With more parts to make, there are more tools to make 🙂
In making the main shaft, which mounts the flywheel and the exhaust valve, I needed to cut 3 flats 120 apart. From my stash of metals I dug out some hex and bored, then reamed for 10mm. A set screw finished that tool off. While cutting the 2.5mm slot in the end I broke the cutter.
After drilling the base plate, the next item was to drill the supports to the same pattern. This was a bit nerve wracking as there is not much wiggle room for ‘adjustments’.
To align the holes in middle of the supports I used a .375 rod in the mill arbor, and a parallel to make it align with the top surface of the support. The spindle was then in the middle, the vertical was then locked into place. The other position was aligned each time with a spotting drill and then drilled 4.2 for the m5 SHCS.
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!
I was hoping to buy these but they are a weird size. The machine came with a couple of hacked up ones, and 3 different sized bolts as well to add to the mix.
A piece of 1/2×3/4 steel was cut to just over 3” length. This gives me 4 nuts 3/4” long and 0.025” for 3 saw cuts.
Some careful markup on the metal provided the guides I needed to make this the correct size. Measuring at close stages resulted in a symmetrical part. A bit of careful work with a centre punch meant that the bolt holes were centered in the slot. I tapped these 5/16×18 for a set of studs and standoffs that I hope to buy later this year. This is the first time that I used power tapping, what a joy compared to using a tap handle. A blip or two on the drill press power switch does the job. Only works for through holes though.
This was the first real test of my milling machine and my skills. The result is quite decent. And lots learned about the machine and its capabilities.
The horizontal milling machine has a stop on the X axis (left-right movement). This allows setting the travel within preset limits. Unfortunately only the LH adjustable limit came with the machine.
So today I made a RH one. Essentially a mirror image of the LH one, it is made from 1/2×3/4 steel. A 5/16” end mill did the hard work, with my coolant mister keeping things cool and lubricated.
The t-nut to hold the limit in place was made from a bolt. A bit of lathe work resulted in the final part working perfectly. One step closer to working on that model engine again!
These are photos of the machine as it arrived. The photos actually make it look better than it was. Lots of accumulated grime, oil and grinding dust mixed together for over 80+ years. Several coats of paint add to the patina.