Stuart 10H build

wce4 · Dec 1, 2023

No machining today,

start capacitor went kaboom on the lathe.

Pick up a replacement , I will be back up running tomorrow.

BaronJ · Dec 2, 2023

wce4 said:
Jasonb I really like your Idea on machining a rectangular pocket and fit proper split bearings with retaining plate. From where I'm sitting it looks better than the original design. I might just change it on my engine after I finish it as design. Thank you.

That is basically how I did my bearings. machined square pockets !
Two gotchas here, you must make sure that the holes and edges are properly
de-burred. Any harrage will cause a problem with getting the crank to run properly.

Even after drilling and reaming the bearing before splitting and parting off the crank just wouldn't turn. Using a length of precision ground bar across the bearings would bind. I found that burrs left by the drilling caused misalignment and binding.

I used M4 cap head screws to secure the bearing half's to the base.
Note that this is not a casting, I used galvanised bar stock.

You can see here that the piece of ground bar stock goes right through and the whole lot rotates without any binding.

The bearing was made in one piece. Then the mounting screw holes were drilled M4 tapping size, after which the bearing was split using a 25 thou slitting saw. The top half had the screw holes opened out so that the M4 screws just went through, whilst the bottom half was tapped M4. Putting the two half's together like this ensured that both bearings would be in line when drilled and reamed for the crankshaft.

Note that In order to make sure that the bearing caps were placed on the correct bottom half I used red and green marker to identify them.

I cheated a bit here because I used the four jaw chuck on the lathe to centre the bearing for drilling and reaming on the split, after which I divided the bearing into two ready for mounting on the base.

Jasonb · Dec 2, 2023

I tend to go with separate caps, either flat which look similar to the Stuart extrusions, this was drawn with the intension to cut the sole plate from solid.

Or you can add a bit more shape to the caps like this one I fabricated

wce4 · Dec 2, 2023

Jasonb said:
I tend to go with separate caps, either flat which look similar to the Stuart extrusions, this was drawn with the intension to cut the sole plate from solid.

View attachment 151886

Or you can add a bit more shape to the caps like this one I fabricated

View attachment 151888

Thank you for the dwg. I will add to my steam engine dwg files and use it for future reference.