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Discussion starter · #81 ·
After looking at the cow catcher, I decided that it had a closed up look, not like the cow catchers I’ve seen. The entire bottom was a solid piece of brass joining the vertical ribs so that one could not see through the ribs down to the tracks.
Here’s the before picture:

So I used my vertical mill to remove the solid bottom portion, opening up the bottoms of the vertical ribs and then chemically blackened it.

I made a muffler and exhaust pipe out of various sizes of brass tubing. I added a drive shaft & rear axle support rods, all attached to a wooden simulation of a transmission and Model-T’s IC engine’s lower end. In this picture you can also see the machined bottom side of the cow catcher.

I painted up a number of Ozark Miniature detail items; track tools, jacks, hammer, wrench, shovels, rake, pick, chains, bucket and added them to the truck bed area & driver’s side of the bed’s stakes & rails. In the 1st picture you can see the exhaust pipe just below the bed's frame on the left side.



I also converted a CO-2 type fire extinguisher casting to simulate an old carbon tetrachloride fire extinguisher like those available in the 1920s and mounted it in the passenger’s side of the cab. The Model-T driver now has a companion dog riding along in the cab.

You'll notice that the hood is missing in all of these pictures. I'm in the middle of making louvers for the side hoods. The louver forming tool is designed and machining has started.
More later!!
 
Discussion starter · #83 ·
OKAY, I’ve completed making louvers in each of the hood’s side pieces.

Here I’m documenting the design, building & testing of a dedicated piece of hard tooling used for making the hood louvers---another first-time-ever activity for me. It’s probably not very helpful to anyone else, since it’s unique to the Model-T Rail Truck project. I’m after repeatability here, so that’s why I’m making this tooling. There’s always a possibility that I will need to make another set of hood louvers or for that matter, another rail truck. I also will be able to try different louver widths, if needed.
Anyway, here is a picture of the prototype hood louvers I’m going for.



The louver forming tool is made up of 6 pieces. The tool itself is 3/32” x ½” oil hardened flat tool steel stock while the base/die & its retainer/stop, the tool holder & its retainer and the side alignment stop pieces are all aluminum. Here are the plans I’m using:


At this point the aluminum pieces have been rough cut, faced-off to size, marked up with Dykem blue layout marker and ready for laying out the drilling positions. I’ve also cut 3 copies of the steel tool, so I can experiment with the louver’s possible end shapes and whether I’m going to use the tool strictly as a forming tool by precutting slots through the brass louver material or to use the tool as a punch by sharpening & then hardening the edge of the tool so that it can be used to punch thru the brass.


The aluminum for the base/die is 1.5” x 1.5” x 2.5”. It has a side alignment stop secured to the base/die by 2- 4-40 x 3/8 socket head cap screws.

The die portion is for a single louver shape is ½” long by 3/32” wide. The die is machined into the edge of the base piece at a 30degree angle. It creates a louver that protrudes at a 30egree angle from the flat hood surface. Because of the narrow width of each louver (3/32”) a work piece retainer (1.250” x 1.5”) is secured with 4- 4-40 x 3/8 socket head cap screws across the face of the die to keep the formed brass in line with the front edge of the die.

It also aligns the front face of the base/die with the front face of the tool holder.


The tool holder is aluminum 1.5” x 1.5” x1.0”. It has a slot milled on its front face to match the width & depth of the actual tool.

A 1” x 1.5” retainer bar is screwed across the front of the tool body’s milled slot giving a repeatable movement of the tool against the die. Again 4- 4-40 x 3/8 socket head cap screws were used.


The 1/2” wide x 3/32” thick steel tool itself is machined at a 30degree angle on one end in addition to being ground at a compound angle at the top & bottom edges, yielding the shape of the louver and its edges.




The tool holder’s bottom face is secured to the base/die’s top face by 4- 10-32 x 1 ¼ socket head cap screws. The screws provide for firmly holding the work piece in place while forming a louver. Loosening the screws allows for advancing the work piece to the next louver position.


The die represents the outside shape of a louver while the tool is shaped to be the inside shape. Using a hammer to hit against the top of the tool, the brass work piece is formed into the shape of the die.

For a first test, I used thin .006” shim brass to see if I could punch through the brass with the tool and form a louver. If this test yields successful results, I’ll oil harden the tool’s edge for use on the thicker brass of the hood side pieces.


This test did not produce the uniformity of one louver to the next that I wanted. Alignment for punching the next slot was, at-best, hit’n’miss.

I decided to precisely precut slots in another test piece with my mill, this time using .015” thick brass like the actual hood side pieces. I did a 6 louver test to see how repeatable and uniform the results would be.
For this test I needed to cut 6 slots, ½” long every .134” across the face of the test piece. To do this, I mounted my .012” thick x 1 ½” dia. slitting saw blade/mandrel in my mill. I mounted the brass test piece to a wood block and CA’d it in place; then mounted it in my mill’s vise. To get the ½” long slot, I laid out a ½” long chord on the face of my slitting saw blade. The distance from the center of the chord to the edge of the blade was measured at .047”. Then by advancing the x-axis .047” the blade would plunge into the brass/wood block, producing a ½” long slot. Now I could advance the z-axis .134” to position the blade for the next slot, and so on. Here’s the saw setup:

With the slots so accurately cut, by removing the tool retainer, aligning the tool with the next slot was very precise. After running the test piece through the forming tool process for each of the 6 louvers I got the following:


Much better quality, but I’m going to reduce the space between each louver from .134” to .118” (about 1/64” closer together). So, now I’m on to repeat the above process for the real hood’s side pieces. Here’s one of the hood side pieces completed & the other being setup In the forming tool with 4 of the 6 louvers completed.


After some sharp edge clean-up of the formed louvers with a file I reassembled them with the rest of the hood.



Another possibility mentioned early will be to decrease the width of each louver….a future task will modify the forming tool to allow for a 1/16” width tool, 1/3 narrower.

But for now, I think I’m done, if that’s ever possible with one of these projects.






Thanks to all who have added their ideas and supportive comments. As always, it's appreciated.
 
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