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.
(http://www.moltenvoltage.com/downloads/forums/saw1.jpg)
(http://www.moltenvoltage.com/downloads/forums/saw3.jpg)
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).
(http://www.moltenvoltage.com/downloads/forums/saw2.jpg)
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.
(http://www.moltenvoltage.com/downloads/forums/saw4.jpg)
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 (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?function=Search)
That thing looks dangerous!
Look out you'se kids... don't put yer lips ohne it!
Have you even tried a paper shear?
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.
Ah, a DIY fingertip remover, handy! :icon_mrgreen:
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 (http://www.waterfront-woods.com/Articles/Tablesaw/tablesaw.htm)
While you could potentially loose a finger that thing looks cool!
If you use your knees to clanmp the enclosure so it doesn't spin, :icon_mrgreen: 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
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90757 (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90757)
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.
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 (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/photos/42300-42399/42307.gif)
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=42307 (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=42307)
I also found cheap carbide bits at HF (20 for $5.49). They're new, but you don't know what sizes you are getting:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=44924 (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=44924)
They came with about 5 that were larger than .032 in spite of the way they are advertised. There were also some repeats, but I was just looking for the .032 one anyway.
Thanks for the comments!
This is pretty clever use of a Dremel and it's saw attachment.
http://www.youtube.com/watch?v=61Q_6-cRua4&feature=fvw
That's pretty nifty.
I love that, it's really simole and neat, but knowing me i would just go and forget to turn the dremel off and go off to put the kettle on then come back and take a seat, OUCH !! lol
"No Mr Bond I expect you to die" (http://media.monstersandcritics.com/articles/1236313/article_images/iexpectyoutodiemrbond.jpg)
These (http://cgi.ebay.nl/Proxxon-bench-circular-saw-KS-230-model-makers_W0QQitemZ110491624015QQcmdZViewItemQQptZUK_Home_Garden_PowerTools_SM?hash=item19b9d0624f) are regularly offered second hand on eBay, and don't cost an arm and a leg new. I wonder if they are handy for cutting pcb's. I have a Proxxon pillar drill I use to drill pcb's, and it is very nice, much better than that flimsy plastic Dremel thing. If the saw is the same quality than that's a good deal.
I used this for quite a while:
(http://www.harborfreight.com/cpi/photos/93200-93299/93211.gif)
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93211
But, this is much better:
(http://images.lowes.com/product/converted/039725/039725031433lg.jpg)
http://www.lowes.com/pd_22199-46922-3385-01_0_?productId=1207605&Ntt=band%20saw&Ntk=i_products&pl=1¤tURL=/pl__0__s?newSearch=true$Ntt=band%20saw$y=0$x=0
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
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
Ha ha, viva DIY! :icon_razz:
Quote from: danielzink on February 12, 2010, 09:38:14 PM
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).
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.
Quote from: Jarno on February 12, 2010, 04:04:53 AM
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.
ABSOLUTELY!!! The blade of a table saw should almost never be more than about a tooth's depth above the top of the workpiece. You could improve this pretty simply by putting a piece of plywood or something like that on top to act as a scrap table, and make sure you bold it down. This would also give you the advantage of a larger table, and you could even work up some kind of fence which would vastly improve safety. Also, by doing this you would have a zero clearance plate, which pretty much eliminates most chipping and tear-out.
And a bearing is also very important if you want the thing to run at all true.
I also have a slight problem with the saw blade. If I'm not mistaken, that's a screw slitting blade. They are wonderful things for certain purposes, but they are not intended to cut through things. Now, that may not seem like a big deal, but the problem is they do not have any set to the teeth, which means they will tend to bind, burn, and to dull very fast.
Quote from: John Lyons on February 12, 2010, 05:09:42 PM
The band saw is infinitely safer that the table saw types.
Yup. While it is, in theory, possible to cut off your finger with a band saw, I've never been able to figure out how. I know that a lot of people every year do so, but it isn't NEARLY as big of an issue as table saws. The two primary dangers with saws are self-feeding and kickback. Radial Arm saws are self feeding, and table saws will kick-back. Band saws don't do either - in order to cut anything off, you have to actually push it the whole way through. I've nicked my fingers on my band saw a couple times, and while I don't recommend it, they were both Band-Aid injuries. Your typical table saw injury costs over $60,000 in medical expenses. (Not all band saw injuries are as minor as mine happened to be - I was very lucky. Don't push your luck.)
A table saw is a VERY different animal. It can grab your hand and cut things off faster than you can imagine, and running the blade at a slower speed can actually make things worse. First of all, the blade will be MUCH more likely to catch, kickback, and to throw the work piece (including, potentially, right at your head, which can have enough kinetic energy to make you a vegetable!) Also, somewhat counter-intuitively, you can build up more heat at slower speeds, because at higher speeds (and, more to the point, higher feed rates) the dust from the workpiece work will work as a lubricant. It does depend on the material, and with metals that doesn't work, but with the fiberglass faster speeds tend to make the blade safer.
Gabriel
I think most injuries with a band saw occur BECAUSE it seems so well mannered. "let me put my finger against the workpiece there to make that tight curve", and oh oh, there it goes.
Quote from: Jarno on February 13, 2010, 06:04:33 AM
I think most injuries with a band saw occur BECAUSE it seems so well mannered. "let me put my finger against the workpiece there to make that tight curve", and oh oh, there it goes.
Actually, I'm pretty sure that most serious band saw injuries happen in butcher's shops. Certainly, no woodworker I've ever known has had one. I know there are guys who have, but I've never met one. Same for metal workers.
Gabriel
I just watched that video that someone posted earlier - the feller that had made a saw table from a dremel and a plastic stool. It gave me a funny feeling in my willy, and not in a nice way.
All those spinning sharp metal things scare me. I've got a fairly well equipped metal-bashing workshop, but I try to do things using hand tools wherever possible. If I really have to use the big dogs, I'm keen on clamping stuff down really well, and wearing more protective clothing than a tiger trainer.
I might be a fraidy cat, but I've still got my good looks. And all my fingers. BE CAREFUL OUT THERE!
I have to chime in on this. That thing is AWESOME! That is some amazing resourcefulness for sure, it's like a pocket table saw. I thought of something, you said you are using oil for the lubricant for the shaft. Rollerblades use a ball bearing system that is sealed up and interchangeable, you might look into those for a better fitting and less ad hoc axl.
Quote from: R.G. on February 12, 2010, 09:40:27 AM
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90757 (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90757)
I use a shear as well, or a hacksaw. PCB's are often so small your fingers will be uncomfortably close to a power tool, if something grabbed, etc. When things happen with power tools, they happen
fast. Say your naive medieval grease only axle gets hot and dries up and seizes, the whole saw seems like it will flip up towards you, since it doesn't look like it is secured down, or very heavy... Sorry Karl, I don't like it.
Quote from: markeebee on February 13, 2010, 07:22:52 AM
All those spinning sharp metal things scare me. I've got a fairly well equipped metal-bashing workshop, but I try to do things using hand tools wherever possible. If I really have to use the big dogs, I'm keen on clamping stuff down really well, and wearing more protective clothing than a tiger trainer.
Typical metal worker! ;D ;D
It's a funny thing - metal workers usually have their work piece clamped down, and either move the table or move the cutter. Woodworkers usually do not clamp down the work piece, and keep the table and cutter stationary. That said, if I were to cut circuit boards with a table saw, I might be tempted clamp it to a sliding table to insure my fingers were well out of the way. I do something similar for the wood pickup rings I make.
Be careful about clothing when using power tools. Gloves and long sleeves have a tendency to get caught in blades and such, which is REALLY dangerous. It may be different for metal working, where your hands are usually further from the danger and the metal filings are a bigger concern, but with a table saw the safest clothing is long pants, normal shoes with good traction, a tee shirt, and no dangling jewelry. Its best not to wear a wrist watch either.
Oh, and Norm Abram is wrong about the most important safety precaution being safety glasses - they are hugely important, but the most important safety precaution is knowing how a tool works, what will go wrong, and how to position yourself so that WHEN it goes wrong you're not in the way! I caught a very small piece of debris (maybe 1/32"X3/4"X6" - just an off cut that fell between the blade and the throat plate, and got kicked back) in the shoulder once - and have the scars to show for it - and it drove home (quite literally) the importance of keeping out of the path of danger. I was lucky it was small and all I got were a couple puncture wounds and a big bruise - it was small enough not to have enough kinetic energy to do any serious damage. By the time I noticed the cut off was falling into the blade like that, it had already bounced off my shoulder.
Gabriel
Quote from: Processaurus on February 13, 2010, 10:51:21 PM
Say your naive medieval grease only axle gets hot and dries up and seizes, the whole saw seems like it will flip up towards you, since it doesn't look like it is secured down, or very heavy... Sorry Karl, I don't like it.
VERY serious concern.
Gabriel
There aren't many power tools that make me nervous--I was taught how to use most types of them properly (lol...except for the safety guards--those were always removed) from when I was little.
My grandfather's custom furniture shop still has all kinds of nice machinery sitting unused since he passed. The only one I haven't used is the raised-panel router table, because I'll never forget the day Pap wrapped his hand in his handkerchief and drove himself to the hospital while everyone else was still trying to call 911.
He lost 2 fingers to a 4" version of one of these:
(http://www.woodcraft.com/Images/products/828801.jpg)
I get the same feeling when I see ANY kind of makeshift table saw. I'd stay FAR away from that stool one. Woo.
:icon_eek: :icon_eek: :icon_eek: Im scared of this thing :icon_eek: :icon_eek: :icon_eek:
Quote from: Processaurus on February 13, 2010, 10:51:21 PM
When things happen with power tools, they happen fast.
Yeah - and the machine doesn't stop to see why you're yelling. One thing my previous employer was persnickety about was training on power tools. No training certificate, no operation. Firing offense. I had to get "trained" to use the manually operated lever-shear and brake in the shop. The training for these two consisted entirely of "OK, you put the work in there, pull down on this lever here, and you're done. Don't put your fingers in it."
I was young then, and had been raised on the maxim "Question authority". Had a couple of T shirts that said that. So I asked why the training course was days or weeks on the power equipment and so nearly-nothing on the manual stuff. The machinist training me grinned and replied "We all figured out long ago that if you're supplying all the power by hand to a whatsit that's hurting you, you'll stop on your own before it gets worse. A power tool doesn't stop." Then he signed off on my manual-tools-only training chit and handed it to me.
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... :icon_lol:
When things happen with power tools, they happen fast.
While looking for a mellow saw in the Dewalt, Ryobi, B&D etc. catalog at Lowes, we discussed saws and bigger trucks with more towing capacity, noting a likeness, except where lower powered saws are concerned.
I turned on a circular saw:
The Lights Dimmed.
The saw tried to jump out of my had.
The overstressed side-bearing and general fierce chatter is enough to make you want to find a different cutting method alone. The numerous test cuts were each total failures. New blade/straight edge, depth set etc.,
The grain is blown to splinters on both but severely on the deep face grain.
The clamped straight edge line is shown as a wavy line where the blade cut.
The squareness of depth cut is wavy too.
Plumes of smoke, fried blades, burnt bearings...
The other circular saw had a little bit better looking body, aesthetically speaking.
I designed the Rail Saw. It doesn't have enough current to start wood smoking or heat a blade,
The ''Twin Rail Guide'' [modded radial arm saw arm, just the ''arm'' thank you] gets clamped 2'' from where the cut line, and controls the slow RPM blades teeth, keeping them in a more perfectly straight, square line, instead of reaching all the way around the back of the workpiece, up the pole, back out the arm.
The Auto-Super-Slow Drive system [allows the blade to nibble on a few fibers each pass] is a simple slip-clutch driven Rail Guide Screw, it advances the blade [specially designed so it can't take large bites] at a snails pace.
Very slow, very limited cutting depth, ability to go back in it's bag and hang in the closet after making perfect rips, crosscuts, dado's...all the stuff the amazing powertools just can do [if you like super-high-speed 3-blade-pack prices, radial saw footprint and price].
I've got time to take breaks while the wood glue dries...and there are many extremely important safety issues which require time to contemplate, while the snail-rail-cutter does it's fine workpiece preparations, you'll have time to do these contemplations.
Necessity is the mother of invention, seems like such an obvious thing...oh yea...almost forgot the slide/clamps on the bottome of the Snails Rail Saw.
Quote from: R.G. on February 14, 2010, 02:23:39 AM
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.
I'm using the score and snap method, and then I finish the edges with a tile dressing stone. It takes longer than I like, but the edges are perfect, and I can be extremely precise with where I cut it, which I like. I've gotten to the point now where it takes me maybe a minute for each edge. Occasionally, when I need a weird shape, I'll use a coping saw, but I still finish it with the dressing stone, as it leaves a really nice finish very fast.
Still, there is a part of me that wants to get a little band saw for my house, which is where I do all my electronics tinkering. I'd use the one at the shop, but it takes me less time to do it here at home (because I don't have to go down there), and I neither want to dull our woodworking blades nor to have to constantly change them (which is a PITA). Its just hard to find the space for a band saw here in the house.
Gabriel
http://www.probotix.com/FireBall_v90_cnc_router_kit/
Well, I certainly wouldn't want anyone to get hurt copying this idea, so do so at your own risk!
Will post severed finger photos as they become available...
well i like it...if you loose a finger with that thing you deserve to loose a finger. i'm not saying that to be a jerk...if you don't have the commonsense to know how to use a tool like that then you probably don't have the common sense to know that you shouldn't use a tool like that and it might be better to learn your lesson and hurt yourself on a this little guy than a unisaw. i'll bet a dollar that that drill doesn't have any where near high enough rpm to over heat the grease and if your running it for that long then you should be looking for a better way to do it. with that said a set of bearings would probably be worth it in the long run. and yes mounting it would not only make it safer but easier to use.
i've been a wood worker for 20 years now and i can easily say that i've cut myself more times with a utility/exacto knife than i have with a table saw and i've been a cabinet guy for the last 8-10 years...
i will say that the dremel footstool saw scares the crap out of me...
Jaco, my older brother [the Real Guitarist of the famm], was making the rounds at a joiner [I think it's called] running a whole lot of 3/4'' mahogany through there.
He lost a couple fingertips in his left hand, while looking for them they realized [with all the blood everywhere, kinda hard to see] they were still barely attached and swingin'.
The surgeon in Bitburg was very very good, very very nice fellow, he managed to put some of the pieces he had left to work with back in there, it didn't infect...
Lucky is Jeff's middle name...he plays amazing guitar techniques, I mean development way beyond 'normal' guitar...and uses his 1rst and second fingers of left hand which have no 3rd joint articulation to do it.
I said lucky...yepp, dern lucky !
Lookin' all over for those fingertips...all but about 1/8'' was completely separated, crushed/bruised/missing pieces...that Dr. was very very good...I think I said good 'n lucky like 8 times...
a few years back i dipped a finger into a jointer and all i got was 3 little cuts on the side of my finger. i couldn't believe how lucky i was. they looked like shark gills. the jointer came from a navy shipyard (if i remember correctly) and it seemed as though no one ever thought to sharpen the knives which i think was in my favor...
Quote from: R.G. on February 14, 2010, 02:23:39 AM
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... :icon_lol:
No, but you can cut your finger (or thumb) like this:
(http://www.diyguitarist.com/Images/CutThumb.JPG)
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! :icon_lol:
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.
I TOLD YOU SO
(http://www.moltenvoltage.com/downloads/forums/smph.JPG)
(http://www.moltenvoltage.com/downloads/forums/smwrap.JPG)
Oh bummer dude :'(
I really hope your OK and heal up well.
Are you gonna do it again ?
YIKES! Now that's a bummer! I hope you learned your lesson. :(
I had to cobble together a board-cutting rig in a hurry and came up with this:
(http://lh5.ggpht.com/_IOaMdfilLYg/S50b2sH5boI/AAAAAAAAAhE/Qa_aUrTzc6w/s400/DSCN1556.JPG)
Actually works surprisingly well.
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. :icon_mrgreen:
Quote from: UncleFluffy on May 11, 2010, 01:01:30 AM
I had to cobble together a board-cutting rig in a hurry and came up with this:
(http://lh5.ggpht.com/_IOaMdfilLYg/S50b2sH5boI/AAAAAAAAAhE/Qa_aUrTzc6w/s400/DSCN1556.JPG)
Actually works surprisingly well.
The tech guys at my work did the exact same thing... ha ha. Works pretty well.
OOOOWWWWW!!!!
Quote from: MoltenVoltage on February 15, 2010, 05:20:40 AM
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.
Quote from: MoltenVoltage on May 11, 2010, 12:14:48 AM
I TOLD YOU SO
(http://www.moltenvoltage.com/downloads/forums/smph.JPG)
(http://www.moltenvoltage.com/downloads/forums/smwrap.JPG)
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
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.
What happened ? What did go wrong ? Did it flip ?
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.
Quote from: Skruffyhound on May 11, 2010, 05:52:30 PM
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.
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!!
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.
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?
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.
Thanks R.G.!!