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Foundry questions (kind of long)

72bwhite

Titanium
Joined
Sep 26, 2012
Location
California, Ventura county
No need to go all wild with 3d printing you can use your original part as a mold
or use it to make a negativity mold. and then mold a pattern from that
There is a guy on this site that does quite a bit of those kinds of parts mostly for fire engine restoration.
Metalcasting forums
not really that bad if you know what you are doing
 
No need to go all wild with 3d printing you can use your original part as a mold
or use it to make a negativity mold. and then mold a pattern from that

Yeah, I suggested that to him in an earlier post. :)

Here's a pattern I duped a while back, to core a new version to reduce weight.

Old pattern:

smt_patterndupe1.jpg


smt_patterndupe4.jpg


Both sides done:

smt_patterndupe5.jpg


skipping some steps including a pass through the widebelt sander after pouring the repro parts:

smt_patterndupe11.jpg


New patterns mounted in new matchboard, and machined through to eliminate cores, similar to what could be done with a MC case half. :)

smt_patterndupe18.jpg


Freemans makes a range of stable and low-shrink products for duplicating patterns, positives or negatives.

smt
 

PDW

Diamond
Joined
Jul 24, 2006
Location
Australia (Hobart)
The more I read the more I would like to have someone else take responsibility for designing the feed system so that if things don't work (which appears to be not uncommon) it gets to be redone at their expense, not mine.

I can absolutely guarantee you that that will not happen. If you make someone else bear the risk of failure, they will price the job accordingly so as to cover such costs based on their prior experience. It still might be a good way to go, but you won't be shifting the costs, merely the risk which will be priced accordingly.

I like pattern making. I'm quite bad at it, but the foundry turns out nice stuff for me anyway. However nothing I have ever done is as complex as what you are attempting.

PDW
 

lucky13dave

Aluminum
Joined
Jul 21, 2007
Location
Boston, MA; USofA
Hi Micheal,

If you are interested in getting some hands on experience in foundry, you might consider looking into adult extension courses at California College of the Arts. They have a bronze foundry, can do sand molds and lost wax, and it looks like they even have a 3-D printer (don't know if it prints wax.) My wife graduated from Mass College of Art and Design, majored in sculpture and spent most of her time in the foundry there. And the foundry at Mass art also poured aluminium, many of the foundries at these art schools do. CCA's program looks very similar to the one my wife was in, and people taking extension classes could get access to the shop. It may not be the most economical way to make your part, nor the fastest, but if I understand you correctly this project is more of a hobby than a business venture. If you have the time and inclination, it could be worthwhile.
 

Michael Moore

Titanium
Joined
Jun 4, 2004
Location
San Francisco, CA
I didn't see anything that looked promising on their continuing education curriculum. It made me think to check the TechShop here in SF but they don't list any foundry equipment. I could take classes in foundry arts at the Crucible in Oakland but the tuition is almost twice what it will cost to get enough wrought aluminum plate to machine a set of crankcases.

I've got a bike acquaintance who is a live-steam modeler, so I should give him a ring and see what kind of tutoring/facilities might be available. I know he casts small parts for the models, but some of those models get pretty large so there may be some friends of his or a club with knowledge and/or facilities.

I'm retired and I have no plans for going back to work, so it is definitely a hobby project. But the 2015 race season is not too far away so I might have to shoot for fairly immediate gratification.

thanks for the thought,
Michael
 

Doug

Diamond
Joined
Dec 16, 2002
Location
Pacific NW
We used Seacast for smaller parts than I envision the OP's to be. Ours were aluminum approximately 4" hollow cubes with thin walls with complicated interior/exterior detail.

They accepted a 3D CAD file of the finished part. A few suggestions were made about adding material around the to-be-machined bosses and fixturing pads, etc.

All told, the price was around $800 per piece about ten years ago in single quantity for two different pieces investment cast from 3D printed wax.

The casting process was a complete one stop deal. They got a CAD file, I got a perfect part ready for finish machining in return. I do recall some impatience on their part by my questioning whether the first part would be good, presumably they don't charge if the first part isn't good once they've accepted the job.
 

adama

Diamond
Joined
Dec 28, 2004
Location
uk
I am doing ever more vintage turn of the last century motor bike parts also. Due to the quality and costs of the castings we can get around here (by and large crap) its so far seams to be a no brainer to mill away one hell of a lot of material rather than just go castings. generally a lot of what we have made so far i can buy stock and machine from solid for less than the castings cost, let alone the machining costs it still needs. The CAM side is not too bad. But im very fluent in CAD.

Advatages of soild machining is the materials a way more known and trust-able alloy fee from voids and issues. Disadvantage is the complexity of the milling that some things require.
 








 
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