Cutting and working with FR2 board

[MrBungle]

I've decided to switch to FR2 board for the next few projects. This has been brought on by the fact that I have three big problems with FR4: it's expensive, it eats HSS drills which are also expensive and the dust is pretty nasty stuff. I was using it for enclosures as well but I'm using sheet aluminium or ABS boxes now for that.

Rapid sell 100x160 boards at 10 for £8.73 including delivery which is pretty good so I've bought a stack.

So incidentally, has anyone got any tips on working with FR2? Past stripboard FR2 I've never used it. I know to avoid too much rework or the copper will lift. The main problems are with respect to cutting and drilling it. Can I score and snap it safely or will it delaminate and crack?

[Terry_VK5TM]

It can crack and de-laminate if not scored deeply enough, also you can't cut it with a shear unless heated (the laminate, not the shear) because it will crack.

One other thing to watch is it does give off toxic vapors under any sort of high speed machining, including drilling.

If you need any reasonable size hole, like to mount pots etc, start with a small drill size and work up in increments, otherwise again it will crack (and somewhat blunter drills work better than sharp drills as they wont bite in and split it in my experience).

Terry

[MrBungle]

Thanks for the tips. Appreciated.

I'll see where I get to

Drilling, use tungsten carbide bits, a bit pricey but always leave a good hole.
Big holes, use a conecut ( http://www.gjhalltools.com/tool/cone...ut-tube-drills ) after drilling a pilot.
Cutting, I use a 2mm tungsten carbide cutter in my milling machine with the board stuck down using thick double sided tape. The only other 'nice' way to do it (at home) is a hacksaw and finish with a file.

[Omegaman]

I use one of those small circular saw type tile cutting machines for various types of pcb material. The diamond coated blade goes through like a knife through butter. There doesn't seem to be much dust produced, but it's probably best to take some form of precaution.

[David G4EBT]

I use one of those too - bought for a fiver at a car boot sale - excellent, and the diamond cutting disc is thin too and never wears out. I only ever use FR4 fibreglass boards, and use 0.8mm HSS drills for component holes, which are very cheap, (99p for ten post free from China or Singapore in sizes from 0.5mm - 2.5mm) and I discard the drill after each PCB. They'd last much longer (certainly would on FR2), but I don't risk a drill bit skidding and wrecking a board for the sake of 10p.

A google search for these word strings will find the bits that I use:

0.5-10mm HSS Twist Drill Bits Straight Shank Auger Drilling Tools 10pcs / pack

Or this, (which might not seem to make much sense!):

10pcs 0.5-2.5mm HSS Straight Shank Twist Drill Bits Kit Electrical Drill Tools

A vote from me too for cone drills. I often use thin clear acrylic sheet to protect front panels on my home-brew projects. There's no chance of drilling acrylic sheet for such things as tuning caps, pots, sockets etc with a normal engineers' fluted drill without the drill snatching and wrecking the sheet. A cone drill does the job a treat, and you can go up a step at a time till you have the sized hole that you need. I'd never considered one, but was bought a set of three as a present and use them often. Great for aluminium and steel too.

The only slight downside of fibreglass rather than SRBP sheet is that you don't get that phenolic aroma as you do with SRBP, which I find rather agreeable!

Have fun.

[MrBungle]

Well I just spent half an hour shredding bits of FR2 based on the advice above just to see. Scoring and snapping was a disaster. I cut through what I usually do with FR4 depth-wise, which was admittedly much easier but snapping resulted in corners fracturing and a rather bad edge.

Then I tried hacksawing it which was marginally successful. Worked but edge was rough. I hate using a hacksaw to be honest.

Then out came the dremel with a cutting wheel - went through it like butter and left a nice clean edge.

Standard cheap HSS drills from Rapid in a Dremel chuck did the job. I used larger ones from this set: https://www.rapidonline.com/rvfm-c10...-piece-85-0420 ... and smaller ones individually purchased: https://www.rapidonline.com/ruko-214...-piece-60-7805

The above went through it like cheese at around 20,000 rpm. Drilled up to 3mm which is all I need. Started at 0.8mm and worked up in 1mm steps approx as I'm devoid of fancy drill bits. Nice clean holes.

Have to agree with David; the smell is rather agreeable but I suspect it will probably kill me or something.

Well Dremel it is. I have a dust mask and eye protection for reference.

[stuart_morgan_64]

Another vote for tile cutter circular saw, used this for many years, still the original blade.

Tile cutter, never thought of that, I may have to get one.

[David G4EBT]

If you look for something like a 'Plasplugs DWW200 Compact XL Electric 110mm Diamond Wet Wheel Tile Cutter Saw', they come up on e-bay secondhand for as little as a tenner, (one on there now), or brand new for about £50 - rather a lot for occasional use, but great if you also have tiles to cut. I was lucky to find one at a car boot sale and it's perfect for the task.

[stuart_morgan_64]

Do watch out, I am on my second one, most have a water bath for the blade, my first one the bearing went on the motor due to the water. \Maybe worth checking on a secondhand one.

[Oldcodger]

What I've used on laminate board is a hand tile cutter to mark a straight line and score the copper,then a pair of metal cutters to make the cut. But this was on a 2inch cut.