Back in 2001 my friend Anthony Mount brought along to the Guildford show a rather nice Vertical Concentric Hot Air Engine Bailey's Bee:
(http://lister-engine.com/coppermine/albums/userpics/10007/Bee.jpg)
Tony wrote up his build of his model later that year in Model Engineer and if anyone is interested his short write up starts in ME No 4155 page 270. The model was designed from the engraving in this advert:
(http://lister-engine.com/coppermine/albums/userpics/10007/advert~0.jpg)
I purchased these castings from Polly Models for under £300 the set including P&P but be aware they will have them made to order so will ask for a deposit and the castings will arrive a couple of months later :-\
As I wait for the paint to dry on the base of one of my other models prior to the hand over ::) We have commenced casting fondling:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4335.JPG)
Unlike another of the Stirling models casting sets I have previously purchased from Polly's this one did not come with the stainless tube necessary for the displacer or the cylinder :wallbang: With these ordered from Fleabay I can start looking at the challenge of the bottom stand:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4336.JPG)
Yes the legs curve/taper in every direction :toilet_claw: And if they are not all the same length the model will be lopsided :ShakeHead: As I do not own a CNC jig maker I am using the next best thing my cheap as chips printer to make a couple of wedges of the right shape to hold the casting:
(http://lister-engine.com/coppermine/albums/userpics/10007/IMG_4337.JPG)
This could take a while :thinking:
Jo
A bit more and yes I did remember to bore the top of the cap 32mm :ThumbsUp:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_4434.JPG)
Most of the cap is just turning to size/depth except the outside that has to be cleaned up. I did this by following the profile with a button tool then smoothing off by hand. You can see where there are still dips in the surface if you first coat it with permanent marker before applying the emery paper:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_4435.JPG)
Once I was happy with this it was off to Tgs to mill two slots into which the supports for the main crankshaft brackets will go. To make sure I do not cut the slots too deep I first had to zero the cutter to the depth required (this nut was the 5mm required ;) ):
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_4436.JPG)
Then we can cut the slots (not forgetting to drill the holes in either end):
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_4437.JPG)
and check everything lines up on with the 35mm liner:
(http://listerengine.com/coppermine/albums/userpics/10007/IMG_4439.JPG)
Why did Anthony make the slots 40mm long and 6.35mm wide :headscratch: I will have to make them out of something slightly wider than the piece of 38.1mm that first came to hand :thinking:
Jo