I have gotten out of the habit of regular posting as my current machining focus is a bit off the beam from what this blog started out as. I have finally admitted to myself that it will be a while before significant model railway activity takes place and also have reminded myself why I chose the blog name I did. So, I shall report on what I am doing in hopes that it will be of some interest albeit perhaps not to exactly the same audience.
To recap, I have been developing my machining skills by working on a model beam engine based on plans by Elmer Verburg. This engine is commonly referred to as #24 (Elmer created many plans and made them freely available, may he rest in peace). I have done the base, flywheel bearing, flywheel, eccentric hub, and column. Here is a dry fit of those pieces.
The part in progress is the beam. This is attempt the second as the first effort is now part of the scrap pile with the end of a #55 drill firmly embedded in it. Trying to drill that size of hole with the lathe going at 1100-ish RPM was not a success. The mill going at 4300 and a less ambition depth did the trick.
There are three 1/16th inch reamed holes in that piece. Photographing shiny aluminum close up is still something I need to work on.
Next step will be to flip the part over and mill it down to final thickness and take off the edges at an angle to produce an elongated lozenge shape. I have a plan but it may not work out. On the other hand, the only crucial dimensions on this part are the holes and the thickness of the hub. All else could be done with a saw and a file.