[Harlock]

RMI's website is definitely lacking in some areas. I've attached a picture of RMI couplers and a double pocket (top is for the 2 1/2, bottom is for 1 1/2" as previously discussed) and an RMI fascia that fits over the end. Two more pictures show the assembly installed on our boxcar. I think those couplers are around $100 a pair. Don't remember how much the pocket fascia is. They have two widths of fascia, that is the 'wide' one for the 3" square tube.

I'll PM you Steve Easlon's email address. He has no online presence otherwise. His Pacific Coast style arch bar freight trucks are currently $700 a pair, the best bargain you'll find for 2 1/2" trucks. He does periodic runs of them in batches. I've attached a picture of a pair I added brakes to.

I am not sure if barry is still actually selling those gladhands. I use clippard industrial fittings between cars, though the scale stuff does look nicer.

Tom Artzburger is a good general source for 2 1/2" detail parts. His site is http://tacllc.biz/pleprice.htm

Some things have pictures some don't but in general it's all nice and he offers good, prompt service.

[10KPete]

Thanks Mike, good info. Your first pic; I've seen that type of coupler other places on the net and have a question about the spring sticking out the back of the shank. The pockets shown in the pic seem to have a plate welded across the ends. I assume there is a hole in the plate for the spring(s) to straddle, one inside and one outside. Yes? How do you do that if the pocket is one end of the main frame tube? The other type of coupler I've seen has a pair of springs and a bushing of some sort between the springs, all contained within the shank and accessible thru slots in the top and bottom of the shank. I assume a bolt goes through the main tube and captures the bushing. ????

I've been looking at that caboose you and your Dad have built. It's really beautiful and very detailed, a really great piece of work!

Thanks,
Pete

[Harlock]

Yes, the RMI type draft gear has all thread and springs on the back of the shank, for a continuous tube center frame it requires milling out a square and putting a tab in it with a hole. For individual pockets on the end of each car, you would close off the inside end of the pocket and then drill a hole in it, exactly.

For the shanks with an opening in the middle with the springs, those use a pin. It is better to have a pin you can drop down from above and then put an R-clip in it, rather than screw into a threaded hole in the frame from the bottom. If the latter, blue loc-tite is advised so it stays put but you can remove it when needed. There is a third option, and that is to have a pin you can insert from below, but have an extra surface between which you can trap an R-clip, through a hole near the head at the bottom. I saw this on an Atlantic I'm currently readying for sale.

In photo 1, you can see the hole milled into the continuous tube frame, with a tab welded in to interface with the coupler. Another spring is behind the tab. A lock nut caps it off. The BNC connector is for electrical and the two clippard fittigns are for air, one up to the loco from the resovoir in the boxcar, and the other is the application line back from the valve in the loco.

Cars that go behind the boxcar only need the application line.

In the future I will have a steam air pump on the engine to use as the primary source rather than the electrical pump on the boxcar.

The third photo shows an individual pocket that is custom made for a log car. That one can just be capped off at the end as you said.

This was retrofitted to an existing car that I finished. I built two more from scratch and used the continuous tube on those rather than the individual.