7mm Poor man's Alamosa.

[Overseer]

After a bit of information to those in the know please.

Im looking at building a Red Caboose GP9 kit in the near future, and I believe that its possible to use the Atlas/Roco(?) F9 trucks, and although these run quite well I don't think they be quite as good as I'd like and also the gear and motor tower is quite substantial.

I have found a motorising kit here Drive Kit, Universal, Includes 8514 Ball Bearing Motor, Motor Mounts, Tower, end Transmission, 2 Center Transmissions and all Necessary Hardware to Power a 4 Wheel Drive Locomotive, P&D Hobby Shop: Drive Kit, Universal, Includes 8514 Ball Bearing Motor, Motor Mounts, Tower, end Transmission, 2 Center Transmissions and all Necessary Hardware to Power a 4 Wheel Drive Locomotive but does this work with the Atlas cosmetic sides, or need to source other sides? I only ask as I have 3 of the F9's in stock as I had a crazy idea about kit bashing the 3 to make an A-B-A unit.

Thanks for any info.

JB.

JB, you really need the specific P&D Hobby Shop RC GP9 Repower Kit 2201K 4w/ Brass Trucks. The problem is, as mentioned recently in the US dabblings thread is that P&D seem to be out of stock. It would be a shame if they don't restock. Plus the matching P48 conversion kit from Right-O-Way. The P&D repower kit converted to P48 with the RoW kit run beautifully, smooth with low speed crawl. The kit you have linked to has a shaft through the tank which is not a great look, they might be able to add another tower transmission instead of the centre transmissions, and buy the truck frames separately. The brass bogie kit lowers the kingpin height to near footplate level and the drive shafts are below the cab window level. It would not be hard to drop the motor and drive shafts down lower if building your own mech. You need to be careful with NWSL wheels, I bought some 33" 'P48' wheels recently from them, They are nicely turned nickel silver but flat backed and the profile is not really to P48 profile, they have used something similar to the RP25 Code 110 profile but slightly wider - this means the flange is twice as wide as it should be. They still work but the relationship between back to back and effective gauge is different so could find tight spots through crossings. The flange profile is not very nice either, too square. I wouldn't waste too much time on the Roco sideframes, they are not very accurate and look quite toylike.




Protocraft p48 on left, recent NWSL on right.

 

[mickoo]

The kit you have linked to has a shaft through the tank which is not a great look.

I wouldn't waste too much time on the Roco sideframes, they are not very accurate and look quite toylike.

Good point, it's a replica of the Weaver drive set up, if I'm honest, neither is a great look, drive shafts through tanks or through cabs.

To be fair, all available Blomberg options are quite toy like in one aspect or another, just depends which fence you sit on.

Brass cast ones all suffer from the same issue that large brass castings can suffer from, warping, compensation to allow for casting and often crude details plus little sense of mass, RTR on the other hand suffers the inverse, too much appearance of mass.

Whilst Roco are cheap and cheerful, the brass offerings are not significantly better given the higher price they go for, that's just my point of view, others mileage will vary.

What isn't in doubt is P&D drive quality and I suspect most of that slow speed crawl comes from the Pittman motor, not the trucks and final drive.

It'd be interesting to see how the Roco tower fared when paired with a Pittman, though I'm not sure what ratio the Roco tower is, I think P&D are 7:1 on the Delrin towers and 3:1 on the axle gear boxes.

 

[Overseer]

I think P&D are 7:1 on the Delrin towers and 3:1 on the axle gear boxes.

Just checked, P&D are 14.5:1 total reduction.

I agree the brass trucks are not perfect, the last ones I got are not as good as earlier production. I will be reducing the primary springs so they are mostly concealed and the journals sit at the correct height instead of at the bottom of their travel.

 

[Scale7JB]

Thanks to everyone.. huge information overload point which needs digesting.

One important thing I would say is I’m glad that no one feels the need to go for the $60 milled brass footplate.

I was quietly confident that I could strengthen any areas that needed it with some sheet or profile brass and previous posts have confirmed this.. Thanks!

JB.

 

[Yorkshire Dave]

View of chassis, the RC chassis is plastic and has a tendency to sag in the middle, there are lots of workarounds, Dave did his with I think sheet metal, I opted for brass angle, note the truck retention horns are inboard and the front one impinges into the cab.

I did use brass angle. Instead flipping the drive trucks I removed the truck retention horns and bolted two brass bits of brass angle to the trucks to retain them in the chassis and gain space. This allowed me to file to top of the truck mount frame a smidge to gain a flat surface for mounting the ESU L sound decoder on one tower and a lighitng board on the other tower, with a pair of speakers in the centre. I also retained the Roco Blombergs.

 

[Yorkshire Dave]

I will be reducing the primary springs so they are mostly concealed and the journals sit at the correct height instead of at the bottom of their travel.

This will be something I'll look at on my Roco trucks, just to conceal the springs a tad. Obviously Roco produced their truck frames as if there was no weight carried!

 

[mickoo]

Just checked, P&D are 14.5:1 total reduction.

I agree the brass trucks are not perfect, the last ones I got are not as good as earlier production. I will be reducing the primary springs so they are mostly concealed and the journals sit at the correct height instead of at the bottom of their travel.

That's quite a low ratio, I would have thought it higher to give the smooth slow speed they have.

I initially thought you might have a replacement motor, but looking at Dave's model it looks similar and unless Dave has re-motored then it may be the original Atlas/Roco motor set up. Try as I might, I cannot recall what the original Atlas/Roco motor was or looked like and the GP9 project box is buried quite deep at the moment.

I have to concede if I were looking seriously into P48 then I'd have to think about using the Atlas/Roco trucks/side frames, they are at least the right width and the brakes do line up with the treads, though they might not line up as well in P48. There may be some mileage in pimping them out like Dave did with extra details and etches here and there. I'd also consider a rigid etched inner frame to support the axle end bearings or try to make non tower gearboxes tilting in some way, then add a new side frame, possibly a combination of 3D and etches. All of that is extra work and cost and for me that might not be enough justification to do the work.

The brass truck suspension springs are huge turn off for me, not just P&D but all brass imports I have, they just look terrible and they seem to be massively strong. Unless you add huge amounts of weight they don't appear to do much and are effectively a rigid truck.

At the end of the day, there are several alternatives which is good for diversity and choice.

 

[Yorkshire Dave]

I initially thought you might have a replacement motor, but looking at Dave's model it looks similar and unless Dave has re-motored then it may be the original Atlas/Roco motor set up. Try as I might, I cannot recall what the original Atlas/Roco motor was or looked like and the GP9 project box is buried quite deep at the moment.

Mine is the original Pittman motor which came with the GP9 kit.

The Roco/Atlas F9 drive was similar (as the GP9 drive used common parts) and would expect the F9 can motor to be of European rather than US origin.

 

[Scale7JB]

Many thanks again to all.

I certainly plan to be at the NMRA show in a couple of weeks!

JB.

 

[Yorkshire Dave]

Forgot to mention regarding the Red Caboose GP9s - given the age of the models/kits watch out for split gears on the drive axles if you intend utilising the existing drive. I had at least two and replaced the entire wheelsets with the NWSL drop in replacements.

 

[richard carr]

One thing I'm not clear about where do you get an Atlas/Roco chassis from ?

Thanks

Richard

 

[Scale7JB]

One thing I'm not clear about where do you get an Atlas/Roco chassis from ?

Thanks

Richard

I have 3 of them

JB.

 

[mickoo]

One thing I'm not clear about where do you get an Atlas/Roco chassis from ?

Thanks

Richard

Ebay is the best place, they pop up quite regularly, some people chance it with £100 + prices, don't, sit and wait and one, two, several will turn up at half that. Most will have a side frame popped off, maybe more but so long as the clip is still there....it usually is as it'll still be inside the side frame that's popped off....then it's an easy fix.

If you get one that's intact then it pays to reinforce the clips anyway, they'll only break at some point. I have considered copying the whole truck tower in 3D and making that clip integral as well as adding alternative chassis fixings to get rid of the horns and such like.

I've got a couple, maybe even three, can't recall to be exact, I do know I have three GP9 kits.

 

[Scale7JB]

Well, Father Christmas has arrived and on this occasion happened to also be named Richard Carr…

I got a standard un-decorated Red Caboose GP9, but also via frantic WhatsApp messaging a decorated Bumblebee Rio Grande GP9 as well, and all of crazy prices. Very happy.

I just need to work out now what the visual upgrades are before I crack on and start gluing bits together!

 

[mickoo]

Nice!

Your lucky in that the RC GP9 is based on the early stock model, with respect to roof fans and door grills etc.

As far as I can tell, DRGW GP9 also match that so you shouldn't have to worry about hacking vents off and adding them to other doors, later variations for other railroads had loads of different door vent layouts. The DRGW GP9 also kept the skirts over the fuel tanks, certainly in the period I think you're aiming for.

You should be okay with the kit number boards, headlight packages and classification light enclosures, in fact the stock kit builds a decent model in it's own right, most of the detail work goes into the chassis by adding flange plates and pipe runs etc.

It's a shame RC only did the GP9, the SD9 would have been equally as popular I'm sure.

 

[Big Train James]

Posting this here, and also on the new Red Caboose gp9 thread. I came back across these photos while gathering info for the other thread. They kind of show the difference between NWSL p48 wheels and Right-O'-Way p48 wheels, at least with respect to the back side profile.

Poor Man's Alamosa post #344

 

[Scale7JB]

Thanks Mick.

Thanks James, ill have a good look tomorrow after brain as relaxed after big shoot with Bentleys today.

JB.

 

[Scale7JB]

Well (proper) work is slowing down a little so I can start to get back on to other projects.

Whilst I’ve got 10 minutes in front of the TV, remember that £25 Atlas Caboose?





JB.

 

[Scale7JB]

Couldn’t resist this for £20!

The body looks really good as it’s an intermountain model. Of course the couplings, trucks and wheels need replacing, but no biggie.

I think Rule #1 applies here as Denver is quite a long way from Alamosa.



JB.

 

[JasonD]

Bargain JB. Remind us, have you decided to follow Ow5 or P48?

Good to see you at Stokenchurch (NMRA BR Winter Meet).
Jason