Shop OBEX P1 Docs P2 Docs Learn Events
Another snag...I need to find something to cut PCB's — Parallax Forums

Another snag...I need to find something to cut PCB's

RavenkallenRavenkallen Posts: 1,057
edited 2010-10-15 09:32 in General Discussion
I have amassed all of the needed materials to make my first printed circuit board...

Ferric Chloride..Check
Small drill bits...Check
Nice drill.....Check
Copper clad board....Check
Method of transferring design to board....Check
A way to cut my board....OOOPS

I tried a hacksaw and the term "hack" very well described the end result. I need something to cut the boards with that is cheap(Preferably) and safe. I have seen little power saws at Lowes and i wonder if something like that would work? Or could i use something a little less invasive?
Thanks in advance..
«1

Comments

  • Peter KG6LSEPeter KG6LSE Posts: 1,383
    edited 2010-10-11 17:56
    I used a 10,000RPM 4" harbor frieght angle grinder . its crude but it works well .
  • LeonLeon Posts: 7,620
    edited 2010-10-11 18:14
    I score the material deeply on both sides with a Stanley knife, and snap it. It's easier with the FEC-1 I use than with FR4.
  • Martin_HMartin_H Posts: 4,051
    edited 2010-10-11 18:27
    I use the utility knife scoring and snap technique. I tried cutting with a fine bladed scroll saw, but I found that left ragged edges that kept flaking off.
  • W9GFOW9GFO Posts: 4,010
    edited 2010-10-11 19:25
    A wet saw, like used to cut tiles works quite nicely.

    image_475.jpg

    Rich H
  • ercoerco Posts: 20,260
    edited 2010-10-11 19:28
    Knife-score & snap, followed by a quick hit on disk sander to flatten up the edge.
  • hover1hover1 Posts: 1,929
    edited 2010-10-11 19:40
    I have used a Band Saw for cutting PC boards for the last 20 years. A table top version like this would be useful for not only PC boards, but other projects including enclosures for your projects:

    http://www.amazon.com/Rockwell-RK7453-9-Inch-Band-Saw/dp/B002CJLUYM
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2010-10-11 20:07
    Just make sure you do everything in a well ventilated area! Also, wear a dust mask if you are sanding the board.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2010-10-11 20:31
    If you use a disk sander to sand the board edges flat, pulse it on, and do your sanding with the power off as it slows down. Otherwise, you risk scorching the epoxy filler.

    Small boards can be clamped in a vise with the desired edge aligned to the jaw tops, then filed down flush with the jaws for a smooth, flat finish.

    -Phil
  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2010-10-11 21:30
    Something similar to a "Miter Box" in combination with a hack saw will give good results. I had to do this once where the PCB I was cutting was too small to effectively hold on to and use any of the above mentioned methods. I used stock Aluminum "L" brackets to make a clamping apparatus that I could put in a vise and hold the PCB I wanted to cut, leaving a 'window' where I could run the hacksaw through.
  • T ChapT Chap Posts: 4,223
    edited 2010-10-11 22:43
    On a CNC machine I use this dremel router bit found in all the hardware stores, it lasts forever, doesn't overheat at 10,000 rpms and makes a really nice finish. You could accomplish a similar result without a CNC by mounting a dremel tool on a table, then build a gate to run the PCB against. No sanding required after.
    9902_lg.jpg
    400 x 400 - 21K
  • RavenkallenRavenkallen Posts: 1,057
    edited 2010-10-12 07:33
    Thank you all for the suggestions...I think i will try the "score and snap" method first. It sounds like it is the cheapest/ most straightforward...So basically you are just cutting some of it with knife until it is deep enough that you can snap it off, huh!!
    I wonder if i could drill several holes in the board and then snap it off like that...Of course i will need something to clean up the ragged edges...
    What kind of knife is recommended?
  • John R.John R. Posts: 1,376
    edited 2010-10-12 09:07
    Ravenkallen wrote: »
    What kind of knife is recommended?

    Not one you plan on using with food would be the first criteria...

    One of the large XActo types works, even better is the "box cutter" type things that hold razor blades, or the trapazoid shaped guys.

    You want somthing rigid and sharp, but not too thick.

    Keep in mind, you're not trying to cut through the board, just deep enough to create a stress riser so that when you do the "snap" it breaks where you want. Usually you would either clamp the curcuit board in a vice with the scribe just above the jaws, or do the snap over the edge of a table, with the scribe alighed with the edge.


    John R.
  • LeonLeon Posts: 7,620
    edited 2010-10-12 09:09
    I resharpen the Stanley knife blade with a diamond hone every time I use it ; they get blunted very quickly.
  • Spiral_72Spiral_72 Posts: 791
    edited 2010-10-12 09:14
    Yep, box cutter (a.k.a. utility knife) and a new blade along a straight edge. Keep you blade angle low with moderate pressure and make several cuts rather than high and bearing down on the blade, especially on the copper side.

    Oh, and uh, use clamps for the straight edge, not your own hands...... Trust me on this one. Besides, it's nice to have both hands on the blade for control.
  • LeonLeon Posts: 7,620
    edited 2010-10-12 09:21
    A colleague of mine cut the end of his thumb off when using a Stanley knife.
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2010-10-12 10:05
    Nothing wrong with hand tools. I use a hacksaw because it is fine toothed and cuts through metal. For better control, I put the blade in backwards. That makes it like a traditional Japanese backsaw and it is much easier to pull that push.

    I just draw a pencil line with a square edge, follow the line, and then clean up the edge with a regular 'mill bastard' metal file.
  • localrogerlocalroger Posts: 3,452
    edited 2010-10-12 11:50
    A nibbling tool does a clean, accurate job taking a bit of time but without mounting the board or using power tools; a linear cut will be the width of the nibbling head or about 1/4 inch. Radio Shack used to carry them, Harbor Freight still does, here's one on sale by Amazon: http://www.amazon.com/Parts-Express-Nickel-Plated-Nibbling/dp/B0002KRACO
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2010-10-12 12:47
    One thing to keep in mind when cutting epoxy/glass material is that it's extremely abrasive and will wear whatever you're using to cut it very quickly. So don't waste any expensive tools on it to cut it. In the PCB fab houses, the boards are cut with solid carbide router bits, and even they wear out.

    -Phil
  • skylightskylight Posts: 1,915
    edited 2010-10-12 13:29
    use a guillotine perfect cut every time
  • kwinnkwinn Posts: 8,697
    edited 2010-10-12 22:04
    Home Depot has a cheap tool fot scoring plastic sheets such as flourescent light lenses that works well on circuit boards. Use a straight edge as a guide and make several light scores (on both sides if possible).
  • TinkersALotTinkersALot Posts: 535
    edited 2010-10-12 22:21
    drum roll......

    I use a paper cutter (you know one of those things you sit on a table or workbench with a long levered knife)...

    With the built in gridlines, alignment is easy.

    The trick comes in applying force to the blade handle in a way that pushes the blade up close to the guide edge as you are bringing it down.

    I've seen paper cutters give a good clean cuts every time. Practice some first on some throw away stock to learn how to position the board where you want it cut and to learn how it works.
  • schillschill Posts: 741
    edited 2010-10-13 05:14
    Phil Pilgrim (PhiPi) wrote: »
    One thing to keep in mind when cutting epoxy/glass material is that it's extremely abrasive and will wear whatever you're using to cut it very quickly. So don't waste any expensive tools on it to cut it. In the PCB fab houses, the boards are cut with solid carbide router bits, and even they wear out.

    I've tried cutting boards with a scroll saw and the blade teeth wore down completely after cutting only a few (well, maybe 4) inches. This may say more about the quality of those blades than the method, but I haven't bothered with that approach again.
  • LeonLeon Posts: 7,620
    edited 2010-10-13 05:37
    I've tried a tungsten carbide tile cutter. It works, but I prefer the Stanley knife.
  • RavenkallenRavenkallen Posts: 1,057
    edited 2010-10-13 07:29
    So i am going to Concord today and i am going to pick up some supplies...I guess box cutters are pretty easy to find. Thank you all for the suggestions. I want to try out different techniques, but i am trying the score and snap first.
  • John R.John R. Posts: 1,376
    edited 2010-10-13 08:12
    schill wrote: »
    I've tried cutting boards with a scroll saw and the blade teeth wore down completely after cutting only a few (well, maybe 4) inches. This may say more about the quality of those blades than the method, but I haven't bothered with that approach again.

    Scroll saw blades are great for what they are intended for, cutting soft, non-abbrasive materials. They are specifically not hardened so that they do not become brittle, and snap everytime you put a little twist in the blade as you try and turn the work piece.

    You may have better luck on a scroll saw with the "blades" that consist of a wire with abrasive adhered to it. These are meant for 360 degree cutting (you don't have to rotate the work piece to change cut direction, and with the right abbrasive, may work OK for cutting circuit boards.


    John R.
  • localrogerlocalroger Posts: 3,452
    edited 2010-10-13 08:38
    You can get those abrasive scroll saw blades with diamond for the abrasive. I suspect that would hold up well, but you'd need to use a guide to get a straight cut.
  • John A. ZoidbergJohn A. Zoidberg Posts: 514
    edited 2010-10-15 02:25
    Well, does a paper guillotine cut it well? (no pun intended) I saw a paper cutter in a shopping center and it's pretty cheap but not sure whether it is a safe way to cut PCBs. :D
  • TinkersALotTinkersALot Posts: 535
    edited 2010-10-15 08:04
    John A. Zoidberg wrote: »
    Well, does a paper guillotine cut it well? (no pun intended) I saw a paper cutter in a shopping center and it's pretty cheap but not sure whether it is a safe way to cut PCBs. :D


    Yeah, the cuts are good. The trick to it though is learning where the cut really will end up. So it takes "some practice" to get that right.

    After that, as long as you keep your parts (arms, legs, fingers, well all parts of your anatomy) out of the damage path it is safe.

    As has been said, I may be old enough they have to sell me pretty much whatever I want, whether or not I am responsible enough to have what I want is an unrelated question.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2010-10-15 09:05
    When cutting through glass fiber, a paper cutter will dull very quickly. If you use one, be sure you know how to resharpen the blade. Also, due to it's stiffness, the circuit board will tend to buckle upwards as downward pressure is applied to the blade. Some means clamping it down would be desirable.

    -Phil
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2010-10-15 09:19
    If you have to cut a lot of boards then another option may be a table top metal shear:

    http://www.harborfreight.com/8-inch-bench-top-shear-brake-90757.html

    Cutting boards should be much easier than cutting metal!

    Robert
Sign In or Register to comment.