View Full Version : New Mold Maker

09-08-2006, 02:18 PM
Hi all,

I just started work at a plastics molding company so thought I'd share some of our latest work. I've included pictures of my first project... I spent the first day at my new job designing breasts!

First picture is after the first roughing pass. Next picture is after the final finishing. The mold had vacuum channels milled in the back and pass through holes done by hand. The mold was then mounted to a cooling plate and we formed 10,000 swimsuit hangers the next day. Customer was happy.

09-08-2006, 04:59 PM
Way cool !
You do some really good programing for a days time.
Looks great!

09-08-2006, 05:03 PM
Way to go bud....seems you have a feel for the job :) Way cool moulds there :thumbsup:

09-09-2006, 09:35 AM
Very nice. To get the final finish, what tool and stopover is used? Is the machined finish used for molding, or is the mold polished first?

09-09-2006, 10:41 AM
Final finish pass was with TiN coated 1" & 1/4" ball end mills running at 20ipm, 2500rpm at 2% stepover. It took nearly 48 hrs for the whole program to run but the end result was worth it.
The mold was then given some minor sanding to clear up some rough spots around the strap notches in the shoulders and then put into the former.
We did have some problems with warping after we took the mold off the mill. We started out with a 16" x 40" x 3" block and it must have had some internal stresses because the entire back section of the mold bowed when we unscrewed it from the jig. Luckily this didnt matter as the whole thing was then screwed to the cooling plate - 20" x 50" x 1/2", but it was interesting to see nevertheless. Some thought it was from heat buildup during machining but at those feed rates, under flood cooling the entire time, there was no heat buildup at all.

Fun Stuff.

09-10-2006, 09:50 PM
Nice job!
However, I'll bet the mold warp after machining was just the internal stress relieving of the alum plate.

Taking 0.100-0.250" off the backside first will help reduce
the tweak after cavity machining.

If possible, in the future, leave 1/4" fat all the way around and put it outside in the sun for a week, or a month, is best. A poor man's stress relieve, else pay to have it done at a heat treating company.

Good luck,

09-10-2006, 10:53 PM
I would probably still be hand polishing high points on the mold!!!

09-11-2006, 01:25 PM
The customer rejected a few earlier versions of the design because the drafter based the dimensions on his wife... The mannequin looked fine to him but the customer wanted B size, not DD's!

09-11-2006, 02:56 PM
I would probably still be hand polishing high points on the mold!!!