HI PIX
YES YOU ARE CORRECT ABOUT MORE POLES AFECTING THE SPEED
the floppy magnet allready has many poles...the dvd drive will be the same ...the magnet is manufacterd with the poles ready made so to speak
if u look on my web site ..on the about us page..you will see i built my own high speed motors and use the amount of magnets to vary the speed and ampage draw- as well as a varable speed controler
the control chip on the floppy already has a crystal to set the timing
i have spent a lot of time on brushless...the floppy is the beast thats been undiscoverd,
we should stick to 1 type if we want to move forward to other motors later on ...high speed motors make a lot of noise
HI Iain
yes i think 2 the same floppys will work no problem
YES YOU ARE CORRECT ABOUT MORE POLES AFECTING THE SPEED
the floppy magnet allready has many poles...the dvd drive will be the same ...the magnet is manufacterd with the poles ready made so to speak
if u look on my web site ..on the about us page..you will see i built my own high speed motors and use the amount of magnets to vary the speed and ampage draw- as well as a varable speed controler
the control chip on the floppy already has a crystal to set the timing
i have spent a lot of time on brushless...the floppy is the beast thats been undiscoverd,
we should stick to 1 type if we want to move forward to other motors later on ...high speed motors make a lot of noise
HI Iain
yes i think 2 the same floppys will work no problem
its a toruqe thing the high speed hard drive units are meant to spin fast...im not sure you would have a better "slow" unit(at least without rewireing them)...and u have the hasttle on building a controller....althoght it may well be better in the end
even the floppy hits extra noise i have found at differant RPMs with the vary speed pot in place
more details to follow on this weekend ....
best wishes
j7
even the floppy hits extra noise i have found at differant RPMs with the vary speed pot in place
more details to follow on this weekend ....
best wishes
j7
Is it even possible to just add a pot to controll speed? A google search indicates that it is not.
http://www.epanorama.net/circuits/diskstepper.html
http://www.epanorama.net/circuits/diskstepper.html
postpunk said:
It's not the stepper motor, but the three-phase drive motor for the floppy, which normally runs at 360 rpm. I've used these myself, but I only used the motor as a 3-phase synchronous motor by building a simple 3-phase oscillator and using three low-power drive amplifiers, one for each phase, driving the stator in a 'delta' configuration.
This is the type of 3-phase sine-wave oscillator I use. I've set the frequency to give 33rpm on my turntable, so you'll need to alter the value of the 10k resistors (and perhaps the capacitors) to get the correct frequency for you.
I run ordinary LF351 op-amps on +/6V, which also feeds the three power amps. Any low voltage audio power amps that will supply about 6V pk-pk at a current of 300mA or so will do.
If you dismantle the floppy drive, you'll find the rotor just pulls off. It's fairly easy to trace the three winding connections to the flexible ribbon. Simply connect the output of each amp to one of the stator wires. If the motor rotates the wrong way, swop over any two of the connections.
I run ordinary LF351 op-amps on +/6V, which also feeds the three power amps. Any low voltage audio power amps that will supply about 6V pk-pk at a current of 300mA or so will do.
If you dismantle the floppy drive, you'll find the rotor just pulls off. It's fairly easy to trace the three winding connections to the flexible ribbon. Simply connect the output of each amp to one of the stator wires. If the motor rotates the wrong way, swop over any two of the connections.
Attachments
okay part 2 of the Easy DIY floppy conversion should be uploaded shortly on my site tonight
www.audioorigami.co.uk
it shows the basic unit in a test bed...has two pulleys and or easy vary speed control
total time for the diy job from a basic of the shelf floppy is 1-3 hrs work depending on the model of floppy u use,...every floppy is different...so its best,if you can get a few of the same.
u can interchange pullys...compare/experiment etc
the pure 4volt cell phone battery and charger supply is the main concept in this simple design...i need some help to design a EASY battery charger cut-off circuit ...if any 1 has any information on a cheap and easy system please let us know
best wishes for now
j7
www.audioorigami.co.uk
it shows the basic unit in a test bed...has two pulleys and or easy vary speed control
total time for the diy job from a basic of the shelf floppy is 1-3 hrs work depending on the model of floppy u use,...every floppy is different...so its best,if you can get a few of the same.
u can interchange pullys...compare/experiment etc
the pure 4volt cell phone battery and charger supply is the main concept in this simple design...i need some help to design a EASY battery charger cut-off circuit ...if any 1 has any information on a cheap and easy system please let us know
best wishes for now
j7
Cell phone battery chargers in particular are very very easy. Especially if it's the battery from YOUR old phone...
Use the charger that came with the phone. Especially easy if your charger has a spot for charging a spare battery...slap it on the charger!
This should be available for minimal cost from loads of sources if you can't get one from the manufacturer.
/edit:
I should have mentioned that these chargers may not be optimal for the type of battery in question... battery university says that most cell phone manufacturers will allow their batteries to be charged in a way that may shorten their life because people go through cell phones within a year or two, and battery longevity is not so much of a concern. Of course, replacement batteries are also to be had, so...
Use the charger that came with the phone. Especially easy if your charger has a spot for charging a spare battery...slap it on the charger!
This should be available for minimal cost from loads of sources if you can't get one from the manufacturer./edit:
I should have mentioned that these chargers may not be optimal for the type of battery in question... battery university says that most cell phone manufacturers will allow their batteries to be charged in a way that may shorten their life because people go through cell phones within a year or two, and battery longevity is not so much of a concern. Of course, replacement batteries are also to be had, so...
Don't forget that if you have any small stepper motors with fairly coarse steps (say 10 degrees per step), then you can drive these as a synchronous motor with a two-phase (quadrature) pair of sine waves.
Most steppers seem to have fine steps of 1.8 degrees per step, and I've found that you can't get these to rotate fast enough to use as belt-drive turntable drive motors.
Most steppers seem to have fine steps of 1.8 degrees per step, and I've found that you can't get these to rotate fast enough to use as belt-drive turntable drive motors.
yea a kit is no problem
what would be helpfull if people posted the inner pully and motor pully sizes...and i could work a little data base of models and floppy pully sizes..
i think proviosionally that the linn/thorns type units will be almost the same pulllys as standard
also with a couple of the same floppy units u can have different pullys mounted for 33 and 45 78 or 16 ...the whole magnet and pully just pull of...its fantastic
what would be helpfull if people posted the inner pully and motor pully sizes...and i could work a little data base of models and floppy pully sizes..
i think proviosionally that the linn/thorns type units will be almost the same pulllys as standard
also with a couple of the same floppy units u can have different pullys mounted for 33 and 45 78 or 16 ...the whole magnet and pully just pull of...its fantastic
eric
you just need to cheat 1 or 2 of the mechanical switches the floppy hits when you insert it
and join pin 12 to 11
and pins 16 to 15
its that simple...check the photos on my site
there is no photo interupter needed ..(i think you mean for the floppy heads to move?)
every motor is different so you need to open a few to pick the easy 1 to mod
best wishes
j7
you just need to cheat 1 or 2 of the mechanical switches the floppy hits when you insert it
and join pin 12 to 11
and pins 16 to 15
its that simple...check the photos on my site
there is no photo interupter needed ..(i think you mean for the floppy heads to move?)
every motor is different so you need to open a few to pick the easy 1 to mod
best wishes
j7
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