Cutting neat holes in sheet metal

[ajlelectronics]

At the moment, I've just added 3 mm all round. That was based on a crude rule measurement from the outside of the torch tip to the outside of the hole in the torch tip.

I wasn't too worried about precision at this point, just repeatability. If I can consistently cut holes with a given template, I can measure the resulting holes and work out what the offset should be and then make a new template to suit.

I'm really, really pleased that the 3D-printed templates are surviving. I expected them to end up a molten mess stuck to the steel. Being able to 3D-print the templates will make it very easy to tweak dimensions and also to lay out holes relative to each other.

Put some making tape on and cut. It will astonish you how much of that survives too!

 

[Misterg]

For one panel? Step drill for the round holes and a jigsaw with a metal-cutting blade for the square ones.

You'd have it finished by now!

 

[Dr.Al]

For one panel? Step drill for the round holes and a jigsaw with a metal-cutting blade for the square ones.

You'd have it finished by now!

You might be right, although I haven't designed it yet so finishing it might be optimistic!

I've never tried a jigsaw on thin (0.8 mm) steel. It must need a really high TPI blade (to keep three teeth in the cut it'd have to be 96 TPI I think!).

 

[Gareth J]

Has anyone mentioned step drills?

 

[Dr.Al]

Has anyone mentioned step drills?

Yes (for the round holes, but obviously not for the rectangular ones)

 

[Wallace]

I'm really, really pleased that the 3D-printed templates are surviving. I expected them to end up a molten mess stuck to the steel. Being able to 3D-print the templates will make it very easy to tweak dimensions and also to lay out holes relative to each other.

Try that on the square/rectangular holes and punch the others.

I've never tried a jigsaw on thin (0.8 mm) steel. It must need a really high TPI blade (to keep three teeth in the cut it'd have to be 96 TPI I think!).

Can be a bit of a bugger but is doable. Much easier to remove a chunk by other means and file the sides to size.

 

[Brad93]

I've ordered a 22 mm one to suit my push buttons, but there's no way I'm buying a 45mm square one, a 92mm square one, a 22.3mm × 28.2mm rectangular one, a 6.8 mm × 19.2 mm rectangular one and, and, and, and, and....

Even if all those sizes were easily available and relatively cheap, I'd be using each of them once and probably never needing them again.

Send it out for laser or plasma

 

[oldbikedavey]

Thanks both, those Q-Max things definitely look like they'll be a good option for the 22 mm round holes, but I still need to cut the other non-round holes, e.g. for these:

View attachment 476448

There are square or rectangular Q-max punches....

 

[TEO]

I may be repeating something that's been said before but making the enclosure while quite an involved process, doesn't seem more than a C&G level 2 project involving accurate marking out, cutting & filing. +_ 0.5mm won't make a difference to most push through buttons & a cheap jigsaw or cutting disc on a grinder, Dremel or the like will get within easy filing or die grinding distance of perfect?

 

[voipio]

Square holes can be made with square hole drills, or with Rotaboraches.

 

[Jelly_Sheffield]

You might be right, although I haven't designed it yet so finishing it might be optimistic!

I've never tried a jigsaw on thin (0.8 mm) steel. It must need a really high TPI blade (to keep three teeth in the cut it'd have to be 96 TPI I think!).

Double sided tape and some sacrificial scraps of ply or mdf.

 

[TEO]

I may be repeating something that's been said before but making the enclosure while quite an involved process, doesn't seem more than a C&G level 2 project involving accurate marking out, cutting & filing. +_ 0.5mm won't make a difference to most push through buttons & a cheap jigsaw or cutting disc on a grinder, Dremel or the like will get within easy filing or die grinding distance of perfect?

Sorry, I came back in without having read the whole thread & see that I am just repeating others.

 

[Dr.Al]

Send it out for laser or plasma

Yeah, I'm sure I could do that but I'd rather be self-sufficient if possible. As a hobbyist, my time is effectively free and also available over the Christmas break when I'll be doing this. Subcontracting it will be neither of those things.

 

[Robotstar5]

I've ordered a 22 mm one to suit my push buttons, but there's no way I'm buying a 45mm square one, a 92mm square one, a 22.3mm × 28.2mm rectangular one, a 6.8 mm × 19.2 mm rectangular one and, and, and, and, and....

Even if all those sizes were easily available and relatively cheap, I'd be using each of them once and probably never needing them again.

I had to put some 75mm square holes in half a dozen panels for energy monitors and found it cheaper to hire a cutter/punch than buy one.

 

[ajlelectronics]

I had to put some 75mm square holes in half a dozen panels for energy monitors and found it cheaper to hire a cutter/punch than buy one.

This is true, but when you look at the cost of the cutters to buy, it inspires you to find another option. I was unaware of a hire option.

I do have a 9 Way D type punch should anyone need to borrow one.

 

[daedalusminos]

When using the plasma, punch through (or drill) in the centre then spiral out (over about half a turn) until you hit your template then follow round. The spiral will mean the last bit should cut with little damage outside the hole (though you may end up with a small inner pip).

 

[Misterg]

I've never tried a jigsaw on thin (0.8 mm) steel. It must need a really high TPI blade (to keep three teeth in the cut it'd have to be 96 TPI I think!).

I use the Bosch T118G blades (~36 TPI).

Bosch Bayonet Jigsaw Blade T118G

• Blade makes straight cuts in metal• Milled, wavy-set teeth are ideal for cuts without special requirementsThe fully hardened, high-grade high-speed steel blade material is appropriate for cutting standard-strength, non-perforated sheet metals. Additionally, the blade's very fine tooth pitch...

www.toolstation.com

They cut thin steel sheet just fine. (Best if you have a variable speed saw so you can keep the speed down).

Cut from the 'wrong' side of the panel if you can, or put some masking tape on the 'good' side if you can't.

 

[Martinb]

Multi tool with metal blades for the square holes.

 

[Pete.]

For the square holes I'd scribe the square then rough it out with plasma or jig saw. Then clamp a filing guide (just a strip of hardened flat metal bar) on the scribe line and file up to it.

 

[Martin-Sy]

A Cone Cut (step-less step drill, if that makes sense) would be my first choice for the round holes. Chain drill and file for square/rectangular holes.
I've just had a look. I have 19, 20 and 53.2 round chassis punches which I inherited from my father-in-law. You'd be welcome to borrow if they are of use.