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Make a plastic phone cover using CNC milling
- This topic has 76 replies, 22 voices, and was last updated 2 years ago by
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Hi Guys,
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
Software?
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 😉
Where to find the mould files?
Mold files are in the download pack:https://github.com/hakkens/precious-plastic-kit/archive/master.zip
In this path: 5.create -> iPhone 7-8 mould -> STEP files 😃
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Hey @jerzeek,
me and my friend just started recycling station with a shredder and an injection machine. We ordered the mold for the iPhone 7-8 with the drawings from your download kid and also ordered it from 3dHub but we got this here.
The groove and lip fit perfectly but when we put the insert mold inside then it doesnt fit anymore as you can see on the picture. Id really love to get a fast answer because of the problem is with the drawing then we cant say to 3dHub that it was their fault. So could you just take a look if its in the middle of the aluminum box on the drawing.
thanks Manuel
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Hi Jerry,
Is it possible in any way to manufacture it using extrusion.
My concern in current process is mold opening and ejection is pretty time consuming.
I would like to somehow use it for mass production.
By the way, thank you so much for all the information. I really appreciate what you guys do.
Thanks a ton.
@andyn
@siemenc
@xxxolivierxxx
I’m sure that a 450 euro mill won’t be able to mill this.
Maybe you can mill easier and smaller molds. But then you still need time and materials.
Appearently 3D hubs did up their prices lately so it isn’t 450 euro anymore…
Hi
Can you give me the company name who made the mold?
In Mexico there’s no one who make it
Thank you
Hi @andyn!
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.
First try?
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 🙂
Oh, and… Did you manage to get this to work on the first go or did you have to do a number of trials? How did you determine the minimum thickness you could successfully inject?
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?
Oeh true,
I’m sorry but your right it is not in the download pack anymore, I will later add a How-to with the required files.
But since you want to get started as quickly as possible i uploaded the files to my drive 🙂 https://drive.google.com/open?id=1I6dJtjx3SHH9rYF3vkcv602ZtAwAoGdM
@stampro01
Seems like your video upload expired, would you mind re-uploading it to Youtube?
@jenswilhelm
Mould files are in the download pack:
https://github.com/hakkens/precious-plastic-kit/archive/master.zip
5.create -> iPhone 7-8 mould -> STEP files 😀
hi @jerzeek
I am just getting into your stuff, and have an injection machine up and running. Now considering making and iphone case and wanted to use your mold. But it seems like the files are gone. Can you help me?
Hi, sorry I didn’t reply earlier but I was on holiday..
Better late than never, I know there are still coins at PP HQ, but I think dave took it out of the bazar cause he is in 🇵🇹.
Did Anne already fix the problem or are you still in search of a coin?
Great to see the CNC service offering!
@alex123tscho
You can go thinner but then you need more force to inject it, now we already need 2 persons so then i would suggest to change te machine so you can apply more injection force
@anne-barbier thanks for the offer and the information 😀 if i would have known that sooner i would have bought it from you 😀 🙂
Looks very cool your cnc machine. does it run with a programm on the PC ? Where did you get the programm for the cnc :)?
Hey!
Was wondering how you determine that 2.5mm was the thinnest you could go? And what would i have to change if i wanted to insert-mold an even thinner object to make it work?
Much appreciated!
@jerzeek Hey Jerry, we finished our own clamps and they work good. When Im looking at your phone covers they all look very good and they seme to have the same temp. We have some small problems right now with the prozess because it gets hot but looks like this. In some places slightly burned and at some its good. Can you tell us which Temp. You used and your problems that You had with making decent phone covers :)? The heating elements did You place them in a specific way ?
Thanks for all the time you take to answer all of my questions 🙂
Hi guys!
@manuelmaeder, glad to hear that it’s working! just like the the others i would suggest warming the mold, more pressure, hotter plastic, bigger sprue.
On the part of the clamping, indeed these clamps make the process much faster! But make sure you buy decent ones. The cheap one’s bend easily. also @kunststoffschmiede made moulds with quick releases : here
🙂
Hi @manuelmaeder,
I’m not sure if this is what you’re after but have a look at this topic: http://onearmy.world/community/forums/topic/injection-mold-quick-release/
@jerzeek Hey Jerry 🙂 everything works great with the mold. We want to accelerate our process and therefore we d like to Know what that you used for clamping the mold halfs from the fish mold. It looks like 50 Times faster than using screws for mounting the mold halfs together 🙂 i hope you know what i mean 🙂
@manuelmaeder
Hi
Did you try with ldpe or by warming the mould?
Pictures of the whole installation?
Thanks for the sharing
Precious regards
DiB
@manuelmaeder Try to use another type of pp , try also lpde and i believe for cases is the best!
One suggestion would be to may be increase the mould temperature, to have plastic to cool slightly slower.
Another thing: how do you know the temperature of plastic? Could you may be share a photo / sketch of the orientation of the heating elements + the thermocouple location. It could be that your reading is taken from the heating element and that doesn’t represent actual plastic temp.
It all worked very good i milled the lip away and know it fits with bigger holes for the screws.
So we tried to inject PP in the mold but also with me (84 kg) hanging on the lever arm it only injects as much as you can see on the picture.
What would you suggest me to do ? I think the temperature looks pretty good while injecting its at 260 deg. 🙂
And my second question is about the stamps you have created 🙂 We`d like to make our own stamps with an other logo 🙂 where did you let them produce? It would be great if you could tell me a bit about making those stamps 🙂
greets Manuel.
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