PCB Cutting...again

[Myriad Society]

So, I was in my local Harbor Freight the other day picking up a few things I needed and I came across a few "wet tile saws" that were set up on display ranging from about $45 - $80. Most were pretty small and looked like, with the inclusion of a diamond cutting wheel, they'd be perfect for accurately cutting FR4 and keeping the toxic dust to a minimum.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=3733

I've been growing quite tired of the old hacksaw method; cutting with a Dremel is messy; and snapping is okay but not very precise, a bit ugly and not a good choice at all when you are making a double-sided board at home.

I was just curious if anyone has tried one of these tile saws for cutting FR4 and what their results were? I don't make enough boards to warrant buying a shear but make more than enough so that something like this would be well worth the money over hacksawing everything. Thanks in advance for the help.

[John Lyons]

I've been thinking about an alternative as well. I use a table saw with good results but the dust is starting to worry me. Even with a respirator the dust in the air bugs me... I wonder if there is a small shear that may do the job. Are the metal shears what one would use on board material?

The tile saw seems like a possibility. A lot safer than the table saw as well!

Side note. You mentioned making double sided boards at home. What is your process for this?
I made mine by taking the top and bottom layer traces and a piece of folded paper.
I line up the two trace patterns with a back light so I can see the registration though the layers of paper.
I then make a sandwich with the board in the middle of the two prints lightly glued to the folded paper.
Iron and etch as usual.
How are you doing it?

Sorry, more questions than answers.

John

[Dragonfly]

http://www.amazon.com/exec/obidos/ASIN/B00009363O/floorstransforme

http://www.amazon.com/Heavy-Duty-3-1-Tile-Cutter/dp/B000VUSUOW/ref=sr_1_4?ie=UTF8&s=hi&qid=1205453660&sr=1-4

http://www.amazon.com/Building-Products-49050-13-Inch-Economy/dp/B000FSCN1Q/ref=sr_1_7?ie=UTF8&s=hi&qid=1205453660&sr=1-7

[John Lyons]

Hmmm... I guess I'll have to look at some in person to see if they may work.
I'd need the cutter to work with boards as small as 3/4" square so the bass would have to hold something that small.
Looks like the center is hollowed line out on these manual cutters so maybe this won't work.

Do you have any experience here Andy or did you just run across those links?

John

[O]

I actually just bought this saw a few days ago and so far, I'm really impressed.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=93211

It came with a diamond blade that is perfect for cutting the boards I've been working on. If you set the height just right, you can even score the fiberglass enough to snap it later. It's a bit underpowered for thick material (1/4 inch or more) but it chews through PCB material with ease. I think the smallest board I cut was about .5x.5 inches (it was a bit unnerving since the blade was really close to my fingers).

Anyway, I'm planning on running another production run, so if anyone wants pics, I can provide some.

[Myriad Society]

Here's a cheap general purpose shear that Harbor Freight has. I'm not sure if it would be the best thing for the job or not as I've never used one of these tools before. I'd imagine it would work fine though. Has anyone used something like this that would like to chime in?

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

Here's a few that are specially made for cutting PCBs but they are very pricey and I can't see spending that kind of money at this point. Think I'll try the wet tile saw first as a much cheaper alternative.

http://www.peats.com/cgi-bin/test_new/catalog.cgi?view_subcat=1&id=377&sid=22&cid=107

For the double sided PCBs I haven't been doing anything quite as tech as what it sounds like you are doing John. I will just do a PnP Blue transfer on one side as normal and then, contrary to the usual protocol, I'll tap it and drill the whole thing out before etching. Some very light sanding only on the bare side with at least 320 grit to level off the copper ridges that will form around the holes and then a little more buffing with 500 grit or better so everything is nice and smooth.

Then I'll simply hand draw the traces I need with a sharpie and color in circles around just the holes I'll be soldering to on the top side. Etch...flip after 10 min, flip after another 10 min and then every 3-5 min until it's done. Rinse, dry, same sanding process on the side I hadn't yet sanded down ridges on, clean off resist/sharpie with mineral spirits, poke out drill holes so they are nice and clean, scour both sides with Barkeeper's Friend and ready to go.

I've been thinking up a PnP double sided method sort of like what you were describing but haven't done it yet so I don't know that it will work. Worried about registration (obviously) and about melting resist on one side while ironing the other. Only one way to find out though. Plan on try on the next board I make. If anyone is reading this and thinking about trying to do a double sided PCB, don't forget to leave a little extra component lead on the top side of your board to solder to where needed as you will have to solder certain parts on both sides of the board. It's also easier to start in the middle of the board and work your way out toward the edges when populating so you don't accidentally melt something with your iron you didn't intend on melting.

[tranceracer]

I use this sheet metal shear.  Cuts thru pcb like budda.  One of the best PCB project investments.
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200309554_200309554

I've also found it useful to cut many other things other than just PCBs like aluminum sheet metal and steel sheet metal.

This one also looks good because it doesn't have the 8" limitation.  I would have bought this one but found it after I purchased the one above.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=38413

[frank]

I've been thinking about an alternative as well. I use a table saw with good results but the dust is starting to worry me. Even with a respirator the dust in the air bugs me... I wonder if there is a small shear that may do the job. Are the metal shears what one would use on board material?

I use a heavy-duty hand shear and it works well for paper/resin or thin fiberglass.
For 0,1in. (2.5mm) I am looking for a tile cutter too, since awhile.
I think I will buy one that you can put water under the blade.
I had been thingking that it would be best for keeping the fiberglass dust to a minimum.
Plus there are some that are not very $$$.
It's definitely worth the try, and if it's working tell me.

[R.G.]

I've been through most of the possible techniques for cutting PCB. What works best for me is a 12" shear I got from Harbor Freight. They no longer list this one, but have recently re-listed the 8" shear that they had before, then discontinued. If you can do it in less than 8", it'll work great.

Frankly, if you have compressed air available, the air nibbler at only $26 will do a great job, if a bit noisy.

Best cheap PCB trimming tool? A sheet of medium (100) sandpaper lying flat. Sand those edges.

Files make great tidiers too.

[Myriad Society]

Cool, that answers one of my questions then. I think that I linked previously in this thread to the same 8" shear from Harbor Freight that you just mentioned, R.G., which is easily about the best priced shear of its' kind that I can remember seeing. If you say it works good then that's good enough for me.

I'd imagine that with the tile saw, dust would be kept down pretty well which is a big concern of mine but you may have other problems with FR4 contaminated water splashing around off of the blade so you'd need to be selective about where you used it at. What is the dust level like when using the shear? Also, any problems with cutting accurately, like down to the tenth of an inch or so with it? Sorry about the added questions - I'd just hate to spend $140 on something that ultimately ends up keeping my lawn mower from blowing away. Curse me for trying to run my lawn mower with helium rather than gasoline anyway...I'm through with alternative fuels!

[John Lyons]

RG is the shear you are talking about the shear/brake type or the sheet metal lever type Tranceracer linked to?
It seems like the shear/brake would be easier to get straighter right angles. A lot of times I don't print the board outlines and obviously want close to perfect 90 degree angles. Maybe fitting some kind of alignment fence/miter would be doable.

Thanks

John

[R.G.]

It's the one Myriad linked to. I really like my 12" one, as 8" is a little tight, but it's probably OK for effects stuff. They both include a press brake.

[kurtlives]

I use a Dremel, gets it done quick.

I wear a mask to keep the dust away.

[Albot]

Whats the dangers with the dust? except for that it's dust?

[MicFarlow77]

Hi All,

I use the same 8" bandsaw that I use to build my enclosures. Dust is not a problem for me since the cut is downward and I use the metal cutting blade as well. I can cut almost any shape desired and of course, having a bandsaw is super handy for many other things. The one I have is a Ryobe one I picked up at Home Depot for $99 on the $99 tool isle... can't beat it.

Now I just have to figure out how to cut a hole in the middle of a PCB large enough to hold the 3PDT footswitch.... I'm pretty sure I can get it close with my Dremel and then clean it up with a file... might be able to drill the hole with a large diameter bit and then just square the edges... wouldn't create a lot of dust that way.....hhhmmmmm....just got to finish the PCB layout and try it.

Thanks,

Mick

[MikeH]

Whats the dangers with the dust? except for that it's dust?

It's not just dust- it's fiberglass

[aloupos]

For me, scoring works really well.  I think the difference is that I use a score meant for scoring acrylic(ie. Plexiglas).  If you score through all the copper, then snap the board in a door frame (a vice tends to leave marks), I get a pretty nice edge.  If I want a really perfect edge, I then hit it with the belt sander.  But the acrylic score is key, I've tried a razer before and I find it difficult to get a nice score/snap.

[juse]

I use this sheet metal shear.  Cuts thru pcb like budda.  One of the best PCB project investments.
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200309554_200309554

I've also found it useful to cut many other things other than just PCBs like aluminum sheet metal and steel sheet metal.

This one also looks good because it doesn't have the 8" limitation.  I would have bought this one but found it after I purchased the one above.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=38413

That first shear looks like a winner - compact size, affordable, minimal dust factor...... I'm not sure I would need anything over 8" for effects anyway:



I wonder how small of a board one could safely cut with this?

I can't tell, but it looks like the second one has a 4" shear area on it? I think you got the better of the two, tranceracer.

[tranceracer]

That first shear looks like a winner - compact size, affordable, minimal dust factor...... I'm not sure I would need anything over 8" for effects anyway:
I wonder how small of a board one could safely cut with this?
I can't tell, but it looks like the second one has a 4" shear area on it? I think you got the better of the two, tranceracer.

The largest board I cut is 12"x12".  I'll cut 6-8" on one side then turn the board around and cut it from the other side or cut the pieces the proper size.

As far as the smallest board... you can cut boards down to as little as .25" square and even cut that in half if you wish.   I've made mini PC board spacers by drilling the hole first and cutting around the hole. They were little smaller than .25"

Yes, the 2nd cutter has a smaller blade but the joint behind the blades will allow a continuous cut and you can adjust the angle of the cut if it strays.  The first shear, is kind of difficult to change direction of the cut once it's started so if it is started misaligned.

[jpm83]

I use steel ruler, carpet (exacto) knife and elbow grease. could this kind of paper cutter be useful? http://www.inkclub.com/index.asp?CtryNo=246&LangNo=58

Janne