DIY Mini PCB Table Saw

[Paul Marossy]

You know, it occurs to me that I slice and dice more than 25 PCBs a year. Before the shear, I used a hacksaw. Not pretty, perhaps, but if you clamp down the PCB in a vice or on a table, you can get nice straight edges. A little sandpaper and the PCB looks routed.

Or a coping saw. Or a jewelers/fretsaw.

I can't think of the last time I heard of someone accidentally sawing off a finger or two with a hacksaw... 

No, but you can cut your finger (or thumb) like this:



That was in Dec 2005, and was two weeks after I accidentally cut my thumb with a hacksaw while trying to cut a pipe. What lesson did I learn from this? To put the darn pipe into a vise when you're trying to cut it! 

[petemoore]

  The whole idea is that the project takes a lot of time, then some bit extra.
 The extra time is for consideration of the many varied and important safety issues. This is what I tell a pushy guy, who is barking out orders including "hurry up", in the afternoon after an early morning, at a job site where power tools are carried across floorless joists etc., yes, we must break now so that they are understood by everyone working here [looking right at him]. Period, that shuts 'im right up.
 Nobody wants to stay the extra hour at the end of the day [end of the day...lol...I actually used that stupid term, it is too often used in a way that infers "you are dense'', I feel to use it without sounding insulting requires some subcontext.
 But in this sense I'm referring to 'after a long bout of workin' with power tools.
 Every move is precontemplated to be a smooth action which doesn't lead to unpleasant cleanups, power tools are not the least bit squeemish.

[MoltenVoltage]

I TOLD YOU SO

[Brymus]

Oh bummer dude 
I really hope your OK and heal up well.
Are you gonna do it again ?

[John Lyons]

YIKES! Now that's a bummer! I hope you learned your lesson.

[UncleFluffy]

I had to cobble together a board-cutting rig in a hurry and came up with this:



Actually works surprisingly well.

[head_spaz]

Man I hate when that happens!
Hope you heal up real soon... and that there's no permanent damage.
I broke my wrist over three years ago... and it's still hampering my playing.

But don't lose hope... you could always switch to playing the trombone.

[MikeH]

I had to cobble together a board-cutting rig in a hurry and came up with this:



Actually works surprisingly well.

The tech guys at my work did the exact same thing... ha ha.  Works pretty well.

[R.G.]

OOOOWWWWW!!!!

[MikeH]

Will post severed finger photos as they become available...

I'm sorry for you pain and suffering, I really am, but you have to admit that... and I don't know if it's actually irony- but you have to admit that the irony-like quality of this thread is going to be something you'll laugh about one day.

[G. Hoffman]

I TOLD YOU SO

Thankfully, that looks relatively minor, so its just a learning experience, right.  RIGHT?

I've been discovering recently that table saws are just a really poor way to cut circuit boards anyway.  I'm seriously looking into a small shear like R.G. suggested.


Gabriel

[Brymus]

A hacksaw with a carbide metal blade works great.
You have to sand the edge even if you shear it.
If I were making ALOT of PCBs commercially then a shear and as bench sander would be a good time saver for increasing the labor/cost ratio.
Still on that scale you would be buying large sheets of FR4 which wouldnt fit in the 8" sheer RG linked to.
And on that volume level you might as well outsource them to a PCB house.

[frank_p]

What happened ? What did go wrong ? Did it flip ?

[Skruffyhound]

Sorry to say I laughed Karl, but the presentation was pretty hilarious, I really hope the injury wasn't serious.

Cutting board with those tiny Dremel blades doing thousands of rpm, freehand, now that's scary. This miniature table saw was a good idea, just needed a more precise build.

I've used table saws for years without ever experiencing a kickback and I'm not quite sure what Gabriel means when he says that the blade can grab your hand. I never get my hands anywhere near the blade. That thing's going so fast it's not going to grab anything.
Band saws, on the other hand, scare me much more. My friend's instructor for a furniture apprenticeship cut two fingers off while his words "it'll take your fingers off, just like that" were still hanging in the air. I once saw a 4 metre band get spit out of a big machine and we ran around for what seemed like a minute crapping our pants trying to keep out of it's way while it shot round the room.

I hacksaw my boards, fast, safe,cheap, not a lot of dust. Apart from drilling and maybe polishing I think Dremels are just dangerous.

[frank_p]

I've used table saws for years without ever experiencing a kickback and I'm not quite sure what Gabriel means when he says that the blade can grab your hand. I never get my hands anywhere near the blade. That thing's going so fast it's not going to grab anything.

My friend lost fingers because the circular blade litterally grabbed his hand.  The tooth just sank in the bone and grabbed it firmly. That was it.  His best friend was with him and I have to take him by the arm every time he hear a circular blade running.  He gets pale as a sheet of paper.  A circular blade can really *grab* a finger or any bone near it. No lies: take care with that or the blade will take care of your hand.

[trixdropd]

I have some good kitchen scissors that cuts through some pcb with little to no effort. I used to use my dremmel, but as poster above me said, That's scary!!

[defaced]

What scares me about these DIY table saws isn't the blade, it's the lack of a splitter that keeps the kerf from closing.  Not a huge thing on short cuts, but it can keep the part from moving when you don't use a fence (which you're never supposed to use a table saw without auxiliary support)  Kickback is also a function of blade height.  For PCBs, it had better be pretty low which will increase the tendency for kickback.  Face of the matter is, every piece of industrial equipment has an inherent level of danger associated with using it. 

[caspercody]

I have been using tin snips to cut the vero board, but the board cracks around the cut. Sometimes cracking off the edge so all that is left is the copper and a thin backing. It would be nice to cut this board clean, but I do so little builds it would not be worth buying anything expensive. Has anyone else had cracking issues of the board using tin snips? Or maybe mine are dull?

[R.G.]

Yours are dull. Nice, sharp shears work OK - for a while.

However, glass-epoxy is VERY abrasive. The glass fiber is still *glass*. Anything that cuts it won't cut it for long unless the cutter is carbide or one of the harder abrasives. In drilling PCB stock, you can count on not getting more than about 100 holes out of a high speed steel drill bit. Carbide will last for thousands of holes.

[caspercody]

Thanks R.G.!!