Sunset Models AT&SF 3746 lopsided drivers

Hello,

You might want to contact Sunset Models directly and include this photo and description of the problem.

Steve

You could probably put anything in there as long as the heights match. Brass or even styrene rod would work. I have a few 3rd Rails where the front drivers have solid spring substitutes. Be sure to look in the packaging for a baggie of spares.

Most of these engines have a long screw through the steam chest and two screws under the cab opening. The steam chest screw is between the cylinders accessible from below. The cab screws will be looking right at you if you are looking into the cab, sometimes hidden by the deck plate if it has one.

If it is still binding up, I’d check the driver quartering. You can isolate the driver sets by pulling the rods. You will probably need a 3mm socket. You’ll actually see the rods at odd angles if you rotate the driveline manually.

@Norm Charbonneau thanks for the suggestions. I think that’ll be the best way. I’ll get some brass rod. As for getting the shell off. I’m still at a loss, what you describe is what I tried before and I tried again. I can get the rear loose and free but the front of the boiler still feels secured somewhere.

Norm,

Huge fan of your layout and how to videos.  If the quartering is off, is there a tool/process you use to fix/reattach them.  Is the process different for brass wheels (3rd rail)  vs die cast ones (like mth/ Lionel)  A link to where purchase tool would be great.

Thanks!

Mike

Zach, maybe more photos would help. I’m no expert on the model in question. On some engines the smokebox details can get hung up a bit during disassembly even with the steam chest screw out.

Mike, thanks man, glad you can put up with my unpolished droning. Someday I’d like to have a fully fitted model machine shop with proper quartering abilities. The most common quartering jig I know of is the NWSL one:

https://nwsl.com/products/the-quarterer-iii

Not sure there’s much of a diff between brass and diecast quartering other than diecast drivers being ‘captured’ in a rigid frame.

"Quartering" is not for the casual hobbyist.  There are a number of ways to do it, but you cannot successfully do it on the kitchen table.

My method is described in an early '90s issue of OGR (no, I don't remember which one).  Joe Foehrkolb had a different scheme.  Never tried the NWSL unit -

You need at a minimum an arbor press or substantial cast iron drill press and a special steel fixture.  Cheaper to let an expert do it.

Unless a Sunset driver is loose on its axle, it should not be out of quarter.

Bob, I'd definitely spring for the NWSL jig if I needed it. My J1a project had two sets of slipped drivers at one time. I had it exchanged for a new chassis basically.

The other challenge is indexing the main crank pin angle. Kinda wonder how that's done.

Someday I'd like to have a small modeler's mill and lathe for the shop.

I second the suggestion to contact Sunset models.  I haven't been there in over a year because of Covid.  Before Covid, however, Scott had a couple of people in his shop repairing models.  They may still be there and have the parts to fix this for you.  NH Joe

Thanks for the suggestions. I didn’t get downstairs this evening to take pictures but will do on that. I don’t think this will be a quartering issue. I’ll just start with the easy stuff 😜

Alright hopefully these photos help I would REALLY like to be able to be on the other side of the frame with the shell out of the way but it doesn’t seam like it’s coming loose.

Wonder if that slotted brass bushing up front there is holding you back. It’s slotted for a reason.

Looks like the chuff switches and selector switch is intact, but bypassed in the tender? Should be easy enough to restore.

Still a bit curious about what you described as ‘binding’. I would assume something mechanical as in the gearing/rods/drivers.

Yes,, you need to take a screwdriver and remove the slotted screw. That is what should be holding the boiler in place up front.

I honestly would’ve never guessed that I’ll give it a shot when I get back to the work bench.

Thanks!

Update

thanks for the guidance everything is back together and working good on rollers. Hopefully I’ll get a chance to put it through it’s paces at the club soon