DIY Mini PCB Table Saw

[MoltenVoltage]

I don't know if anyone else has done this, but I was too cheap to buy a scroll saw and it would take up too much space for the small number of PCBs I etch.





The blades are from Harbor Freight and fit perfectly over a 3/8" bolt.  I don't know what the thing attached at the end of the bolt is called, but it was in my parts bin and fit perfectly (held on with red thread lock).



The box is Hammond 1590D. I put used motor oil in the holes for lubrication.  The other end of the shaft has a washer then two bolts to tighten against each other so that the axle moves freely but won't come loose or wobble.



I was originally going to use a smaller electric motor in the box, but then it occurred to me to use a drill.

It's also nice to be able to reverse direction depending on the type of material you are cutting.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?function=Search

[head_spaz]

That thing looks dangerous!
Look out you'se kids... don't put yer lips ohne it!

Have you even tried a paper shear?

[Top Top]

I am sure this is wildly dangerous, but I took a jigsaw and mounted it, via its base, to the bottom of a piece of thick particle board with a slit cut for the blade.

I have a pedal rigged up with a wire to pull down on the switch with my foot.

[Jarno]

Ah, a DIY fingertip remover, handy!  
I'd say that the blade is a bit high if you're only cutting pcb material max 1.5mm thick. Also, I would use some kind of bearing, you can get pressfit bushings, but these will also not last very long with the threaded rod gnawing it's way in there, ideally ball bearings can be used there maybe use epoxy to tie the threaded rod to the inner ring of the ball bearing.
One last thing would be to get some kind of dust removal system in place FR4 dust is not very nice.

But, good on you to find a new application for those hammond boxes!

Edit:
I found a site explaining sawblade height, and apparently, you are expected to run the blade quite high to eliminate kickback. That's different from what I've learned in school. Table saw basics

[bumblebee]

While you could potentially loose a finger that thing looks cool!

[Ice-9]

If you use your knees to clanmp the enclosure so it doesn't spin,   you could potentially cut off you kajangers.

You could of course use the enclosure mounting points to secure the box to a wooden board and use one of those drills that has a clutch, the type used for screwing in, screws.. just to be a bit more safe. i like it tho

[R.G.]

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90757

[Mark Hammer]

I collected enough tape measures that now start at 1" to say that the bench shears are not exactly a paragon of safety either.

Bottom line: You gotta watch what you're doing.

[MoltenVoltage]

Good call on the dust removal.  I'll have to rig up a vacuum system with the shop vac.

They way I use it is relatively safe, I keep the speed lower using a clamp on the drill trigger and I run the blade backward.  It's slower, but a lot cleaner and safer.  Still many times faster and a lot straighter than the coping saw I was using!

I considered bearings, but I might cut 25 PCBs all year so it should last quite a while.

It probably looks a lot bigger than it is in the photos.  The blade is only 2" diameter.

I tested the link to the blades and realized it doesn't work.  Here it is again:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=42805

They actually just came out with a mini cut-off saw that uses these blades which is pretty slick:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=42307

I also found cheap carbide bits at HF (20 for $5.49).  They're new, but you don't know what sizes you are getting:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=44924
They came with about 5 that were larger than .032 in spite of the way they are advertised.  There were also some repeats, but I was just looking for the .032 one anyway.

Thanks for the comments!

[SonicVI]

This is pretty clever use of a Dremel and it's saw attachment.
http://www.youtube.com/watch?v=61Q_6-cRua4&feature=fvw

[soggybag]

That's pretty nifty.

[Ice-9]

I love that, it's really simole and neat, but knowing me i would just go and forget to turn the dremel off and go off to put the kettle on then come back and take a seat, OUCH !! lol

[frequencycentral]

"No Mr Bond I expect you to die"

[Jarno]

These are regularly offered second hand on eBay, and don't cost an arm and a leg new. I wonder if they are handy for cutting pcb's. I have a Proxxon pillar drill I use to drill pcb's, and it is very nice, much better than that flimsy plastic Dremel thing. If the saw is the same quality than that's a good deal.

[bean]

I used this for quite a while:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93211

But, this is much better:

http://www.lowes.com/pd_22199-46922-3385-01_0_?productId=1207605&Ntt=band%20saw&Ntk=i_products&pl=1&currentURL=/pl__0__s?newSearch=true$Ntt=band%20saw$y=0$x=0

[John Lyons]

The band saw is infinitely safer that the table saw types.
The blade goes down vertically and hold down the work as opposed to wanting to
hurl it towards you. If you can figure out a way to hook up a shop vac then even better.

John

[danielzink]

I have one of those mini table saws and I'm constantly buying blades for it. I've often wondered about the skil band saws - but I'm never sure if fine enough baldes are available for them.

Please - Brian and John - give us some idea as to blade life/availability, cleanliness of cuts etc. !

Thanks, Dan

[Paul Marossy]

Ha ha, viva DIY! 

[bean]

I have one of those mini table saws and I'm constantly buying blades for it. I've often wondered about the skil band saws - but I'm never sure if fine enough baldes are available for them.

Please - Brian and John - give us some idea as to blade life/availability, cleanliness of cuts etc. !

Thanks, Dan

With the 4" table saw, I was buying a new diamond blade about every 3 months or so. The way I used it was to rough cut the dimensions, then I would actually use the flat side of the blade to 'shave' it as close as possible. For small boards (under 2" sq.), it works great. For larger ones, not so much. Plus, it kicks up an assload of PCB dust doing it that way. It's pretty disgusting. Eventually the thing just died. I got a lot of life out of it. I probably cut 500 boards on it.

Anyway, I much prefer using the Skil. I got it for $100, and then bought a fine tooth very thin metal blade for it. Works like a charm. Blade life is okay, but not stellar. You do have to tighten it back up every couple of weeks. The thing is you have to cut a lot slower than the table saw, but the cuts are much more accurate. If you try to push it through too fast, you'll end up with a bowed cut (I don't use the alignment bar).

[petemoore]

  10,,,10 on the other side [looking at the board 'thinways'...
  Drill some of the holes to larger along the cut, double drilling efforts toward the edge, score with knife, tortion board some with hand 1, hand 2 gets the wire cutters centered at the jaw, then aligned with the holes/cut/line, ease it in some...snaps right off, not much dust is easy to get on the paper/into trash...use a drill-board, small bit, larger bits require clamping, please don't drill or cut into your hand.