Honajector 1OZ Injection Molding Machine Restoration


The Honajector 1OZ injection molding machine after restoration

At Angeltone, we believe that using real vintage tools together with modern technology allows us
to make the best pickups possible, and this machine is a good example of this idea.

This machine was found in MN after a long search, and is actually part of a machine called a
Honajector Honajectablo. This was a machine designed to teach the fundamentals of blow molding
hollow thermoplastic things, like soft drink bottles or lighted Christmas Santa Claus porch statues. 

The 1OZ (at top) was used in this machine to melt the plastic before molding.
The 1OZ could also be used by itself to teach injection molding fundamentals to students.

The Honajectablo
 
The Honajector 1OZ itself - before restoration


Side view of the 1OZ


 I bought this machine unseen, and if I knew what condition it was in I probably wouldn't have bought it.
For example, the 1OZ's heating system did work...sort of. Two of the machine's three heaters worked,
but the original thermostat wouldn't turn on or off correctly, and the original mechanical thermometer
read 50 degrees F too hot. This meant setting the thermostat for 400F gave you 350F, maybe.
At least all of the parts I needed for converting it into an injection molding machine were included.


This is a photo of the original electromechanical thermostat and two of the three heaters.


Even worse, this plastic was found inside the original heater assembly during teardown.
If you look carefully, you can see at least two metal bolts buried in the plastic.
This caused bore damage to the plastic melting chamber in the heater assembly
which also needed to be fixed.

My friend Tony 'da manic machinist' visited one day, and I showed him my machine.
He said the machine was rebuildable... that is if I could find the parts.

The mechanical parts were as close as the local hardware store, but original electrical parts
were impossible to find. We finally decided to use modern technology to solve this problem.


New Cartridge Heater

After a search, I found the new heaters I needed on Ebay. However, the original electromechanical
thermostat was impossible to find. We then decided to use a modern 'PID' computer controlled
thermostat system used by craft beer brewers to control their brews. I found the system on Amazon
and Tony built the control box (the gray box at left in the photo).



The new PID controller system worked perfectly! It was Tony's idea to test the 1OZ outside to see
how well the controller would hold a set temperature with random temperature changes,
but I think he was really afraid of burning his garage down (LOL).

If you look at the original mechanical thermostat at right, you can see it reads 450F and the new
PID temperature controller at left is set for 400F. The green numbers on the PID are the set
temperature, and the red numbers are the 1OZ heater's actual temperature.

We then decided to see if it could actually still make a screwdriver with its original mold.
We hooked up a air compressor to the 1OZ's air cylinder, filled the plastic hopper at the top of the
heater with plastic, waited for the plastic to melt, loaded the mold into the clamp, turned on the air...
and in a minute had a nice new screwdriver. See for yourself...



The 1OZ all ready to mold, with three shades of plastic pellets for molding. The mold is shown inside
the clamp with the screwdriver blade sticking out at left


Test screwdrivers. Clear plastic molded first to test the machine,
blue, 'coke bottle' green and green

This was a collaborative effort, so I need to thank Scott in MN (who sold me the machine),
Tony 'da manic machinist' (who helped me deal with all its issues)
and my wife *who let me live* :)

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