Tender Trucks

Making the Trusses

The first step for me was cutting the brass straps out of two different thicknesses of brass sheet stock. Then I had to true them up to the desired dimensions. It is the same process as I used in making the thin straps for the bolster columns so it is not shown here.

The next thing I needed to do was to build the tool for bending the straps. I was surprised at how hard the brass strips are to bend and it was soon apparent I would have to build the tool (mini press brake) that Kozo describes. The building of this tool and the modifications to my bench vice is a nice little project within itself.

I always try to leave my extra stock in as large a length as I possibly can. I never know when I might need a longer strip. The pile of straps in the front are destined to become the truss for the trucks.

Here is the trial fit of mini press brake poised as if ready to bend its first strap. Four bolts and the vice can be switched back to its normal duty.

Note the little hole at the 1~2 o'clock position on the top part. I installed a 1/16" roll pin there to prevent the ram part from turning. The bolts are SS 10-32 x 1/2" I had left over from the CNC project.

There will not be much of a duty factor on this tool after the truck trusses are bent, but I tried a simple water cooled hardening and tempering process to make this tool little more rugged. I really don't know if it is any harder or not!

Carefully made but not overly finished. It looks like the wire brush removed some blueing. This color change can't be seen just looking at the part. In fact the parts don't even look blue. Photo editing to make the background white pulled this out. Still, it looks good and was fun to make.

These are the jigs for making the truss. I have to consider, making these tools as accurate as possible helps make the assembly as accurate as possible. The hours invested here are only indirectly seen in the finished product.

A study in quite concentration. Making a dozen truss bars does require some concentration to make sure they are all consistent in dimension and fit. The jigs are the only way this can be done.

Here is the final shallow bent truss being fitted to the small jig. The last (4) deep bend bars haven't been started . All these bars are considerably over length and will be trimmed to the correct length when the complete side frame is assembled.

This is the jigged assembly shown in the above right pix. I am drilling the holes for the journal box mounting. No "crooked" bends were made using the mini press brake so line up was easy.

A lot has happened since the picture on the left was taken. The "Great Wreck" occurred which totally wiped out all shop operations for many months. Almost all my tools and tooling was damaged. The trusses for the trucks escaped the damage.

That was in November of '05 and it is now April of '06! It was not that I haven't been doing anything. There was just an awful lot of other things that got in ahead of the A3 project.

I built a new computer for the office and even filled the home office with some new furniture (long over due.) The old office (and web site building computer) is now the shop computer for CNC. (The old one died in the Great Wreck.)

So now I can make a little progress on the A3.

I have the trusses assembled. The truss on the bottom has not had the ends trimmed and is laying in reverse of the other three.

I first cut the tabs off with the band saw and then used my 12" disk sander to bring in the tab projections as close to the journal boxes as possible. I hate to do a lot of hand filing!

I keep praising the Pan-a-Vice. It gets parts to a position where I can work on them. Here is where I did the hand filing to get the truss stubs truly flush. From this point on I need to number the parts so they will always go back together the same way. I will follow Kozo's numbering method.

Just had to do a quick mock up for inspiration. There is my usual "scale human hand" reference tool. I am now beginning to feel the 3/4" scale of this project.

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