Injection Molding Big and Small

A project log for Modular Continuous Track System

A inexpensive modular tank track system that can be used for robotic and radio controlled vehicles.

jupdykejupdyke 01/30/2016 at 21:120 Comments

It has been another busy week. All the orders have shipped out using the parts we made in house. The past month has been very informative about what processes work, what dont, and what just take too long or are too hard. I always knew that filling the molds by hand would be too much work in the long run. But I also did not want to just straight to injection molding. I needed to gauge my market, and get a lot more parts in hand to test with.

Over the past year my production rate has gone up dramatically. Here is a little breakdown:

No too shabby if I do say so myself. But I have reached the point where more aluminum molds will not speed things up any more and it is still tough work to get 15 parts per hour. So as I have mentioned already I am going to an injection molding company to get 7500 parts made in black. But this is not cheap and I am betting a big chunk of money that I can sell all those parts to break even. I like my odds.

So if I can go to injection molding why would I care about increasing my internal capability for making parts. Well I have several reasons. The first is that with outsourcing the injection molding I will only ever be able to make 1 color and one size cost efficiently. Changing colors has fees and different sizes requires a new mold. So I want to be able to do custom colors and custom sizes.

The second reason is for R&D purposes. I have ideas to expand my system to other sizes and shapes. That means I will need to be able to prototype those parts cheaply and easily.

The final reasons is that injection molding is not cheap. If I can make the parts myself I can keep more of the profits.

So that brings me to the conclusion that I need my own injection molding machine. I could buy a cheap one, or I could save up and buy a nicer one. But this is Hackaday. We build stuff here. So I started toying around with some ideas about building my own micro injection molding machine. It is not that crazy actually. There are quite a few point who have done this, and hackaday has featured a few. Time for me to throw my hat in the ring too.

Ever since I started this project I have been trolling the internet and found a few cool builds or products. Now I started designing my own machine. Over the years I have learned a few things about my projects. The first is that I start way too many, hardly finish them, and they always take longer than I expect. So the way I deal with this is to try and make projects scaleable. What is the minimum amount of work that gets to me to a useful product, and then how can that be improved over time. This way I get something useful earlier, and depending on how useful it is I can upgrade it.

With the injection molding machine the first useful step is just being able to open and close the molds. Right now opening the mold is actually a pain in the butt. Here is a picture of the design so far and a link to yet another project page.

Micro Injection Molding Machine