Okay, so my level says "What's a dremel?" Be prepared... I'm trying to practice on a scrap computer case. I've got a dremel. I'm using heavy duty cutting discs. It's not working. My first cut, I cut about two inches and the disc shattered. I've gone through four since then with no luck. What am I doing wrong?
What kind of metal are cutting? The fiber reinforced discs might work better. Also, they somewhat recently came out with a new system where the shaft is different and the discs for it are dedicated metal or plastic discs. If it's steel, you're going to have to go very slowly. If aluminum, then you shouldn't be shattering them so quickly. If you're going to be cutting steel, you might be better off with an angle grinder. What about the tool speed?
If your cutting large areas like a square window, definitely use a jigsaw. It'll eat through any case 10 times faster than a Dremel, and makes a nice clean straight edge that requires minimal filing afterwards. As Stu said use a fiber reinforced cutting disk. Also if you have a flex-shaft attachment, use it. A trick that seems to work well is to go along a line lightly, so you dig a very shallow groove in the metal, maybe 1mm deep or less. Keep doing this and it will eventually go through. This helps stop the disk from running into a solid edge of metal that will take pieces off. Its like trying to saw through a log by running the saw into the side of the log over and over again instead of going back and forth through it. Sort of. Bad analogy.
It might be steel, I'm not sure. It's just a junker case I have in the garage. I do have a jigsaw. If it's steel, will it cut it or am I just going to ruin some blades?
Okay, the side panel weighs about 3-5 pounds. (I think, hard to judge and my bathroom scale is broken) I'll see what kind of blades I've got for the jig.
Don't try and force the blade to cut the metal. Just use a light light pressure, and allow the blade to do its thing. If it's steel you're cutting, I'd recommend diamond discs (Dremel part number 545)
Just keep in mind the following..you're not using the cutoff wheel as a cutter but a concentrated grinder, you have to think of it as if you're grinding a groove into the metal that will eventually punch through. Slow and easy.. patience is a virtue. However if you're doing a large cut.. as Mattthegamer suggested a jigsaw with an appropriate steel blade will do a WAY better job with cleaner cuts.
I completely agree. Use high rotation speed but go slow with it and use light pressure. If the discs are breaking, you're probably pressing too hard (unless you're using the really cheap thin crappy discs that are about a buck for a 25-pack). Don't try to go through all at once. Yes, it's possible, but it's really a bad habit and it's much easier to break discs that way (trust me). It certainly takes practice, and you've taken the right approach with just playing around on a test piece before going right in. Try to do some more complicated things when just experimenting - it helps a lot. Hang on to discs that have worn down a bit (not down to nothing, but smaller than they started) for finer detail areas. Also, general tip - watch the angle of the disc relative to the piece you're cutting. Try to keep it as perpindicular as possible when you're doing straight cuts. Only have the disc at an angle when you're doing curves or weird shapes and make sure you don't start right on the line when doing so. It's a bit hard to describe in text, but angle the disc so you'd get a cone on the top side of the curved cut (ie, if you're doing a circle, have it so the top of the disc is angled in and the bottom is angled out). I'm personally not a huge fan of the flex-shaft attachment for metal cutting work, but give it a try and see if it works for you. Just be patient. And avoid giving yourself too little clearance to allow for screw-ups (work a little bit inside the line so if you go over, you're not really over). Use plenty of masking tape (I swear by two layers, and it's saved me more than once where one layer wouldn't have) and WEAR SAFETY GOGGLES! Oh, for reference, steel will have sparks flying absolutely everywhere at high speed. Aluminum generally doesn't (just a couple at full tilt is all I've ever seen). Most people swear that alu is easier to cut, but for some reason I alway seem to have an easier time cutting steel (probably because it's harder so it's more of a cut than a grind). Just be aware that the sparks are normal when working with steel (and largely harmless on bare skin, although I'd highly suggest work gloves, just keep them away from the EYES) and that the two metals handle very differently. If you know you're working with steel and aren't seeing any sparks, or very little, you should consider upping the rotation speed a bit. Not all the way - I usually go a bit over half way, but not at lowest speed either. Just experiment, it takes practice. We were all noobs once But seriously, do NOT forget safety goggles.
Thanks for all the tips. I found some steel cutting blades for my jigsaw and did a lot with that today. I also practiced a little more with the dremel, and I'm doing better. Yes, it must be steel because sparks are all over. Only trouble I've ran into since then is trying to secure the piece of metal to the table. I have two clamps and a monitor setting on the other side of it. This seems to work, except when I had the cut-out dangling over the edge. Had to do smaller cuts and secure the window a little more. Quick question about the sparks. Are they hot enough to set a wood table or cardboard box on fire or are they relatively harmless?
Relatively harmless, unless they land in a flammable substance like gasoline. They can be bad for stuff though, like electronics, so its a good idea to do cutting in a 4 sided box to keep the sparks and metal dust in a small area.
heavy duty cut off disks arent very good.. id recommend using a reinforced fibreglass cutoff wheel.. theyre much better and last longer, also, if you find when you are cutting that your dremel is losing speed/torque, back off a bit because they WILL break.. also.. as above somewhere.. angle grinders are good for larger ares although they arent as neat.. Rage.
oooo this is just the problem I'm having as well... well, sort of.. I just got a Dremel XPR 400 set (corded 5k-35k rpm) ...it came with a Circle Cutting attachment, and my mom got me an extra Carbide cutting bit (not a wheel) so that I could cut a window in the case ... I was practicing with an old case and damn was it harder than i expected.. i ran the dremel at speed 10 (highest) as suggested by the manual, however using the Circle Cutting attachment it seemed like I had to put a ton of pressure perpendicular to the bit in order for it to cut away the metal ..there was also a ton of vibration .. anyone have any thoughts on using Carbide bits vs. wheels? It seemed way harder than it should have been! ...maybe I should stick with a jigsaw?
I don't have any experience with the circle cutting attachment but I do know that these work pretty well for cutting complex patterns in aluminum. If the old case you were practicing on was made out of steel, it will take more pressure and work no matter what bits and attachments you use. However, if you're looking to cut a simple window like a rectangle, circle, or oval, a jigsaw would work best. Dremels are slow work and tend to leave rough edges that require a lot of filing. Just be sure to use a blade with the right tooth per inch count.
I think it's a steel case.. lots of sparks flying everywhere.. and I'd figure aluminum would have cut easier Hmmm, yea maybe I'll look into that.... thanks! edit:as an afterthought.. anything you folks recommend as a good bit to file down the rough edges? I was using a drum bit that came with the dremel kit.. seemed to grind it down pretty well.
Yeah, sparks are a big indication of steel. Aluminum really only shoots out sparks if you press hard, from what I have found. A set of rasps will do you just fine. Make sure you pick up set like this one that has some variety to it. That set is a bit expensive though. You could easily find a set for $15 or so at Home Depot.
Hmmm.. so you think using a dremel bit to file down steel burs isnt effective? or do you think it just eats through bits real fast?
It all depends on the bit and the speed used. I prefer using rasps. Despite taking longer, it provides more accuracy as well as a sense of accomplishment when you're done.
