I'm not punching cleanly...

[Beanwood]

As @Pete. said, your punch/die clearance is too large. From your pictures it looks like the clearance is sufficient for the material to fit between the punch and die allowing it to bend down into the die hole and not be cut off. Which is also why the other holes are burred over.

Have a look at the clearance calculators on line to see what your clearance should be.

Personally I'd agree with the other suggestions to start with a single hole punch which should be easy to make to the correct tolerances, and move your material for each hole. A simple jig will allow repeatability.

Thanks- so for the holes I’m using a 4mm drill for the 4mm bar, and 5mm drill for the 5mm bar- so haven’t consciously over sized the die holes. They were drilled together with the punch and die bolted tight to each other- using short presto drill bits. As the material is much less than 1mm, clearance should be tiny also- maybe 0.1mm so thought I was safe there.

Punching 12 holes in a perfect circle with 6 more in a second perfect circle isn’t easy even with a rotary table- now try to repeating that for 40 lids and you may appreciate why I’m trying to punch them using a Die

 

[ukracer]

Thanks- so for the holes I’m using a 4mm drill for the 4mm bar, and 5mm drill for the 5mm bar- so haven’t consciously over sized the die holes. They were drilled together with the punch and die bolted tight to each other- using short presto drill bits. As the material is much less than 1mm, clearance should be tiny also- maybe 0.1mm so thought I was safe there.

Punching 12 holes in a perfect circle with 6 more in a second perfect circle isn’t easy even with a rotary table- now try to repeating that for 40 lids and you may appreciate why I’m trying to punch them using a Die

Drills don't drill accurate sized holes.
You need to use a reamer.

 

[500e]

Post #59 &62 have you tried EF, ukracer's suggestions
Did you turn the p&d it may be the register has moved, it is still a lot better good luck.

 

[DanZac]

Thanks- so for the holes I’m using a 4mm drill for the 4mm bar, and 5mm drill for the 5mm bar- so haven’t consciously over sized the die holes. They were drilled together with the punch and die bolted tight to each other- using short presto drill bits. As the material is much less than 1mm, clearance should be tiny also- maybe 0.1mm so thought I was safe there.

I may be wrong (and often am) but to my eye, the way the material is bent down suggests that it fits between the punch and die, which suggests that your clearance is a lot more than you think it is.

As @ukracer says, a drill is unlikely to give you the tolerance you need on the thin materials your trying to punch.

00Punching 12 holes in a perfect circle with 6 more in a second perfect circle isn’t easy

Probably easier than what your trying to do now though.

I'm guessing the positioning tolerance on the 12 holes is a lot looser than what you need for 12 punch and dies. So 1 punch and a jig to position the work is probably an easier option?

 

[Pete.]

Thanks- so for the holes I’m using a 4mm drill for the 4mm bar, and 5mm drill for the 5mm bar- so haven’t consciously over sized the die holes. They were drilled together with the punch and die bolted tight to each other- using short presto drill bits. As the material is much less than 1mm, clearance should be tiny also- maybe 0.1mm so thought I was safe there.

Punching 12 holes in a perfect circle with 6 more in a second perfect circle isn’t easy even with a rotary table- now try to repeating that for 40 lids and you may appreciate why I’m trying to punch them using a Die

You're probably trying too hard. A couple of stops and 12 felt pen marks would be simple enough to get those holes punched so close to perfect you could not tell. Or a plywood disc and 12 nails, or any number of simple ideas.

 

[Screwdriver]

Just out of interest, do you still have those punches sticking out by over an inch as in your first set of pics?

 

[Erie Fred]

Drills don't drill accurate sized holes.
You need to use a reamer.

Heck, the whole job should be up on the Jig borer, single point those holes for location, and the "holes" should be die buttons.

 

[prepman]

View attachment 433128View attachment 433129View attachment 433130

Have you thought about using a circular part of a dual.sander. adding a jig or two way vice.


might take you a few discs to get the pins level. But.........i am sure you could rig something up.

Have you used the belt sander? It looks reasonable for my purposes. Not a cast base though.

 

[bricol]

No that’s not the look I’m going for.
Give me an idea if you’re able please of how to improve it without spending thousands (as I know you do) on creating a punch and die.

I did earlier in this thread - one correctly specced punch and die, buy them - with the time, effort and materials you've wasted so far, you could have bought several. Make a simple jig to orient your material, punch one hole correct, reposition, repeat.

The punch needs to be accurately guided through it's movement, rigid enough so not to move during the process - and for that you might need to spend money. Punch and die need to be linked in a guide assembly to maintain the alignment and even clearance.

For the numbers you want to make, it will work well enough.

There is no way with a drill, drill bits and bits silver steel you are going to get the precision you need for multiple punches in one hit - that's why the company you went to quote thousands to do it - because that's what it needs in terms of equipment, set-up and knowledge to do it.

Veering off at a tangent - find somewhere with a laser cutter and ask them for a price to cut holes in your 400 lids - you might be surprised.

 

[prepman]

I did earlier in this thread - one correctly specced punch and die, buy them - with the time, effort and materials you've wasted so far, you could have bought several. Make a simple jig to orient your material, punch one hole correct, reposition, repeat.

The punch needs to be accurately guided through it's movement, rigid enough so not to move during the process - and for that you might need to spend money. Punch and die need to be linked in a guide assembly to maintain the alignment and even clearance.

For the numbers you want to make, it will work well enough.

There is no way with a drill, drill bits and bits silver steel you are going to get the precision you need for multiple punches in one hit - that's why the company you went to quote thousands to do it - because that's what it needs in terms of equipment, set-up and knowledge to do it.

Veering off at a tangent - find somewhere with a laser cutter and ask them for a price to cut holes in your 400 lids - you might be surprised.

In first, UK test fires $13-per-strike DragonFire laser weapon against ‘aerial targets’ - Breaking Defense

The UK lauded the test of the laser air defense weapon, developed by Britain’s defense innovation unit, just weeks after an American admiral said it was time to be more "intellectually honnest" about what the class of weapons can do.

breakingdefense.com

 

[ukracer]

Heck, the whole job should be up on the Jig borer, single point those holes for location, and the "holes" should be die buttons.

I understand the OP. Cost outweighs the job returns.
Many times the job can be done many ways. It's a case of getting it done the cheapest way especially if you are not making money out of it.

 

[Erie Fred]

I understand the OP. Cost outweighs the job returns.
Many times the job can be done many ways. It's a case of getting it done the cheapest way especially if you are not making money out of it.

Yes.
However the OP should have not taken on a multiple punch die in thin material, and these need to cosmetic clean as well.

Fools rush in......

 

[Screwdriver]

Yes.
However the OP should have not taken on a multiple punch die in thin material, and these need to cosmetic clean as well.

Fools rush in......

Whoa! Slow down there Tonto. We can't all be perfect all the time. The OP is asking for advise and while any of us may choose to offer it, no one can demand to be obeyed nor is it foolish to attempt a task just because you may risk failure.

 

[Beanwood]

Yes.
However the OP should have not taken on a multiple punch die in thin material, and these need to cosmetic clean as well.

Fools rush in......

Thanks @Erie Fred for your kind understanding - or not. Why shouldn't I take on a multiple punch die - surely that's my prerogative? It may be that you in your fully equipped workshop can do something clever and better than me - but that won't stop me trying. I don't have a mill or jig borer - part of what you said before makes no sense to me, so I won't dwell on that.

To the rest of you - I apologise if I haven't taken on board all of your advice yet - and I truly value and appreciate your continued support and ideas.

@bricol - I honestly hadn't considered how difficult it would be. I thought it may be tricky - but as I managed 8 holes on a single punch/die set I made previously I had high hopes. I may not be able to manage this yet - but that won't stop me trying as apart from some bits of metal, and a few new tools, it isn't costing me a fortune, and I am learning a lot. I would LOVE to spend £1000 on someone making me a die set to fit in my flypress - but for two problems 1. Nobody is going to do it for that much, 2. I haven't got £1000 spare for the job. I do though like the idea of subbing it out to a laser cut. Do you have any ideas of a name that deal in low volumes please? (If I want the really easy route, I just import direct from China - but where's the fun in that)

@Screwdriver - yes the pins are still too long - probably 15mm protruding from the die - but that's to allow length to go through the stripper plate - and I've been to cowardly to cut them shorter in case I messed it up!. It may well be that I should reduce them down a bit more.

@DanZac - you're also right - I think the die holes are probably too large. I have just remade one of the punch pins on one of the major problem holes, and that improved the situation. So maybe I had taken too much off that pin when cleaning off the burrs from originally cutting it. Or I've stretched the holes by being cack-handed in my attempts to date.

I think the main problem is PROBABLY the holes in the die plate are too big. As I started out about 4 pages ago: "perhaps the die holes are too large, so allowing the 'stretch not shear'. I've been making the holes with short drill bit (Trying to minimise hole drift). Would I be better making a smaller drill hole, and finishing with a reamer?"

So...

As I am bloody minded, pigheaded and obstinate dedicated and determined, I am going to try again with my multiple pin punch. But this time, I will ensure I have a better method of consistently aligning punch and die. I will design the stripper plate better to cleanly push of the punctured material. I will then reduce the length of the pins to only as long as they need to be. The pins will be cut cleanly, and deburred as @Pete. suggested (That was my biggest improvement/learning on this project so far - thanks @Pete. ).

I would like to finish the 4 and 5mm holes in the die with a reamer - can I do that in the drill press? If so, what size drill bit would I need to use a 4mm and 5mm reamer?

Thanks all.

 

[Screwdriver]

What you could do even at this stage is buy a load of cheapo HSS drill bits the correct size, just slightly larger ideally. Remake all the holes as carefully as you can with the die+punch holder having some sort of registration. Cut up the drill bits with a slight angle and dress them nice and flat or ideally slightly concave (using a Dremel).

For thin tin you really only need it to penetrate by 2-3mm, any more and you increase the risk of alignment error. You may also find that with smaller penetration there will be no problem withdrawing even without a stripper.

Just for laughs, if you don't have a Dremel or means of cutting hardened steel, chill the drill bits in a freezer and snap them off (at the shank) in a vice! Wear goggles. You might find even a ragged sharp edge will be perfect since they will all cut in a slightly random order, spreading the load...

 

[steve t]

Wouldn't take that long to drill the holes with a simple jig either.

 

[Beanwood]

Wouldn't take that long to drill the holes with a simple jig either.

Then we get back onto the question of drilling 5mm holes in very thin metal - not as easy as it seems… and it’s MUCH slower than hanging off a fly press handle…

 

[Beanwood]

What you could do even at this stage is buy a load of cheapo HSS drill bits the correct size, just slightly larger ideally. Remake all the holes as carefully as you can with the die+punch holder having some sort of registration. Cut up the drill bits with a slight angle and dress them nice and flat or ideally slightly concave (using a Dremel).

For thin tin you really only need it to penetrate by 2-3mm, any more and you increase the risk of alignment error. You may also find that with smaller penetration there will be no problem withdrawing even without a stripper.

Just for laughs, if you don't have a Dremel or means of cutting hardened steel, chill the drill bits in a freezer and snap them off (at the shank) in a vice! Wear goggles. You might find even a ragged sharp edge will be perfect since they will all cut in a slightly random order, spreading the load...

Apart from the excitement of snapping frozen drill bits and seeing if the splinters can avoid my eyes Would broken bits be much better than hardened silver steel?

 

[Erie Fred]

Whoa! Slow down there Tonto. We can't all be perfect all the time. The OP is asking for advise and while any of us may choose to offer it, no one can demand to be obeyed nor is it foolish to attempt a task just because you may risk failure.

Whoa....I'm saying, a lack of understanding of the tolerances involved is the problem here.

If you can't properly bore a hole for the die, and can't align 1 single punch correctly (which we see here)
adding several punch stations together compounds the problem greatly.

Very Greatly.

OP needs to follow the advice of a few posters that said "punch one hole at a time, use a template to locate them".

Or try a different method of making the holes in the product altogether.

 

[Screwdriver]

Whoa....I'm saying, a lack of understanding of the tolerances involved is the problem here.

If you can't properly bore a hole for the die, and can't align 1 single punch correctly (which we see here)
adding several punch stations together compounds the problem greatly.

Very Greatly.

OP needs to follow the advice of a few posters that said "punch one hole at a time, use a template to locate them".

Or try a different method of making the holes in the product altogether.

I understood you the first time and the above merely confirms my suspicions.

How do you know there is a "lack of understanding"? The OP might perfectly well understand what they would like to achieve and it is also perfectly possible the prototype/first iterations fulfil the basic requirements for the product.

As for "if you can't" <then you shouldn't>, does that mean there is no room for experiment? No evolution both in skill, ability or design? Does everyone here have to be perfect on their first attempt and if they ask how to improve, be forbidden from even trying? Sheesh, you should see some of my welding, I mean I do understand the process but...

"The OP needs to follow the advice", again, it's a "no" from me. I am happy to offer advice such as it is but like a gift, it is something I like to do and not something that places any obligation on the intended receiver.

I often find myself on the wrong end of an argument, batting from a sticky wicket due to lack of skill, experience or sometimes, understanding. Thee's nothing I like more than to be shown where I am wrong so that I might learn. This is how we progress. As Einstein once famously said "If we knew what it was we were doing, it would not be called research, would it?"