[SEL] Re: Alamo piston pattern update

[Curt]

Dave Otto wrote:

>Hi Curt
>
>Thanks for the gate and riser tutorial; A couple more questions, the part
>called the sprue down button is located on the cope side of parting board,
>correct? What is its purpose? Will this be opened up to create the opening
>to pour into?
>  
>
Dave,
This is one of the items I add because the books and the old foundry man 
tells me I should. Truthfully I really don't understand why one can't 
just pour direct in the riser which is open on top. Maybe Rick can 
elaborate. I know one of the small Stickney patterns I made last year 
has a simple riser and gate and the pour is straight into the riser. The 
local foundry instructed me to do it that way. Maybe this only works on 
small parts.....
Once rammed I understand the proceedure is to carve out a funnel in the 
green sand just over this button and to punch a small diameter sprue 
straight down into the top of this button. The metal then flows across 
to the riser, thru the gate, and into the mold.

>>The riser on the cope side is 1 3/4" diameter at the parting board.
>>    
>>
>
>Don't you mean drag side? The cope side is 5" or am I missing something
>here?
>  
>
I meant the cope side. Yes the cope side of this flask is 5" tall. 
Incidentally the drag side is 4" tall on this flask set. So the riser is 
1.75" where it hooks on the top of the parting board and tapers to a 
smaller diameter in its' 5" height. The taper is roughly a 1/4"/ft. taper.

>I'm still waiting to find out what size to make the parting board? What size
>did you settle on?
>  
>
The board wound up being 32 x 12 I think! Huge board and way overkill 
for your Falk piston. I have offered to put the flask dimensions on CAD 
and these drawings could be on the Tod Works site for reference. I'm 
supposed to get flask dims for this Herc pattern I'm working on now and 
since your Falk pattern is only about 2" longer maybe this same flask 
will work for it. If so I'll email you the drawing of it today.

>I will let you know how the pattern splitting operation works out. I'm going
>to wait until I'm ready to mount it on the board to lessen the chance of
>warping or splitting of the wood. It is nice and dry but you never know.
>
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? I gave up having sucess and ultimately made a tool that the 
3 jaw chuck could hold and this tool is screwed to the end of the block 
right on centerline. Even so, with the new tool I was off about .030 on 
this last pattern (the Herc) I made over the weekend. I am going to have 
to mill a little off one side and build up a little on the other to 
compensate. Obviously I've still got work to do making a better tool.

> 
>
>The Alamo is a way cool engine; it looks like a heavy beast for the
>horsepower.
>
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....

> The vertical flyball governor is also a nice feature.
>
Yes the 3 ball vertical governor and the walking beam that operates the 
exhaust valve, ignitor, and fuel saver are the neat features of this 
engine.

> Do you
>have all the parts or will there be more pattern making and casting work?
>  
>
The engine was missing only 1 part, the latchout arm. With pictures Edd 
Payne in Oz sent I was able to make a pattern and Rick cast it. That was 
a tricky bit of machining, but it has been done several months now. I am 
now waiting on a time slot with a local machineshop to bore the cylinder 
on a Cinn Milcron horizontal boring mill to clean up the cylinder. After 
that the fixture to pour the mains can be inserted in the clean and 
straight bore and the mains poured. Once Rick casts the new piston I can 
machine that and it will be assembly time. I've already rebuilt 
everything else like valve cages, made oversize valve stems, rebuild the 
water pump, made all new screws and studs, bushed and bored the conn. 
rod, etc. I'm kind of at a standstill 'till I get the boring work done.

See ya,
Curt

>Regards,
>
>Dave
>
>
>Dave Otto
>Boise, Id
>USA
>Dotto at velocitus.net
>http://community.webshots.com/user/otto1960
>
>
>
>
>
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>  
>