My first engine...

[arnoldb]

Not much done today... Started on the base for the engine, from some pieces of flat bar.

All ready to be welded (at least my stick welding is better than my silver soldering :big: )

Weld cleaned up with my small angle grinder; turned around, another weld & cleaned up:

After some effort with a flap disk in the grinder:

I'm pretty sure my neighbors will be glad that's done!

Started making the crank bushes, and ruined it on the last cut; under size on the OD :rant: - and that was some phosphor-bronze! - Oh well, more stock for smaller future engines.
Regards, Arnold

 

[arnoldb]

Some progress - Re-started & finished the crank bushes. My fiddling with the crank means that the main shafts came out too far below the 10mm they were supposed to be, so I did the next best thing...

I didn't have a small enough boring bar, so made one from silver steel, hardened it on the tip only. I didn't bother to temper - just climbed in with the oilstone and got good sharp finishes on the cutting edges. Then with some patient cross-feeding & tiny (not even 1/4 thou) infeed, got the bushes smack-on with a nice ID finish.

Close-up of the boring bar - the specks of "gold" is swarf from the final cuts:

Installed the bushes in the bearing blocks - crank runs nicely in them. A lot of marking-out on the base, bearing blocks and cylinder mount ensued - below is where I ended off today:

Well, tomorrow it is back to work - wish I had a couple more off days!

Regards, Arnold