[T2SF]

I would love opinions on how this inside chamfer was made.

Its a movie prop that I'd love to recreate.

It looks to be one solid piece and not mitered cuts.

Thanks for any help!

[Wilson1]

If you are talking about the interior angles, It can be done with the correct sized Mill/Drill.

[Khalid]

For 2D you can use Vbit and for 3D you can use end mill/ball nose bit

[LeeWay]

That is actually going to be a little tougher than it looks. A fairly large mill drill will do most of it, but getting crisp beveled corners is where the trouble will be. I don't have a solution yet.

[Routerfiend]

If I were going to make this piece i`d use a 2mm single flute straight cutter on a 3 axis machine using a profiled geometry
with a .25 step over. Not the fastest way to achieve this piece but for quality this strategy would do the job.

[mactec54]

T2SF

The box was pressure die cast, the mold would of been quite easy to make, that is how the one you have was made, to machine it like you have, is not easy, it could be rough machined & then finished on a EDM, this would give you the same as what you have

Normal machining will not give you the sharp bevel corners that you have, there would be a radius in the beveled corner of what ever the cutter size is

I think you can do the sharp beveled corners with the Vectric Aspire, Cut 2D/3D software

[Routerfiend]

Looking at the main picture the internal corners do have a small radius ( At a guess 1mm ). The stepover strategy would work plus some hand finishing.

[hjl4]

Mactec, clearly, you can see the cutter chatter in the last picture top left of the inside pocket. It was machined.
No one die casts anything for one time deals unless you have a ridiculously large budget and require many copies. You can even see the bad step over cuts leaving a stepped edge on the inside of the box.
Depending on the tool used, when the cutting direction is changed at 90 degrees, they can leave a sharp and crisp edge.
Also, why do you instantly think everything was done by CNC? Would it be too far of a stretch that maybe a hand file was used after the machining process was complete, to sharpen the corners? Or to have even done the whole thing on a manual machine?
As far as movie props, they are one of a kind items.

p.s. personally, I think this part was almost scrapped by the maker. judging by the tapped holes being so close to the edge, he must of considered it.

[mactec54]

Mactec, clearly, you can see the cutter chatter in the last picture top left of the inside pocket. It was machined.
No one die casts anything for one time deals unless you have a ridiculously large budget and require many copies. You can even see the bad step over cuts leaving a stepped edge on the inside of the box.
Depending on the tool used, when the cutting direction is changed at 90 degrees, they can leave a sharp and crisp edge.
Also, why do you instantly think everything was done by CNC? Would it be too far of a stretch that maybe a hand file was used after the machining process was complete, to sharpen the corners? Or to have even done the whole thing on a manual machine?
As far as movie props, they are one of a kind items.

p.s. personally, I think this part was almost scrapped by the maker. judging by the tapped holes being so close to the edge, he must of considered it.

It is clearly you don't know what you are looking at, look at the back side, in the pocket you can see the draw marks which you get when the part is ejected from mold, tapered holes edges Etc are to release the part from the mold

[hjl4]

Ok, so i don't know what I'm talking about.

You are 100% right.

Mactec, I will go learn something today if it's not too late.

Truly you have demonstrated how complete your manufacturing experience is.

Again, I'm so sorry I will never forgive myself.

[hjl4]

Now,seriously. The typical draft angle for an aluminum die cast box is between 1.5 deg to 2 degrees depending on total height of the wall. The typical minimum wall relief for any threaded hole is, hole diameter x 2.
When I mentioned the chatter in the pocket wall, I meant the top right of the last picture.

I don't know you Mactec, but here is a little history of mine In case you think you know better..

5 Yrs die casting aluminum parts for CC out of Winnipeg. 5 yrs at Dyn Machine Winnipeg as machinist. Yes I got my Journeyman's ticket. 16 Yrs as an Electro/Mechanical engineer for DTI Canada.
I still do mould work everyday.
I can confidently tell you that this was milled from a slab of aluminum, and very poorly at that. And even more, that the milled pocket was done on a manual machine.

The draw marks you mention are very inconsistent with die casting. And not only that, they usually only reveal themselves on just a tiny bit of the upper edge at most due to the draft angle.
If they left scores like the ones you think are in the picture, it would F***** up your die in no time.
Another point I could be making is the special coating sprayed inside the die that prevents theses scores from happening.

So you see Mactec, I'm not at all ignorant in manufacturing processes.

[ihavenofish]

I feel sorry for you. first you had to endure winterpeg. then mactec.

for the record, those inside bevels are very easy to cnc machine via several different methods.

BUT, sometimes you need to take the more obvious route to an answer.

its a film prop from terminator 2. so it was done by hand with a manual mill, files, die grinders and bondo at ILM in about 1990. tweet adam savage and he might actually know the guy that made it.

[hjl4]

I agree.
As for Winterpeg, well, you know. Enough said. LOL

[mactec54]

hjl4

The electronic cases were made in the 1990s, These were used for building door security, they had a KeyPad,Led screen, Plus a card reader there were hundreds of them made, I'm sure most have been recycled for more up to date security systems

I never said it could not be machined, I make parts everyday that is more complicated than this, but this is not an easy part to make as you all have been saying, if he just wants to do a one off then he could mold it with urethane or something similar

As to how it was made as I have already said they were made in a mold with die-cast aluminum

[ihavenofish]

hjl4
As to how it was made as I have already said they were made in a mold with die-cast aluminum

why the hell do you insist on making random bad guesses even after being told the correct answer?

[ihavenofish]

here is the prop in the film:

[mactec54]

why the hell do you insist on making random bad guesses even after being told the correct answer?

They were being used in Building in the 80s through the 90s there may be some still in use, but they would be out dated, this is of one many, that would of replaced the one in the photos, it has a thumb reader as well

I'm aware that there was one used in the terminator 2 movie, they gather props for there movies wherever they can get them, & as cheaply as they can

I hope the original poster does some more posts, & says where he got the one he has from

[ihavenofish]

They were being used in Building in the 80s through the 90s there may be some still in use, but they would be out dated, this is one one many that would of replaced the one in the photos, it has a thumb reader as well

I'm aware that there was one used in the terminator 2 movie, they gather props for there movies wherever they can get them, & as cheaply as they can

I hope the original poster does some more posts, & says where he got the one he has from

I don't think he owns that prop. its likely in some collectors hands. people spend a lot of time replicating movie props, its an industry unto itself.

while ilm does "kitbash" many props from real world items, this one not based on a real keypad of any kind that I know of. its a hero item that would have been based on art department sketches. if you think it is a real keypad, show me some pictures of one that matches.

that aside, its absolutely not die cast as the back of it you can clearly see is machined out by hand on a manual mill.

[mactec54]

this one not based on a real keypad of any kind that I know of. its a hero item that would have been based on art department sketches. if you think it is a real keypad, show me some pictures of one that matches.

That part you got right, the real one's had a button keypad, the mock up key pad & the card reader is not original, in the photo, the housing is the same as the original, if you take the mock key pad out of that case there will be a open rectangle hole right through to the back of the case

[ihavenofish]

" This prop security pad was custom-made for use by various actors and as set dressing on the Cyberdyne Systems set. The security pad is constructed of aluminum with internal circuit board and lighting system. The power supply lines have been cut, so the lights are untested, though the previous owner stated they had the lights working at one time. Measures 7.5" x 4.5" x 1". Wear from use is present."

that's from the auction for the prop. custom.