Hole saw or Punch to cut round PCBs...?

[Promocom]

I want to make 1" round circuit boards with FR-4 (.8mm) and need a recommendation for the best way to cut them out of a bigger board. A thin wall hole saw or a maybe a punch?

 

[Visitor]

You could use a hole saw but the dust is nasty both to your lungs and any tools you use to do this.

You could have pcbs made in China. Ten 100mm × 100mm boards can be had for $10 or less. If you penalize your 1" diameter boards and use mouse bites to separate them, you could probably get 10 or more on a panel....so something like 100 disks for 10 bucks.

 

[dr pepper]

I have some 20mm and 25mm hole punches, they use a 6mm bolt as a pilot, I dont think they would do for cutting Fr4 though.
A hole saw might be better unless you want 100's of them, in which case have them cut out by someone with a cnc drill/mill.

 

[MaxHeadRoom78]

A hole punch would splinter the board.
I had some made that were circular in nature.
Failing that maybe the better way to go, if you know someone with a small CNC router/mill, they may oblige.
Max.

 

[Nigel Goodwin]

A hole punch would splinter the board.

Interesting to know, I suspected it might - and as in post #3, a big hole in the middle might be an issue

It's a pretty good question though - the obvious 'answer' is to have the PCB's made for you - but that's avoiding the question really.

 

[Visitor]

I have used a shear to cut circuit boards (both a sheet metal shear and a shear for floor tile) without any issues, so a punch (like a Greelee punch) would probably be ok....except for the hole in the middle.

 

[MaxHeadRoom78]

I have used a shear to cut circuit boards (both a sheet metal shear and a shear for floor tile) without any issues, so a punch (like a Greelee punch) would probably be ok....except for the hole in the middle.

Tried it with GreenLee, the center hole is not the issue usually, although it depends on the outer diameter, the problem is a GreenLee does not punch in the same plane, it pierces in one corner and removes at an angle, progressively .
Max.

 

[gophert]

I want to make 1" round circuit boards with FR-4 (.8mm) and need a recommendation for the best way to cut them out of a bigger board. A thin wall hole saw or a maybe a punch?

The best way is to submit the design to jlcpcb.com. They are running a $2 special right now. With shipping it is under $10 to the US for 5 boards 100 x 100 or less. I think they do round at no extra charge.

 

[Nigel Goodwin]

The best way is to submit the design to jlcpcb.com. They are running a $2 special right now. With shipping it is under $10 to the US for 5 boards 100 x 100 or less. I think they do round at no extra charge.

Yes, had some arrive today, and ordered some more as well this afternoon, £1.61 for 5 at the moment - plus £15 odd DHL delivery. Presumably under $10 is just for slow delivery?, I'd sooner pay more (work pays anyway) and get them a lot faster.

No extra charge for circular, although I've never had any - the ones that arrived today were rectangular, but the ones I ordered this afternoon are cut to fit a specific case, and I've often ordered ones with various curves.

Turn round time is same as always, about a week from order to arriving.

 

[KeepItSimpleStupid]

FR4 dust is bad to breathe and is hard on tools. The dust is abrasive and will destroy the brushes in a typical motor.

Probably the best way is to route them with a router. You could try a jig saw,.

Most hole saws would have a hole in the center.

Do you have a hole that can be used to hold the board?

 

[gophert]

If you want something thing quick and easy and you are willing to have a hole in the center, drill from the back side with a spade bit. The thin 0.8mm board you are using will have a very small chamfer on the bottom edge if you enter from the bottom. 18mm to 36mm are pretty easy.

Just make sure you use the kind of spade bit with the deep spurs on the outside edge (so it cuts through before the chisel blade starts scrapin the board).

 

[Promocom]

Thanks for all the good ideas! I actually submitted my design to jlcpcb.com and it looks pretty good... 50pcs for $9! So thanks a lot for the tip!