The completed trucks are a full 4 axle, fully flanged wheel set, all 4 axles driven by two motors....for each motor block!!
Here's a thought... Why not take some HO scale or similar motors and figure out a way to install them as traction motors. Then instead of 4 motors total you could have 8 total. Realistically that would be the correct! As a side note, I wonder how long it would take the model train industry to get to that point? G gauge is definitely easier to work with in regards to this, compared to HO scale. Can you imagine the pulling power of something that had 8 traction motors?
This project has been in the works for years...
It went from simply glueing to sd45's together like George Riley Curry did a number of years ago.
Are goal is to have a finished model by Marty's get together in September.
The engine will have 2 Phenix sound cards with the speakers mounted under the exaust fans and run off the 10 amp Revolution board with self contained batteries
I think one problem using such small motors - that would fit plus related gear train - slot car / side winder style stuff - would probably be the reduction in over all power to a truck....
Lots of work here, wan'a build one Craig? even a test motor block?
Just a 3 axle unit to play with..
I have to admit, getting to the full powered 4 axle unit did not come over night. It was a long - not deliberate - approach. Our expectations did not start with we wanted a 4 axle motor block... It started out with just a 3 axle block unit and a tag along 4th axle to make it look like it was correct.... Having all 4 axles powered came as an after thought, and more by evolution and accidents than anything else, just from working with it so much.
Once I got more familiar with the details of the loco, I started seeing so many items that needed work! Turns out the side frame step/ladder needed a spot to sit next to the fuel tank, which resulted in a back cut angle of the fuel tank corners. This allowed the steps to not exceed the loco width.
Installed on the frame -
Here a strip of Box car roof decking is used to create the decking on both sides of the frame. It works so well, that light shines off the upper tank surfaces even. So it should add a great deal of impact to the completed loco!!
Umm, years of fabrication in steel, custom body work and painting, show thru on occasion in My model work!! Just hoping to stay on track thru the entire project.
A trip to My Dad's in So. Cal. this weekend, helped with this model also. I got to "stand" on a DDA40X loco at the Pomona Fairplex, UP 6915. First visit to see one of the these large monsters, and also UP 4014, Big BOY...!!! My Wife kept looking at the loco - it's SO BIG, what is it she says?? "Honey", it is the same loco we ran in the World's Longest Model Train... 3 of 'em - As soon as I pointed that out she "Knew" the loco!!!!!
I have saved most every pic off the internet for the DDA40X loco build, but there is a lack of really good close-up detail shots of critical parts..The side radiator grill work, the side step ladders by the tank, and the corner steps at both ends. I took many close-ups of just these pasts for now to help with the model!!!
These will help Me move forward with work on it. Also took My own set of all 4 corners showing the access covers - part of the cooling sections at each end of the hood! These are nearly complete currently, but this will also help.
I will try to reconstruct what we lost last week so we can get on with life again!!! And building trains.....
I did get pix of Me on the monster loco, DDA40X, and next to an even larger BIG BOY loco while on our recent trip to LA to visit My Pop!!!
What's this - does this fit here? It's big, and Oh so black!!! OH A BIG BOY, got it!!!
A close up of the front and all the detail work to do someday! Lots to work from in a pic like this also.
The radiator cooling grills are the most often missed item for a DDA40X in close-up pix. SO these were My number one thing to get good pics to work from for this build. Once seen, they do not look so intimidating to recreate in miniature. Just needed to know what they were really like, not like a SD45 radiator either, so don't be fooled by the similar shapes here overall!!
These are the correct side frames that will be copied for this loco, they are from UP 6915, but clearly the same as UP 6936 frames are!
The side fresh air cooling section right behind the cab on the Engineers side of the loco. Many details here, access covers and related items for them are easy to see here, for each side of the loco, followed by the Fireman's side next...
I should also point out that some parts are much different on UP 6915, and this is why UP 6936 is always the loco used for any final reference work before any building is undertaken. So there is always a hunt for the right and correct detail, yet many pix are needed to get the right feel also, some of which may not be from UP 6936. All this takes a fair amount of time to sort thru. And sometimes gets confusing also!! What FUN!!!
So with that lesson, here is a section I built copied from a photo always at hand and right next to the work in progress.
This wall section and the other 3 matching walls have been the most challenging for Me to build so far. These will be glued to the mid-sections for the engine bays using GP-38 hoods cut up. We'll get into that later tho! I built a small jig for these walls so they would all be the same, building 2 lefts and 2 right sides, and even adjusting the small stops for the grill work on each side. Again, I will get into this more next time I check in here. Until then,.. safe modeling!!
The glad hands are small enough to be in scale for the smaller MU hoses. And they are functioning and able to lock into each other. Remember the 3 hoses face different directions.
The main res. hose should face inward like the train line, and the outer two should face towards the outside. I've thought about trying to model all of the underside piping before, but it would be quite the project.
Why not take some HO scale or similar motors and figure out a way to install them as traction motors.
As an aside, for anyone considereing "axle-hung, side-suspended traction motors" - we have been playing with that idea for our EBT M-1 model, which essentially used Brill streetcar trucks with a motor on each axle. NWSL used to make a "Magic Carpet" drive but have abandoned the gauge-1 version. This is a UK-sourced equivalent. (Google "nwsl magic carpet drive".)
This is quite the project you've taken on here, I thought reworking the GP9's was a major undertaking. I'll have rethink that one.
Some of the links being provided by others on this build and mine are most helpful and are certainly worth keeping in a project file.
The idea of using individual motors on each axle is something maybe the commercial manufactures should consider looking at, even if it was offered as an option. I know there would be a significant cost increase with such an option, but for some of us I think this would be pushed aside by the increased pulling power and general overall performance improvements.
I'm really looking forward to watching your progress on this engine, it is quite the monster.
Harvey and others, As far as single axle motors go - I think it would be incredibly novel to build a set of trucks based on the concept!!!
I was not ready to get into the power trucks yet, but the door seems to have opened here, so now is as great a time as any!! :~}
I am not sure of power increases however in the true sense, in model form! A single motor as shown in a previous post above are much smaller than say a given USA SD70/SD40 motor currently used in power trucks. Power would than be combined from several smaller motors, and would need to exceed the larger motor already used in power trucks. There are other issues surrounding the practical aspect of using multi-motors also!!!! As the current load goes up, as a result of using more motors, they will need increased battery capacity to provide a reasonable run time.
Having traveled this road for two projects, I have reached some conclusions regarding making more power in a loco.
One issue regarding increased power centers on the completed locos weight, and it's ability to create "traction", for a given increase in power as We know it. If one simply added more power in a stock loco, not much will result, as the driver traction will not have increased, and it will simply be easier to spin the wheels, something they can do now!! To prevent the wheels from slipping, more weight needs to be added on the drivers to help them achieve their potential to "use" the increased power. There have been enough discussions here regarding the choices of using traction tires, - they break, ammm - prevent slipping - which I disagree with, purely from having seen a loco spin the tires, under increased weight conditions. ( if a 20 pound loco can spin traction tires, why cannot a 10 pound loco do the same? )
Traction tires are tougher on the gear train also...
So we have limits to achieve traction that can really be used in model form.
Battery supply - in current capacity, is the next issue in powering more motors for more power! Read Amp hours here!!! How long do you want a loco to run? Track power will also be a issue, either way, multi-motors "consume" more current to feed and run!! So planning is required here also..
For this loco, a two motor unit was eventually created to power the DDA40X model. It is based on 2 USA Trains SD70 motor blocks, built into a unit given the needed wheel base to match the side frames. The gives us all 4 axles powered per truck.
But it needs to be "fed" now by more battery power also, to match!
Here is what I developed for this model!! Compare it with a "stock" SD70 block on the far left side, and also in the middle a dual-motor "re-placement", 3 axle block, that will go into a SD70, or in this case one of My own SD90 Mac loco projects!!
All of these multi-motored trucks "have been run" on a layout. They have pulled cars and some issues where found, nothing to stop the concept from proceeding further, except for the issue for battery power needed to run a decent length of time!
Yes, I think more power is possible.. but at what cost?
For the DDA40X, Matt also had me build a SD70Mac. It is simply a battery loco, and therefore is up-powered. Wiring runs between the two at the rear of the DDA40X. There are provisions made to allow a battery box car behind the 70 Mac even for additional power... The DDA40X carries its own batteries too!
Battery expense can become an issue. I have seen some operators running 3 locos, in a set, with the center loco just as a battery loco, leaving 2 powered units to pull a train. This looks cool, but adds cost for an un-powered loco!
I'm reaching a conclusion to go with single locos, with their own batteries that can be powered and coupled into units of 3 or 4 or 5 locos, and pull a train. This is looking like the most practical way to go for more power and the best run times also!
Using My SD70Mac as an example, it will pull 8 - 8 1/2 pounds at the coupler. This is well beyond 100 cars on level track. Running it at say 50 to 60 cars keeps it at a very conservative and practical load setting, while allowing decent run times, from a 9 Amp hour battery set, on board. Matt's loco is mostly for running his 30 plus passenger car train, not a freight drag, tho he has mentioned pulling 100 hoppers at times with me!!
There is much to bear in mind when powering up Your favorite loco! The design weight for the DD will be about 24 pounds. It will not be running traction tries!
I can say that My heavier 70Mac runs "very smoothly" - couples at incredibly slow speeds, sits and rides well on rails. It just feels like a real loco!! It is an armful to carry too!!
Harvey - while your rethinking your build levels, here are two other projects of mine!
A SD60T, a stretched SD70 frame - adding 3 inches, standard cab, and dual motor trucks!! Reworked 70Mac hood.. added SD45 steps, and replaced the tank with a stretched SD45 tank, not shown at this point...and heavy duty coupler mounts...
The beginnings of a SD90Mac, completely scratch built frame - complete with full length I-beam frame, stretched fuel tank, custom hood to come, mods to cab still.
Thanks for the information update and the photographs of the extended four axle truck.
I'm toying with the idea of building some three axle flexicoil trucks. but just need to figure out what to do about that centre axle.
One thought I have was to extend a standard USAT GP9 truck with a shaft extension to the third axle and make the centre wheels independent with no through axle. Something like and independent rear suspension used on some vehicles today.
It's no wonder we don't sleep at night!!
Thanks again for the info.
Harvey, What does not show in the stock 3 axle up-graded power block are only 2 powered axles, for each end. The center axle floats in the side frames, unaltered bearing supports which are free to float up or down, against spring pressure, and is not powered. I just got lucky on most of this and the results that came on their own!
To maintain the stock wheel base I was not able to power the center axle. Frankly, it all worked out well..
What loco do you want to put your flexicoil trucks under?
If I'm able to gather up enough dimensional data I would like to have a go at scratch building a GMD1.
I'm going out this weekend to have a look at one in a museum about three hours from here. I've taken some photographs of the one's remaining with CN, but they get a bit snitty when I get too close. Maybe if I went through official channels I might get better access. I think I could certainly get good access to one if I visited Cuba again. CN seems to be selling them of to Cuba, heck I might even get to drive one there.