RS-3's with Fixed Pilots?

Atlas does show them in their diagrams with part no’s. . They don’t seem to offer them for sale. An e mail with what you want to do may give you some answers.

I model the Rutland which until recently. Nothings been really produced. Luckily there are a lot of close enoughs and decals to get close to what you want.

I have done 3 MTH RS1’s to fixed pilots. The RS3’s are probably similar. After the first one. I bought a cheap heavily damaged basket case just to reference the frame. Some 1/8 aluminum from the hardware store and some basic tools and  I made them in an afternoon. Once you figure how to mock one up for the holes. The second one goes quicker. The laborious part is cutting and filing out the steps. None are available 3D printed that I know of.  It will be a skill I’ll never have. The aluminum takes time but it’s something I can do with the tools I have.  Basically I use the tapped 3mm holes for the headlight bracket in the MTH chassis to hold the spacer. I secure the headlight bracket with some stand-off nuts. I tapped holes for the coupler mount and to secure the 3 rail pilot. Still have some cleaning up to do. But it will probably be a year before I see the engine.

Atlas made an RS-1 in 3 rail with truck mounted pilot and in 2 rail with a fixed pilot.  Parts are available to convert a 3 Rail locomotive to fixed pilot.  Here are the parts diagrams and parts order page:

2 Rail parts
3 Rail parts
Parts Order Page

Here is the pilot of my Atlas 3 Rail RS-1

To convert, you will need the pilot spacer.  The 2-Rail front pilot looks very similar the the 3 Rail pilot, so you probably can adapt the existing pilots (or order 2 new 2-rail ones).  There are 6 steps attached to each pilot that are separate parts.  If you go with new pilots, you will might be able to recycle the steps from the old pilots if you can remove them without breakage.   I am not sure if you will be able to use the lobster claw couplers once the pilot is fixed, but most modelers replace the couplers with Kadees.  In that case, you will also need the pilot insert.

Personally I would just order 2 pilot spacers ITEM# 787039 and 2 pilot inserts ITEM# 787041 and adapt what I have.  Then install Kadees.

Note that the Pilot insert is not listed in the parts ordering page, so you should email Atlas about availability.  If not available, it would not be difficult to build it from styrene.

Bob

The Weaver "Ultra Line" RS-3s with fixed pilots can be made to run very well--probably better than ANY vertically-motored diesel.  They had large Pittman motors and can be fitted with a very large flywheel--or even two--for serious coasting!  They can easily be geared down so that 800 RPM = 4 scale mph.  That's good enough to earn full points in an NMRA contest without any need of closed-loop "speed control."  All this, and there is still enough room inside for a fully-detailed cab.  The centrally-motored drive will negotiate O42 curves; the body-mounted couplers will limit your minimum diameter.

Although this drive can be made to run slowly and smoothly, it's a bit light-duty.  There are a lot of nylon gears, U-joints, etc.  After 35 years, you might encounter shrinkage and splitting.  The good news is, replacement parts are still available from P&D Hobby (pdhobbyshop.com) at a modest cost.  If you change the ratios or mess with the nylon drive chain, make sure the flashing/burrs on each molded link are on the outside of the chain (not the sprocket side) or it will inhibit smooth operation.

Another drawback is that these diesels are feather-light.  You don't have to worry about zinc pest, because there's almost no metal!!  The last generation made by Weaver was sold with one rubber-tired axle.  Even though I hate rubber tires, I added a second rubber-tired axle to mine, for a total of four tires.  (With this design, you can easily replace wheelsets--you could do a full 2-rail conversion with nothing more than hand tools!)  I also added  at least a POUND of lead (custom weights built from laminations of sheet lead and contact cement.)  I believe the shell and chassis are made of styrene.  Unlike the ABS plastic used by other brands it's brittle, and won't withstand a lot of abuse.  Couple carefully, because the stock body-mounted couplers pivot on styrene posts which are easily broken.

Bottom line, if you have a little patience and an appetite for customization, the Weaver units are the most realistic and smoothest-running RS3s yet made for 3-rail O.  I don't have the room for O72 curves anymore, but when I did, I had a lot of fun upgrading and running mine!  I only wish someone would have made a sturdy metal frame for these as they did for the contemporary Red Caboose GP-9.  Good luck. Whatever you decide to go with, please post up some pics to show off your work!

Been hoping 3rd rail would do the RS3 — I think it would sell very well

If 3rd Rail made RS3’s I would jump on them in a heartbeat

I would be in for 3rd Raill PRR versions with sealed beam headlights with "T" and LONG tank versions-no "cookie cutter" battery box centered fuel tank versions. There's enough of those on the market!

I've seen photos of a recent-production 3rd Rail SD9 "undressed."  I was shocked at how tiny the flywheel is!  Scott, if you make an RS-3, please use a bigger flywheel this time.  Advanced electronics are great, but the last time I checked Sir Isaac Netwon still has a few things to say!

I'd love to see 3rd Rail do these as well.  Please make your interests known directly to Scott. 

I have a Weaver CNJ RS-3 in 2 rail with the old chain drive that I removed and made into a dummy 3RS locomotive before I decided to migrate to 2 rail for my CNJ and PRR models.  I have the parts for it somewhere to put it back together in it's original configuration.  Of all the O scale RS-3s I've seen, the Weaver still is the best mass produced one I've seen to date.  My complaints are the plastic handrails more than anything else on those.  They are much more fragile than brass ones.

A more accurate dual service variation would be awesome!  I'd also be interested in a few in PRR. 

I’ve been wishing for 3rd Rail to offer an RS-3, and the 6-wheel trucked RSD-4 and RSD-5, for a long time!  I would need to take out a loan to afford all the road names I would want!

I agree with Jonathan that the Weaver model is by far the closest to scale proportions; however, it has way too many molded-in details when compared to today’s higher-end locomotive offerings.

@sdmann, hope you'll consider putting it out there to see how much interest really exists!!

It is the logical diesel engine for Scott to make after the FA's are done. Ive certainly asked him. If the GP7/9's get two runs the RS3 would sell better I am sure