Injection Molding

Gallery of projects completed with MeshCAM

Injection Molding

Postby Scott » Tue Nov 01, 2011 4:41 am

I finally got around to looking at Roberts casting links on the blog. I thought I would share my recent, loosely related, adventures. I made an injection molder earlier this year and I have been making molds with MeshCam and making a few items.

My raw materials for molding come straight out of the recycling bin. Some is even saved from the garbage because my recycling company does not accept polypropylene.

freeze_part.jpg
Some copies of a Lego part for my kids
freeze_part.jpg (40.5 KiB) Viewed 4460 times


hex.jpg
Hex bug saddles for Lego guys that I downloaded from Thingiverse
hex.jpg (48.16 KiB) Viewed 4460 times


coin_part.jpg
Some coins I was experimenting with
coin_part.jpg (34.51 KiB) Viewed 4460 times


More items I have made and more information about the process is available on my web page:
Home Plastic Injection Molding

All of the items on the linked page were made using MeshCam. Some imported as STL files and some as grayscale images.

Scott
Scott
 
Posts: 19
Joined: Fri Nov 19, 2010 6:12 am
Location: Oakdale, MN

Re: Injection Molding

Postby Randy » Thu Nov 03, 2011 11:18 pm

That is really cool, Scott. Is the process predictable enough that you can compensate for material shrinkage when you machine the molds?

Randy
All opinions in this post are mine alone. I am not a MeshCAM employee, nor do I speak for MeshCAM. I do not have a financial interest in MeshCAM. Professional engineer on closed course, your mileage may vary. :ugeek:
Randy
 
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Location: North Texas, USA

Re: Injection Molding

Postby Scott » Fri Nov 04, 2011 6:12 am

I don't really have a good feel for how predictable the shrinkage is. I have not been too concerned with the nityy gritty tolerances on the parts that I have made so far.

I have noticed that there is a difference between materials though. PETE does not shrink much at all, polyethylene (HDPE/LDPE) shrinks a lot and polypropylene seems to be in the middle somewhere.

Out of curiosity I did a quick checked onthe diameter of the polypropylene coins, they all come out about the .015 undersized, on a 1.2 inch dimension, and they were all roughly the same size (about +/- .003).

Scott
Scott
 
Posts: 19
Joined: Fri Nov 19, 2010 6:12 am
Location: Oakdale, MN

Re: Injection Molding

Postby boltz » Fri Nov 04, 2011 3:38 pm

It looks like you have a good command of Meshcam for 2.5D milling. Did you figure out any tricks along the way?

-Jim Hart
boltz
 
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Location: Minneapolis, MN

Re: Injection Molding

Postby Scott » Thu Nov 10, 2011 8:08 am

Sorry, I don't have any good MeshCam tricks... I usually keep the milling pretty simple.

Scott
Scott
 
Posts: 19
Joined: Fri Nov 19, 2010 6:12 am
Location: Oakdale, MN


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