powered trucks

[papajohnf]

I need drawings to scale of 1.5 inch powered trucks for my diesel project any prints and pic would really help is there a model tec mag or other source i can use?

papajohnf

[Shakeyjake36]

Papa if you get any response to this post let us know. I have been hiding away parts and pieces to build a "diesel" but have not come up with a design for a truck. I would like to put the hydraulic motor between the axles . I've see this done and works slick, I guess the trick is to put the motors in series rather than parallel .

[steamin10]

Series, no. One motor will only see what the first one passes. You need equal pressure and flow to both motors, and that means adequate supply. Even with 600lb low pressure hydraulics, you will find a hydromotor will produce alot of torque, but the drawbacks will be heating of the fluid from pressure, as that usage produces a pressure drop that sheds heat. Leaks for hydraulics are an issue, as any seepage does not 'dry' and only collects dust and puddles to drip someplace.

Two hydraulic motors in a unit will be mechanically locked by the traction of the rail, so they will both mostly self regulate as far as speed according to supply and the usage rate of fluid for the pressure required for the work load.

[srrl5]

It depends on how close to the limit of traction you will run, with motors in parallel if one brakes traction all oil will flow through the slipping motor and the other will get no flow. I have built and run both series and parallel. the only one I would own and do own is series.

David Rohrer

[cbrew]

It depends on how close to the limit of traction you will run, with motors in parallel if one brakes traction all oil will flow through the slipping motor and the other will get no flow. I have built and run both series and parallel. the only one I would own and do own is series.

David Rohrer

Unless you want to lay out the $$ for a flow divider. which is unnecessary running in series.

[Shakeyjake36]

At first I though parallel also, but it was explained to me by an old timer like this; with the motors in parallel , if you drive the end of the engine off the steaming bay for example, the fluid would take the path of least resistance. In a sieries all the wheel have to turn together and it can drive itself back on the rails. Anyway I could see this thread going on and on about this. Any chance someone could post some pics of a freelance truck they use, on or off the engine?

I'm not looking for a super detailed truck. just a simple powered truck, that can be fabricated without alot of castings and fussing around. Any help would be appreciated . Thanks

[steamin10]

Proportion valves are available at fairly low cost.

I know breaking tractiion will cause a pressure drop and flow changes, despite the fact the now idling motor (nonspinning) will see the same pressure as the (spinning) drive. In fluid drives of any kind, flows are not the same in all areas, only the pressure exerted in that part of the system.

I want to know how you can justify the mechanics of a dragging motor in a power system. It is limited by the volume of the preceeding motor, and at reduced pressure, by virtue of the work being done by the first in line motor..

What is your view?

I have a set of drawing sheets for an 1939 switcher truck. They are full size soo I cant post them.

[DianneB]

I built a pair of trucks patterned after Brill trucks for my streetcar that are fairly simple, mostly built-up from plate and angle.

Streetcar chassis

Each axle has a 100W motor, 4 in total, and it has good power and acceleration.

Motors should be run in parallel so that each motor can develop its maximum torque and so that the driving force of each motor will be equal. Torque will then depend on the voltage applied.

The problem with series is that if one motor begins to slip or looses its drive, more voltage will appear across the motor with the light load and it will limit the current flowing in the series circuit thereby reducing the overall tractive effort available.

[cbrew]

I need drawings to scale of 1.5 inch powered trucks for my diesel project any prints and pic would really help is there a model tec mag or other source i can use?

papajohnf

do you have a prototype truck you want to be close too?

[steamin10]

Dianne: What you said is true for the most part, and electric drives can be simple or complex as the electronics designed for it.

You missed we were flogging a hydraulic drive and its nuances. It is much more mechanically based and has some querks that electric drives dont see. Except for certain drawbacks, I believe electric drives most suitable for the small work of our track machines. They lose out where superior power must be had, and Hydro-mechanical becomes a better deal for small units.

Simple electric drives are easy by comparison, I think to get things rolling. Just my opinion.

[Shakeyjake36]

Cbrew , I don't have a specific engine I'd like to model. I do have a hodge podge of stuff including a petter diesel engine that I would like to put together to form a workhorse. Detail will take a back seat , I just need something simple to pull work trains. Most of this project is built in my head but I always get stuck when it come to the trucks.

[BobbyT]

How about something like this. It is my take on a switcher truck I built for a NW2. The truck was built up from bar stock and a couple pieces of pipe. Hydraulics were run in series.