MadModder
Gallery, Projects and General => Gallery => Topic started by: Joules on April 06, 2017, 11:06:22 AM
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Here’s a prototype job I did a few years ago, and it is with kind permission I present some of the story here. I was given a design brief for a new product, something I was not familiar with, and asked if I could turn the idea into a working prototype. I went through quite a few iterations of CAD modelling trying to get a pleasing shape. Once that was achieved, how can it be made in the real world. I had an idea, but it had to be tested as a prototype, I hadn’t seen any examples of this before. Thats not to say it’s unique, just I hadn’t seen it, the design asked for components that could be crimped together.
(http://i.imgur.com/jdHGFST.jpg?1)
With the design and a method of attachment figured out, I needed to make the first part for testing. It would need a mould, as I didn’t have CNC facilities and basically the design budget was….. I started to machine the parts in the workshop. This called for some quite intricate curved parts to be made, so the curves needed to be mapped. I didn't want to make form tools as the setup I have isn't that rigid and surface finish was an important part.
(http://i.imgur.com/8hiqcGs.jpg?1)
Boy, did I wish I had CNC during this part. It was early days in my 3D printing, so that didn't help much as I couldn't produce the accurate parts I can now to use as templates.
(http://i.imgur.com/XPJuoZC.jpg?1)
A lot of machining later a set of parts for the mould. At this point other than the base they still needed profiling and drilling for alignment dowels.
(http://i.imgur.com/fBRl2El.jpg?1)
On with profiling the internal parts and getting the vents in the mould ready. At last a full set of mould parts that all fit together.
(http://i.imgur.com/B9O5ZjC.jpg?1)
Some would say skill, but I would call luck that I made it this far without having to remake any of the parts. All the internal scraping worked out, just a smidge out of tolerance getting things smooth.
(http://i.imgur.com/4tgdrAy.jpg?1)
The above is a simplified version of the mould to produce the required part. Now its mould time.
(http://i.imgur.com/rknm3WL.jpg?1)
First few attempts produced partial casts as I needed to up the mould pre heat and find the sweet spot.
(http://i.imgur.com/zLNaj2M.jpg?1)
First full cast out of the mould and looking pretty good, till I turn it around. The lead pulled back as it cooled as I expected, just the vent didn't do it's job right.
(http://i.imgur.com/EYMq4DM.jpg?1)
The inlet vent needed further work, a few minor adjustments and after a few more tests I start getting consistent results.
(http://i.imgur.com/QhukUxs.jpg?1)
The initial idea for crimping the parts together was just too fussy and probably would result in rippled edges, so I redesigned the crimp tools.
(http://i.imgur.com/GSYRH9K.jpg)
Now thats the result I was after.
(http://i.imgur.com/TI4hpKQ.jpg?1)
A good crimped surface, the rest of the prototype was completed and several more made for testing. Upon completion of testing it was put into mass production and I am pleased to say tens of thousands have so far been made. This is some of the work I do, normally covered by confidentiality clauses, hence i rarely get to show the real stuff I design and make. My thanks to Mick for letting me share this part of the journey with you all.
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Good to see the results of someone else' s toil.... :bow:
You have given me some inspiration to pursue another of projects....injection molding....
Know anything about this process? :scratch:
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Yep, desktop injection moulder sat in conservatory much to my other half's dismay. I sold my bigger old automatic moulder and got this one as it can use the same plastic I use for 3D printing, so I have a ready supply of feed stock in many colours. It's also a lot cheaper making moulds for it.
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Thanks for showing, very interesting, is the one mould sufficient for thousands, or are more moulds made by a third party?
John
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The mould was for a very limited run of prototype parts. Upon completion a set of industrial moulds were commissioned overseas and the parts mass produced.
The mould was made in multiple parts so I could modify it easily if different parts needed moulding. As it turned out the client was very happy with the overal design and no further alterations were needed.
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Thanks for sharing.
Dave