[modeleng] Back to it

I've gotten back into the workshop this week after being away for a while and 
rather than start in on my main project (the 2X Tich) I've decided to shake the 
rust off by taking a short detour and do a Stuart D-10.  The castings have have 
been under the workbench for some time and are from early Jones & Bradburn (the 
current owners) production and this is my first Stuart engine which has NOT 
been out of the old Stuarts in Henley.

My first discovery was the prolonged "normalizing" process has apparently done 
nothing to improve the main castings.  These are rough and brittle and there is 
an occasional dead white hard spot.  Even with gentle machining chips of metal 
break off any square edge which will need to be filled before painting.  I 
continue to find dimensional errors on the drawings which requires that I now 
check through all the dimensions.  If I wanted this kind of experience I could 
have bought some old Clarksons castings, nevertheless, it won't build itself so 
I will soldier on.

The first job was the crankshaft which in this kit is to be built up of mild 
steel flat and rod.  I actually prefer this method anyway, using Loctite & 
pinned assembly, and the crankshaft has come out perfectly.  I must admit that 
I was never ever able to finish off one of the old drop-forged #10 engine 
crankshafts without pretzelizing it and I wouldn't bother with one now.  I have 
another Stuart kit (a "Launch" engine) which is from the old Stuarts but which 
includes a pre-brazed crankshaft, essentially a built-up version of the forged 
crankshafts.  I will probably go to a Loctited & pinned crankshaft on this one 
also.

I'm presently shaping the bearings and in this version the drawing calls for 
the middle bearing to be split, which of course is a necessity.  Something I 
don't care for however is they call for the middle bearing cap, which is on the 
under-side of the shaft, to be loose and simply rest in the bearing slot and 
rely upon being held captive in close quarters to hold the cap in place.  Since 
I don't have a ball-nosed milling cutter of the size needed to make the slot 
as-designed I'll probably substitute a squarish split block in a squarish slot.

I plan to spiff the engine up a bit, extra detail in a few places, to make it 
look a little less "Stuart-like", but not to go overboard.  There was a chap 
some years ago, "Anthony" IIRC, who spiffed up a Stuart #4 or #5 and #9 with 
much more prototypical detail and they made beautiful engines and each was 
featured on an ME cover at least once.

The Stuart 10's are thought of as beginner's engines but none are a piece of 
cake, they force you to use almost the entire range of basic model engineering 
skills.  In 1982 Tom Walshaw began a series on ME entitled "Handmaiden" which 
described the building of a Stuart H10 using only hand tools.  He claimed it 
took him very little longer than building with machine tools.  One assumes he 
had better castings.
Regards,
Harry

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