Increasing the capacity of a Rabit 2/3 injection molding machine?

[Tenaja]

Considering the higher quality of the scans of my manual, you might consider migrating your extra pages into my file, instead...

The schematic on pg 47 with the timing diagram on pg 48 is something I added. When I got my machine, it had two timers on it that were supposed to cycle the ejector pin, but they did not work. I replaced them, and also added that circuit so the ejector pin would not run continuously when the machine stopped.

[JRR]

It turns out my machine is perhaps ten years older than the one covered in the manual. Most of the mechanical functions are identical, however the controller for my vintage machine is a digital logic (TTL logic - date about 1982/1983) based system, whereas the manual describes a machine that uses a 6809 CPU and a LCD type of display. My machine has simpler LED displays that show just numeric values (Temperature, number of cycles, etc.).
A quick question for those of you with CPU controlled machines - have you backed up the EPROM? The EPROM is a 2764 and can be easily read and stored or copied as a backup - highly recommended!!!
I would like to find the manual on the earlier machine like what I have, but I suspect this is a bit of a wild goose chase. My serial number is P300 by the way - I wonder if that is for Prototype? That may be wishful thinking though on my part.
My next project will be to get this controlled by an Arduino like device so the parameters can be set more easily. The suggestion was raised that I use more than one injection stroke in order to make products of greater than 2 grams, this may not be too difficult to accomplish using the Arduino or other controller.
I do see that the schematics show a company named CIRRUS REYNOLDS LTD. drew up the schematics, and perhaps they designed the electronics. I will see if they still exist (don't seem to) and have records going back that far. I would prefer to interface my controller to the existing electronics rather than make everything more from scratch. Of course I first will test the device using the controller I have to see if it performs correctly and learn how to use it. Should be a bit of fun!

[Tenaja]

If you are going to update, I would recommend a Raspberry Pi over the Arduino. More flexibility, fewer restrictions, and in the grand scheme of things, the same price.

Does your control look like this?
https://www.youtube.com/watch?v=BpyDre_IuVo

The machine is simple enough, I don't really see much benefit of my 6809 controller vs what I saw in that video. They just took two timers (mold closed time & mold open time), and a temperature control, and replaced them with a cpu.

The biggest benefit to going with a home-brew or PLC control is an easier implementation of the ejector time-out timer setup that I tacked on. In your case, you have a compelling reason to try...you might be able to get two shots to work. No guarantees, though. Unless you are doing it for entertainment, you are probably better off finding a larger machine.

What volumes are you trying to run? I have a few small machines that have much more capacity than the Rabit.

[JRR]

I've played with the Arduino and understand it, although I did buy a Raspberry Pi to try out and may as well try that. I was indeed looking for more control over the press cycles, in the hopes of making parts larger than the 2 gm ones the machine can currently run off.

I am actually only looking to do runs of a few hundred parts at most for the unit. This machine is overkill for that sort of thing, but the runs are probably too much for hand operated machines.

That video IS of my machine (same blemishes on the rods that show about 55 seconds in), although it was sold to the person I bought it from and they kept the water cooling machine.

What other machines are out there that may be more suited for parts up to about five square inches with runs of only a few hundred? I really bought the Rabit on a whim, so while I am interested in using it, I am also open to considering other options - like selling it to buy machines closer to what I need.

[Tenaja]

For just a few hundred, something like the Morgan Press is well suited. Sure, you have to stand there and pull parts, but setup time is so much faster, and the molds are super simple.

[JRR]

A few hundred for a Morgan press? Where on earth do you see that sort of pricing? The least I've ever seen them is around $1500USD or higher..

[Tenaja]

A few hundred parts are well suited to that machine.

For a few hundred bucks, you should have someone else run them. It's not worth the hassle.