Large Scale Central

Need Advice on Power Truck

Modeling Motive Power
#1

I collected this strange beast for the cost of shipping when I acquired a couple of tenders.

It is an amalgamation of a Bachmann rail truck front with a boxcar rear end. Quite nicely done if you want a Goose-type device. It came with an archbar truck (temporarily installed at the back, possibly too far back,) and no front truck, so I put a Bachmann small truck under it, as they are only $8 each.

Anyway, the builder hadn’t thought through the drive. The motor runs when you put power to the pickups, and the circuit board is in the truck bed inside the box. There drive shaft won’t reach the new rear truck location.

So I am puzzling about what to do about driving the wheels. I can get bevel gears - friend Clem runs a slot car track and he can supply all sorts of bevel gears, and I have some skew bevels. Do I really need to drive both axles, or will one be enough? The RGS Goose #2 had a chain drive to the second axle, which I could replicate, I think.

Any thoughts? Anyone have a spare Accucraft goose gearbox assembly or similar? Anyone have a railtruck front truck to spare - I’d like to get the inside frame look?

#2

Depending on how heavy the thing is, and how freely it rolls, you might be able to get away with powering one axle. My Delton Doozie only has one axle powered in the rear truck, and it runs just fine.

#3

I think it would be more of a matter of traction, slippery rail, grades, if the rail is wet.

Greg

#4

Assuming that you still have the original rear end/differential couldn’t you just extend the drive shaft with some brass tubing? Cut it in half and add flexible couplings (some kind of hose or tubing, heat shrink) to join together.

#5

Mark, the rear axle on the Bachmann is a single axle. It was replaced with a 2 axle truck. So chances are, the original Bachmann wheel and rear gearbox has been lost. If its still with the beast, the geared axle/wheel-set, would not fit into the truck without some serious modification.

#6

It wasn’t totally clear to me what Pete had so I made an “assumption” in my reply, wrongly I guess.

He might consider something like a NWSL Large Scale Self-Powered Trucks, Drives - #1 Gauge Power Truck at bottom of page, again assuming availability and cost considerations.

#7

Those are kinda pricey. If the Bachmann (Aristo) power truck can still be found, it would be a lot cheaper, as would the USA power truck. Heck, he could even buy an eggliner and strip the power truck out of that.

#8

Mark Hadler said:

Assuming that you still have the original rear end/differential couldn’t you just extend the drive shaft with some brass tubing? Cut it in half and add flexible couplings (some kind of hose or tubing, heat shrink) to join together.

The original came with it - but Jerry (Naptowneng) already says he wants it as his railtruck is stripped. [We’ll have to take it apart when he gets back from NNGC.]

David Maynard said:

Those are kinda pricey. If the Bachmann (Aristo) power truck can still be found, it would be a lot cheaper, as would the USA power truck. Heck, he could even buy an eggliner and strip the power truck out of that.

NWSL is definitely a possible source - they have the little gearboxes too, and I could probably put 2 of them in the truck. However, NWSL is in a state of flux (I got an email back that they aren’t taking orders yet when I was looking for something else,) so that might take a while.

I do have an Aristo truck handy, but it and the NWSL truck seem to have widely spaced axles. The motor in the truck works fine, so I was hoping to reuse it, not replace it.

One or 2 of the Grandt Line skew bevel gears on the crossbox (like the one on my railcar,) would be nice, but they seem to be defunct.

#9

Then look at slot car and RC car parts for the bevel gears you need to take the driveshaft output and turn a truck axle with it.

#10

Pete Thornton said:

I collected this strange beast for the cost of shipping when I acquired a couple of tenders.

Anyway, the builder hadn’t thought through the drive. The motor runs when you put power to the pickups, and the circuit board is in the truck bed inside the box. There drive shaft won’t reach the new rear truck location.

So I am puzzling about what to do about driving the wheels.

Any thoughts?

Can you cut and extend the driveshaft? They do it for real cars all the time.

#11

I am wondering if a Hartland power trucks might work nicely, as it won’t be as long as the Aristo.

#12

Then look at slot car and RC car parts for the bevel gears you need to take the driveshaft output and turn a truck axle with it.

I have Clem’s phone number should I need it. A 15:1 NWSL gearbox might be easier to fit, as I think the rail truck motor is direct drive (ungeared) and the gear reduction is in the axle (pics on their parts site.)

Can you cut and extend the driveshaft? They do it for real cars all the time.

I will have to extend it to the new rear truck, and yes, I can! I think some universals will be needed, and maybe a sliding joint like a shay as the truck pivots.

#13

Pete Thornton said:

Can you cut and extend the driveshaft? They do it for real cars all the time.

I will have to extend it to the new rear truck, and yes, I can! I think some universals will be needed, and maybe a sliding joint like a shay as the truck pivots.

I don’t know what the existing shaft is like (i.e., round or square), but regardless you could use some K&B square brass tube with the next size up I.D. from the existing drive shaft and the next size up brass square tube to let one slide within the other without slipping.

#14

I don’t know what the existing shaft is like

Neither do I, it’s missing! All I have is the universal poking out. Actually, Jerry’s truck is handy for comparison - I recall it is the usual round shaft. The square tube will probably work, as will a longer universal fork.

#15

I concluded that I had no better use for the skew bevels I bought off eBay, and I could easily fabricate a ‘crossbox’ [2 shaft holders at right angles and 1/8" apart.] The bevels are 3/32 shaft and my 1/8" brass tubing is 3/32 inside, so all I need is a 3/32 shaft, a jig to hold it at right angles while I solder the tubes together and to figure out which truck axle type is closest to 3/32.

Progress reports to come, now I have fixed the railcar, finished coach #5, and replaced the gear in the 4-4-0. This rail truck is the next problem project.

I did check the original railtruck axle (B’mann) and it is almost 1:1 ratio. I assume the motor is a geared type - anybody know? The parts exploded drawing was not a lot of help!

#16

Pete Thornton said:

I don’t know what the existing shaft is like

Neither do I, it’s missing! All I have is the universal poking out. Actually, Jerry’s truck is handy for comparison - I recall it is the usual round shaft. The square tube will probably work, as will a longer universal fork.

Outta my league …but watching with interest on a solution