Injection Machines Basic Specs Limitations

Firstly Dave is a Legend, full credit. I think I’ve watched every video, read every page. Also full credit to all the good people helping Dave.

In the interests of sharing, I’ve been researching manual / basic / DIY / homemade injection moulding machines to complete a 35gm to 70gm project.

I hope the info I share helps someone, the limiting factor of all these machines appears to be the shot size (Volume/Weight) that can be injected.

I’ve found these machines of interest:
A.B. Plastics AB 400M = 14grams
LNS Technologies 150A = 20grams
Galomb Inc MODEL-B100 = 1 cu. inch. (16 cm3) – aprox. 17g of PS by weight
Gingery = about 1/2 ounce (15 gm) of plastic
Medium Machinery (Air) = 2oz = 56.7 grams
CR Clarke 25H = 25 grams
Tekca rebuild = 8 cubic inch = 131 cubic cm = 124 grams of high density polyethylene
Travin Mini Moulder TP1 & TP2 = 21grams

As you can see most manual machines don’t do over appx 25grams, this is very small and light plastic part.

Can anyone tell me the shot size of any of Dave’s injection machines? I notice the shapes injected by Dave’s machines so far have been large/simple, could they inject for example a cellphone protector case with walls as thin as 1.5mm?

Also for anyone interested download the blueprints for Dave’s Injection Moulding Machine V1 , the physical properties of plastics info is great. Dave, do you have the data for ABS plastic?

Dave thank you for making the world a better place 🙂

something went wrong with my first try, or hit the wrong button.

Hi ‘win’.

The volume will be 180cm3, dia=26mm and a stroke of 340mm.
But that’s a volume of granulate.
Might only give you 90cm3, or even less??, of molten plastic.
I, more a less, based the volume on the biggest mould Dave had.
Until now my workflow was, fill it with shredded plastic, let it heat, compress and fill up again, etc….
The check on how much plastic comes out in one clean shot, let’s put it on the ‘to do’ list :).

regards Kees

Hi guys 🙂 How do you edit a previous post? I’d like to edit my first post with this info: Tekca rebuild device = 1.5″ dia x 5″ stroke (8 cu. inch./144cm3 ) = 4 cu. inch. molten shot = 65.5 cm3 = 62 grams of high density polyethylene

Calculator for volume to weight of plastic: http://www.aqua-calc.com/calculate/volume-to-weight Does anyone know of a calculator with more materials? The drop down box doesn’t let you choose and the search bar only accepts exact terms.

Hi Kees, Thanks for the volume info, I believe your calculations are correct I think I read somewhere that liquid shot size is appx half of granule volume. 90cm3 of liquid plastic should equal appx 85grams of high density polyethylene. That puts the Precious Plastics Injection machine at the top of the list for volume! I’m really excited about that 🙂

Hi Dave, thanks for that I look forward to the ABS info, I’d like to know your source of that info, it’s great! I’ll try and attach some specific gravity info I found for different types of plastic.

What kees said, ABS will add it on the list for V2.0, also thanks for the kind words!