Injection Molding with the PCNC?

by: Greg Jackson

Sneak Peak – Plastic Injection Molding Accessory
Here’s a preview of something I’ll bet nobody was expecting


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It’s an accessory for your PCNC mill which will make it into a plastic injection molding machine.  It simply clamps on to the spindle nose.  You use your machine vise to hold the mold.  There is a pressure feedback sensor that plugs into the accessory port on the operator console of the mill.  Cut the mold with the mill, attach the molding accessory, then mold a part.  Sweet.

No release date or price established yet.  Right now the product is in the process of moving from working prototype to production product.  It seemed like a cool idea at the time of inspiration, but once got into it we were pretty surprised at how well it actually worked.  As developments go, this one has seen relatively few roadblocks so far.  We expect to release this sometime in 2011.

Story Behind the Invention

There have been desktop injection molders available for years. They generally have just a few primary components:

  1. Heating chamber for plastic
  2. Ram, acting as piston in the heating chamber
  3. Vise to hold a mold
  4. Vertical motion system, able to deliver high force
  5. Rigid framework for all

When we looked the standard desktop molder, we realized that a PCNC mill already has items 3, 4, and 5.  All it needed was 1 and 2.  Standard desktop injection molders take a bit of skill to get the right combination of temperature, pressure and mold fill time for a good injection.  We developed a system using a sensor, the accessory input port, and the mill control, to automate all that in a repeatable fashion, once the right recipe is found.

The system works well and produces good moldings using many different types of plastics.  This is not going to put anyone into the production business, but it’s great for making a few parts, making a specialty product, or testing out a concept.

Out of the Left Field?

OK Tormach watchers, I know this product seems to come out of the blue.  But if you squint your eyes just a bit, or have a couple beers, you might see that is a method to our madness.  The Tormach touch probe, Duality Lathe, Tormach Speeder, CNC Scanner, and others of our unique accessories, they all have a common theme.  What they do is take advantage of the PCNC mill, using it as a foundation to extend the capability of the machine and provide greater range of functions to your shop.  For many PCNC owners, the mill is the most expensive tool in their shop.  What we’re trying to do is to allow people to leverage their investment, making it possible to do more for less.

Do you have an idea for a useful mill accessory?  Let us know, maybe we can help.  Whether we’re doing the development ourselves, or assisting as we have done with the Tormach Approved program, we like to see these crazy ideas come to come to life.

Greg Jackson

President

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Greg Jackson

About 

After nearly three decades of machine design, research, and development, Greg Jackson founded Tormach LLC, a premier manufacturer of affordable CNC mills and accessories. Since its inception in 2002, Tormach has grown from a garage business to a global operation based out of Waunakee, Wisconsin. Jackson holds both a BS and MS in Mechanical Engineering from the University of Wisconsin, Madison and has been awarded 4 US patents.

24 Responses to “Injection Molding with the PCNC?”

  1. Wow the Tormach is turning into a Transformer !!! I like to think of mine as Megatron. 8)

    Nice job Andy, looks very interesting. One thing I can’t see in the video is how the injector and mold match up. Is there some sort of o-ring seal insert that feeds into the mold ?

  2. John says:

    Awesome. I only have one problem with this video: Andy – what happened to the scruff!

  3. Andy G. Andy G. says:

    Haha. Little bit of time traveling going on here – Shot this movie in November.

  4. Colin K says:

    How much benefit does the control of the injection speed and pressure provide? Does it mean you easily knock out 50 perfect shots after dialing it in, versus say a 20% failure rate by hand?

  5. This is so awesome, it opens up a new window of R&D for me to do. I mean it could easily do 50-100pcs a year for what I would need.

  6. David Crissman says:

    Dear Greg and Andy:

    You guys at Tormach are the best. Great idea and great product..

  7. Dave Hultman says:

    Really cool, I want one… I was very impressed with your machines, facility and personal when I recently attended your Sprutcam training class, keep up the good work.

  8. Andy G. Andy G. says:

    Guys, Thanks for all the comments. I’m planning on bringing this to the Digital Machinist Workshop in June if you like to see in person:
    http://bbs.homeshopmachinist.net/forumdisplay.php?f=10

  9. Andy G. Andy G. says:

    No, Nothing like that. Just a metal nozzle that you position over the sprue hole. Works really nice.

  10. Andy G. Andy G. says:

    Basically, yeah – it lets you control two additional process variables that you can’t control with a hand activated ram. So you’re getting the same shot every time, more or less.

  11. Randy Hearn says:

    You guys continue to surprise me. I was actually about to write a check for a machine, but now may hold off. It looks like I may be able to make larger molds with the Tormach?

    Please tell me this will work on the 770 as well:)

  12. David Borden says:

    So freaking cool!! Man you guys are dreaming up some really awesome add ons!

    David

  13. Dave M says:

    Andy, after seeing this perhaps I should ask you (before I shell out a couple grand on the purchase of a different machine I’ve had my eye on) – any plans for adding an extruder head for a 3D printer attachment? You’ve already got the heater controller, just need an additional axis for a stepper driven extruder.

    Should I wait a while before purchasing one? :)

  14. Andy G. Andy G. says:

    Dave, we’ve thought a bit about this. But not much more than that at the moment. I have seem some cool homebrew plans, I think it was somewhere on the RepRao site. Also, some of low-cost printers on the market now look to be very capable. Which one are you looking at?

  15. Andy G. Andy G. says:

    The 770 version needs a few pieces resized around the heating chamber, but will share most of the parts otherwise. I think something might be available shortly after the 1100 version.

  16. david_f_knight says:

    Very, very cool!

    Is it too early to tell us what the maximum volume shot size will be?

  17. Dave M says:

    Andy, the 3D printer I’ve been looking at is the Ultimaker. They’re still ramping up for production so they aren’t available for order yet. Looks like a pretty capable machine with about an 8″ x 8″ build volume. There’s also the Up printer that’s about twice the cost, but has great output quality. The build volume on that is too small for some of the parts I’m looking at prototyping. I know there’s been talk on the Mach Yahoo Group about adding an extruder head to a cnc mill, but I haven’t seen anyone do it yet. I suppose my Series I PCNC1100 might be a little slow compared to how some of those little printers can move.

  18. Randy Hearn says:

    Thanks Andy.. I think you guys should start designing on the 770 and scale things up so we 770 owners get things first:)

    For the 3D printer I have already bought a RepRap and considered adding an extruder to the head of the 770. But due heating/cooling I figured it would just tie up the CNC. I plan to use the reprap to spit out first article prototypes while the 770 is cutting the actual prototypes. But if you get something working I am all ears, would probably need some sort of heated bed.

  19. Andy G. Andy G. says:

    Thanks David. Its about 1 oz. Maybe 1.5oz. I haven’t done a final measurement to confirm yet, but its in that range.

  20. Andy G. Andy G. says:

    Nothing really going on a 3D printer attachment here. I thought a plastruder attachment might be a cool design contest for the blog – don’t know how many people would be interested, though…

  21. Andy G. Andy G. says:

    Actually, I hoping to have something 770 specific on the blog very soon. The parts are supposed to show up today..

  22. Andy G. Andy G. says:

    I hadn’t seen the Ultimaker before – what’s different between that one and maker bot? Look similar on the surface

  23. Randy Hearn says:

    Hey Andy.. I’ll be watching. My tax return comes in the 22nd of this month and I need something new to play with. I was to buy the scanner software soon as well:)

  24. Andy G. Andy G. says:

    Okay

    Just confirmed – the Shot size is 1.0 oz.