Manual injection molding machines

straight up it will depend on your skill and knowledge of injection molding and plastics

if you know moldmaking and mold processing, then you can handle it and understand its limitations

its not hard,
but if you are going into it expecting perfect results right away, then you will be disappointed.

there are a few good resources(blogs) on injection molding at home , read them, they talk about machines like this

also research on real injection molding
these things are mainly for prototyping or at diy at home kinda shit

>>1136861
Mfw all i want is to die cast aluminum parts without a 4 million dollar machine

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>>1136934
this + other.


like pic related

>>1136861

I built one for a school project. Had automated PID heating and automated injection ram. No cooling or ejection tho, and it was for plastic only.

>>1136943
I'm just looking for plastic and no spring ejecting molds. Do you have any samples of what you made using your machine.

>>1136861
https://www.youtube.com/watch?v=qtZv96ciFIU

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>>1136861
I've built manual moulders and cast injection moulds before.

My focus was on producing figures as cheaply as possible from shredded waste plastic (for science).

What I've learnt is that it's basically all about the moulds.

To get a professional finish you need to Mill mould from atleast aluminium (which I can't).

The good news is that the only real limitation of the small manual moulders is "shot size". So you could potentially produce professional results if your moulds are good enough (professionally made).

>>1137104
That's very interesting. Have you ever tried a 3d printed mold? I'm thinking about getting a SLA printer and injection molding machine, but I could get a taig cnc mill instead of the printer.

But if have to learn how to operate a mill

>>1137115
>Have you ever tried a 3d printed mold?

No. For my purpose the cost would be prohibitive.

I just want to make stuff for personal use, which doesn't require excessive hand finishing, from materials which are cheap and/or easily obtained - that I've built myself.

But I think Formlabs sell Resin for their Printers which can be used for small Injection Moulds.

So that's one potential route, the other I guess is CNC Milling.

When I revisit this I'm going to cast moulds from Aluminium or Brass - to free myself of the need to buy Resin for the moulds.

I thought something like
>cast two part plaster mould
>create male copies of each half from Investment Plaster
>Fire male copies in Kiln
>Pour Metal over them.
>????????????
>Profit???????

>>1137104
>Rogue Trader beakies
You're doing God's work, anon

>>1137126
How much did it take to build your own injection molder?

>>1137186
Mine's sort of like this one>>1137048

But as cheap a shit.

They're really simple. When it comes down to it they are basically just glorified hot glue guns built into a frame (and with more accurate temperature control).

I just used a length of Steel tube, with male threading on each end, and found a length of round steel bar stock which fit snuggley inside it. Screwed a Brass fitting to the tube for the Injection nozzle. Ground a hole in the side of the Tube near the top (to put plastic in through). Drilled a hole in the Steel bar, bolted a Steel handle to it. There's also a spring between the top of the tube and the handle to guide the bar straight down, and to lift it off the bottom once you're done injecting.

Then I attached it to a wooden frame and insulted it from the metal parts with ceramic fibre wool - so it doesn't catch fire.

I stuck an oven thermometer onto it and attached two long 500 watt Cartridge Heaters which are wired in parallel and controlled by a 1000 watt dimmer switch.

Moulds are clamped to the injection nozzle using a trolley jack. You need a lot of pressure clamping too - otherwise plastic will just piss out the top of your mould (in between it and the nozzle) rather than be forced into the mould cavity.

You also need a respirator, because plastic isn't dangerous (unless you burn it) but it is unpleasant. Best to do it in a shed or something -unless you don't mind your house smelling like Taiwan.

Do you think it's feasible to build a DIY CNC mill to mill moulds from aluminium with a high enough quality to make plastic models and figures?

>>1137250
The short answer is "yes", the long answer is "depending on what tools you have, your budget, and how complex your models would be"

>>1137222
What about plastic quality? Is it affected during the injection process?

>>1138050
No

I use Recycled Plastic and mouldings have the same colour and properties as the original plastic.

The only plastics I've used though are PP, HDPE and HIPS. I mostly use PP now because I have an infinite supply different coloured tub lids and I find it easiest.

Originally I would cut my Injection moulded stuff off its sprue then cut the sprue up and remould it a second time.

I don't do that anymore - there's a definite drop in colour and increase in brittleness after the second time.

So if you use waste plastic just use it the once, don't send it round and round again like I was doing - that's dumb.

>>1138200
Any idea on how to mix plastic colors?

>>1136861
Just buy a 3D printing pen and use some pepakura models as molds.

>>1138234
I'm looking to make some highly detailed figures, probably in parts. I looked at resin before but I'm not sure I have a good area to vent all the fumes from resin, and I need a nitrogen blanket and what not to keep it dry.

>>1138200
>I don't do that anymore - there's a definite drop in colour and increase in brittleness after the second time.
>So if you use waste plastic just use it the once, don't send it round and round again like I was doing - that's dumb.


as soon as you regrind and remelt plastic, you shorten the molecular chair making it shittier and shittier every time.
if you reuse those sprues, you can minimize scrap and plastic degradation

, but PP is a pretty easy plastic to process and doesnt require drying which is a big plus

ontario bro?

>>1138050

if you have to proper temperature and low resonance time then it will be fine

if you over heat it or let it cook in the barrel, it will be trash

>>1137115
>Have you ever tried a 3d printed mold?
I'm thinking about getting a SLA printer and injection molding machine

dont bother. they will be shit, require a lot of post processing to make it usable, the layer lines will make it shit, it will be a low yielding mold, slow cycle times, and you will still need to make the rest of the mold out of at least aluminium


>>1138232
find the colour you want
mix it with white

>>1138465
>find the colour you want
>mix it with white
I've looked at some mixers but they're large industrial ones. I just need small batches. How can I mix the color without one of those industrial mixers? And wouldnt it be better to use natural plastic rather than one with white already mixed in?

>>1138465
>if you have to proper temperature and low resonance time then it will be fine
>if you over heat it or let it cook in the barrel, it will be trash
So the plastic should be used as soon as it's the right temp? What about cooling in the mold? Is it better to have active cooling, like water running through the mold, or is letting it cool by air fine?

>>1138465
>dont bother. they will be shit, require a lot of post processing to make it usable, the layer lines will make it shit, it will be a low yielding mold, slow cycle times, and you will still need to make the rest of the mold out of at least aluminium
I was looking at the formlabs form 2. The prints look pretty high quality with very smooth surfaces. Why would the layer lines still make a big impact on a molded part?

>>1138465
>ontario bro?

Nah, British

> but PP is a pretty easy plastic to process and doesnt require drying which is a big plus

I never understand why it isn't used more as 3D printing filament. Although couldn't manage to Thermoform sheets of it - so maybe it's just particularly well suited to Injection Moulding.

Anyway I want to look at extruding filament sometime so I'll probably have a go with PP and maybe HDPE.

>>1138576
>What about cooling in the mold? Is it better to have active cooling, like water running through the mold, or is letting it cool by air fine?

For the small manual moulders you're overthinking it. If the mould is metal then it's a heatsink anyway. And manual processing isn't like fully automated Injection moulding were you're producing constantly.

As an example I have to

>bolt two mould halves together
>clamp the mould to the moulder with trolley jack
>Inject
>release pressure from jack
>unscrew and remove bolts from mould
>open mould and remove moulding
>repeat, stopping occasionally to retract the plunger and add more plastic

In short I'm lucky if I can produce one moulding every few minutes - so the mould has more than enough time between cycles to cool down.

> I looked at resin before

What are you making? Does it have articulation and lots of small moving parts like an action figure or toy?

If it doesn't need to be strong and wear resistant most the time Resin is good enough IMO.

>>1138576
>mixers, natural vs white
now, since yours wont have an injection screw, colour blending might not work aswell, but i can contaminate the next 5 shots of white plastic with a pinch (5 pellets) of coloured plastic

>white/natural

what ever is cheaper or easiest to get
im pretty sure our natural plastic which get colour mixed are natural and has a white colour
some are a little tan/off white, but most of them seem to be a semi translucent white

when parts call specifically white, they have much deeper white pigment, so it doesnt have a translucent feel

>>1138576
>So the plastic should be used as soon as it's the right temp?

Ideally, the longer it cooks, the more the chains break down and it gets degraded, and will make bad parts that flash out or burn

>What about cooling in the mold?

active cooling would help reduce cycle time , but from what >>1138742 is saying, you should have more than enough time for it to cool before the next shot it ready. depending on the plastic being used and the part being made, cooling time is about reducing warpage/shrinkage in the part. the part has to cool inside the mold so it can keep its shape. in injection molding we say "cooling", its really more relative term because we "cool" the molds to much above ambioent temp. for easy plastics like HDPE or PP, they dont require much cooling, but for engineering plastics like nylon or abs, they have tendencies to warp


>>1138576
>Why would the layer lines still make a big impact on a molded part?

more so on a FDM, but layer lines create uneven suirface finishes and can create undercuts, making removal of the part difficult,
but because of the pressures involved, it will not last as long

but this related back to the cooling time. plastic retains heat 30x more than any metal, so with the 3d printed molds you see online, the cycle time is long as shit, and they dont get as many usable parts as with an aluminium mold

but dont let me discourage you, i am less inclined towards now a days

here are some helpful links about injection molding at home and 3dp molds

https://www.protolabs.com/blog/why-3d-printed-molds-arent-everything-theyre-cracked-up-to-be/

https://formlabs.com/blog/3d-printing-for-injection-molding/

http://www.instructables.com/id/Home-Plastic-Injection-Molding-with-an-Epoxy-Mold/

http://www.scorchworks.com/Injection_molding/injection_molding.html

>>1138742
>What are you making? Does it have articulation and lots of small moving parts like an action figure or toy?
>If it doesn't need to be strong and wear resistant most the time Resin is good enough IMO.

I'd say action figures, mini figs/statues, and statues. Eventually I think I'll get a setup for resin casting for statues, because of a volume advantage, but right now I'd say injection molding is better suited for me. And like I mentioned I don't have a good way to vent resin fumes and keep the stuff dry. I'll be setting up in my basement, so minimal fumes is ideal.

>>1138789
>now, since yours wont have an injection screw, colour blending might not work aswell, but i can contaminate the next 5 shots of white plastic with a pinch (5 pellets) of coloured plastic
Do you get a nice even color by doing this? I recall seeing some sort of mini plastic mixer somewhere but I've forgotten where it was, it was quite expensive though at over $3000.

>>1138793
I guess a cnc mill is the best option then. It's at least a lower cost than an SLA printer so that's nice.

>>1138828
>mini plastic mixer

those dont really melt, they just do an automated mix ratio, more for shit that is continuously running, other shit is just mixed like cooking, into one big bowl, but because injection units have screws, and its usually 5 shots from the back to the front of the barrel, so theres more opportunity to mix

the colour comes out beautiful

>>1138859
>the colour comes out beautiful
So you don't have to mix your thing at all? How does the color get distributed. And I'm assuming you use master batch coloring pellets and just drop some in

>>1138863
sorry man, i dont use these personally, the other anon does

they have units that attach to a drillpress

>>1136934
Die cast aluminum? You can do that at home easyer than plastic injection.
Just a furnace, mold and mold release.

>>1136939
That's fucking rad

How much pressure can manual machines exert onto the plastic?

>>1139028
As much as you design it for. Hell, you could feasibly have the same force of a commercial press if you had enough gears and shit between you and the plates. You have to have a specific machine in mind to know how much pressure that one can exert.

>>1139033
The pre-made and assembled ones all seem to have the same lever design going on.

Like the one in the OP and this
https://www.micronanotools.com/collections/plastic-processing-equipments/products/manual-benchtop-injection-molding-machine-mim-200

>>1139028
>>1139028

Popular Mechanics 1970

https://books.google.co.uk/books?id=kdgDAAAAMBAJ&pg=PA184&dq=popular+mechanics+injection+molding&hl=en&sa=X&redir_esc=y#v=onepage&q=popular%20mechanics%20injection%20molding&f=false

>"...operated by a pipe handle lever which exerts pressure of some 2000 pounds per square inch on a vertical ram..."

Reading around 1200 psi seems to be the bare minimum to fill most moulds.

>>1139153
Is 2000psi enough? For a detailed mold.

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>>1139216

>>1139033
Probably just going to buy a premade one as I don't have any the means of welding metal or any serious metal work.

I'm also still looking for a reliable way of coloring plastic, which is important.

>>1139876
Dyes or stains work; I don't know the english terms but they're surface colourants.