Some background
Hi All:
Thank you for the kind words...it's nice to get some back pats for all the mind bending and labor that went into this tool, especially from those who understand all of what it takes to make things from scratch.
To answer some specific comments and questions:
wjr: Which fit line!!! Must be an optical illusion. Do I need to be embarrassed? You've got me worried now :<)
Pixman: Yeah, I remember when a well equipped toolroom in my area had a couple of Excello turret mills, a lathe, a couple of grinders, a saw and a radial drill, and maybe a Sparcatron sinker EDM or a Deckel pantograph.
When I started out, a really good toolmaker was a guy who was a whizz on the rotary table, or one who could blend in a free-form cavity with a pencil grinder after popping in the co-ordinates with a ball cutter using the DRO on the turret mill.
How times have changed!!
Davis in SC: Good observation: the mold will be rotated 90 degrees in operation so the slides run horizontally.
I do have pretty hefty ball detents under the slides to hold them back until the locks pick them up as the mold closes.
I've also got a microswitch under the ejector plate so the mold can't close until the ejector system is pulled all the way back.
I sure hope the molders remember to hook the microswitch into the press...if they don't it's going to be one helluvan expensive crunch, and there's no way to put effective safety pins in this mold.
Much hopping up and down was done to make them very aware of this; let's see how she goes.
Bruce: the tool went out to the molders today...I'll post pictures when I get sample shots back.
ions82: You learn to resist the calls to hurry when you're a toolmaker...pisses off the management at times, but it's way way cheaper not to screw it up in the first place.
Toolmaking is a lot different than production machining...you learn to make different trade offs, like programming to be kind to a cutting tool or a fragile workpiece rather than going hell-bent for cycle time optimisation, as you need to, to make money in production.
It can be a bit intimidating to punch the green button on an unproven program with a part in the vise that's got a hundred hours of work in it already, but by and large you get used to it.
And, as Greg points out; there's always the welder to fall back on.
In fact, I have a laser welder in my shop...best confidence builder money can buy!!
Fortunately I didn't need it on this build, but yes, sometimes you put a nice signature divot in your expensive mold insert and have to cry for a bit.
mthomure: I started the design of the mold when I started the design of the parts, so I knew exactly what I could and couldn't get away with by the time I was ready to model the tool in Solidworks.
There's probably a hundred odd design hours in the mold itself, with the hardest part making everything interchangeable without having to tear the whole mold apart for changeover.
If you've been around molds a bit, you'll see some unconventional things like mounting bolts visible from the parting faces of the mold...that's to allow changeover without having to pull the mold from the press.
It's a nuisance for the molder, but it saved the customer about 2/3 the cost of building individual tools for all twelve parts.
cnctoolcat: Yeah, I was a dentist for a brief moment in time (8 years actually), but I just couldn't resist making stuff for a living...building molds is way more fun than dentistry, at least for me.
Doug925: I haven't had a chance to calculate the hours yet, but I've been off and on this tool since last September when I started the design.
At a guess I'd say around a thousand hours, including design, making 40 odd electrodes, all the wire EDM, sinker EDM, fitting and polishing hours.
The CNC milling time was probably less than two weeks.
There are a lot of hidden things too...the assembled mold actually doesn't look like all that much, especially when you see it in person.
It's only 7" x 10" x 6" high, so it's pretty tiny, but it's got a bunch of hidden parts in the second stage ejection system that you will never see unless you pull it apart.
Antarctica: I'm pleased you like my site...most everyone who does websites for a living thinks it's awful...way too wordy and not snappily commercial, but I don't care.
Thanks for the compliment!!
HuFlungDung: Building molds for a quoted price is a really good way to lose your ass, but it's a lot of fun too.
A bit like making model airplanes when you were a kid, except you get paid for it.
I got my training from a crusty dutchman who apprenticed with Phillips in Holland back in the day.
He was a truly gifted toolmaker, and we used to sit around the breakfast table after the morning shift with a boxful of parts he was quoting on, and brainstorm how we were going to do them.
It was a priceless education, and I owe him a debt of gratitude.
Joe 788: Yeah my head hurt from time to time too!
Cheers
Marcus
Implant Mechanix – Design & Innovation - home
I've never been asked to make an injection mold, but I'd sure like to give it a whirl. But designing one, well, I don't know where to get the 'common sense' from to make it correctly.
