Scratch Building - OMG, I am pumped Up!

[Alyn]

In another thread, John Pol asked for some tips on building an electric fuel pump similar to the style used in 60's and 70's drag cars. The first thing that came to mind was Stewart Warner. I've built a few electric pumps, but they were generic cylinders with fuel line fittings on each end. Here's an example on the chassis of a Revell 32 Sedan (in front of rear axle).

I'm sure this in not what he had in mind, so I decided to try building one a little more like the old SW pumps.

The pump consists of a main body, with some slightly larger diameter bands, and a sediment bowl on the bottom. Essentially, this breaks down to various diameter cylinders. Rather than glue a bunch of cylindrical slices together, I went a different route. 1/8" tube was used for the main body. To duplicate the protruding bands, I wrapped some styrene strap around the 1/8' body. The strap in this case is .015" X .040". For starters, the strap was laid perpendicular across the body. A small amount of liquid cement holds it in place.

After a short waiting period, the glue was set enough to finish wrapping the straps around the 1/8" rod.

More drying time, and then the excess strap was cut off with enough left to completely circle the body. Now it's time for yet another application of glue. This represents the main body casting for the pump.

Now for the sediment bowl. I found a scrap of 3/32" rod which is slightly smaller in diameter than the body. Another scrap, in this case 1/16" hex styrene rod, was glued onto the 3/32" rod to serve as a mounting pin. It will slip into the end of the pump body. Why make it separate? This piece and the body will be different colors. To get the best color separation line, the pieces can be painted separately and then assembled. Here's the sediment bowl.

[Alyn]

Here's a mock-up of the two parts. At this point, the pump is still part of the longer piece of styrene. The extra length makes for a nice handle while you're working on the part.

Here's the completed part which is about 1/4" long not counting the silver sediment bowl. Two 1/32" holes have been drilled into the side for fuel inlet and outlet. Two smaller .017" holes are drilled on opposite sides of the lower pump body to accommodate the sediment bowl retainer. This is merely a small length of 30g plated copper wire bent into an appropriate shape and inserted into the holes.

Finally, here's the newly created part shot in Tamiya gold topped with Testors dull coat. The sediment bowl is covered in Model Masters Aluminum Plate. With the gold finish, It looks a lot more like a fuel pump. I inserted a couple of small lengths of insulated wire to show where the inlet and outlet lines go. To do it up right, you would want to add some hex fittings here along with the fuel line of your choice. Another option might be a mounting plate with PE nuts or screws to be glued behind the pump.

[patami]

Some of us do what we can and others do what they want to. Great tut have to give it a try some time. Or steal the idea and make me some Stromberg carbs.

[Dr. Cranky]

Alyn, you are always on the lookout for great how-tos. Nice job. Thanks for sharing. You are helping keep this place energized!

[John Pol]

Here's a mock-up of the two parts. At this point, the pump is still part of the longer piece of styrene. The extra length makes for a nice handle while you're working on the part.

Here's the completed part which is about 1/4" long not counting the silver sediment bowl. Two 1/32" holes have been drilled into the side for fuel inlet and outlet. Two smaller .017" holes are drilled on opposite sides of the lower pump body to accommodate the sediment bowl retainer. This is merely a small length of 30g plated copper wire bent into an appropriate shape and inserted into the holes.

Finally, here's the newly created part shot in Tamiya gold topped with Testors dull coat. The sediment bowl is covered in Model Masters Aluminum Plate. With the gold finish, It looks a lot more like a fuel pump. I inserted a couple of small lengths of insulated wire to show where the inlet and outlet lines go. To do it up right, you would want to add some hex fittings here along with the fuel line of your choice. Another option might be a mounting plate with PE nuts or screws to be glued behind the pump.

Thanks a million for this how too it helped alot. Now for one on break lines and parrachute chutes line. Once again thanks a million times.

John Pol

[John Pol]

How do you save this to your computer so i can use it down the road.

John Pol

[crazyjim]

How do you save this to your computer so i can use it down the road.

John Pol

I print hard copy and maintain a book of tips & techniques - mostly because I have no idea how to save them to a computer file.

Excellent info Alyn. Thanks. You did the distributor using half rounds I believe and I'm been trying to make them.

[scalenut]

How do you save this to your computer so i can use it down the road.

John Pol

John at the bottom of the thread on the left there is a row of icons , you can choose download ,print,email .ect.

Edited December 11, 2011 by scalenut

[crazyjim]

That is cool. Thanks, Andy. I'm going to have to go through all the Tips & Techniques posts and do the download thing. I wish I would have know about that download button a long time ago.

[Darren B]

wow thank you for sharing scratch building is something that i am getting into more and more and sharing your skills helps us all get to be better modelers.

[Evil Appetite]

I copied all the tip's i could possibly want to use over at Brians Model Cars, and pasted them into a word document, named each one appropriately and organized them into folders. works well for me.