The bottom plate is up next. I need to mount the bearing/shaft supports so that I can measure dimension changes needed for the shafts. The material is Imperial, the drawings metric. Without redrawing everything I think this is my best approach to arriving at parts that fit together.
I bought a full set of ER32 collets so that I can use the horizontal mill for drilling as well as milling. I used a 5/16 end mill to counter-bore the holes, I really wanted to make some metric counter-bores, but need to use the tool grinder to finish those. The end mill worked out ok but not great. Thankfully I am the only one who will see the 2 bores that are out of center 🙂
After cleaning up the lathe and removing some surface rust, it was time to make a bench. Having a good selection of used heating pipes in various diameters up to 4” provided lots of options. A gifted Mig welder topped off the setup.
Pipes and 1 1/2×1 1/2 angle iron were cut to length and welded up into 3 leg assemblies. 2 layers of wood bonded together form the top. The 2 main areas are further strengthen with 2×4’s on edge, glued and screwed to the bottom of the top.
The end result is a very sturdy arrangement for the lathe and milling machine.
I am now proficient at boring! Both to size and to depth, without a DRO. There are 6 bearings to counter bore for and a hole to prep for tapping M12x1.5.
The general sequence for each hole was to align the workpiece to the collet/spindle using an 8mm HSS ground tool rod. The table height was fixed after the first alignment process. Once the work could move on the rod easily, I switched out to the boring head. I found a 0.7mm depth of cut was my limit for stressing the head and its small 6mm bar. After lots of setting changes to get to the correct diameter, it was on to the next hole.
Emboldened by progress so far, without any significant whoopsies or rework, I proceeded to the 2 main supports.
Having recently bought a paper copy of Textbook of Advanced Machine Work, I had seen how planning out work was a relatively straight forward but necessary step. The book is replete with Sequence of Operations charts, mostly starting with “oil the machine” I planned out the sequence of operations so that I didn’t machine myself into a “can’t get there from here” scenario.
To that end I sized and squared up the 2 main support pieces. I marked out the 3 shaft holes and drilled then using a N drill, followed by an 8mm reamer. This allows me to use some 8mm ground HSS tool steel as alignment pins.
After a too long absence from making this engine, today some real progress. From my other posts you will have seen that I now have a real milling machine. I took some time to sort that machine out and make some enhancements. Now I am taking advantage of those improvements.
The Outer Shaft Support is fairly simple, most of its lines are cosmetic in nature. Or a test of your machining and setup skills or both I had already learned to make a Sequence of Operations for parts, doing so means you don’t machine yourself into a corner where you can no longer hold the part!