Re: [Grubb's] Random Thoughts of the Day
Posted: Sat Jan 12, 2013 3:32 am
Use of Windex (with ammonia) on the front glass is fine, and it'll make it look pretty nice. It's not the greatest cleaner for pretty much anything else on the machine, but you're unlikely to cause any real damage. Read Ho's article on how to do this:
http://www.indyddr.com/features/stage.htm
BTW, I would not recommend using Windex (or similar cleaners with ammonia) on the monitor tube face itself or on the clear plexiglass pieces in front of the speakers. It could cloud the plexiglass, and if the monitor has an anti-reflective coating, it will do REALLY bad things to it. Most arcade monitors don't have an AR coating, but YMMV and simple surfactant cleaners are generally fine for that application as it's just fine dust and not oils (from hands, etc.).
As to removing screws, here's the process I use (in order):
1. CLEAN OUT THE HEAD BEFORE YOU DO ANYTHING. Any dirt in the head will just make the driver not seat correctly and cause you to strip it out. A small flat screwdriver is handy for this. Dental picks or similar work great, too. For loosening really packed in dirt, you can use a smaller size Philips (like a #0) and tap it lightly with a rubber mallet (I don't recommend a hammer).
2. Attempt to unseat USING A MANUAL SCREWDRIVER (no power yet) the screw. Use the appropriate size screwdriver for this. For the trim pieces on DDR, this is a #2 (the "normal" size). For the stage corners, it's a #3 (the big size). Push hard and turn slowly. If you see it start to cam out, STOP as you'll strip it. You need more downward pressure.
3. If that fails, make sure the head is REALLY clean. Apply power driver on medium torque. The optimal torque setting is just below where it will start to cam out given the amount of downward pressure you can exert. It probably won't immediately loosen, but let it bang on the torque limiter for a while. This is a poor man's impact tool. It sometimes loosens it up.
4. If you have a real impact tool, try that. If not, just keep increasing the torque limit on your power drill even if it does start to cam out occasionally. You may strip out the head at this point, but if you've gotten to this point, it wasn't going to budge, anyway.
4a. At this point, it's worth pointing out that if you can get a pair of Vise-Grips on the head, you can try turning it that way. You may snap the head off, but if that happens, you were going to end up at #6, anyway. Watch out that you don't scratch the piece below it, if it's cosmetic.
5. If the head is already stripped out (or you got there via #4), take a Dremel with a cut-off wheel and cut the thinnest slot into it you can. You need to go deepish, but not so deep that you cut the head in half or damage the metal below. You go all the way across the head ensuring the bottom is as flat as possible and the sides have minimal bevel. Apply a large manual flat head and attempt to turn. Use Vise-Grips on the screwdriver and even a cheater bar on them if necessary. Don't bother with the power tools as you'll develop way more torque on the manual, believe it or not. Again, you need downforce to prevent cam out, but it's more in your favor than the Philips head (which was actually DESIGNED to cam out in this situation).
6. If this fails (either you can't turn it, you strip the slot, or you bust the head), you'll need a screw extractor or proceed directly to #7 (unideal but actually somewhat better if you end up at #8 anyway). You probably don't have one, so go buy it. Make sure you size it appropriately for the M6 screws on DDR (stage corners, trim are I think M2.5). Spend the money and get a good one line an Irwin; you'll thank yourself. If you can't find anything that's advertised as sized for metric, use whatever is sized for a #12 UTS. Note that I'm not saying you can use a #12 screw in place of an M6 (the results are disastrous but not as bad as using a 1/4"), just that you can size the screw extractor that way. Follow the directions carefully. If you have to buy a drill bit separately, get cobalt coated. Consider doing this even if the extractor comes with a bit. You're working with stainless steel; I'd say it's "tough as nails", but your typical nail isn't even this tough.
7. If the screw extractor breaks or you elect not to use one, your second to last resort is to drill the head off entirely and try to feed the remaining stud through the back. Obviously this only works if the back isn't blocked by something, but that's true in most places on a DDR. Use a drill bit somewhat larger than 6mm (such as 1/4") or whatever you're drilling out and center yourself as best you can. STOP right when it pops off. If you go any further, you risk damaging whatever is below the screw head including possibly the threaded hole itself. Be warned that things will fly all over the place when this happens, so be ready for it to walk, etc. Use modest pressure - let the drill do the work and keep the chips small. Again, you're working in stainless steel, so get a cobalt coated bit if possible. Once you've got the head off, grab the back of the stud by any means practical and start trying to turn it "tighter". With any luck, you can feed the remnant through the hole.
8. If it STILL won't budge, you can either re-try the screw extractor or just drill the whole thing out. I've had to do this on my IIDX once or twice. It sucks. Ideally, you use a drill bit that's just a little smaller than the preferred drill for tapping. For an M6-1 (coarse, as used on DDR), the preferred tap drill is 5mm so try a 4.8mm. You may have better luck finding a #12 (4.801mm) in the US. For M2.5 (DDR stage trim), the preferred tap drill is 2.05mm, so try a 1.95mm or so (a #48 is 1.93mm). Center yourself as best you can and drill all the way through. If you can get the workpiece on a drill press, that's ideal. The result should be a bunch of chips in the hole that you can clean out with a clean-up tap or, in a pinch, a clean screw from the hardware store. If you can't get the tap started, you can either drill it out just a little bigger (e.g. go up to the preferred tap size above) or try scraping it out with a pick of some sort like the dental tools I mentioned earlier.
9. If THAT doesn't work for some reason, just drill it clean for the next size screw and re-tap at that. It won't match anymore, but at least you've got something usable. M6.5 doesn't really exist, so you may want to go either go 1/4" UTS or jump to M7. For trim, you can go to M3. You'll need an appropriate drill and a corresponding tap, obviously. A drill press is highly recommended since you'll always wobble on a hand drill, but at 7mm size it may not be a big deal.
Always wear safety glasses when doing all this, but especially when drilling metal.
FWIW, I had a bunch of screws cross-threaded on my IIDX that required me to get all the way to #7 above (skipping the extractor step). One or two required #8. The big DDR stage screws usually seem to respond to at least #5.
Also, if you need stage corner screws, McMaster-Carr part number 92467A420 is a very good match and easy to buy in any quantity.
It's also worth pointing out that the inverter output to the CCFL lights is something like 600V @ 40kHz. It's hard to get bitten as they did a pretty good job keeping it out of the way, but it'll hurt like crazy if you do. If practical, ensure that these lights don't turn on while performing service.
http://www.indyddr.com/features/stage.htm
BTW, I would not recommend using Windex (or similar cleaners with ammonia) on the monitor tube face itself or on the clear plexiglass pieces in front of the speakers. It could cloud the plexiglass, and if the monitor has an anti-reflective coating, it will do REALLY bad things to it. Most arcade monitors don't have an AR coating, but YMMV and simple surfactant cleaners are generally fine for that application as it's just fine dust and not oils (from hands, etc.).
As to removing screws, here's the process I use (in order):
1. CLEAN OUT THE HEAD BEFORE YOU DO ANYTHING. Any dirt in the head will just make the driver not seat correctly and cause you to strip it out. A small flat screwdriver is handy for this. Dental picks or similar work great, too. For loosening really packed in dirt, you can use a smaller size Philips (like a #0) and tap it lightly with a rubber mallet (I don't recommend a hammer).
2. Attempt to unseat USING A MANUAL SCREWDRIVER (no power yet) the screw. Use the appropriate size screwdriver for this. For the trim pieces on DDR, this is a #2 (the "normal" size). For the stage corners, it's a #3 (the big size). Push hard and turn slowly. If you see it start to cam out, STOP as you'll strip it. You need more downward pressure.
3. If that fails, make sure the head is REALLY clean. Apply power driver on medium torque. The optimal torque setting is just below where it will start to cam out given the amount of downward pressure you can exert. It probably won't immediately loosen, but let it bang on the torque limiter for a while. This is a poor man's impact tool. It sometimes loosens it up.
4. If you have a real impact tool, try that. If not, just keep increasing the torque limit on your power drill even if it does start to cam out occasionally. You may strip out the head at this point, but if you've gotten to this point, it wasn't going to budge, anyway.
4a. At this point, it's worth pointing out that if you can get a pair of Vise-Grips on the head, you can try turning it that way. You may snap the head off, but if that happens, you were going to end up at #6, anyway. Watch out that you don't scratch the piece below it, if it's cosmetic.
5. If the head is already stripped out (or you got there via #4), take a Dremel with a cut-off wheel and cut the thinnest slot into it you can. You need to go deepish, but not so deep that you cut the head in half or damage the metal below. You go all the way across the head ensuring the bottom is as flat as possible and the sides have minimal bevel. Apply a large manual flat head and attempt to turn. Use Vise-Grips on the screwdriver and even a cheater bar on them if necessary. Don't bother with the power tools as you'll develop way more torque on the manual, believe it or not. Again, you need downforce to prevent cam out, but it's more in your favor than the Philips head (which was actually DESIGNED to cam out in this situation).
6. If this fails (either you can't turn it, you strip the slot, or you bust the head), you'll need a screw extractor or proceed directly to #7 (unideal but actually somewhat better if you end up at #8 anyway). You probably don't have one, so go buy it. Make sure you size it appropriately for the M6 screws on DDR (stage corners, trim are I think M2.5). Spend the money and get a good one line an Irwin; you'll thank yourself. If you can't find anything that's advertised as sized for metric, use whatever is sized for a #12 UTS. Note that I'm not saying you can use a #12 screw in place of an M6 (the results are disastrous but not as bad as using a 1/4"), just that you can size the screw extractor that way. Follow the directions carefully. If you have to buy a drill bit separately, get cobalt coated. Consider doing this even if the extractor comes with a bit. You're working with stainless steel; I'd say it's "tough as nails", but your typical nail isn't even this tough.
7. If the screw extractor breaks or you elect not to use one, your second to last resort is to drill the head off entirely and try to feed the remaining stud through the back. Obviously this only works if the back isn't blocked by something, but that's true in most places on a DDR. Use a drill bit somewhat larger than 6mm (such as 1/4") or whatever you're drilling out and center yourself as best you can. STOP right when it pops off. If you go any further, you risk damaging whatever is below the screw head including possibly the threaded hole itself. Be warned that things will fly all over the place when this happens, so be ready for it to walk, etc. Use modest pressure - let the drill do the work and keep the chips small. Again, you're working in stainless steel, so get a cobalt coated bit if possible. Once you've got the head off, grab the back of the stud by any means practical and start trying to turn it "tighter". With any luck, you can feed the remnant through the hole.
8. If it STILL won't budge, you can either re-try the screw extractor or just drill the whole thing out. I've had to do this on my IIDX once or twice. It sucks. Ideally, you use a drill bit that's just a little smaller than the preferred drill for tapping. For an M6-1 (coarse, as used on DDR), the preferred tap drill is 5mm so try a 4.8mm. You may have better luck finding a #12 (4.801mm) in the US. For M2.5 (DDR stage trim), the preferred tap drill is 2.05mm, so try a 1.95mm or so (a #48 is 1.93mm). Center yourself as best you can and drill all the way through. If you can get the workpiece on a drill press, that's ideal. The result should be a bunch of chips in the hole that you can clean out with a clean-up tap or, in a pinch, a clean screw from the hardware store. If you can't get the tap started, you can either drill it out just a little bigger (e.g. go up to the preferred tap size above) or try scraping it out with a pick of some sort like the dental tools I mentioned earlier.
9. If THAT doesn't work for some reason, just drill it clean for the next size screw and re-tap at that. It won't match anymore, but at least you've got something usable. M6.5 doesn't really exist, so you may want to go either go 1/4" UTS or jump to M7. For trim, you can go to M3. You'll need an appropriate drill and a corresponding tap, obviously. A drill press is highly recommended since you'll always wobble on a hand drill, but at 7mm size it may not be a big deal.
Always wear safety glasses when doing all this, but especially when drilling metal.
FWIW, I had a bunch of screws cross-threaded on my IIDX that required me to get all the way to #7 above (skipping the extractor step). One or two required #8. The big DDR stage screws usually seem to respond to at least #5.
Also, if you need stage corner screws, McMaster-Carr part number 92467A420 is a very good match and easy to buy in any quantity.
It's also worth pointing out that the inverter output to the CCFL lights is something like 600V @ 40kHz. It's hard to get bitten as they did a pretty good job keeping it out of the way, but it'll hurt like crazy if you do. If practical, ensure that these lights don't turn on while performing service.
