Technical Sand cast cowl steering blister

Hi everyone, I've been casting parts for awhile now, mostly motorcycle parts for friends on the side. I dig cowl steering and am going to run it on my 29 roadster project. I wanted to design and cast something for a "blister" to make the pitman arm look a little more integrated to the cowl. I have the luxury of having access to 3-D cad and 3-D printer so this is the model or "master" that I designed.


There are several postings on here how guys have cast various components so I won't go into intricate detail on the process itself but here are a few shots just to see the basics.

This is one half of the mold, note the funky parting line and the angle of the master. Proper drafting and orientation of the part is necessary in order to pull it from the sand.

Here is the other half, the white stuff is talcum powder which prevents the part and sand from sticking to the other half.


Here is a shot of the mold filled and setting up. I use petrobond sand as opposed to green sand as it gives better detail in my opinion.

Here is the part removed from the sand after about 20 minutes. Note the attachment of the sprue and riser. You basically fill the sprue with the molten aluminum until you see it fill up the riser. These features allow the aluminum a place to draw material from as the part starts to "setup" and shrink.

Above is a shot of the "master" or "pattern" along with parts that are "as cast" and polished followed by a few beauty shots of the finished part with the center removed.



The following shots are of it mocked up on the car. I spray bombed the pitman arm and shaft just to show contrast.



So that's pretty much it in a nut shell. If anyone has questions regarding the casting process or anything else I would be glad to fill you in!

 

nicely done, I do lost foam casting, play around with it. I made a clam shell the size of a soup can so I have a good head pressure on mold. I made it out of 3" pipe and a hinge and it has 2 handles, one on each half. when I pour through it. I hold it together with a radiator style clamp, when poured and set for a few minutes, I take the handle and break the whole thing off the sprue, then I can loosen clamp and open and drop out the nice alum plug for remelting later. Its a lot easier. sand casting I guess you can reuse your cans

 

Unique part for sure,like it.

 

Nice work.
I've been wanting to try out some sand casting. Gotta get to it.

 

Very nice ,

 

(.)(.)'s

 

That is REAL nice!!!

 

We did and casting in high school metal shop. It was a fun experience.

 

That's awesome. Great job.

 

by chance did you cast your wind shield frame?

 

The windshield frame is a Sellers piece that I bought from Pat on here.

 

For those interested in trying some casting, petrobond is an oil based sand and gives great detail. The biggest downside of using it is that the smoke generated smells like a tire fire in the neighborhood.

 

Great work.

 

That is too cool!

 

Nice work!....How about some pics of the rest of the cowl steering setup to show how it all goes together?

 

Great looking part! Thanks for sharing the project with us!

 

Great work!

 

YES, it is !!!

 

Heck yeah!

That's a neat part.

Rich

 

Love it, right nice bit of kit that. That 3D printer makes life a lot easier making the master I would think. Hmm, something else to go on the Christmas list .......


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>>the white stuff is talcum powder...

Of course it is.....

 

Hey Fourspd
Pretty cool stuff, have you ever looked in the ' Rubber Plaster Mold ' casting process as it is like lost wax but no wax
You have two female plaster mold half's glued together, and that is it and your finish is almost as nice as lost wax investment casting

DND

 

Very unique piece,I would imagine you will get a few PM's about having a few made. HRP

 

I am using the mopar cowl steering setup similar to how Ratty55 and Dreadman did theirs, here is Ratty55's link
http://www.jalopyjournal.com/forum/threads/my-mopar-cowl-steering-inspired-by-dreadman.305256/
Right now the steering system is mounted in the car but here are a few pics of what I can show as of now.


As I said nothing really new here, the mopar setup has been done and covered in the past, however I should mention that the location of the pitman shaft/arm exiting the cowl is exactly where I wanted it and the angle of the 18" steering wheel is very comfortable. Here is another pic of the finished blister centered and mocked up on the cowl.

The pitman arm length is 7" center to center which matches the length of the steering arm. The steering link is parallel to the frame rail as seen here.

 

BTW thanks to everyone and their kind replies. Mostly everything I've learned about hot rods over the last 10 years has been due to this website, the people who run it and the great fabricators who share their talents. Thanks to all.

 

The pitman arm fits the blister perfectly!....very well engineered!

 

That is a very neat process since you are allowed to create features that would otherwise trap the part in the mold. The downside is the plaster is good for one shot only whereas the sand in sand casting is reusable indefinitely. With petrobond it only requires re-oiling also known as mulling after many uses, basically if it passes the squeeze test where you pick up a clump squeeze it in your fist and it holds together it is fine.

 

That is so cool and looks like a fun hobby. Thanks forgiving me something to try and do before I die.

 

awesome! if you decide to make another one pm me!