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Hey all,

I've got a Premier H-9 Consolidation that was originally configured for PS2.  I assume it's a variation of item number 20-3098-1 that I bought empty from the MTH auction and finally getting around to filling her up with some guts.

Got the electrical figured out for a PS3 board, but I'm struggling with the motor selection and motor mount / Flywheel.  There just doesn't seem to be enough room at all for what I am doing if I'm going to use a 'typical' premier steam setup with a large motor and dogbone coupling.  The chassis already has the worm and the dogbone coupling going into the gearbox, so I know that's right. But  I made up a 3D model of my chassis and mount dimensions (measured directly from my actual chassis and shell and...well I don't get it.

I had a couple Pittman 9434 motors but they are by far too big / long to fit into the tight area.  I tried with a 3-D model of a Mabuchi 555, but even that seems to be too big for what I can fit in.  In my image below, I've drawn the exact position of the dogbone coupler and worm shaft, then you see a 30mm flywheel 10mm thick (which is the thinnest flywheel that I can find with the dogbone coupling installed), then a space for a mount bracket (that doesn't look like it will fit in front of the frame edge along the red line) then an RS555 motor.

I have to keep the motor between the two planes shown in blue / orange in order to clear the inside of the shell, and there are only two mount holes for a motor mount in the frame instead of a more typical 3 or 4.

Can anyone who has worked on one of these let me know

  • (a) is this actually a front flywheel mount or is it a rear mount?
  • (b) does the premier H-9 use a large 555 type motor or does it use one of the smaller motors like you would find in the diesels?
  • (c) What mount bracket does it use (it's not on the MTH site, nor is any other 2-8-0 H-9.  There's a 2-8-4 parts list that shows what appears to be an incompatible mount bracket)

Photos of what I've got: Thanks for your help!


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Original Post

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I worked backwards and used the new MTH parts and sales looking for H-9 to get parts lists. No picture, but part  number, then used that number- knowing there would be a dash added.

also note the special flywheel with recessed coupling- also moving the motor forward.

Screen Shot 2024-02-12 at 11.13.45 PMScreen Shot 2024-02-12 at 11.14.08 PM

And he matching motor

(AMETEK) (9432) (12VDC) (PITTMAN) (no flywheel)
Note: LO-COG was earlier version.

Screen Shot 2024-02-12 at 11.18.58 PM

That's what changes this arrangement

#1 the bracket is clearly just one 90 degree bend (OK, maybe not 90 exactly, but one single angle bend)

#2 special recessed flywheel coupling allowing shorter distance to worm shaft.

#3 specific motor 9432


Images (3)
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Last edited by Vernon Barry

Also, a thin flywheel and 9432 motor, and tach bracket versions

Last edited by Vernon Barry

Do dealers have a different database, or am I going to have to make a bracket?

I'm trying to find alternate parts and coming up a bust- you might have to make the bracket. No, I don't know of any different database for buying parts- we use the same interface as you the consumer on MTH parts and sales. If it's not listed for sale- either they really do not have it, or it's buried on one of those pallets and not yet in inventory.

Does MTH dimension those from center of rotation bosses or overall length?

I don't know. I'm thinking overall length end to end of the ball shape.

Vernon, With the Pittman, the recessed coupling flywheel, and a 22mm dogbone (center to center) looks like it'll work.  I'll need to make my own bracket, will probably send to  They can do quick laser cuts and basic bending for 3 bucks per bend as long as the part is 19 bucks or more, so I'll just have to bite the bullet on that.  Odd that I was so crunched for space, but the short body Pittman actually brought the flywheel backwards a bit and made the dogbone longer.

But look how the (red) bracket as designed just barely clears the inside of the thinner part of the boiler, and the motor body clears the inside of the cab with not more than a millimeter to spare.  It's a TIGHT fit in there!


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Can your shell take a 30mm fw?  PS-3 tach bracket is different and would require a 27mm fw.  You could customize the tach location just ensure it never touches shell or chassis ground.  You also can add those parts to your cart and that will trigger an email when available.  Doesn't look like Mike finished the H9 yet, but those parts may be in his possession.  G

@GGG : Based on my measurements, yes, it appears that a 30mm flywheel will fit with about 1.5mm clear to each side where the loco shell tightens in.  Also, you can see in the image above that the motor mount bracket has the two edges cut off right at 30mm width, because the shell actually needs to just scrape by the motor mount at the high corner (where my work plane shows it cut off).

Worst that can happen is that the bracket doesn't fit, and I will just mount the tach somehow to the motor like I've done in the past.

Update:  MTH has already shipped all the parts that were in stock (impressive)!

I don't think the tach bracket will work, as it looks like the tach was for a 27mm flywheel, so either way I'll have to find a way to rig the tack to the motor body or mount bracket.

Speaking of the mount bracket, since they're out of stock at MTH, I drew up my own and forwarded to Price to make two (including bending) was about 11 bucks each, but if I was doing 10 of them they'd be 4 bucks each.  If y'all aren't familiar, they are a super fast laser cutting / light fab service that's done completely online.  Perfect for metal parts like this.  Here's what I sent them (along with an STP file) and I'll have the parts by Friday!


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@GGG not a machinist but have worked with them for 25+years. I'm the engineer the machinists ***** about when I'm not around.

Well, not really. At least I hope not. But (as you might guess from my username) I get to help design and build some pretty interesting stuff. I've found some of the skills transfer nicely to my model RR hobby, and this type of work fits right in.


Finally got all the parts in (except for the recessed coupling flywheel which is out of stock) and progressed a bit.

Had to warm up a regular 26mm flywheel, remove the coupler, bought a size T stubby drill bit and sunk the coupling as deep as it would go without interfering with the setscrew:


Then I mounted it onto my custom motor mount from sendcursend (had to countersink the mount screws to be able to push the flywheel as far backwards as I could, and was able to use the PS3 tach mount)



Unfortunately, still have a couple challenges. Even with the recessed coupling and after shaving off the bulbous ends of the 15.6mm dogbone, and warming up the coupling on the worm so I could push it 2mm further forward, when the motor is installed the couplings are still too close together, and the dogbone squishes in there and forces the motor to bind. So I need a shorter dog bone, should have just got the 10mm one to start with.


But the bigger challenge... Even with the 'appropriate' motor for this guy, and even though it looks like it should fit, there's still a tiny bit of interference between the mounting posts at the rear of the cab shell and the OD of the rear of the motor. I'm going to chamfer the sides of the rear motor cap next...

It's a hobby, right?


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Got everything in from MTH (including some marker lights that I realized could be added) and got it together mechanically and electrically.

My measurement was about half a millimeter off for the height of the motor mount, which led to an eccentricity in the dogbone coupling. It worked, but some small vertical shims made it a bit better.

So as for fitting the shell posts over the motor... Well, I did some surgery. I filled the lower part of the gap between the post and shell with some metal epoxy, then (crudely) cut away the center of the posts so they could clear the motor. Only one of my JBweld concoctions held, bit it was enough for me since I know the engine and know to lift it carefully from the chassis when putting in on and off the track.

Finally, uploaded a Premier H-9 sound and chain file and the cab lights, firebox and markers all sprung to life! (I actually swapped the pins for the firebox and cab light, but I can fix it easy enough).

Except for the rear backup light, I'm calling this one finished and added to my fleet! Lubed up and pulled her first consist. Thanks for your help guys!



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