Tool and Die question

[Berzerker]

Don't know if anyone here has worked in this field but I guess it won't hurt to ask. I'm wondering is it better to use a punch press or a CNC milling machine to make repetitious parts?

I need to punch holes in an 1/8" aluminum plate ranging from 5/64" (.078), 9/64" (.140), and 1/4" (.250). These will be tapped all but the 1/4" hole it's a line up hole. If I ever get going there will be hundreds if not thousands of these.

 

Can you punch a hole in a 1/8" plate with a 5/64" or 9/64" punch or do you think it will break?

A milling Machine costs thousands and to tool up a press would be about the same. I think the press would be faster just slide a part in a press the buttons and in about 1 to 2 seconds a part comes out all but tapped. Milling machine one hole at a time.

[BIGAL]

What about laser ?

[Berzerker]

I was thinking about an in house type of thing. I guess I could just send out specs and see what comes back. A piece of 4' X 8' sheet is about $230 and a piece of 1/8" X 3 1/2" X 6" long is about $3.10 per piece. If I'm doing my calculations right a 4' X 8' would get  about 195 pieces but I don't know how much (yet) for the laser cutting per piece.

If I do it myself once you pay do don't have to come out of pocket for a little while.

 

Edit: I guess I just answered my own question

$3.10 X 195 is about $605

Edited August 21, 2020 by Berzerker

[SLW210]

I would suggest a waterjet.

 

You will not be able to punch holes smaller than the thickness, plus, punched holes are tapered, not optimal for threading. Laser holes are not great for tapping either, I found they needed to be small enough to drill out some material before tapping as the metal on the edges were too hard to just tap or even ream.

 

You might try pricing pieces already to size and drilling/tapping on a drill press versus having a full sheet cut and processed. 

[Berzerker]

Thanks SLW210

I'm only in the prototype phase right now. I do have a drill press. When I asked that question I was probably getting a little ahead of myself. You have an idea and all kinds of things go through your head. My buddy is printing the covers, I only like a few more parts before I can put it all together and see if it even works (?)

 

Your right, I once worked for a company that flame cut sprockets and according to how cheap of metal you bought it could be full of carbon and once the flame hit it, it could get as hard as a file.

You posted this just in time I was looking into ways to get my hands on about 3 of these for testing. 

[ammobake]

a plasma cutter table would also work.

Send it a DXF and it will do all the work for you.

 

I wouldn't recommend a CNC for sheet metal type work, specifically.

 

There are autocad add-ons that will create layout for a specific part to maximize your yielded parts per sheet.

 

I worked for a sheet metal company back in 2005 and probably spent half my time creating layouts and sending DXF cutouts to the plasma cutter - mostly for ductwork.

But occasionally got to work on some unique jobs.

 

-ChriS

 

[Berzerker]

@ammobake

Believe it or not I got an email from one of the people I contacted about the plasma cutting.....You won't believe what I got back.

 

We do have a plasma table that we could have some material cut for you but the rule of thumb is to not cut a hole smaller than the thickness of the plate. For example on a 1/2" plate, I could not cut anything smaller than a 1/2" dia. hole. If you can give me some more specifics I will let you know what we can and cannot do. 

Thank you,

 

So is this guy telling me if I wanted to cut a piece of metal 1 1/2" thick I couldn't put less than a 1 1/2" hole in it . That's the dumbest thing I ever heard. You just tell it what size hole to put in it point and hit start. The plasma doesn't know it's not suppose to put a certain size hole in a certain size piece of metal or plate. I mean the person controlling it tells it what to do not the other way around.

Edited August 24, 2020 by Berzerker

[steven-g]

Well I believe it. Firstly I have absolutely no idea about the validity of that comment, but I can well see that with the temperatures involved that you would end ep with a cone shaped cutout being a great deel bigger at the rear when the Plasma has managed to heat up the core of that hole.

[Berzerker]

You may be right steven-g. I have no idea about plasma cutters either. But I do remember we would cut a 1" hole in a 1 1/2" to 2" plate with gas cutting table with no problems.

[ammobake]

Per plasma cutter - If the hole diameter is smaller than the material thickness it can end up distorted.  It is possible that you can end up with holes that are rounded over or not square but there are a variety of factors that can be "tweaked" to a degree to improve quality of the cuts.

 

I believe in your case you were wanting to cut 1/8" stock.

 

It's possible that at slow speed you could end up with a good cut at 5/64 diameter with 1/8" thick material but it would take trial and error.

 

And when it's just easier to design the product with hole diameters 1/8 and up to avoid those issues - that would make more sense in my view.

 

As far as sourcing fabrication for this kind of thing, i have no idea what the cost comparison would be between water jet or plasma.  But from what I've seen plasma cutters are more commonplace for sheet metal/plate which gives u more options for pricing.

 

-ChriS

[BIGAL]

Good idea the water jet it may be best with aluminimum. It also can cut all sorts of material like vinyl.

[Berzerker]

@ammobake

I can not change the size of the holes on the PCB's They take a #3 screw, I just went with the lesser threads #3-48. I have been thinking to just buy the 1/8" X 3 1/2" bar because it's only the prototype anyways. All I'll have to do is drill and tap the holes by hand. I could just print the hole layout with small dots in the middle of the holes and tape it to it and center punch them. Then I could cut all the out side with a saw I have in my shed. It won't be real pretty but I use to be pretty good at stuff like that but I haven't done it in years.

 

@BIGAL

I called the waterjet people in my area this morning so far they haven't emailed me back with a quote.

 

All it does is it's glued on the bottom of the speaker to hold all the components and the cover protects it.

 

 

[BIGAL]

If lasered or plasma just get as you say a centre punch hole then drill at home. If you want lots of them. Then nice clean hole.

[Jack_O'neill]

On 8/21/2020 at 5:26 PM, Berzerker said:

Don't know if anyone here has worked in this field but I guess it won't hurt to ask. I'm wondering is it better to use a punch press or a CNC milling machine to make repetitious parts?

I need to punch holes in an 1/8" aluminum plate ranging from 5/64" (.078), 9/64" (.140), and 1/4" (.250). These will be tapped all but the 1/4" hole it's a line up hole. If I ever get going there will be hundreds if not thousands of these.

 

Can you punch a hole in a 1/8" plate with a 5/64" or 9/64" punch or do you think it will break?

A milling Machine costs thousands and to tool up a press would be about the same. I think the press would be faster just slide a part in a press the buttons and in about 1 to 2 seconds a part comes out all but tapped. Milling machine one hole at a time.

 

I spent nearly 30 years in tool and die.  For what it's worth, if it were me, I'd go with a mill. Since you have to tap the holes anyway, you might as well do it all on the same machine.   There would be no problems with the holes being the right size, you wouldn't have to worry about location or being tapered or any of the other problems the others have mentioned.  Center drill them all, drill all the first size, then all the second size, and so on.  Tap all the first size, then all the second, etc...ream the location holes and you have a finished part at the end of every cycle. Probably have to deburr the bottom side but that's no sweat. You do that while the next part is running in the mill. This would eliminate or at least greatly reduce the chances of breaking one of those tiny taps because the whole wasn't round or quite the right size.   All the ideas here are good ways to do it, and they will all work.  Not saying my way is THE way...it's just the way I would do it if there were thousands of them to do.  And especially if you are looking to expand to other products in the future, a mill will give you many options that some of the other tools won't.   Nothing wrong with either approach, a mill will have some limitations too. Just depends on which path you wish to take. 

[Berzerker]

@Jack_O'neill

In my early years I was a machinist then as I got older I went into maintenance but always in the back of my head this project kept popping up. I was cleaning out my back room when I ran across the old speakers. I might be getting a little ahead of myself asking the question about how to make these in a production line but your answer makes good sense.

You know "Big dreams". But I also know nothing comes without a price. If you want it, you got to go for it and I'm not getting any younger. I've put time and money into it till I can see the prototype getting close to completion. I wasn't sure about punching a .078 hole in a piece of 1/8" plate that's why I asked (?) I did do some work for a guy once that punched plates and it only took a second or two to have a part. Slide the part in hit the buttons and down and up and here's a part that's why this came to my thoughts first. Fast, repetitive and accurate.

But I can see the fault in wanting to punch a hole so small in a 1/8" plate, It would be like punching a 1/16" hole in a 1/2" in. plate....It just won't work.

[BIGAL]

If making say 2 at a time then yeah just glue the paper print on the ali plate, a steel blade in a jig saw will cut 1/8 plate very quick. A home drill press will do holes and keep the taps vertical and use gentle pressure.

 

You can buy ali blades to use in a bench saw faster for chamfers etc.

Edited August 26, 2020 by BIGAL

[Berzerker]

@BIGAL

Yeah this was my thoughts also. I might just need to stick with the idea of getting the prototypes done and see if they work. Still have a a few parts that I'm looking over to get the best deal for the best price. 

[Jack_O'neill]

On 8/25/2020 at 10:11 AM, Berzerker said:

@Jack_O'neill

In my early years I was a machinist then as I got older I went into maintenance but always in the back of my head this project kept popping up. I was cleaning out my back room when I ran across the old speakers. I might be getting a little ahead of myself asking the question about how to make these in a production line but your answer makes good sense.

You know "Big dreams". But I also know nothing comes without a price. If you want it, you got to go for it and I'm not getting any younger. I've put time and money into it till I can see the prototype getting close to completion. I wasn't sure about punching a .078 hole in a piece of 1/8" plate that's why I asked (?) I did do some work for a guy once that punched plates and it only took a second or two to have a part. Slide the part in hit the buttons and down and up and here's a part that's why this came to my thoughts first. Fast, repetitive and accurate.

But I can see the fault in wanting to punch a hole so small in a 1/8" plate, It would be like punching a 1/16" hole in a 1/2" in. plate....It just won't work.

It could save you some time to have the plates stamped and have them include the 1/4" holes.   Punching the little holes can be done, but it's tricky when material thickness is is more than the diameter of the hole. You'll have to experiment with the clearance between the punch and the die, and the temper of the aluminum will make a huge difference.   6061-t4 and t6 will be stronger and will punch more cleanly than 5052-0 or some of the others. The main advantage to a mill is that if you need to change something, you won't have to completely re-tool.  Same for if you develop an alternate product that is arranged differently, all you have to do is reprogram.   

 

Good luck with it.  Either way will get it done.  Depends on what you are most comfortable and familiar with. 

[Berzerker]

@Jack_O'neill

Thanks Jack 

The originals had a 1/8" plate bolted to the bottom of them. The company (MindBlower)'s designer had to design a speaker with a double wound coil to accommodate the first design of these and to have the holes drilled on the bottom of the magnet to attach the plate. The speakers I have/bought don't have holes drilled in them. I had to figure out a way to attach the circuit board to the magnet and mount the cover to protect it all. I have looked into some UHMW also but I'm still researching to see if it will take the heat generated by the IC (intergated circuit) and the heatsink.

 

My friend also called me and said one of the covers had finished printing but also stated I might have to touch them up. He's new to 3D printing but I have a cover now to make sure everything fits together correctly. I will get it sometime this weekend.

Edited September 5, 2020 by Berzerker

[BIGAL]

Re touch up changing the extruder dia will give smoother output, 0.4 0.3 0.2 etc but smaller dia = way more printing time.