1. #1
    Hi Everyone

    Electronics is my area of expertise but I have been drawn into the world of CNC routing/milling by the need to create some plastic packaging.

    My company supplies electronic components mainly to hobbyists; hackers; makers and that means taking components from large trays or tubes that they are supplied in by the manufacturer and packaging them individually. If you have ever bought components on-line you will find that they are typically just put in a little bag. I wanted to come up with a better packaging solution that would give more protection to components in the post and just be nicer than a plastic bag.

    I decided that vacuum formed plastic packaging would be the way to go and started to look into what was involved. Naturally I contacted packaging companies and although I had anticipated that there would be costs for creating moulds I had no idea how expensive it would be. The problem being that components are all different shapes and sizes so a tiny LED is not going to work very well in a plastic container big enough to fit a 28pin chip in it, it will just rattle about in there. Each different shape would require a new mould and considering many of these components are sold for pennies that was not going to be an option to spend hundreds or even thousands for a large aluminium mould for each shape of component.

    Well what is someone like me who likes to make things and solve problems?

    My fist thought was to use a 3D printer to make a temporary mould that I could take a couple of forms from to create a master mould that could be filled with a resin mould compound to create the final mould. Despite all the hype 3D printing just isn't good enough for this purpose, laying down layers of plastic leaves imperfections in the surface that need to be manually worked on afterward otherwise these marks would show in the final plastic.

    This lead me to laser cutters that unless you spend 10's of thousands really don't have the ability to cut deep enough and are limited in the materials that can be used. Then finally I decided to look at a CNC router or mill to cut the mould as it gives the most accurate results and the most flexibility in the materials I can use. I can create prototypes and short run moulds from MDF, slightly longer lasting moulds from a block of epoxy resin or possibly even a long lasting one from Aluminium.

    I started out looking at the many small low cost CNC machines on eBay from Chinese sellers and then discovered by reading this forum and a lot of sites on-line that while those machines are pretty good for the money that the typical 800W spindle based models are not really well suited to mould making especially if there is any work on aluminium.

    So now I am looking at getting a machine that will be a bit better suited to aluminium probably with a 2.2Kw spindle and a moving bed rather than moving gantry for less vibration.

    Anyway I decided to join the forum as I'm sure I still have a great deal more to learn about milling machines and CNC and hopefully share some of what I have learnt along the way with others. Especially anyone looking to do vacuum forming with moulds made on their CNC machine.


  2. #2
    Darren, components in a little bag is fine by me, but if you want to go further then that's fine too.
    Last edited by EddyCurrent; 09-10-2014 at 10:00 PM.
    Spelling mistakes are not intentional, I only seem to see them some time after I've posted

  3. Bag works for me too. I don't get what you propose. Say I ordered 10 Red 3mm LEDs ,10 330R resistors and a couple of 16 pin DIP chips. Today I'd get a Jiffy bag with a tube for the ICs and a bag for the other items and the resistors would probably be on a strip carrier/bandolier (is that the right term.) How would they now be packaged in your brave new world?

    Also there are other issues to consider e.g.:
    - anti-static material? Can you get it and vacuum form it? I wouldn't want my expensive chips sent in something that wasn't anti-static.
    - postage. Is this going to add weight o and/or bulk and increase costs?
    - creating mould is one thing, making the actual package requires a vacuum forming machine as well.

    I can see other issues such as increased handling costs to unpackage parts to fit the new packaging; e.g. resistors typically come on a paper bandolier if you buy more than a few of same value so how would that work?

  4. #4
    I'm with the others here.! Whats the point or need.? . . . . .Also not sure you've factored just how long fine detail 3D tool paths for moulds can take.? . . . There's a reason why moulds are so expensive.!!

  5. #5
    Hi i work in the thermoforming industry and as jazz said the run times on moulds are very long, not to mention the back work and water cooling of the moulds, but it seems that yours would be a bit simpler how would you be wanting yo run the mould on a machine or by hand, on a manual vacume former?

  6. #6
    I think my reply to irving2008 is stuck waiting for moderator approval, hopefully that will get approved soon.

    totts, yes the intention is to run the mould on a manual machine. It appears one of the reasons for the high tooling costs from packaging manufacturers is that they use high speed automatic machines that require aluminium moulds with cooling channels for temperature control. Using a manual process I think the moulds can be a lot simpler. I should be able to use aluminium filled epoxy casting resin for the low volume moulds. Considering that each pocket for a 3mm LED would only be a draw depth of 4mm and perhaps 4mm x 30mm, that is a lot of blisters on a single impression. on a small formech 300 machine that would be over a hundred blisters per impression. So it is only going to take 10 impressions to get 1000 and a resin mould should be good for a good few hundred impressions from what I have read.

    I think another reason moulds are expensive is that they are manufactured to very high standards with very smooth finishes that is important when making clear retail blisters that have to look the the part in my case the primary aim is to protect the component so some blemishes are not going to be a big issue.

    Now realistically something like an LED I am probably going to have to produce an aluminium mould as it is a popular item but for other less popular shapes I expect an epoxy mould would be adequate.

  7. #7
    We use resin moulds as trials and they are formed 500x or more in order to get a stack and test how they sit in transit so a resin mould would be the cheapest way to go. If you are stuck on an aluminium mould like you are saying then yes on a manual machine there is a lot less work involved, and as you say if its only to protect the part then no polishing is needed on the mould just a few vent holes and minimal clean up. It is also possible to get a cast aluminum mould which the price sits between a resin and billet aluminium mould.

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