Critique my patterns, please

[chucketn]

(08-28-2013, 07:39 PM)dallen Wrote: when you put your photos in photobucket if you left click where it says IMG in the square that says links to share your photos

will show up here like this




the first thing I would do is the dividing head is split it the same way John did his, your going to need draft on all the sides that aren't round so that when the pattern starts to be lifted it will clear the sand, your going to need some wood filler or bondo the patterns have to be smooth or they will be hard to pull.

look at this pattern I did. draft on this pattern was cut with a tapered endmill that had one degree of taper, the pattern has a slick finish from the paint on it and the sand rams up on it so hard I have a tough time getting it back out of the mold.


if possible use a good hard tight grain wood like maple. also follow the rule that if it gets machined add and eight inch to the measurement for machining nothing worse then doing the pattern making the pour and finding out that the things too short.

use colors that show up better in the photos it will make the patterns easier to look at also the bolt holes will have to be filled in.

also see if you can get that book I mentioned.
DA

Thanks for an instructive critique, dallen. I will work on adding draft to the patterns. I am aware that it is needed. The steady rest should be split vertically? and the draft should be toward the center, right?
What about the base I added to the DH? That was needed to mount it to my cross slide. I will add another base to mount it on the mill. Still split the DH like Doubleboost did?

Chuck