Ben Posted June 16, 2006 Report Share Posted June 16, 2006 I'm going to be winding 3 or 4 pickup coils soon, so I want to build a motorised pickup winder. I've got everything sorted...execpt my source for the motor. I was going to use an old turntable, but its been disposed of without me knowing So now I need a motor... I have a few possibilities; a VCR, a cassette player and a CD player. The VCR and cassette player seem best IMO (fast forward could be useful).. but the DANGER OF DEATH DO NOT OPEN stickers on the back put me off a little... RC car is another idea, but it was an expensive one that probably would have a decent resale value on eBay. I'm wiring it up to my PC for the counter. Any ideas? what sort of household things might have a useable motor? (and no, we dont have a sewing machine, and the motor in my old lego is broken) If all else fails I can always buy a motor, but wheres the fun in that? Quote Link to comment Share on other sites More sharing options...
crafty Posted June 16, 2006 Report Share Posted June 16, 2006 Unplug the VCR for a few hours and discharge the big caps on the power supply with a screwdriver. I doubt there's enough lethal voltage inside when the unit is unplugged. It will probably have the most powerful motor other than the R/C car. Quote Link to comment Share on other sites More sharing options...
Ben Posted June 16, 2006 Author Report Share Posted June 16, 2006 The VCR has been unplugged for 2 years! I guessed that the caps would have discharged long ago, theres just so many big warning stickers on the thing that I got scared I guess you discharge the caps by bridging the two terminals? I have a far bit of theoretical knowledge about electricity (from physics lessons), but not so much practical experience; which is what makes me feel a little cautious of things with stickers on them telling me I'm gonna die. Quote Link to comment Share on other sites More sharing options...
Mattia Posted June 16, 2006 Report Share Posted June 16, 2006 Ben: check local, small sewing machine repair shops. I placed a 'wanted' add on the largest national free ads site, got a reply from a repair shop that had an old but fully functional sewing machine motor with speed control pedal for E7.50, which is about a fiver. Quote Link to comment Share on other sites More sharing options...
Ben Posted June 16, 2006 Author Report Share Posted June 16, 2006 Ben: check local, small sewing machine repair shops. I only know of one... Its not that local, but its not too far. I like the idea of the freead website. A while back I used a site called 'freecycle' and got a load of nice wood. I'll post an add now actually. I may still disect the VCR though, its not like it will ever get used again for anything else. Thanks! Quote Link to comment Share on other sites More sharing options...
Ben Posted June 16, 2006 Author Report Share Posted June 16, 2006 OK, I've begun to disect an old hifi. The inside looks a lot like a computer. Oh, and I'm not dead (yet) btw The thing has 2 tape decks and a CD player, so plenty of motors to try. The reason I'm disecting the hifi and not the VCR is because I want to convert the rest of it into an amp If I plug my guitar into the headphone socket it works as a pretty decent amp. Has reverb too. I just plan to pull the circuit board out of this and hook up the 2 large speakers it came with I have a feeling the motors may well be two weak, but its worth a try. BTW those power caps are HUGE. There's plenty of pots and switches to salvage too. Quote Link to comment Share on other sites More sharing options...
Ben Posted June 16, 2006 Author Report Share Posted June 16, 2006 Salvaged a motor from the tape deck, and theres another identical one in there that I cant get at without a smaller screwdriver. It has 4 wires for some reason, but using 2 it will run from a battery, so it looks like it will work! Its pretty feeble with a 1.5V battery, but more power should make it stronger. I'm going to try to make it into a winder now Quote Link to comment Share on other sites More sharing options...
Ben Posted June 16, 2006 Author Report Share Posted June 16, 2006 HELL YEAH!!! it works! Heres my VERY crude pickup winder It looks so crappy its almost funny, but it works! -The base is expanded polystyrene from the packaging our TV came in. -The copper wire is mounted on a pencil that I jabbed into the polystyrene. -The wire guide is something I found in the cellar -The big tube thing was the method I used to hold a whole pack of AA batteries in series giving a total voltage of 6V for the motor. Heres the carnage from the ex-hifi I'm thinking of using a reed switch and wiring the winder up to my computer via the serial port (as described HERE) That way I can use the computer to count the turns and set an alarm off when its wound enough. I might also try to neaten it up too, maybe construct a wooden base and set it up to run from the mains (with a transformer obviously) Ill also add a proper on/off switch and a pot to vary the speed. Quote Link to comment Share on other sites More sharing options...
Mattia Posted June 17, 2006 Report Share Posted June 17, 2006 Minor detail on the wire for winding, keeping in mind I'm a complete newb at this: you don't want to 'roll' it off the spool like you would toilet paper off a roll. More like put it down on a flat side, and pull it off the top so that the spool itself doesn't need to move when the wire comes off of it. Quote Link to comment Share on other sites More sharing options...
dave293 Posted June 17, 2006 Report Share Posted June 17, 2006 I'm thinking of using a reed switch and wiring the winder up to my computer via the serial port (as described HERE) That way I can use the computer to count the turns and set an alarm off when its wound enough. I made one of those counters and it works well, i'm still looking for a motor for my winder though. I thinking of using a stepper motor, it seems perfect you can control the speed, number of turns, direction of turns from a computer, my only worry is it won't have enougth power to spin the bobbin. I've heard the same thing as mattia in regards to rolling the wire of the spool. Quote Link to comment Share on other sites More sharing options...
Ben Posted June 17, 2006 Author Report Share Posted June 17, 2006 Minor detail on the wire for winding, keeping in mind I'm a complete newb at this: you don't want to 'roll' it off the spool like you would toilet paper off a roll. More like put it down on a flat side, and pull it off the top so that the spool itself doesn't need to move when the wire comes off of it. Do I need to remove the top of the bobbin then?, or will the wire just bend around it? (if that makes sense) Whats the problem with the bobbin rotating? Thanks! I'm glad to hear that the counter works well too! Quote Link to comment Share on other sites More sharing options...
Ben Posted June 17, 2006 Author Report Share Posted June 17, 2006 Also, anyone have any idea how I can isolate which parts of these huge circuit boards is the mic amp that I was going to try to salvage? Quote Link to comment Share on other sites More sharing options...
crafty Posted June 17, 2006 Report Share Posted June 17, 2006 Also, anyone have any idea how I can isolate which parts of these huge circuit boards is the mic amp that I was going to try to salvage? Figure out where the mic jack is connected to the circuit board. Quote Link to comment Share on other sites More sharing options...
Ben Posted June 17, 2006 Author Report Share Posted June 17, 2006 I've found where the mic-jack is connected- its on a seperate board. Looks like it has been bought prefabricated and stuck in the unit as an after thought or something.... Theres a separate circuitboard that the mic-jack's connected to, its a different colour to all the other boards and stamped 'sony'. It has a chip on it with 5218A stamped on it. I looked it up- its an op-amp. It looks too small and simple to be the power amp.. could this be the pre-amp or something? Theres loads of wires that were connected to the main PCB coming from it. I'd guess the 'real' amp is located on the big board... I'll try to find the point at which it used to connect to the main baord Quote Link to comment Share on other sites More sharing options...
Ben Posted June 17, 2006 Author Report Share Posted June 17, 2006 Ok.... I'm looking at where it connects to the main board.... There seems to be another amp there (I've been googling the chip names to see what they are), but I have no idea how to tell whats useful and whats not. It gets really crazy and complicated... If all else fails it would make a cool guitar top Like this guitar: http://www.girlbrand.com/electroB.jpg Or I could salvage some of the components maybe... what do you think one of the huge 3300 uf caps would sound like on a tone pot? Quote Link to comment Share on other sites More sharing options...
Ben Posted June 17, 2006 Author Report Share Posted June 17, 2006 It would look cool embedded in resin on the top of a guitar! Quote Link to comment Share on other sites More sharing options...
Mattia Posted June 17, 2006 Report Share Posted June 17, 2006 The problem with 'spinning' the spool, rather than simply letting the wire unwind off of a stationary spool is breakage and tension: the wire's VERY thing, speeds can be pretty high, and relative to both rate of wire unspooling and wire thin-ness, the spool's got a boatload of mass to overcome. Quote Link to comment Share on other sites More sharing options...
Ben Posted June 17, 2006 Author Report Share Posted June 17, 2006 (edited) That makes sense... Just one more thing I'm unsure about then: on the diagram I've drawn a big red arrow pointing to the bit I'm concerned about- it sounds to me that an angle like that would be a likely place for the wire to break.. or do I need to remove one end of the bobbin as in the right of the pic? Alternatively the tape deck has some nice smooth bearings in it that could reduce the stress on the string if I mounted the spool on them... Thanks Edited June 17, 2006 by Ben Quote Link to comment Share on other sites More sharing options...
crafty Posted June 18, 2006 Report Share Posted June 18, 2006 I've found where the mic-jack is connected- its on a seperate board. Looks like it has been bought prefabricated and stuck in the unit as an after thought or something.... Theres a separate circuitboard that the mic-jack's connected to, its a different colour to all the other boards and stamped 'sony'. It has a chip on it with 5218A stamped on it. I looked it up- its an op-amp. It looks too small and simple to be the power amp.. could this be the pre-amp or something? Theres loads of wires that were connected to the main PCB coming from it. I'd guess the 'real' amp is located on the big board... I'll try to find the point at which it used to connect to the main baord It probably is the preamp for the mic. The power amp is probably going to have some big aluminum heatsinks attached to the power transistors on its board. Quote Link to comment Share on other sites More sharing options...
GuitarGuy Posted June 18, 2006 Report Share Posted June 18, 2006 That makes sense... Just one more thing I'm unsure about then: on the diagram I've drawn a big red arrow pointing to the bit I'm concerned about- it sounds to me that an angle like that would be a likely place for the wire to break.. or do I need to remove one end of the bobbin as in the right of the pic? Alternatively the tape deck has some nice smooth bearings in it that could reduce the stress on the string if I mounted the spool on them... Thanks The wire unloops very loosely. Unless there is a burr on the edge of the spool the wire shouldn't snag or break. If you find the wire is breaking. sand the rim of the spool. Quote Link to comment Share on other sites More sharing options...
has-sound Posted June 18, 2006 Report Share Posted June 18, 2006 I use an old sewing machine motor with the foot controlled speed control. Wound about a hundred so far with no problems. -Stan Quote Link to comment Share on other sites More sharing options...
Ben Posted June 18, 2006 Author Report Share Posted June 18, 2006 It probably is the preamp for the mic. The power amp is probably going to have some big aluminum heatsinks attached to the power transistors on its board. Ok... I'm an idiot: I'd spent ages looking aty all the huge PCBs I pulled out of the thing and tracing wires... the damn thing's sitting inside the case that I'd put to one side! The fact that it has STEREO AMPLIFIER printed on it in huge letters just adds insult to injury Its apparantly a "STK4152IIAF power amplifier (30W + 30W) in 18-pin 4040 package." I still cant believe I missed it... The wire unloops very loosely. Unless there is a burr on the edge of the spool the wire shouldn't snag or break. If you find the wire is breaking. sand the rim of the spool. O'k I'll give it a try then. I'll have to try to find a good place to mount the spool. I use an old sewing machine motor with the foot controlled speed control. Wound about a hundred so far with no problems. -Stan Thats my backup-plan Still one thing thats puzzling me a little... The black thing with 'stereo amplifier' printed on it is apparantly made by Sanyo, but the board its on says Sony on it... does that mean that the amp itself is inside the black box... if so whats the PCB for? Quote Link to comment Share on other sites More sharing options...
Ben Posted June 18, 2006 Author Report Share Posted June 18, 2006 (edited) Thats what I think is the preamp... the grey cable is the one with the pink arrow on it on the next pic... This is where the preamp output connects to the big board This is a better view of the big board- the bit where the preamp cable joins is circled And this is where the board joins the transformer and the power amp The problem is that the amp is shared by the mic, the CD player, the cassete deck and the radio, and that the signal from the mic doesnt go straight to the amp, it goes through loads of EQ stuff first... Ideally I just want to work out a way to bypass all of that and hook the preamp up to the poweramp, and then hook that up to a speaker. Obviously I'll want a volume control too I might want some EQ stuff later, but I think I'll use some schematics off the internet for that, since the stuff in this thing is really complicated. I dunno if any of the above photos show anything useful, because I dont know what to look for. Any thoughts? EDIT: The things with the red and black tabs on them behind the 2 big caps are the speaker outputs BTW Edited June 18, 2006 by Ben Quote Link to comment Share on other sites More sharing options...
crafty Posted June 18, 2006 Report Share Posted June 18, 2006 It's an eye-opening experience when you first realize that most of the components inside a "big-name" stereo like a Sony have actually been sourced from the so-called "cheap names" like Sanyo. Most of those consumer-grade low power power amps are housed in a package like that with all the power transistors on one chip, versus a pro-grade guitar amp that actually has individual power transistors for better sound quality and heat dissipation. FWIW, I wouldn't bother trying to separate out the mic/headphone section and all that. I'd just build or buy a preamp for your guitar input and run that into the power amp section. Quote Link to comment Share on other sites More sharing options...
Ben Posted June 18, 2006 Author Report Share Posted June 18, 2006 Theres parts with sanyo, motorola, mitsubishi, philips... allsorts printed on them. I can actually only find 1 component with Sony printed on it! Is the power amp just the big black thing, or shall I keep it attatched to that little board its on? Also, looking at some of the premade amp units on this site: http://www.maplin.co.uk/Module.aspx?Module...%20AMP&doy=18m6 They all have large caps on them. On mine the caps are all on the main board... You know, when it was still in one piece as a hifi, the mic would always be on when you plugged it in; it wasnt like you needed to set it to 'microphone mode' or anything, it just had one pot to control the mic mix, I'm wondering if I could just clip everything back together, plug my guitar in and see if it works! I'd do that if I wasnt so terrified of mains electricity Whatever happens, theres no way I'm testing anything I've made without one of those RCD things. Quote Link to comment Share on other sites More sharing options...
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