Make a plastic phone cover using CNC milling

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

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:
In this path:   5.create → iPhone 7-8 mould → STEP files 😃


is there a link to the digital files for this mold?

edit: found it! (in the download kit of course)

Many thanks!

have you published anything else regarding moulds?

If yes, is it possible to have all of them?

Kind regards,

Here you go!

Hi mate,

many thanks for your answer, but in reality I was looking for the other mould files you previously had in the package i.e. the compression mould for making a bowl…

Kind regards,

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 🙂


Hi, I think you removed all the files from the packages, together with other mould files you mentioned in other videos (i.e. the compression mould for making a bowl).
If that was a mistake, could you please re-commit them to the repository?

If not, could you please send an alternative link?

I just spent hours trying to find the Precious Plastic mould files with no luck at all.

Kind regards,

Seems like your video upload expired, would you mind re-uploading it to Youtube?


they look great.
I see myself getting jealous, cause you dont have to stamp them 😀

also nice logo milled in the mould:)

Thank you very much @Jerzeek

here is totally raw video  with that mould

!!These look absolutely gorgeous!!
How do you get the case of the mould?

Great work man!

Hello @csejal
according to my tests doesn’t matter the thickness of the mould at compression machine because all the mould reach high temperature…
only at injection machine you need specific thickness  cause the mould is cold

the thickness depent from:
-the size of the mould
-from the type of plastic
-the force of the injection

*maybe this question is not for this topic

Thanks for your interest, you are making a compression machine with band heaters?
The thickness was mostly through trial and error, thicker is always easier.

Greetz, Jerry

Can anyone here tell me what calculations are to be done to decide the thickness of the mould for compression moulding. We are using cartridge heaters.

Thank you.

6061-T6 to be precise,
but I dont think it matters much. 😉

what series of alumunium you use?

I was wondering, what is the radius of the holes that you made for the screws?
Also what is the radius for the injections cutout in the mold that you pour the molten plastic into it?

Mould files are in the download pack:

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?

Hey Jerry, Anne fixed the problem 🙂 thank you