My Bender

JJ & C RailRoad

My Homemade Rail Bender

My bender is made up from cheap parts and some items that were laying around the house. First off, cost. I have less than $11.00 invested into the whole deal. Its made up from the cheapest drill press vise I could find at one of the local El' Cheap O tool stores and ran me $9.95. The fact that it was a cheap vise also meant that it was soft metal and easy to work with. I had to buy 4 fine thread 5/16" hex head bolts, 4 fine thread 5/16" hex nuts and a wing bolt that all cost less than $.50 with tax. The wheels are made up from an old pair of roller skates that I bought way back when the movie Roller Boogie came out with Linda Blair (remember that one?).

The pictures above are the finished bender. It works like a charm.

Here's what I did to make it.

1. I started off by buying a cheap drill press vise. Once I had it at home I took the two metal jaw plates off that were on the inside of the jaws just to get extra room. Then I used my drill press to drill three holes in the vise. The first two holes are drilled in the top of the stationary jaw at the ends. I was not worried about how far apart the holes would be other than the fact that they needed some space between them for movement. The wheels are kind of big for what the project calls for but hey, it works very well. I did make sure to leave enough metal at the ends to still give plenty of support to the wheel bolts. I measured in from the ends 3/8" of an inch and drilled the holes at that mark. I also centered the holes front to back on the jaw. The third hole is on the adjustable jaw of the vice all by itself. I drilled this hole right in the center of the jaw measuring from side to side as well as front to back. Then I tapped the holes with a 5/16" 28 thread per inch tap. That's really it for the vise part.

2. This was the hard part. How was I going to cut the grooves with the profile of the track into the wheels? I don't have a metal lathe in my bag of goodies so I ended up using my drill press as a lathe. If you look really close to the picture on the right you can just make out the bearings in the wheels. I took the bearings apart on the wheels and then put the outer bearing races back into the wheels. I found a old nut and bolt that just fit through the bearing race's and bolted them tight into the wheel. That made the bolt and races centered in the wheel. Then I put the long end of the bolt that was sticking out into my drill press and tightened it up. Each of the three wheels had a small bit of wobble when the press was turned on but a little adjusting of the nut and bolt got them strait enough to make me happy. After that, I took a piece of Brass code 332 rail that was about 4 inches long and faced the end on my bench grinder so it was very strait and sharp (a clean 90% angle) on both ends. That rail became my lathe bit. Then I put my good drill press vise on the deck of my drill press with the rail lathe bit clamped in it nice and strait. I adjusted the drill press deck so it was at just the right height where I wanted to make my groves to be at on the wheels. I then proceeded to grove each wheel with small easy cuts until the rail laid in the profile on the wheels just right. One thing I should mention is, the wheels I used are super old and the rubber material was harder than some metals I've worked with. Because of that fact I had to regrind the ends of the rails flat about 6 times per wheel.

3. When the wheels were done I put the bearings back together but this time I used a new 5/16" nut and bolt instead of the original axle to hold the bearings in place. The length of my bolts gave me about an extra 1/2" to screw into the vise for mounting. Your bolt length will depend on how wide your wheels are. I also added small washers under the nut and bolt head so the bearing races would not get ground up if the surfaces started to move while the bender was under pressure from the rail when it was being bent. Each of the 3 wheels was then screwed into the holes on the top of the vise jaws and tightened. I did a quick test to see if it worked at all and to my surprise it worked pretty damn good! At this point I was pretty geeked up and thought I had it made so I hurried to finish it up (a mistake I'll tell you about in a minute).

4. All that was left to do was make a crank and handle to make bending go a little easier than turning the middle wheel with my hand (which got me a couple of ouchies when my finger got between the wheels). I found some flat metal stock laying around that was 1/8" thick by 3/4" wide and cut it down to 5 1/2" long. I tried to make it look clean so I ground the end to match the radius of the wheels and put another 5/16" nut and bolt at the outer end to be my handle. I used a couple of #10 Philips head machine screws to bolt the handle on the center wheel. If you look at the picture on the left you will notice that the handle has a bend to it. That was put into it so the crank doesn't rub on the other wheels when turned. Done!?!

The mistake:

When I finally started to bend my rail I noticed a bad thing. The very first rail came out with a nice smooth curve that went up to just about the very end (which is a good thing). But, when I laid the rail on the cement floor in my garage I noticed that the rail had a angle to it. What I mean is, when set on the floor looking down at it, it was perfect. When you looked at its profile from ground level, the rail was not perfectly vertical (strait up and down), it leaned inward towards the center of the radius. "What the heck?" was almost the exact words that came out of my mouth. Time to think. More time to think. Looking at the bender.... Uh oh. The wheels were not perfectly aligned to each other. When I looked at the bender from the side I could see that the three wheels were not at the exact same height. So the groves that the rail moved through were miss aligned a tiny bit. I ended up shimming the center wheel about .010" and the wheel farthest away (in the photos above) close to .020". Then I re-bent the rail that was messed up and it came out perfect. Another rail?. Perfect. Yes!

Later I noticed my bends were not all coming out the same. Upon inspection I realized that the adjusting bolt had some play in the end movement so I put a couple of thin washers between it and the adjustable jaw to take most of the endplay out. It was then that I also added the adjuster hold down wing bolt at the back of the vise. It ensures that the adjuster will not move in or out when the rails are being changed. You may have also noticed that the groove's on the wheels are very close to the bottom. I did that with the thought that I would be putting less pressure on the bolts thus giving less flex to the wheel assemblies. Not entirely true. The amount of pressure on the unit is pretty light. So, if you want, another set of groove's could be made for another rail code... Just make sure the grooves are lined up perfectly.

Sorry this picture is so small. This is 4 sections that I just bent (there are 2 in each stack). They are 8' radius.