today's casting

[sasquatch]

Nice work Dave, looking great!!

[dallen]

I did a write up on the casting process for another forum that I belong to, and casted the same part as the subject. heres a photo of it, after I did a bunch of whittling on the pattern to thin it down some, I'm actually wishing that I had of used the scroll saw I borrowed for cutting the wax and just of left it with straight sides no wider then it is. anyway enough rambling heres the photo's


I put in a big super thick runner to use as a shrink bob to stop the shrink spots that showed up on the first one

[dallen]

didn't have a lot to do today so I started on the knurler that I ask for a drawing of, the pattern is made from some PVC 12 inch pipe that I had a very short piece of that I heated in the oven till it was soft then set a 8" bison chuck and some other things on top of to flatten it out.

Pattern, this thing gave me a heck of a time trying to get the slot to pull clean as you will see in the next photo

Casting, the finish on this is just amazing, I milled the two straight sides so they should be good to go for the next set which is to mill the slot and cut the bore in it. Hope to actually make the pattern so that I can put in a core and not have to bore the hole, but one step at a time.


DA

[doubleboost]

Nice work
Every time you do a casting you learn something new
Good finish on the aluminium

[dallen]

John your right there on the everytime you learn something, sometimes I relearn that I don't know near enough. I just wish that one end of the slot had not of pulled off leaving that ugly filled in spot. Now for the pattern for the frame.

DA

[doubleboost]

I use oil based sand for detail work (petrobond) backed up with green sand
Are you giving the pattern a good rapping before you draw it
John

[dallen]

yea the slot was too tight, not enough draft, anyway it cleaned up nice. oil bonded sand is all I use due to water bonded sand dries out faster then I can add water to it in the summer here and in the winter unless your inside well I guess you have the same problems. I do all my castings aluminum Copper based, and cast iron in homemade petrobond, just makes it easier on me.



DA