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High level work-bench
I was watching a bit of film of a master goldsmith/jeweller at work. His
workbench was at chest height, because mainly close-up work. He then had forearm rests, fixed to the bench, for doing the precision manipulation work. Does anyone here who regularly repairs/reworks SM boards have a similar setup? Could of course be a standard bench height but cut-down stool. |
High level work-bench
"N_Cook" wrote in message ... I was watching a bit of film of a master goldsmith/jeweller at work. His workbench was at chest height, because mainly close-up work. He then had forearm rests, fixed to the bench, for doing the precision manipulation work. Does anyone here who regularly repairs/reworks SM boards have a similar setup? Could of course be a standard bench height but cut-down stool. Ha, I once worked in a music shop, and the benches in the workshop had been made the exact same height as the bar top in the pub round the corner, because someone thought that was a good idea. Problem is, it meant lifting heavy power amplifiers onto these benches reulted in multiple hernias. You want a bench the height that does not require a clean and jerk to achieve this feat. Really. Cheers, Gareth. |
High level work-bench
On 03/27/2014 04:12 AM, Gareth Magennis wrote:
"N_Cook" wrote in message ... I was watching a bit of film of a master goldsmith/jeweller at work. His workbench was at chest height, because mainly close-up work. He then had forearm rests, fixed to the bench, for doing the precision manipulation work. Does anyone here who regularly repairs/reworks SM boards have a similar setup? Could of course be a standard bench height but cut-down stool. Ha, I once worked in a music shop, and the benches in the workshop had been made the exact same height as the bar top in the pub round the corner, because someone thought that was a good idea. Problem is, it meant lifting heavy power amplifiers onto these benches reulted in multiple hernias. You want a bench the height that does not require a clean and jerk to achieve this feat. Really. My human engineering handbooks say 32 inches is optimum. You are free to use a short chair. |
High level work-bench
On Thursday, March 27, 2014 8:26:07 AM UTC-4, dave wrote:
My human engineering handbooks say 32 inches is optimum. You are free to use a short chair. I had an employee with a back problem. We bought her an adjustable desk. She would sit for a while, then press a button and the desk would raise so she could work standing. This allowed us to keep a good employee productive, it was win-win. Seems like that would also solve your heavy amp lifting problem. |
High level work-bench
On Thu, 27 Mar 2014 09:42:26 +0000, N_Cook wrote:
Does anyone here who regularly repairs/reworks SM boards have a similar setup? Could of course be a standard bench height but cut-down stool. I sometimes use a piano stool that lowers me down to working level, which puts my chin about 6 inches above the table. Unfortunately, that hurts my back if I do it for too long. I also don't do that often because I need to see the work from above when using a hot air SMT desoldering tool, or my USB microscope. With the USB microscope, I can be at any height or position because I don't need to shove my face into the PCB. For really fine work, I now have several microscopes. I've never needed or tried arm rests, but I do have several sand filled shooting rest bags, that will probably suffice. These might help: https://www.google.com/search?q=hydraulic+lift+table&tbm=isch I don't know if they're stable enough. Probably not. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
High level work-bench
dave wrote:
On 03/27/2014 04:12 AM, Gareth Magennis wrote: "N_Cook" wrote in message ... I was watching a bit of film of a master goldsmith/jeweller at work. His workbench was at chest height, because mainly close-up work. He then had forearm rests, fixed to the bench, for doing the precision manipulation work. Does anyone here who regularly repairs/reworks SM boards have a similar setup? Could of course be a standard bench height but cut-down stool. Ha, I once worked in a music shop, and the benches in the workshop had been made the exact same height as the bar top in the pub round the corner, because someone thought that was a good idea. Problem is, it meant lifting heavy power amplifiers onto these benches reulted in multiple hernias. You want a bench the height that does not require a clean and jerk to achieve this feat. Really. My human engineering handbooks say 32 inches is optimum. You are free to use a short chair. All the benches I've used for repair were much higher than 30 or 32". The idea was you could work standing up. If you wanted to sit, you grabbed a tall stool, which would eventually get in your way. super heavy and large things were left on carts. There was never a reason to lift a console television or rear projection TV onto a bench. Old microwaves were not worth the lifting effort either and could sit on a lower work surface, (like a console television with a rug on top). At home the benches are set something like 34" so they're not too low for use with a drafting stool. I don't spend hours and hours at these though. |
High level work-bench
On 27/03/2014 15:48, Jeff Liebermann wrote:
On Thu, 27 Mar 2014 09:42:26 +0000, N_Cook wrote: Does anyone here who regularly repairs/reworks SM boards have a similar setup? Could of course be a standard bench height but cut-down stool. I sometimes use a piano stool that lowers me down to working level, which puts my chin about 6 inches above the table. Unfortunately, that hurts my back if I do it for too long. I also don't do that often because I need to see the work from above when using a hot air SMT desoldering tool, or my USB microscope. With the USB microscope, I can be at any height or position because I don't need to shove my face into the PCB. For really fine work, I now have several microscopes. I've never needed or tried arm rests, but I do have several sand filled shooting rest bags, that will probably suffice. These might help: https://www.google.com/search?q=hydraulic+lift+table&tbm=isch I don't know if they're stable enough. Probably not. Do you have any tips for USB microscope use? Retort stand or ex-lamp/mic gooseneck mount? Any way of increasing the useable workspace between board and objective lens? Ideal light source, assuming not the built in oneor at least its fixed posistion? |
High level work-bench
On Fri, 28 Mar 2014 07:38:56 +0000, N_Cook wrote:
On 27/03/2014 15:48, Jeff Liebermann wrote: On Thu, 27 Mar 2014 09:42:26 +0000, N_Cook wrote: Does anyone here who regularly repairs/reworks SM boards have a similar setup? Could of course be a standard bench height but cut-down stool. I sometimes use a piano stool that lowers me down to working level, which puts my chin about 6 inches above the table. Unfortunately, that hurts my back if I do it for too long. I also don't do that often because I need to see the work from above when using a hot air SMT desoldering tool, or my USB microscope. With the USB microscope, I can be at any height or position because I don't need to shove my face into the PCB. For really fine work, I now have several microscopes. I've never needed or tried arm rests, but I do have several sand filled shooting rest bags, that will probably suffice. These might help: https://www.google.com/search?q=hydraulic+lift+table&tbm=isch I don't know if they're stable enough. Probably not. Do you have any tips for USB microscope use? Not really. I'm still playing with it, trying to make it work. The difficult part is learning to manipulate objects while watching them indirectly on an LCD screen. The coordination required does take some practice and is not coming to me easily. I can do it with a microscope, because I've had practice doing it over the years, but the USB microscope seems to require a different skill, which I'm apparently lacking. Another problem is that the USB microscope has to be fairly close to the work. That's not much of a problem when working with a soldering iron and tweezers, but is difficult with a hot air SMT desoldering station, which is big, wide, and gets in the way of everything. Even worse, the heat from the SMT desoldering station tries to melt the USB microscope and coat the lens with condensed flux. (I use household cellophane wrap to protect the microscope. Retort stand or ex-lamp/mic gooseneck mount? The stand that comes with these USB microscopes is totally awful. It doesn't stay in place and is difficult to lock in place. A gooseneck is worse. Small movements and vibrations are amplified by the lens power into small earthquakes on the screen. When I was using a gooseneck mount, I could see doors open/close and nearby traffic. The best so far is a test tube clamp and stand. Any way of increasing the useable workspace between board and objective lens? That's the basic problem. The cheap USB microscopes use cheap optics which require a close focus. Getting farther away is better because the depth of field improves. However, it would require something with the optical complexity of a real inspection microscope, which is unlikely to be cheap. I'm sure there are some out there, but I haven't seen anything I can afford. If you can get an inspection microscope with a long working distance, then you can get a USB camera that fits into one eyepiece. I have one of those that I use on the microscope. Be sure to get the 0.5x expander, so you can see the entire field of view. Ideal light source, assuming not the built in oneor at least its fixed posistion? The lights are a ring of LED's surrounding the lens, which produces fairly even lighting, and no shadows. You can find those separately on eBay etc. https://www.google.com/search?tbm=isch&q=microscope+light+ring I have to confess that I sometimes hold my pocket Maglight in my mouth while working for better illumination. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
High level work-bench
"Getting farther away is better because ..."
Of ocurse that woud probably tend to amplify the amplification of vibration as well and increase the intensity of your earthquakes. However it like it's necessary in some cases. I wonder if maybe a convace lens in front of its lens would help in that respect, of course with some tradeoff in magnification. Trade it off enough and you might get to the point where you could use a mirror, which seems like it might be very advantageous. I might have to pick me up one of those gizmos, although I am sure I will at least start with an el cheapo until the thing pulls its weight somehow. |
High level work-bench
Now available in English.
"Getting farther away is better because ..." Of course that would probably tend to amplify the amplification of vibration as well and increase the intensity of your earthquakes. However it seems like it's necessary in some cases. I wonder if maybe a concave lens in front of its lens would help in that respect, of course with some tradeoff in magnification. Trade it off enough and you might get to the point where you could use a mirror, which seems like it might be very advantageous. I might have to pick me up one of those gizmos, although I am sure I will at least start with an el cheapo until the thing pulls its weight somehow. |
High level work-bench
wrote in message ... Now available in English. "Getting farther away is better because ..." Of course that would probably tend to amplify the amplification of vibration as well and increase the intensity of your earthquakes. However it seems like it's necessary in some cases. I wonder if maybe a concave lens in front of its lens would help in that respect, of course with some tradeoff in magnification. Trade it off enough and you might get to the point where you could use a mirror, which seems like it might be very advantageous. I might have to pick me up one of those gizmos, although I am sure I will at least start with an el cheapo until the thing pulls its weight somehow. I investigated microscopic photography using various cheap microscopes and webcams etc. I very soon came to the conclusion that: 1. All these devices are VGA at best. They claim otherwise, but they lie. 2. The optics are plastic and totally ****e. 3. You can get much better results from a cheap half decent camera by simply zooming in on the far superior image. You need to remember that no amount of hardware/software is going to improve the image from a piece of ****e lens that probably costs less than a dollar. Gareth. |
High level work-bench
On Fri, 28 Mar 2014 21:51:14 -0000, "Gareth Magennis"
wrote: I investigated microscopic photography using various cheap microscopes and webcams etc. I very soon came to the conclusion that: 1. All these devices are VGA at best. They claim otherwise, but they lie. Well, 640x480 VGA is 0.3M pixels. Physically, it's difficult to cram a larger CMOS (or CCD) imager into a 23mm eyepiece tube or into an endoscope. Usually, the 0.3M pixel variety is often a tiny 1/6" sensor. The better 3M pixel cameras use 1/2" sensors with 2048x1536 such as the Aptina MT9T001: https://www.aptina.com/products/image_sensors/mt9t001c12stc/ https://www.aptina.com/products/image_sensors/ I think (not sure) that 1/2" is about as big a sensor as can be practically crammed into the 23mm microscope tube. With a 0.5x expander, a larger imager can be used that covers the entire field of view. For example: http://www.ebay.com/itm/191110578518 With that arrangement, higher resolutions are possible. 5M pixels are common and not too outrageously expensive: http://www.ebay.com/itm/190519880676 Amscope specifies the (Aptina) sensor they use, which I think you'll find is far better than VGA resolution. 2. The optics are plastic and totally ****e. Yeah, that's a problem at the bottom end. I don't have a clue where to find a microscope with glass optics or what it will cost, but I'm sure it's not cheap. Incidentally, I use both glass and plastic eyeglasses. The glass lenses last many years longer than the plastic lenses. 3. You can get much better results from a cheap half decent camera by simply zooming in on the far superior image. True, but there are limits. I've used old digital cameras as microscopes with good results. The first Sony Mavica FD73 digital camera has a collection of screw on closeup lenses that were really nice for use as a microscope or for taking macro photos. However, past about 100x, it was useless because spherical aberration and poor depth of field conspired to ruin the photo. For larger magnifications, a real microscope is better. However, both are better than the USB microscope. You need to remember that no amount of hardware/software is going to improve the image from a piece of ****e lens that probably costs less than a dollar. My hardware. I cut-n-paste into Irfanview to clean up the photos: http://802.11junk.com/jeffl/pics/white-plastic-rot/slides/microscope-setup.html http://802.11junk.com/jeffl/pics/drivel/slides/Olympus-BHC-Microscope.html I also have Bausch and Lomb inspection microscope, which I sometimes use for SMT work. http://802.11junk.com/jeffl/crud/Bausch-and-Lomb-microscope.jpg Note the large work area. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
High level work-bench
On 28/03/2014 21:51, Gareth Magennis wrote:
wrote in message ... Now available in English. "Getting farther away is better because ..." Of course that would probably tend to amplify the amplification of vibration as well and increase the intensity of your earthquakes. However it seems like it's necessary in some cases. I wonder if maybe a concave lens in front of its lens would help in that respect, of course with some tradeoff in magnification. Trade it off enough and you might get to the point where you could use a mirror, which seems like it might be very advantageous. I might have to pick me up one of those gizmos, although I am sure I will at least start with an el cheapo until the thing pulls its weight somehow. I investigated microscopic photography using various cheap microscopes and webcams etc. I very soon came to the conclusion that: 1. All these devices are VGA at best. They claim otherwise, but they lie. 2. The optics are plastic and totally ****e. 3. You can get much better results from a cheap half decent camera by simply zooming in on the far superior image. You need to remember that no amount of hardware/software is going to improve the image from a piece of ****e lens that probably costs less than a dollar. Gareth. So a camera macroscope rather than microscope. I'll investigate that to see what depth of field v magnification advantage. In either case , like magnified inspection lamps (the lens must be made of glass) the lens of a camera or microscope for this use must have a piece of microscope glass slide fitted over the lens to protect any coating or glass from solder spatter |
High level work-bench
"N_Cook" wrote in message ... On 28/03/2014 21:51, Gareth Magennis wrote: wrote in message ... Now available in English. "Getting farther away is better because ..." Of course that would probably tend to amplify the amplification of vibration as well and increase the intensity of your earthquakes. However it seems like it's necessary in some cases. I wonder if maybe a concave lens in front of its lens would help in that respect, of course with some tradeoff in magnification. Trade it off enough and you might get to the point where you could use a mirror, which seems like it might be very advantageous. I might have to pick me up one of those gizmos, although I am sure I will at least start with an el cheapo until the thing pulls its weight somehow. I investigated microscopic photography using various cheap microscopes and webcams etc. I very soon came to the conclusion that: 1. All these devices are VGA at best. They claim otherwise, but they lie. 2. The optics are plastic and totally ****e. 3. You can get much better results from a cheap half decent camera by simply zooming in on the far superior image. You need to remember that no amount of hardware/software is going to improve the image from a piece of ****e lens that probably costs less than a dollar. Gareth. So a camera macroscope rather than microscope. I'll investigate that to see what depth of field v magnification advantage. In either case , like magnified inspection lamps (the lens must be made of glass) the lens of a camera or microscope for this use must have a piece of microscope glass slide fitted over the lens to protect any coating or glass from solder spatter This works very well indeed on any bridge or digital SLR camera. http://www.raynox.co.jp/english/dcr/...exdcr150eg.htm Depth of field is always a problem at high magnification though. Alternatively you can use the "reversed lens" technique, by literally reversing the lens, even on an old 35mm film camera. https://www.dpchallenge.com/tutorial.php?TUTORIAL_ID=40 These techniques may or may not help with the real world of fixing electronics in real time on a bench, but you might be able to cobble something together with what you have already. Gareth. |
High level work-bench
"Jeff Liebermann" wrote in message ... On Fri, 28 Mar 2014 21:51:14 -0000, "Gareth Magennis" wrote: I investigated microscopic photography using various cheap microscopes and webcams etc. I very soon came to the conclusion that: 1. All these devices are VGA at best. They claim otherwise, but they lie. Well, 640x480 VGA is 0.3M pixels. Physically, it's difficult to cram a larger CMOS (or CCD) imager into a 23mm eyepiece tube or into an endoscope. Usually, the 0.3M pixel variety is often a tiny 1/6" sensor. The better 3M pixel cameras use 1/2" sensors with 2048x1536 such as the Aptina MT9T001: https://www.aptina.com/products/image_sensors/mt9t001c12stc/ https://www.aptina.com/products/image_sensors/ I think (not sure) that 1/2" is about as big a sensor as can be practically crammed into the 23mm microscope tube. With a 0.5x expander, a larger imager can be used that covers the entire field of view. For example: http://www.ebay.com/itm/191110578518 With that arrangement, higher resolutions are possible. 5M pixels are common and not too outrageously expensive: http://www.ebay.com/itm/190519880676 Amscope specifies the (Aptina) sensor they use, which I think you'll find is far better than VGA resolution. 2. The optics are plastic and totally ****e. Yeah, that's a problem at the bottom end. I don't have a clue where to find a microscope with glass optics or what it will cost, but I'm sure it's not cheap. Incidentally, I use both glass and plastic eyeglasses. The glass lenses last many years longer than the plastic lenses. 3. You can get much better results from a cheap half decent camera by simply zooming in on the far superior image. True, but there are limits. I've used old digital cameras as microscopes with good results. The first Sony Mavica FD73 digital camera has a collection of screw on closeup lenses that were really nice for use as a microscope or for taking macro photos. However, past about 100x, it was useless because spherical aberration and poor depth of field conspired to ruin the photo. For larger magnifications, a real microscope is better. However, both are better than the USB microscope. You need to remember that no amount of hardware/software is going to improve the image from a piece of ****e lens that probably costs less than a dollar. My hardware. I cut-n-paste into Irfanview to clean up the photos: http://802.11junk.com/jeffl/pics/white-plastic-rot/slides/microscope-setup.html http://802.11junk.com/jeffl/pics/drivel/slides/Olympus-BHC-Microscope.html I also have Bausch and Lomb inspection microscope, which I sometimes use for SMT work. http://802.11junk.com/jeffl/crud/Bausch-and-Lomb-microscope.jpg Note the large work area. Hi Jeff, I must admit it was a few years ago that I was looking at microscope/webcams and I found nothing remotely in budget that was better than VGA. Seems they've improved technology since then. Anyway, with regards using USB microscopes/cameras on the bench, I've just taken a couple of rough screenshots with my Canon 100D with the kit 18-55mm lens reversed. The reversal ring cost £3.59 on Ebay. The screenshot of a stick of DDR RAM is just to demonstrate that this is exactly what you would see when the camera is connected to a computer using Liveview. (The software comes free with the camera) One is max zoom at 18mm, the other at 55mm. These focal lengths equate to 28.8mm and 88mm in the old 35mm film camera world, and on full frame DSLR cameras. (The D100 is a cropped sensor) Unfortunately the camera has to be pretty close to the subject using lens reversal - 7cm at 55mm and 4.5cm at 18mm, so how useful this would actually be in practice is pretty subjective I guess. http://tinypic.com/r/m8mp9s/8 http://tinypic.com/r/2hdntyp/8 Cheers, Gareth. |
High level work-bench
On Sat, 29 Mar 2014 16:52:50 -0000, "Gareth Magennis"
wrote: I must admit it was a few years ago that I was looking at microscope/webcams and I found nothing remotely in budget that was better than VGA. Seems they've improved technology since then. To the best of my limited knowledge, the microscope resolution followed the introduction of higher resolution imagers (sensors) for digital cameras and USB computer cameras. I don't recall the exact time frame, but I think the cheaper megapixel CMOS imagers arrived in about 2004. http://en.wikipedia.org/wiki/Active_pixel_sensor I've had my various microscope camera for about 5 years. I don't know what went wrong, but you may have been looking at computer cameras, which go through amazing lengths to lie about their optical resolution and usually offering electronically zoomed pixel figures. Anyway, with regards using USB microscopes/cameras on the bench, I've just taken a couple of rough screenshots with my Canon 100D with the kit 18-55mm lens reversed. The reversal ring cost £3.59 on Ebay. The screenshot of a stick of DDR RAM is just to demonstrate that this is exactly what you would see when the camera is connected to a computer using Liveview. (The software comes free with the camera) One is max zoom at 18mm, the other at 55mm. These focal lengths equate to 28.8mm and 88mm in the old 35mm film camera world, and on full frame DSLR cameras. (The D100 is a cropped sensor) Nice, but my DSLR (Canon S5-IS) does not have a removable lens. Unfortunately the camera has to be pretty close to the subject using lens reversal - 7cm at 55mm and 4.5cm at 18mm, so how useful this would actually be in practice is pretty subjective I guess. That's a very real problem, which I also mentioned in my comments on using a cheap USB microscope. The lens has to be so close, that my hot hair SMT desoldering tool can easily melt the plastic lens. Same with splatter from solder flux. That's what's nice about the Bausch and Lomb microscope. The distance between the lens and the work is about 10 cm and there's a slot for a protective lens cover. http://tinypic.com/r/m8mp9s/8 http://tinypic.com/r/2hdntyp/8 Good photos. Are those tin whiskers between the IC leads? Offhand, it looks more like steel wool residue. I'm at home now and don't have any pictures handy. The best I can do is this series of photos of an RJ45 plug, taken with the cheap USB microscope: http://802.11junk.com/jeffl/pics/RJ45/index.html What I really want is a Mantis viewer from Vision Engineering. http://www.visioneng.us All are beyond my limited budget. Maybe used: http://www.ebay.com/bhp/mantis-microscope -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
High level work-bench
Nice, but my DSLR (Canon S5-IS) does not have a removable lens. Unfortunately the camera has to be pretty close to the subject using lens reversal - 7cm at 55mm and 4.5cm at 18mm, so how useful this would actually be in practice is pretty subjective I guess. That's a very real problem, which I also mentioned in my comments on using a cheap USB microscope. The lens has to be so close, that my hot hair SMT desoldering tool can easily melt the plastic lens. Same with splatter from solder flux. That's what's nice about the Bausch and Lomb microscope. The distance between the lens and the work is about 10 cm and there's a slot for a protective lens cover. http://tinypic.com/r/m8mp9s/8 http://tinypic.com/r/2hdntyp/8 The advantage of using Closeup lenses instead of Reversing, is that you can be much further away from your subject. I bought a really cheap set of them on Ebay for £10 just to experiment with the different sizes. http://www.ebay.co.uk/itm/3007056402... 4.m1439.l2649 Suffice to say that optically they are total crap, pretty much unuseable. Here's the +2D one on the Canon zoom at 250mm. This gets your camera a much nicer 32cm away from the subject - the screenshot has the image zoomed in via the software, otherwise it would be much smaller. http://tinypic.com/r/1676v46/8 The Raynox Closeup lenses will fit many compact/bridge cameras, it's a clip-on device, though you might need an adaptor in some cases. Optically they are very good, having 2 elements, so that the chromatic aberrations from the first are cancelled out by the second. My girlfriend has that and the Raynox 250 at the moment, so I can't demo them unfortunately. Cheers, Gareth. |
High level work-bench
On Sat, 29 Mar 2014 10:54:40 -0000, "Gareth Magennis"
wrote: "N_Cook" wrote in message ... On 28/03/2014 21:51, Gareth Magennis wrote: wrote in message ... Now available in English. "Getting farther away is better because ..." Of course that would probably tend to amplify the amplification of vibration as well and increase the intensity of your earthquakes. However it seems like it's necessary in some cases. I wonder if maybe a concave lens in front of its lens would help in that respect, of course with some tradeoff in magnification. Trade it off enough and you might get to the point where you could use a mirror, which seems like it might be very advantageous. I might have to pick me up one of those gizmos, although I am sure I will at least start with an el cheapo until the thing pulls its weight somehow. I investigated microscopic photography using various cheap microscopes and webcams etc. I very soon came to the conclusion that: 1. All these devices are VGA at best. They claim otherwise, but they lie. 2. The optics are plastic and totally ****e. 3. You can get much better results from a cheap half decent camera by simply zooming in on the far superior image. You need to remember that no amount of hardware/software is going to improve the image from a piece of ****e lens that probably costs less than a dollar. Gareth. So a camera macroscope rather than microscope. I'll investigate that to see what depth of field v magnification advantage. In either case , like magnified inspection lamps (the lens must be made of glass) the lens of a camera or microscope for this use must have a piece of microscope glass slide fitted over the lens to protect any coating or glass from solder spatter This works very well indeed on any bridge or digital SLR camera. http://www.raynox.co.jp/english/dcr/...exdcr150eg.htm Depth of field is always a problem at high magnification though. Alternatively you can use the "reversed lens" technique, by literally reversing the lens, even on an old 35mm film camera. https://www.dpchallenge.com/tutorial.php?TUTORIAL_ID=40 These techniques may or may not help with the real world of fixing electronics in real time on a bench, but you might be able to cobble something together with what you have already. Gareth. Several years ago I went through this problem of wanting to look at something under pretty high magnification while at the same time needing the lens to be out of the way. I finally figured out I needed a telescope, not a microscope. Using a book called "Popular Optics" that I bought from Edmund's (now called "Edmund Scientifics") for the education and surplus lenses from Surplus Shed I cobbled together a telescope that was about 2 feet from the tiny parts I was making on the lathe. I used a surplus digital camera too but I don't remember where I bought it from. Surplus Shed is still in business and the Popular Optics book is still available for 30 USA dollars. The monitor I used was another surplus deal, a flat screen that was very bright with a touch screen overlay. Anyway, it all worked well for me so maybe that's a road to go down. It's hard to buy good coated optics new for the kind of money I'm willing to spend, so for my cheap ass I look for surplus stuff. There's a lot out out there, especially if you are flexible. Eric |
High level work-bench
Several years ago I went through this problem of wanting to look at
something under pretty high magnification while at the same time needing the lens to be out of the way. I finally figured out I needed a telescope, not a microscope. I have a clever little optical device made in Wetzlar, called an Emoskop. You can rearrange its components to make various optical devices, including a 2.5x magnifier with a long working distance. http://www.submin.com/binocular/manuals/emoskop.htm Haverhill's still sells it, under the name Episcope. |
High level work-bench
On 3/29/2014 9:56 PM, William Sommerwerck wrote:
Several years ago I went through this problem of wanting to look at something under pretty high magnification while at the same time needing the lens to be out of the way. I finally figured out I needed a telescope, not a microscope. I have a clever little optical device made in Wetzlar, called an Emoskop. You can rearrange its components to make various optical devices, including a 2.5x magnifier with a long working distance. http://www.submin.com/binocular/manuals/emoskop.htm Haverhill's still sells it, under the name Episcope. I have one of those too. Works great. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net |
High level work-bench
http://tinypic.com/r/m8mp9s/8 http://tinypic.com/r/2hdntyp/8 Good photos. Are those tin whiskers between the IC leads? Offhand, it looks more like steel wool residue. I'm at home now and don't have any pictures handy. The best I can do is this series of photos of an RJ45 plug, taken with the cheap USB microscope: http://802.11junk.com/jeffl/pics/RJ45/index.html I'd be very interested to see what a good quality USB microscope or similar can achieve, compared with a DSLR with various fudging going on. Perhaps a DDR RAM stick is the obvious control photo. I notice your photo's are heavy with JPEG artifacts. I'm guessing this would be a result of taking the photo, rather than what you might see on a live monitor? I don't know if they are tin whiskers or not, I just thought it was fluff, but on inspection it probably isn't. This stick has been lying around unprotected for years, don't even know if it works! Cheers, Gareth. |
High level work-bench
On Sun, 30 Mar 2014 21:34:48 +0100, "Gareth Magennis"
wrote: I'd be very interested to see what a good quality USB microscope or similar can achieve, compared with a DSLR with various fudging going on. Perhaps a DDR RAM stick is the obvious control photo. Not enough detail in a DDR RAM stick. Enlarged currency is the ultimate test with the bonus of the flat bill not having a depth of field problem. I'll see what I can do, but probably not for a few days. Too many projects right now. I notice your photo's are heavy with JPEG artifacts. I'm guessing this would be a result of taking the photo, rather than what you might see on a live monitor? The artifacts are from compressing and enhancing the photo with Irfanview. I rarely post photos in the original resolution. For this test, I'll crop the photo, but not reduce it in size. I don't know if they are tin whiskers or not, I just thought it was fluff, but on inspection it probably isn't. This stick has been lying around unprotected for years, don't even know if it works! Looks more like steel wool or file shavings. Whatever it is, it looks conductive and should not be under the chip or between the leads. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
High level work-bench
"Jeff Liebermann" wrote in message ... On Sun, 30 Mar 2014 21:34:48 +0100, "Gareth Magennis" wrote: I'd be very interested to see what a good quality USB microscope or similar can achieve, compared with a DSLR with various fudging going on. Perhaps a DDR RAM stick is the obvious control photo. Not enough detail in a DDR RAM stick. Enlarged currency is the ultimate test with the bonus of the flat bill not having a depth of field problem. I'll see what I can do, but probably not for a few days. Too many projects right now. Finally got my hands on the Raynox lenses. Here is the Raynox150 on the end of the Canon zoom at 250mm: http://tinypic.com/r/x45ir7/8 and software zoomed in: http://tinypic.com/r/15xwxs0/8 Here is the Raynox250 on the same lens: http://tinypic.com/r/5v23o2/8 and software zoomed in: http://tinypic.com/r/ofprol/8 The Raynox150 puts the camera 20cm from the subject, the 250 is 12cm. Gareth. Cheers, Gareth. |
High level work-bench
On Thu, 27 Mar 2014 09:42:26 +0000, the renowned N_Cook
wrote: I was watching a bit of film of a master goldsmith/jeweller at work. His workbench was at chest height, because mainly close-up work. He then had forearm rests, fixed to the bench, for doing the precision manipulation work. Does anyone here who regularly repairs/reworks SM boards have a similar setup? Could of course be a standard bench height but cut-down stool. If money is no object, you can get electrically adjustable workbenches (eg. the Lista Align series) that will let you go back and forth at the touch of a button. Cut down stool wouldn't be quite the same- your legs would be folded up. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
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