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Orpheus

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  1. Like
    Orpheus got a reaction from Fred in Giveaway Entry thread   
    Oh, sorry. I guess I wasn't clear
     
    I simply meant "having posted here, I'm off to read other 43oh threads and see if I can contribute there, because it feels wrong to only show up for the giveaway".
     
    Believe me, I understand the necessities of board administration.
  2. Like
    Orpheus got a reaction from oPossum in Cutting PCBs   
    I've experimented with many ways of cutting or scoring PCBs over the years.
     
    My favorite is based on a pencil-like 1/8" micro die grinder (often $10-20 on sale at Harbor Freight). Its size and 56,000 rpm makes even my trusty Dremel feel clumsy (caution: don't use cheapo generic cutting wheels at its full speed) -- but it's not suitable unless you have a compressor.
     
    Usable, but less good, is an oscillating saw (like the Stryker saw used to cut casts without harming skin) Harbor Freight's single-speed (11,000 strokes/min) which is often as low as $17 (and rarely sells for as much as $30, despite it's "official" $60 price) on sale works fine, but if you're going to *also* use it as an oscillating saw (it's a great hacking tool], I'd probably go for the 21K strokes Genesis saw from Amazon (the initial production run, at least, was great). For casual use, I wouldn't go spendier (a Fein Multitool can run $400 and $40/blade). I've done a LOT of home remodeling using the inexpensive ones with no real complaints.
     
    (HF also has a pneumatic oscillating saw, which I don't own, but is cheaper and probably better than their electric one. Pneumatic tools tend to be cheaper, smoother and more powerful than their electric counterpart)
     
    Any of the above is easily attached to a frame or stand cobbled together from scrap wood -- they exert minimal vibration or lateral force. I've made more versatile, better designed "permanent" stands, but I still happily use some of my quickie stands in my garage or on my electronics bench, vs. my basement wood shop.
  3. Like
    Orpheus got a reaction from bluehash in Cutting PCBs   
    I've experimented with many ways of cutting or scoring PCBs over the years.
     
    My favorite is based on a pencil-like 1/8" micro die grinder (often $10-20 on sale at Harbor Freight). Its size and 56,000 rpm makes even my trusty Dremel feel clumsy (caution: don't use cheapo generic cutting wheels at its full speed) -- but it's not suitable unless you have a compressor.
     
    Usable, but less good, is an oscillating saw (like the Stryker saw used to cut casts without harming skin) Harbor Freight's single-speed (11,000 strokes/min) which is often as low as $17 (and rarely sells for as much as $30, despite it's "official" $60 price) on sale works fine, but if you're going to *also* use it as an oscillating saw (it's a great hacking tool], I'd probably go for the 21K strokes Genesis saw from Amazon (the initial production run, at least, was great). For casual use, I wouldn't go spendier (a Fein Multitool can run $400 and $40/blade). I've done a LOT of home remodeling using the inexpensive ones with no real complaints.
     
    (HF also has a pneumatic oscillating saw, which I don't own, but is cheaper and probably better than their electric one. Pneumatic tools tend to be cheaper, smoother and more powerful than their electric counterpart)
     
    Any of the above is easily attached to a frame or stand cobbled together from scrap wood -- they exert minimal vibration or lateral force. I've made more versatile, better designed "permanent" stands, but I still happily use some of my quickie stands in my garage or on my electronics bench, vs. my basement wood shop.
  4. Like
    Orpheus got a reaction from bluehash in Which to buy: NI USB DAQ or DSO Quad or other?   
    I recently bought a Tektronix 2440 from an estate liquidation sale for under $150 including S/H. When it came out in the late 80s, it cost more than most cars; I was doing biomed consulting at a local major engineering school which shared one for 3 floors.
     
    I could tell from the pic that it had been well-cared-for, and but I bet the seller was scared to death by a flurry of system failures on boot (if it had passed the detailed system self-check, they'd have posted a pic of the summary screen). I was 90% sure that this was solely due to a failure of the built-in batteries. I replaced them with a more modern, non-battery NVRAM for under $10, and spent <$30 building a circuit to re-calibrate it (I didn't have access to a sufficiently good 250MHZ square wave generator with a 1 ns risetime and minimal overshoot/ringing) It was a gamble, but it paid off as I expected, and I'll probably recoup my costs by selling the calibration circuit on the Tektronix Yahoo group. Tektronix's calibrator runs $600+, used.
     
    With some hand-holding from the Yahoo group, this was an afternoon project suitable for an an advanced beginner or intermediate who trusts their soldering skills (not all do, or should). Mine were honed by endless hours salvaging PCB parts as a broke kid.
     
    More importantly, as a kid I'd always been in awe of the wizards who could casually fix o-scopes. Now I somehow am one!
  5. Like
    Orpheus reacted to bluehash in Hot air pencil recommendation?   
    Sorry, I did not get what you said.
     
    You are now above the spam threshold limit of 3 posts for inserting links.
     
    Link what orpheus was talking about: http://www.sparkfun.com/products/10326
  6. Like
    Orpheus got a reaction from bluehash in Hot air pencil recommendation?   
    Sorry, I previewed this at least 15 times, making changes and broke the URL up with underscores in 3 places. The board still said
     

     
    It barely lets me say the Sparkfun product is #10326, and is 110VAC, for those of you who use a higher line/mains voltage. I'm sure that i'll figure out where it draws the exact lines -- around the time they no longer apply to me.
     
    BTW, the error message misspells "the SP-word", IMHO -- and "the FR-word" is a VERY GOOD word in my book, not a bad one.
     
    In re: light dimmers and motor controllers
    I have a bunch of "external dimmer" type boxes scattered around the house, and consider them a standard tool.
     
    Several [still operating from when I was a kid] are just standard hardware light switch dimmers ($10) wired in a box with an outlet and a power cord -- but I gotta say 'they don't make em like they used to'. I've had several fail, and on disassembly, they seem to cut every possible corner now, even if they are "American-made". I suspect that reflects the purchasing policies at "big box" hardware warehouses and contractor desires more than any national priorities.
     
    The Harbor Freight units are MUCH more robust. Just don't look at the soldering inside. It looks like something I did at age 9.
     
    For many applications, a sewing machine foot-pedal is a great speed controller (Don't laugh! I've used one on a 10" Table Saw and 1/2 hp router on for 25 years) Alas, these are hard to find and expensive, but here's a tip: old sewing machines from the 80s or before (including the pedal) often sell for $0-15, including the pedal controller, in your local classifieds or Craigslist. No one wants them. Consider the rest of the sewing machine as bonus motors, belts, pulleys, gears, etc -- and often a stand/worktable
     
    The best thing about these? No wiring. Plug one end into the wall, and plug your device in the other. I had one of those old Ronco Showtime rotisseries, and found it almost useless (too high a roasting temperature for truly tender chicken or prime rib) until I used a controller to drop its power to 75-80%. Back then, they used wind-up timers to shut off the motors. The newer ones use digital timers which may not work so well [or at all] with a thyristor-based dimmer.
  7. Like
    Orpheus got a reaction from gordon in Hot air pencil recommendation?   
    Sparkfun has a $9.95 300W "fat pencil" that might suit your needs. It's called the Heaterizer XL-3000 Heat gun. It doesn't show up on a search for hot air or other terms you might check, and I can't link it directly because I'm newly reregistered after my much neglected 1-post account was deleted. I have one, but haven't used it much. All I can say is: it's too cool for solder rework out of the box, so it may suit your needs (but I cut a small metal cone with tin snips to decrease airflow, and that raised its air output to the light rework range). I plan to experiment more with hacking it later, but I only took a brief glimpse inside.
     
    I can see no reason why it wouldn't work with a power tool motor speed controller (Harbor Freight commonly has these for $15 with coupon). The inductive load of the small motor should be minimal, so it should be 95% resistive, and therefore compatible with the common <$10 "incandescent only" light dimmer, if they go up to 300W. (I hack things with these dimmers all the time)
     
    It's much more like a handheld desktop tool than pistol or hairdryer-style hot air guns are
  8. Like
    Orpheus got a reaction from bluehash in Hot air pencil recommendation?   
    Sparkfun has a $9.95 300W "fat pencil" that might suit your needs. It's called the Heaterizer XL-3000 Heat gun. It doesn't show up on a search for hot air or other terms you might check, and I can't link it directly because I'm newly reregistered after my much neglected 1-post account was deleted. I have one, but haven't used it much. All I can say is: it's too cool for solder rework out of the box, so it may suit your needs (but I cut a small metal cone with tin snips to decrease airflow, and that raised its air output to the light rework range). I plan to experiment more with hacking it later, but I only took a brief glimpse inside.
     
    I can see no reason why it wouldn't work with a power tool motor speed controller (Harbor Freight commonly has these for $15 with coupon). The inductive load of the small motor should be minimal, so it should be 95% resistive, and therefore compatible with the common <$10 "incandescent only" light dimmer, if they go up to 300W. (I hack things with these dimmers all the time)
     
    It's much more like a handheld desktop tool than pistol or hairdryer-style hot air guns are
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