Body-mounting IM and PM 3 Bay hoppers

[jagged ben]

So, what have you guys done about body mounting your Intermountain hoppers?   Tips and pictures appreciated.  I imagine this has been discussed before but several minutes of searching was fruitless.

I'm talking specifically about the Intermountain 4750 CF like these, and the similar but different old Precision Masters hoppers.

I recently obtained a bunch of these, never used, for a good price, but unfortunately the trucks on the IMs are the old IM ones like these (thanks Spookshow) that come with the crappy knuckle coupler shown.  And the PM cars of course came with even crappier  Rapido trucks.   And I would prefer body-mounted 1025's, anyway.

Once upon a time N scale of Nevada made a body mount coupler adapter for the PM cars, which I like.  It's called the BMCA07 and it practically takes a genius to figure out that that stands for Body Mount Coupler Adapter (no instructions).  It also says "PM 3-bay Covered Hopper" on the packaging, and if anyone has a couple of those 3-packs lying around, please message me.

I'll probably reuse the IM trucks with FVM wheels (.553" axle?), and I'm debating what trucks to obtain for the PM cars.
(These should have 36" wheels, right?)

[James Costello]

Precision Masters also used a do a body mount adapter for their cars, just a simple black plastic piece with a lip on one end and two guides on the other end. Not as stylish as the NSN piece, it was effective though and worked well.

Body mount adapters such as the NSN piece for all currently available covered hoppers remains one of my great hopes for 3D printing evolution.

[SD452XR]

I body mounted my 4750's using styrene and ACC. I glued a piece of .015x.156 #117 between the bolster and the end frame. Before I glued it, I used a black permanent marker to paint the piece black. I used micro trains 1025's as well. If you use the supplied 00-90 screw, it will stick up quite a bit when mounted. I ordered some 00-90 screws from a mfg (Morris http://www.jimorrisco.com/) that are only 1/8 of an inch. This way they don't stick up. The only problem is when screwing it in, you have to be very careful not to strip the hole. I pre drill the styrene. When I am ready to mount, I apply a very small amount of ACC in the hole. I then mount the coupler. Seems like one out of 20 I overtightened the screw so it wont hold. I then just used the 00-90 screw from micro trains. I just paint the part of the screw sticking out black. You might be able to use a thicker piece of styrene. If you decide to use a thicker piece, do some testing first. I used what I had on hand and liked the results. When completed, they are quite strong. I have done some testing with 30 to 50 car trains with no problems. That's good enough for me as I don't plan to run over 25 car trains on my layout. I used micro trains trucks with Fox Valley Wheels. Hope this helps.

Steve

[jagged ben]

Thanks for the replies, and for the link on the screws.  (I can think of a few other cars where those screws would help.)

Either the PM or NSN adapters would be a welcome find, but that's gonna take some luck to find them.  And in any case, I don't think they'll be suitable for the IM cars.  The IM cars already have diagonal braces on the ends so really just need the center piece to hold a coupler.

I was thinking brass instead of styrene, but I guess it's not crucial either way.

Would 3 printing (i.e. Shapeways) be economical for adapters?  Not trying to spend a lot of money on this.  Thoughts appreciated.

[nkalanaga]

I body mount mine with a strip of Evergreen styrene.  The easy way is to notch the body bolster with a chisel-end knife blade, so there's a ledge for the strip to sit on.  Done right, the coupler is at the right height, and with the outer end sitting on the underside of the "end sill", there are no weak butt joints.  On these, the key is to use the flat side of the blade against the end sill, so the first cut has a flat upper surface, and make sure the blade is level.  The lower cut is made with the blade reversed, and the piece in between can be popped out.  With practice, a car can be done in a couple minutes, although the glue needs to set well before you start drilling.  Mine all seemed to need 0.03 inch styrene for 1025s. 

I think I have one car with the NSN adapter, and several packages stashed.  The styrene was easier than gluing a metal casting into a plastic car, and the adapters, being a "one size fits all" solution, didn't always fit that well.

[jagged ben]

nkalanaga, thanks for the tips.  I'm not sure though if you are talking about the IM cars, or PM cars, or both, but I think I follow (after reading and re-reading!).

For the PM cars I like the NSN adapter, so I will PM you about those.    The IM cars are different and the NSN adapter isn't suited for those, so I will try your method.

[Spades]

July? issue of MR Jim Kelly in his N scale column, touches on this very subject.  He uses two pieces of styrene, so no notching. He also gives the priceless tip of not making the mounting strip wider than the coupler pocket.  It could interfere with the truck movement.

G

[Catt]

I have some of the J-N-J cast metal adapters if your interested.2 1/2 packages (enough for 5 cars) if your interested.PM me if you are

[coosvalley]

Anyone care to share a pic of their conversions?..Especially styrene on IM 4750s?

[nkalanaga]

Spades:  I don't see how the mounting strip could interfere with the wheels.  The couplers are designed to be mounted to a flat surface, so if the wheels stick up above the coupler, they'd hit the floor on a boxcar.

His method works fine in the example shown, where the body bolster has a flat surface.  Many of my conversions have a round surface, meaning that a butt joint would only be glued at one spot.  The notch gives more room for gluing. 

On the other hand, making it wider than the coupler doesn't look good under an open car.  The 1025 box is 3/16 inch wide at the car end, so that's why I usually use 3/16 strip.

As always, there are many ways of accomplishing the same result, and I won't claim my way is the best for everyone.

[Spades]

Spades:  I don't see how the mounting strip could interfere with the wheels.  The couplers are designed to be mounted to a flat surface, so if the wheels stick up above the coupler, they'd hit the floor on a boxcar.

Not me, (I've done worse) but if the mounting pad is too wide and the car body long and the curve is sharp, it can limit the lateral movement of the truck.  The back of the wheel has struck the platform.  I had a buddy do it. Miniscule chance, unlikely but is possible.

G

[craigolio1]

Spades:  I don't see how the mounting strip could interfere with the wheels.  The couplers are designed to be mounted to a flat surface, so if the wheels stick up above the coupler, they'd hit the floor on a boxcar.

His method works fine in the example shown, where the body bolster has a flat surface.  Many of my conversions have a round surface, meaning that a butt joint would only be glued at one spot.  The notch gives more room for gluing. 

On the other hand, making it wider than the coupler doesn't look good under an open car.  The 1025 box is 3/16 inch wide at the car end, so that's why I usually use 3/16 strip.

As always, there are many ways of accomplishing the same result, and I won't claim my way is the best for everyone.

He's talking about it interfering when the truck turns.  If the mount is wider than the coupler then it limits the turning radius the car can negotiate.

Craig

[nkalanaga]

Craig:  "He's talking about it interfering when the truck turns.  If the mount is wider than the coupler then it limits the turning radius the car can negotiate."

That's what I don't understand.  If the coupler is under the strip, and the wheels don't reach higher than the top of the draft gear, how can the width of the mounting strip matter operationally?  It's just a floor, like any other car, although for appearance reasons it should be as narrow as practical. 

For that matter, Center Flow covered hoppers have a solid floor under the ends, so a narrow strip there is actually unprototypical.