First Steam Engine Build

[stevendavis]

Thanks Minh!

[stevendavis]

Have to take a break from the loco until I can get some more materials, so I did some more work on the Coles. Got the hole drilled for the rod bushing and installed the bushing. Everything seems to be working good so far.

<a href="https://www.youtube.com/watch?v=gE5aptxMP0M" target="_blank">http://www.youtube.com/watch?v=gE5aptxMP0M</a>

[stevendavis]

Milled out a base for the Coles and got it set up to start milling on it. Took a bit to get it where I wanted it. The base is big enough to mount a few extras on when I decide to. I'll probably add a governor and possibly a feed pump.

[stevendavis]

After several days of rendering, I finally finished the video for the Crosshead assembly.

<a href="https://www.youtube.com/watch?v=N0dMhb4CCpE" target="_blank">http://www.youtube.com/watch?v=N0dMhb4CCpE</a>

[stevendavis]

After spending some time thinkng about building a new crankshaft, I think I'm going to give it a go. I milled down some stock and just need to make a few more cuts before I can start machining it. I hope I don't get too much distortion by making the cuts!

[pirmin]

what realy helps when hogging out a crankshaft from thick bar stock like you do is to round the corners with a coarse handfile so that you have a almost round rod. it safes a lot of shallow passes on the lathe

[crueby]

What kind of steel are you using for the crankshaft? Some will deform more than others. 1144 Stressproof Steel is heat treated to prevent that issue, though its only available in round bar, no flat bar that I've found.

[stevendavis]

Thanks pirmin! I will do that.

crueby, not sure what it is. I cut it from a 1.5 x 1.5" square stock. It looks like it might be cold press. I think I can heat it up to red and let it cool to remove any stess, but not sure about cold press?? Hope I don't waist a week of my life!! But it's possible!

[crueby]

Cold rolled steel is usually the worst for deforming when cut. If you have another piece several inches long, a quick test would be to take a cut down the middle, and put a straightedge on the outside of one of the halves and hold it up to the light. If you see a gap in the middle, then it warped when cut. The longer the piece, the bigger the warp will be.

[stevendavis]

Thanks crueby!
I'll cut the big chunks out and see how much deformation I have before I get machining it. At least it will save me from waisting time. The one I'm most woried about is when I cut the wedge out of the web after the main journals are done. Seems like that will be the most troublesome area.

[internal_fire]

The one I'm most woried about is when I cut the wedge out of the web after the main journals are done. Seems like that will be the most troublesome area.

I would saw cut the complete outline first and then glue a filler piece into the gap, before any lathe work. The metal may move a lot when cut, but should not move much more when the final shaping is done on the lathe. You can straighten it after the cut if the warping is really bad.

Attempting to anneal the steel by simply heating with a torch will not work very well. Proper annealing requires careful control of temperature ramps and soak times. Torch anneal will probably remove some stresses, but will create others.

Gene

[stevendavis]

Thanks Gene!
I hadn't thught about cutting the web out and adding a filler. I will definitely do that!!

[pirmin]

i would first of all remove the millscale from that piece of steel and then start with all the other operations.

[internal_fire]

i would first of all remove the millscale from that piece of steel and then start with all the other operations.

I think all that "millscale" is actually black marker pen on a freshly cut surface. 

Gene

[stevendavis]

i would first of all remove the millscale from that piece of steel and then start with all the other operations.

I think all that "millscale" is actually black marker pen on a freshly cut surface. 

Gene

Yep, its marker! All millscale is gone.