Briggs Models MLW RS-3 Build Thread

[mmagliaro]

Thank you, Max, and an interesting suggestion.  Not sure if I have any PC board lying around, so might get some next trip to the electronics store.


Tim

Yes, you can solder one rail's lead to one side of the board, and the other rail to the opposite site, and then just push the board in between the frame halves before you tighten the screws.  The PC board itself forms the insulator between the sides.  You will probably need the 1/16" thick board.   I know I have done this on at least one engine project.  I just have to remember which one so I can show a picture.

[GaryHinshaw]

I would guess a PC board tie from one of the hand laid track suppliers would do just the trick with very little work.  I would offer you some of mine, but I am in Montreal for a month...  Nice progress though!

[peteski]

I would guess a PC board tie from one of the hand laid track suppliers would do just the trick with very little work.  I would offer you some of mine, but I am in Montreal for a month...  Nice progress though!

Max recommended a double-sided PC board. Are PC-board ties copper-clad on both sides?

[narrowminded]

I have an assortment of thinner sizes that I could cut a few pieces from if needed.  In single sided I have .007" and .020".  In double sided I have .008" and .010".  For your purposes I don't think it would matter if it were single or double sided. 

I also have some .005" phosphor bronze sheet that I could cut a strip from if a contact pad or strip were desired. 

(Edited to correct double sided dimensions.  Originally I posted .007" and .008".)

[GaryHinshaw]

Max recommended a double-sided PC board. Are PC-board ties copper-clad on both sides?

Yes.

[mmagliaro]

The idea is to keep this simple with a 1-piece solution.  I think I used a 1/16" thick piece of double-sided PC board.  That avoids have to use two 1-sided pieces with a shim between them, or anything like that. 

It would be a simple matter to figure out what a good thickness is by testing with some styene shims.

The PC board tie material sounds promising.

I remember where I did this.  It was on my 4-6-2 steam loco project a few years ago.  The piece fits between the frame halves of a Kato C55 chassis.  I would bet the same side PC board would work almost anywhere.  I did this to power a headlight off the frames but that doesn't matter.  The leads could go down to the trucks to pick up power.

[BCR 570]

Thank you all for the tips on the PC board spacers.  So far the styrene ones are working brilliantly but I might change them up at some point.

This past weekend's Vancouver Train Expo was an opportunity to test drive RS-3 574 with the modified pick-ups as our PGE-BCR Modellers group had set up its usual Unitrack loop spanning eight tables.  To my delight the engine ran flawlessly and I can now continue with construction.

Tonight I recorded a short video on a smaller loop at home which I am using to run in several new mechanisms prior to conversion to DCC:

All three mechanisms seem to be a bit noisy and this one has a buzz when stationary.  I have yet to solve that.

Following several test prints and fittings, I am looking forward to receiving the final version of Jeff's new RS-3 pilots which will include mounting holes for the Atlas handrails.


Tim

[daniel_leavitt2000]

I really wish this truck contact idea popped up months ago. I ended up ferreting the wires on my M420 though to the top of the frame and securing them with 00-90 screws. It works, but it's a bit of a kludge. This is a much more elegant solution.

[BCR 570]

Yes, I will also need this method for my M-420s when I get there, and my replacement RS-18s with small fuel tank, and my replacement RS-10s . . .

Tim

[garethashenden]

That seems like it would be a good solution to the Like Like SW pickup problem as well.

[BCR 570]

Back to work on some models after a long absence due mostly to illness.

I received Jeff's final version of the RS-3 pilots after several adjustments were made.  They had to include a correctly placed and sized opening for the Micro-Trains #1015 replacement couplers:




and include correctly located and sized holes for the stock Atlas end handrails, which would hopefully result in a nice tight fit:




Also the final version of the 1200 gallon rectangular fuel tank and air reservoirs, pictured here with the six pilots:




The next step is to fabricate cut levers (the BLMA ones are not the correct shape and size for the RS-3s) and figure out how to locate and drill the mounting holes for the eyebolts to hold the cut levers in place, and the grab irons inside the cut levers.


Tim

[BCR 570]

My plan for the cut levers was to bend them from .008" brass wire and mount them using BLMA lift rings for the eyebolts.  For the centre protrusion of the lever I would use BLMA 18" grab irons rather than attempt to bend the protrusion.  I used a styrene bending jig to form the cut levers so that they would be consistent in shape and size:






This approach was successful - here are the six completed cut levers with a sample eyebolt:




I needed a way to locate all of the holes for the cut levers and grab irons accurately and consistently.  I made a styrene drilling jig to sit snugly on top of the pilots and took a lot of time to accurately locate and drill the necessary holes.  I also made another styrene jig for the pilot to sit in while drilling. 




I held the pilot between the two jigs in a pair of smoothjaw pliers and drilled the holes:




After drilling holes in a spare pilot and analyzing the results, I was confident that this approach would work.  Here is a pilot with the various component parts sitting loosely in place for a test fit:




The next step will be to mount the pilots to the decks and then affix the various detail parts with CA.


Tim

[BCR 570]

Also progress on the replacement 1200 gallon fuel tank for 574.  The bottom plate locates on ridges inside, and the air reservoirs snap onto locating ridges on the outside.  The stay bolts, fuel filler pipes, caps and gauge are printed in place so there are no details to add.  Here is the assembled tank:




And pictured with the modified mechanism upside down:




The sides of the tank extend up to the underside of the mechanism and the final version has a better ride height above the ground:




Tim

[craigolio1]

Looks really good Tim.

Was there any modification to the motor cradle needed to shave the chassis down? I don’t see the snap in tabs that are normally located at the four corners on each side (on other locos - not sure the RS3 has them?).

 Craig

[philippe.whyte]

Excellent work Tim.  Nice to see you progressing this project.  I really like those jigs you made.

Philippe