Working on a 10V as a filler project. Problem is I’ve encountered several hard spots in the arch casting making accurate machining of the guide ways and cylinder flange difficult. Is there any thing I can do in the way of heat treating the casting to help soften then up?
Hard spots in Stuart 10v cylinder support
- Thread starter myrickman
- Start date
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You can sometimes get away with heating the casting to red heat and holding it there for some time then allowing to cool slowly, often done by putting in an open fire or wood burner for the evening and then allowing to cool in the ashes until morning. Metal needs to get to about 850deg C
Carbide tooling will also help with the initial machining which is often enough to get through the chilled edges and corners and allow HSS drills and taps to be used for the holes.
Carbide tooling will also help with the initial machining which is often enough to get through the chilled edges and corners and allow HSS drills and taps to be used for the holes.
oldengineguy
Well-Known Member
I have found hard spots in Stuart casting as well. I bought an ( old 40 plus years) unfinished Triple kit a while ago and the high pressure cylinder had been badly machined beyond use. I got a replacement from Stuart and the cast iron is very different from the old stock. The ears /brackets that the columns bolt to were so hard that a carbide end mill just skated ,a file did the same. The main body of the casting was hard but machineable . I ended up using a grinder to rough shape the ears and a die grinder to finish. Wish I had asked this question back then and put it in the fire. If there is a next time I will try that .Thanks Colin
Thanks gents for the replies. I did a search and someone on on of the live steamer boards suggested putting the casting in manganese dioxide powder in a sealed container and heating to red heat and slow cooling. I’ll try the heating the part sans powder first and if that doesn’t work try the powder as plan b.
Tug40
Well-Known Member
I feel your Pain.
I need to drill 4-3/32 holes for 4-40 tapped holes, (5 thou large on purpose).
4 ears on my cast iron engine frame.
Rest of frame drills/machines fine. The 4 ears are very, very hard.
Finally got 2 drilled no joy on other 2.
Ordered 2 3/32 carbide drill bits & a 3/32 R8 collet, (myR8’s only go to 1/8”).
If still no luck, it’ll be time to attempt annealing the frame.
I need to drill 4-3/32 holes for 4-40 tapped holes, (5 thou large on purpose).
4 ears on my cast iron engine frame.
Rest of frame drills/machines fine. The 4 ears are very, very hard.
Finally got 2 drilled no joy on other 2.
Ordered 2 3/32 carbide drill bits & a 3/32 R8 collet, (myR8’s only go to 1/8”).
If still no luck, it’ll be time to attempt annealing the frame.
Update: I contacted Andy at Stuart and he graciously sent me a new standard casting to replace the one with all the hard spots. This one was much better and I was able successfully bore the ways and finish it up today.
