Make a plastic phone cover using CNC milling
I made an instuction video on how to make this, and in this thread i want to reply on questions that you guys might have!
Why not design the injection point on the inside of the phone cover? – by @jegor-m
This is cause the inside has an insert to mold around, and in general you want to prevent injecting through inserts.
Where does the air go
Yes on big injection machines this is a problem, but here the tolerances are not so thight, one scratch and you will have plenty of ventilation…
What material did you use?
The mold is made out of Aluminum
How much did the mold cost?
We paid €400 for the mold, €50 for shipping
I used Solidworks mainly because i know the program very well and the iPhone can have difficult radii. you can easily use fusion360, thinkercat or any other (free) program, but im still learning those 😉
Nice! I just watched the video. The end product is very professional looking. I like how you also show the application of the stamp.
When you designed the mould, did you oversize it to allow for any shrinkage of the plastic? Perhaps it’s not necessary, and even creates a tighter fit of the case on the phone.
You don’t mention your choice of plastic, but I note you used PP which will flow better into thin sections and also shrink less than say, HDPE. Though it took the weight of both you and Dave on the injector handle to generate enough pressure, the results are impressive. It’s good to know that the injection machine is capable of producing relatively thin cross section items like this.
Are you going to be selling these phone cases on the Bazar?Toggle replies
Thanks for your questions 🙂
Did you oversize the mold?
Yes initially i did oversized the mold, 3%. But after making a couple of cases we noticed that the case is still quite loose around the phone… this is because the product is fully cooled down while still in the mold, this way the product cannot shrink much. the files in the download kit are changed to a oversize of 1%, this should result in a better fitting case.
Choise of plastic
Initially i was planning to use HDPE, this is cause its more flexible and doesnt break, but we found that it’s way more difficult to inject HDPE with such a thin product then PP, so from now on we will mainly use PP.
Sell it on bazar?
Not anytime soon, maybe later we can pass the mold to someone else who want to make a lot of them.
Oke so the first try of the phonecase mold was actually succesfull 😀 We made a good case, but afterwards the results where a bit mixes, sometimes it wouldn’t fully inject, i would say 60% of the injections give a good phonecase. but before we made different molds(not cnc) and there we figured 2mm is the thinnest we would do 🙂
Don’t want to sound like a know-it-all, but for €450 I think you could have purchased a cheap CNC and a +18.000rpm spindle and make the moulds yourself. Cheap CNC machines are not made for milling metal but if you make the GCODE to mill very slowly, it should work just fine 🙂Toggle replies
And don’t forget that the mould is made from several sizeable aluminium billets that probably cost 100 euro on their own.
It is possible to buy a cheap CNC router for 450 euro, but I doubt it would give acceptable results and even if it could it would take days or weeks to do it.Toggle replies
I am a student and also a young entrepreneur. I am currently busy with a project where I want to design my own iPhone cases made of recycled plastic. While brainstorming about this idea I did some research and found your video. I am not very handy so I have no idea how to make a mold or anything that have to do with this. So, I have some questions about the producing process of this and I like to ask them to you.
I am from the Netherlands and I love to meet you if it is possible. I hope you could help my further with the problems that I now have.
Scott van den Berg
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