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Model Engineer Beam Engine - Reeves Kit

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Jasonb:
How does the casting compare with the drawings particularly lengthways? I'm not sure it was always supplied as an aluminium casting so the pattern may have been made to suit the shrinkage of iron.

propforward:
Thanks for looking in Jason. It seems like the casting is on the large side, by between .03" and .05" depending on where and what is being measured. So small features are long / oversize by about .03", distances from center vary between .03 and .05 as you move further out. This is good from a height standpoint as it means there is a little more material to take off and keep everything correct, but it means a bit of thought needed for the hole patterns. If I just establish center of the square plinth and use that, then everything will work and all patterns will be aligned relative to each other, but the circular pattern on the cylinder boss will definitely not be concentric to the boss. May not be so important when everything is bolted in place.

Anyway, likely what I will do is split the difference between the square and round plinths. Once assembled that shouldn't show up particularly. I can always dust off the outsides of the cast features also, although I'd rather leave those as cast.

Likely putting too much effort into this balancing act but I enjoy it and ultimately should make for a nice fitting engine. Need to double check the beam casting before starting to make sure the bosses on that are close enough. I really don't want to alter engine dimensions though. I recall doing that when I first got the castings and don't recall any red flags, so should be OK.

The only thing that likely won't be made to print is the very outside dimensions, and locations of bolt down holes in the oval tabs. Those I will best fit to the cast features and merely dust off the outsides the minimum needed to clean and square it up. For sure if I went with drawing dims the outside would eat into the oval feature and several of the holes would be off visually.

Hoping to cut metal tonight - but a big trip coming up so I need to prep for that, so may be a week or two before this makes any real progress.

EDIT: The supplied plans show this as an iron casting, so yes indeed this is a change from original. Maybe because the iron one was too undersized and / or twisted? Also or maybe solely on cost.

propforward:
Hehe - I see I've got a dimension snapped to the end of a center line rather than a hole center. A few things to check there before I cut anything! This is one of the pitfalls of redrawing stuff.

Michael S.:
Hi Stuart, I don't know if my pictures will be of any use to you to check the size of the base. I don't know what year the aluminum base is from either.

Michael

propforward:
Thank you Michael! I’ll do a comparison tonight. Looks like I’ll be able to get enough time to make start on actually cutting.

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