WC-51 3/4 ton weapons carrier

[Chariots of Fire]

This is the start of a new project.  This forum does not ordinarily deal in military subject matter but this is still a 3/4 ton truck no matter what it might be used for.  The WC-51 is the result of some early WW II era experimenting and planning for a 3/4 ton rated truck that would take the place of some half-ton rigs that were not quite rugged enough for heavier work.  It saw service during the war in all of the theaters of action and had many different roles.  One of them was to be a tow vehicle for the Class 1000 fire pump trailers used by the Army Fire Fighting Platoons.  Since I have already built the trailer it is now time to focus on its hauler.

This is a restored one and is a basic rig that will be the basis for the model.

Here is the start.  From technical manuals and photos the frame was drawn to 1:25 scale with paper prints glued to 0.040" Evergreen sheet stock.  Once cut out and sanded down, 0.020" x 0.125" strip stock was glued to the top and bottom edges as flanges.  The frame in the foreground has been modified from the one in back because I made a mistake in the frame width.  The one in back needs to be cut and widened out both in front and back.   Springs are made of soldered brass strips.

The tires and wheels came from an Ertl 1:25 scale Dodge Power Wagon diecast.  I used the tires and wheels as masters, created molds and cast copies.  The thin disks in front are locking rings that were made from an aluminum lathe turned master and then cast.   They go on the outside of the wheels.  The tires are 9.00x16's and the locking ring helps to hold them on the rim.  The WC carries a spare tire on the driver's side running board.  Thus the 5th tire.  The differentials were also cast and have been drilled out for brass axles.  Larger axle sections will be added along with the hubs for the wheels.  Will post additional photos as work progresses.

Edited June 27, 2021 by Chariots of Fire
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[redneckrigger]

Great to see this one start, Charlie. I am still following every post you make, while not being able to devote any time to my own building. BUT, your projects are sustaining me! Keep those posts coming!

[hct728(Bob)]

Wow, a great start to another ambitious project! Love the brass leaf springs and the wheel details, looks like you’ll need a lot of hex heads for those! And here I thought the trailer build was awesome, never realizing you couldn’t leave it without a proper tow vehicle…

[Chariots of Fire]

15 hours ago, hct728(Bob) said:

Wow, a great start to another ambitious project! Love the brass leaf springs and the wheel details, looks like you’ll need a lot of hex heads for those! And here I thought the trailer build was awesome, never realizing you couldn’t leave it without a proper tow vehicle…

I'll use some plastic hex strip stock for the bolts on the locking rings.  I don't even have the trailer any more.  It went to Hawaii like the Class 325 did!

[Snake45]

Very cool project! I love the WC-51 so will be watching. Drive on! 

[Chariots of Fire]

A bit of an update for work done on the engine.  Danbury Mint made a nice looking 1/25 scale 1941 Dodge pickup with a 6 cylinder engine.  I took the diecast apart and removed the engine for sizing.  Since I plan on making two WC-51's I wanted two engines that were alike.  But with only one diecast that I did not want to surrender, it only made sense to copy it.  That is what is in the partially completed box in the photos below.  Using measurements of the diecast engine as a basis I built up the block and oil pan.  In addition to the diecast, a page in a technical manual had photos of the engine as put together and in side views.  The diecast engine is good for some things but not all as a study of the photos revealed.  So the photos are the real source of what the final result will be.  RTV has been ordered and as soon as it comes in, the mold will be filled over each of the components.  From there is it only a matter of adding the details but the big ticket items of the engine will be identical.  The bell housing and transmission came from the parts box and is actually from a small Ford V-8.  The shape is similar, not the same as in the photos but close enough as most of it will be in back of the firewall and below the floorboards.  The small round disk is a piece that was at the front end of the diecast generator.  It is actually finned so it was included for casting.

The oil pan is made of Ren Shape as is the center of the engine block.  Sheet stock was used in other places.  The diecast engine has very nice pulleys but I will turn those for each of the new engines and retain the originals to put the diecast engine back together.

Here's the page out of the technical manual.  It shows that there are some differences with the diecast so I'm going with the photo references as much as I can.

For the mold box I'm using foam illustration board and putting it together with hot glue.  The interior will be sprayed with mold release to make sure that the parts come out easily.  It takes a good 4-6 hours for the RTV to set up properly but the quality of the mold is typically very good.  The only thing to make sure of is that when the RTV is poured, there are no air bubbles that get trapped.  That is eliminated by using a stick to move the liquid RTV around for a few minutes after it is poured.

 

Edited July 1, 2021 by Chariots of Fire

[hct728(Bob)]

Great job! Your fabricated parts look better than the production diecast model engine! So good to see them being cast too.

Reninds of some casting I have to do, got the molds done but was waiting for a hot day, as the instructions say the resin is supposed to be at 100 degrees to cure properly. Never seen that before. 

Nice to see such progress with yours!

[Chariots of Fire]

What kind of resin are you using?  The resin I'm using does get warm as it cures and if the mold is cool it takes longer for the resin to set.

[hct728(Bob)]

3 hours ago, Chariots of Fire said:

What kind of resin are you using?  The resin I'm using does get warm as it cures and if the mold is cool it takes longer for the resin to set.

I’m using Alumilite “Amazing Casting Resin” I bought at Michaels using their 50% off coupon. I don’t do enough casting to get the good stuff, it would go bad. Temperature should actually be 150 not 100F and I don’t want to stink up the house so outdoors I go! Will be doing several pieces, mainly a Volvo semi dash and a grille(!), and an engine maybe, I  made a mold of my little Cummins as a test. Good to have extra molds handy in case I mix too much for the main project, I find it hard to tell how much will be needed.

Thanks for the how-to and inspiration!

[Ace-Garageguy]

Cool project. I love these things. A few were still in service when I was a much younger man, and our local fire department and forest service guys used surplus units when I was a kid. 

As usual, your work is first-rate and very inspiring.

[Chariots of Fire]

Bob:  I use the resin from Micro-Mark.  It's 1:1 mixing and hardens quickly.  I don't have to worry about the temperature of the mixture.  Just mix and pour. 

[Chariots of Fire]

Got some more done in the engine.  All basic building materials used in the construction.  Ren Shape for the block and oil pan.  Evergreen sheet, strip and tube stock for all of the detail parts.  Aluminum rod turned into fan belt pulleys, brass wire, common pins, small brass imitation bolt heads, bead wire, fusion beads for hex nuts.  The only kit pieces are the manifold that came from a cannibalized Opel Blitz kit and the bell housing which was from an old Ford V-8.

[hct728(Bob)]

Wow, nice job on the engine! I love all the brass and aluminum details, they sure bring the resin to life, shame you have to paint them!

[Chariots of Fire]

I painted the engine yesterday.  The black acrylic has dried but it is so damp and humid the rest won't dry!  Still sticky after nearly 24 hours.  If it doesn't dry out soon I may have to strip it and start over.

[Zippi]

Looking pretty sharp.  Very kewl little project.

[Chariots of Fire]

Bit the bullet and made a change in the fan.  I was not entirely happy with the plastic fan even though it looked ok.  The blades were just too flimsy and kept breaking off.  So after being encouraged by another builder, I made a fan line drawing and then cut a new one out of brass.  A twist of the finished blades with some small pliers, some finish filing of the edges and we are back in business.  The first one I made got installed on the shaft backward so I had to unsolder it and turn it around.  The photos that follow show the fan and how it was made.

The fan on the engine in the background is backwards.  It is now reversed with the blades going the right way.  In this photo the drawing of the fan is taped to a piece of brass sheet.  Cuts are made with a cutting disc in the Dremel.  The first cut goes all the way to the circle in the middle.  On the adjoining blade, the cut is made only as far as the first cut above it.  That leaves a small amount of area on each blade than can be twisted a little as a real fan blade would be to draw air through the radiator.

Here's a look at the fan that was finished.  The leading edge of the blades should be the long side so it was removed from the shaft and turned around.  Not in the photo but it is now correct.  The unfinished fan will be saved for the second of the two WC-52's that are being made.

[hct728(Bob)]

Ha, even you need a little nudge to push the envelope, LOL! Great job, another neat little detail. I had to look up which way an engine turns, seems CCW is most common, now scratching my head and trying to figure out which way the blades should be oriented to pull air thru the rad - my head is starting to hurt!  Things are really coming together for you, great progress, thanks for sharing!

[Chariots of Fire]

CCW it is.  That is why I had to switch the fan around and put the longer cutting edge outside.

[hct728(Bob)]

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Edited July 10, 2021 by hct728(Bob)

[Paul Payne]

Charlie, I love to see projects like this, you can learn so much! Beautiful work! Question- how did you remove the wheels and tires from the power wagon? I would like to remove mine but do not want to break the axle ends.

[Chariots of Fire]

6 hours ago, Paul Payne said:

Charlie, I love to see projects like this, you can learn so much! Beautiful work! Question- how did you remove the wheels and tires from the power wagon? I would like to remove mine but do not want to break the axle ends.

I pried the tires off with a small screwdriver.  The wheels as snapped onto the axles on the inside and I could not save them so I had to cut the axle just behind the wheel.  If I put the diecast back together it will have to be with a new axle made like what I'm doing now.

[gotnitro?]

Fabulous work !!

[Chariots of Fire]

The gnomes have been busy in the shops the last few days with all of the rain we have had.  Lots of detail stuff to get out of the way on the chassis.  Plenty of brass works to get done and soldered up.  Here's were we are as of today.

A look at the various parts that have been made up for the frame and running gear.

An upside down look at the axles, hubs and tie rod in place.

It's up on all 4's now.  Short and stubby but with a 98"wheel base and 9.00x 16 tires that's the look you get.  And it is a 3/4 ton vehicle besides.

[hct728(Bob)]

Wow, looks great! Nicely photographed too, looks great from every angle!

[Zippi]

That's coming along nicely.  Once you get some color on those wheels it will really pop.