[SEL] Re: Alamo piston pattern update

[Curt]

Dave Otto wrote:

>I don't think you indicated what this height was?
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Dave, the height of the drag side one is about 1" maybe an 1 1/4". It is 
the same 1.75 diameter at the parting board, 5° draft.

>Thanks for the flask size drawings; do I need to put the 2" holes in the
>parting board?
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Yes.

> Also I have the Freeman locaters on order,
>these will still be used, correct? And am I safe to assume they need to be
>placed in side the dotted line?
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Since Rick has stepped up to using real flasks you really don't need the 
Freeman locators. The 2" holes on each end are clearance for a piece of 
angle iron and this fits in a guide to allow the cope and drag flasks to 
re realigned after the pattern board is removed. Lets hope they are in 
good shape and are straight! It won't hurt a thing to add the mold lock 
buttons if you like, and yes they will need to fall inside the dashed 
line. Glue them in with 2 part epoxy.

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>>Hey I noticed you chucked one end of your block in a 4 jaw chuck. How
>>did you assure that the center of rotation was dead on the parting
>>centerline? 
>>The two pieces that made up the blank were the same size, so I just centered
>>the blank in the chuck.
>>
Tell us more about this. How did you accurately center this? Because of 
the huge square corners there is no indicator that will back out of the 
way enough to allow the square corner to go by to indicate the flat on 
the other side. Did you just use a scale and some reference on your lathe?


>>There were actually three steps, the first to make it round. The second to
>>turn the part around and put the round part in the three jaw chuck, and
>>center drill it. At this point the core print end was machined. The third
>>step the part was turned around again, indicated in and the piston end was
>>turned to size and length.
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Interesting method. This lets you finish the crown end, eliminating any 
hand finish work where it was chucked. I just made my block 2 or 3" too 
long and chucked it in the 4 jaw and turned the block round up to the 
chuck jaw. Then turned core print and pattern in one setup (pattern on 
the left, core print on the right. Last I rotate the carriage around to 
the 5° and part it off as deep as I can on 5° draft. The last inch or so 
I cut with a coping saw and hand finish the end.
How'd you like turning basswood? Sure makes some wicked birdnests as you 
approach a shoulder doesn't it! The first ones I did were in basswood. 
The last two I've done in poplar and this is some great turning wood. No 
birdnests and excellent finish. A little strip sanding both directions 
of rotation with 220 paper and it's smooth as glass.

>>One thing I did find out pretty quickly is the blank would not clear the
>>cross slide of my 13" tool room lathe. So my first cuts had to be deep
>>enough to make it clear.
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Yes I had the same problem with the huge block of wood to make the 
Stickney funnel. Had to make an offset tool that hung way left of the 
carriage to rough the part enough so the carriage would go under.

>>Oh goodness it is a heavy beast! I will HAVE to put it on wheels despite
>>it originally being a skid mount. I simply have no way to move it around
>>otherwise. Hopefully all that mass will make a slow smooth running
>>engine. I have yet to see one at a show so have no clue how they run....
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>Rob Skinner has a couple of large engines that are on skids, I know he shows
>then because I have seen pictures. Maybe he can tell us how he loads and
>unloads them. Rob are you there?
>
>It would be fun to see the progress; you are taking pictures aren't you?
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Unfortunately I have not documented this engine too well. A lot of the 
engine was in boxes when I bought it and my intention was to just put it 
back together and mechanically restore it later when I got some other 
project done. But to make this go together, that had to be fixed, then 
something else, etc., etc. 6 months later I've nearly done the whole 
thing. I just didn't take the time to pick up the camera and take many 
pictures. Sigh...
Curt

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