Texaco Doodle Bug Tanker

[Saltie Olds]

I’ve been interested in doing a model of one of these. I’d like to know how I’d be able to convert a semi truck to be a rear engine rear drive truck. So then I could build this cool and cute truck. Thank You Everyone.

[peteski]

Buses are like trucks, some with the engine in the rear.  Maybe start with a model of a bus?  Just saying . . .

Or just build the model as a  curbside, and don't worry about detailing the engine or the underside.

Edited May 23, 2022 by peteski

[Saltie Olds]

2 hours ago, peteski said:

Buses are like trucks, some with the engine in the rear.  Maybe start with a model of a bus?  Just saying . . .

Or just build the model as a  curbside, and don't worry about detailing the engine or the underside.

Thank You. I like your idea about building it as a curbside. I haven’t had much luck finding 1/25 scale rear engine bus kits.

[Fat Brian]

Some rear engine buses use this rather ingenious method of getting the power to the wheels. It will be a good bit of scratchbuilding but would be interesting. 

[Saltie Olds]

43 minutes ago, Fat Brian said:

Some rear engine buses use this rather ingenious method of getting the power to the wheels. It will be a good bit of scratchbuilding but would be interesting. 

Awesome. Thank You.

[Fat Brian]

6 hours ago, Saltie Olds said:

Awesome. Thank You.

If you didn't want to fab up the angle drive setup you could probably accomplish the same thing vertically since you don't have to worry about a bus floor. Set the rear axle with the pinion facing front like normal then set the engine facing backwards behind the axle. Now comes comes the fab stuff, you'll need to build some kind of transmission where the output shaft is higher than the rear axle differential, then a short driveshaft to a drop box that bolts to the front of the rear axle. Something like this but with the input and output on the same side, driveshaft comes in the top and the bottom is bolted to the rear axle where the pinion shaft comes out.

[Saltie Olds]

8 minutes ago, Fat Brian said:

If you didn't want to fab up the angle drive setup you could probably accomplish the same thing vertically since you don't have to worry about a bus floor. Set the rear axle with the pinion facing front like normal then set the engine facing backwards behind the axle. Now comes comes the fab stuff, you'll need to build some kind of transmission where the output shaft is higher than the rear axle differential, then a short driveshaft to a drop box that bolts to the front of the rear axle. Something like this but with the input and output on the same side, driveshaft comes in the top and the bottom is bolted to the rear axle where the pinion shaft comes out.

Cool. I like that idea. I’ve also thought about just mounting the engine backwards, flipping the front drive axle around, and use the driveshaft, that goes between the two rear axles, to go from the tranny and the rear end. I’m thinking about using a Cummins of some sort or a Cat. Now to figure out what truck to use, for the engine and chassis.

[Fat Brian]

4 minutes ago, Saltie Olds said:

Cool. I like that idea. I’ve also thought about just mounting the engine backwards, flipping the front drive axle around, and use the driveshaft, that goes between the two rear axles, to go from the tranny and the rear end. I’m thinking about using a Cummins of some sort or a Cat. Now to figure out what truck to use, for the engine and chassis.

If you want a single rear axle I'd either use the Freightliner cabover with the red and white truck on the box, it has both the single and dual drive suspensions, or one of the Ford C600 kits.

[Saltie Olds]

2 hours ago, Fat Brian said:

If you want a single rear axle I'd either use the Freightliner cabover with the red and white truck on the box, it has both the single and dual drive suspensions, or one of the Ford C600 kits.

Ok, Thank You. That Freightliner has a Cummins?

[Richard Bartrop]

The plans you showed are pretty clear that the engine hangs out the rear with the transmission behind it, bending around like Brian showed, with the driveshaft going forward and underneath the engine. For the particulars about the engine and other details, maybe research other '30s vintage Diamond T trucks, and see what they use.   If you can't get the info, perhaps save yourself some hassle, and build it curbside.

[Fat Brian]

12 minutes ago, Saltie Olds said:

Ok, Thank You. That Freightliner has a Cummins?

Yes, it has the 250hp non-turbo Cummins. It's technically a bit too modern for a 30s vehicle but you can always say it was repowered. The 30s is right in the transition period from big gasoline truck engines to diesel so its possible this was intended to have something like a Hercules straight six gasoline engine. These were big flat head sixes.

[Fat Brian]

17 minutes ago, Richard Bartrop said:

The plans you showed are pretty clear that the engine hangs out the rear with the transmission behind it, bending around like Brian showed, with the driveshaft going forward and underneath the engine. For the particulars about the engine and other details, maybe research other '30s vintage Diamond T trucks, and see what they use.   If you can't get the info, perhaps save yourself some hassle, and build it curbside.

I hadn't even noticed that on the original plans. The rear axle is backwards with an offset differential, I imagine the transmission output also moved over so the driveshaft could clear the oil pan. 

[Richard Bartrop]

This is what Diamond T was using in its trucks during the '30s.  It's a flat six, so maybe some surgery on a straight eight from the recently reissued AMT 1932 Imperial or some other vintage car kit would get you in the right direction.

 

A fun fact about the Doodlebug.  So the driver would know when to shift, there was a microphone in the engine compartment that ran to a loudspeaker in the driver's cab.

Edited May 24, 2022 by Richard Bartrop

[Saltie Olds]

Awesome. Thank You, to both of you. I’m going to be a bit different and go with the Cummins. I’m thinking I’ll use the one from that Freightliner kit, or a AMT Kenworth Kit, or go a bit more modern and do the Cummins 5.9 6BT intercooled engine.

[misterNNL]

From my perspective while the mechanical aspects may very well be solvable that aerodynamic body is gonna be a real problem. Those curved surfaces are going to require some very serious scratch building and some long sessions of putty/sand/repeat/putty/sand/repeat.

[Saltie Olds]

11 hours ago, misterNNL said:

From my perspective while the mechanical aspects may very well be solvable that aerodynamic body is gonna be a real problem. Those curved surfaces are going to require some very serious scratch building and some long sessions of putty/sand/repeat/putty/sand/repeat.

I’ve been thinking about how I’m going to pull it off. One idea I got was to use a giant Easter egg toy and use it to make the front and the rear part of the truck.

[peteski]

On 5/23/2022 at 3:50 AM, peteski said:

Buses are like trucks, some with the engine in the rear.  Maybe start with a model of a bus?  Just saying . . .

Or maybe make it like the old balsa and tissue airplane models with ribs and tissue.  But instead use styrene for both the skeleton and covering.  That will make the shape of the models slightly faceted, but you can then apply some putty on the surface to make t smooth.

[Saltie Olds]

4 hours ago, peteski said:

Or maybe make it like the old balsa and tissue airplane models with ribs and tissue.  But instead use styrene for both the skeleton and covering.  That will make the shape of the models slightly faceted, but you can then apply some putty on the surface to make t smooth.

I like your idea. Thank You

[Ace-Garageguy]

On 5/24/2022 at 8:38 AM, Saltie Olds said:

...One idea I got was to use a giant Easter egg toy and use it to make the front and the rear part of the truck.

If you analyze the shape carefully, you'll see that most of the thing can be built from flat panels, or panels that only curve in one direction. Easy enough.

The only parts that have significant compound curves are the "forehead" above the windshield, and the upper part of the tail.

I just happened to notice I have an older wired mouse that looks like it would be perfect to make the upper tail section from, and I'm certain there's something lying around that could supply the compound curve for the front "forehead".

Your Easter egg toy sounds like a possible way to go too, but don't overlook things like old mice, molded plastic packaging, etc.   

[Saltie Olds]

11 minutes ago, Ace-Garageguy said:

If you analyze the shape carefully, you'll see that most of the thing can be built from flat panels, or panels that only curve in one direction. Easy enough.

The only parts that have significant compound curves are the "forehead" above the windshield, and the upper part of the tail.

I just happened to notice I have an older wired mouse that looks like it would be perfect to make the upper tail section from, and I'm certain there's something lying around that could supply the compound curve for the front "forehead".

Your Easter egg toy sounds like a possible way to go too, but don't overlook things like old mice, molded plastic packaging, etc.   

Cool. Thank You for the ideas. Another idea I got was that I could build up a model of the body, on my computer, and then 3D print the body.

[peteski]

40 minutes ago, Saltie Olds said:

Cool. Thank You for the ideas. Another idea I got was that I could build up a model of the body, on my computer, and then 3D print the body.

If you have (or willing to learn) the required CAD skills, considering where this hobby is currently, 3D printing the model is an excellent choice.  You just shift where you hobby time will be utilized.  From physical scratchbuilding (the old way) to "virtual scratchbuilding" on the computer.

[Saltie Olds]

1 hour ago, peteski said:

If you have (or willing to learn) the required CAD skills, considering where this hobby is currently, 3D printing the model is an excellent choice.  You just shift where you hobby time will be utilized.  From physical scratchbuilding (the old way) to "virtual scratchbuilding" on the computer.

I’m familiar with CATIA, so that won’t be a problem there. I’ll just have to figure out and learn how to get the model from my laptop to a 3D printer.