Injection Molder

Just some updates on the Boy molder and progress, the heater PID controllers had to be installed to get the machine running.

I purchased 3 of these PID controllers and Ben the genius was able to figure out the wiring and install them in the machine.

We then got Buzz to laser cut a frame to hold the controllers in place, and then went on to testing the machine.

We found that for some reason only 1 of the heaters was working of the 3. After a few hours of trying to figure out why and checking wiring Ben found that the issue was infact the 3 phase plug socket. The wiring was wrong and dangerous inside the socket.

We tried another socket and it all heated correctly.

Photos below

Some machine info

Manufacturer: Dr Boy
Model: 15 S
Injection Molding Machine
• Year 1986
• Clamping force 15tonne
• Opening 200
• Mould height 200.00 mm
• Injection 30g
• Distance between tie bars 254 mm
• Power 8,7
• Screw diameter 24mm (30gr HP)
• Mold height 200mm
• Opening the mold 200mm

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Next up I have to find a 30amp 3 phase plug, we can then plug in and test all features of the machine and produce some plastic parts with the temporary mold in the machine.

If anyone has a plug please give me a shout.

I would like to get as many people involved and interested in this machine, so if your interested in helping and using it let me know. If your interested in making a side project associated with it please feel free to get stuck in. Below are some things that will have to be built if you think you have time and skills to make them let me know.

A small steel hopper will need to be made with a clear acrylic lid to stop dirt getting in like the one attached below

A stainless steel bar magnetic bar like the one attached is placed in the hopper to catch any stray metal parts from entering the machine. It sits in the plastic inside of the hopper and doesn’t need to be as complicated as the picture attached, but it obviously shouldn’t be able to enter the machine itself or have loose parts.

Finally at the moment the machine will run for atleast 30 minutes before the hydraulics heat up and it will have to cool. We use a more industrial version of this water cooling tower in work, however this smaller diy cooling tower will work great, they really dont need to be that big. A feed can be take off this for cooling molds in the future also.

All of these are very simple and can be made from scrap lying around.


This tower can be placed outside and garden hose fed in.

Just to give people an idea of what can be done with the machine. The plan is to take old molds machine out pockets in them, and placing interchangeable inserts for people to produce parts.

This means you dont make a mold each time, just an insert. as shown in the image attached. These inserts can also be printed but can be expensive.

Inserts can be bought and shipped from China for cheap.
Sliding inserts can also be created but more expensive and complicated.

The cnc in the metal shop should be good enough to machine aluminium molds for parts.

I will get an old mold machine a pocket for the insert to fit into (hopefully with huld) and then have dimensions set out for those wanting to make insert for the mold.

So good. So exciting!

You know 3d hubs are CNCing molds now.

I worked out this is about $700 AUD for the milling.

I’ve only got 10a plugs. You can get them on ebay pretty cheap.

I’d advise caution when using the machine and playing with wiring, as those outlets aren’t RCD protected and will not hesitate to mess you up real good.

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Off-topic, but are there issues with using RCDs on 3phase in this sort of environment? Is it worth installing a big one at the board, or if sufficiently rated ones are cost-prohibitive, perhaps just a 3phase breaker box with RCD to put in-line with any gear that’s being opened up and worked on - by the looks of it on ebay such a thing might be a few hundred.
I am biased - I was converted to RCDism after a few nowhere-near-death experiences in my youth :slight_smile:

They’re not really that cost prohibitive but at the same time anyone who isn’t licensed and trained really shouldn’t be playing with mains electricity in the first place. None of our 3 phase machines are likely to electrocute anyone unless they’re touching things they shouldn’t be.

Everything single phase at the space is RCD protected as those are usually handheld devices and things that are more liable to be dropped in the bathtub for example.

Have a chat with Ben hes very qualified. Cheers for the link for the plug il look into that now. Ye the machine spec is above so if you want to machine anything make sure it fits between the platen and tie-bars. There is also opertunites for casting aluminum blocks and machining them in house with the cnc table.
I should be able to produce some parts next tuesday if I get this plug

Sucess myself and Ben got the first few parts out of the injection molder, all functions were tested and it looks like everything is working great. Setting the machine up is what takes time adjusting the plastic injection volume and cooling time. Once done the machine will run basically unattended and is capable of producing 100,000s or even millions of parts. Attached are some pictures and videos. Big thanks to @Thermoelectric for sorting out the sockets close to the lathes, it makes our job a lot easier!

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Lincoln is possibly interested in building the hopper for it, I will probably get started on the cooling system for the hydraulics. Hopefully we will get some molds cleaned up and machined for people to create inserts. If your interested in this please get in contact and feel free to chat to me about it down there.

Video here


Awesome work guys

Nicely done, although it’s a bit difficult to figure out what’s going on with the camera at all kinds of unusual angles.

Might be better to stick to a landscape orientation. :slight_smile:

Cheers guys, ye the angles a bit wonky! Its just to show a cycle, when I make the next mold I will probably have a night displaying and trying to answer questions. Once set up it worked like a charm and would pop out perfect parts in a matter of seconds.

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Ok so the latest on the molder is that im looking into getting some carbide 12mm flute bits to cut the pockets in the mold. Once this is done, people can start working to the template size to make an insert and produce parts. Big thanks to @Svenska for his help so far with machining, we will hopefully have another shot at it soon. Attached you can see wherre we started pocketing

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So myself and @lincolnbphillips001 took a swing at the hopper upgrade and the result tutned out really good. Stainless is tricky but for what we need it for it going to work great