Instructables

Single HD Gyro Image stabilizer

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Picture of Single HD Gyro Image stabilizer
me with img1G.jpg
park position.jpg
stroring.jpg

 
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Step 1: History

Before making my 2 Gyro stabilizer http://www.instructables.com/id/Universal-2-Gyro-Image-stabilizer/ from 2 hard disks, I had been thinking about the concept for about a year.

In an experiment, I connected a loose HD to a computer power supply, and felt the resistance to its change of  position. I figured a HD in the horizontal and one in the vertical plane (X- and Y- axis) would dampen almost all unwanted shaking.

The 2 Gyro stabilizer model is very successful, but practical use of the device is limited, due to bulk and weight.

A single Gyro has its theoretical limits. A strong Gyro in the front / back plane (Z - axis) could dampen shaking, but would not correct rotation. But if rotation around the optical axis is only a minor component of motion blur... , the advantage is less weight and power requirement.

Step 2: Design

Picture of Design
design 1G.jpg
storage.jpg

The camera is mounted on a hinge with fastening screw. The other part of the hinge mounts a HD.
The HD can be tilted in the vertical ( Y-) plane from way under the camera to a hugging position for storage.

(my understanding of...) the theory would indicate the best position of the axis of rotation is parallel to its optical axis.

But in this design, any position of the HD Gyro can be tested. It also makes storage and transport much easier than the 2 Gyro model.
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snakeii4 years ago
Have you considered trying a 2.5" hard drive from a laptop? I wonder if it would produce enough force to provide stability for a camera. They run on 5 volts so the 12 volt supply could be eliminated.

I'm curious what voltage is actually used for the platter motor, if I can find another junker drive at work I'll check. I just trashed 5 old scsi drives last week... Perhaps you could still eliminate one of the voltages with a 3.5" drive. You should be able to get rid of the PCB as well, and run the power straight to the motor. The magnets and head assy can be removed. The magnets and their mounting plates add quite a bit of weight.

Good idea, its a good use for a bad hard drive.
yaly snakeii2 months ago

weight is good as long as it's comfortable to hold

You can't run the power straight to the motor, it's a DC brushless spindle motor. You need the driver circuit on the controller board to run it, unless you make your own driver circuit. Also, a laptop drive would theoretically work, except that you'd have smaller, lighter discs. Today I finished putting my own hard drive gyro together, but I eliminated the spacers and the read/write assembly and packed it with as many platters as could fit (9 in my case) and super glued them all together. Now for the driver circuit!
yaly2 months ago

I guess a microdrive such as the 1.8" in iPod Classic would be nice, they're 4200 RPM drives, the only need 3.3 volts, so a much smaller battery is needed. Although they use a ZIF connector which is hard to find somehow, there are two soldering pads next to the ZIF socket on many of them for auxiliary power. Please tell me if anyone had any success with that.

fizzzbang1 year ago
Wonder if laptop drives would work but I guess you need the spinning mass right?

The kinetic energy in a gyro is proportional to the square of the angular velocity, but only linear in proportion to the mass, so the speed of rotation is the significant factor.

Brushless motor for RC helicopter!
http://www.hobbyking.com/hobbyking/store/__17922__NX_4005_650kv_Brushless_Quadcopter_Motor.html
mpritchard42 years ago
SATA drives ought to still run on 5V and 12V, otherwise the Molex-to-SATA converter leads wouldn't work. Nice tutorial!

I've been playing with an old Seagate five-platter SCSI drive today, poking and prodding the TPIC1533 motor drive IC. Unfortunately whilst the motor runs on 12 volts, and one side of each driver (pulling the motor wire down to ground) uses 12 volt pulses, the other side of the driver (pulling the motor wire up to 12 volts) uses pulses of 24 volts so that's yet another supply rail to deal with! Obviously other drives may be easier (or harder) to control, but for this old Seagate I need a 6 phase, 480Hz, 12/24 volt power supply so it's a job best left to the drive itself!

Swings and roundabouts with faster drives, too. 10K drives have slightly smaller platters, 15K drives smaller still (think 2.5" platters in a 3.5" drive and you get the idea) so the increased gyro speed (and whine) is countered by the decreased spinning mass.
Morgantao3 years ago
I tried to do the same kind of gyro a while ago, with 3 different HDs (two Wenstern Digitals and one Seagate), and all gave me the same problem...
When I connect them to a PSU the spin for a few seconds and then stop. the only way to start them spinning again is to disconnect them from the PSU and reconnect.
How do I keep them spinning for more than a few seconds at a time?
bknight23 years ago
I used two rumble motors from a game controller,
took off the weights,
mounted two at vert and horiz,
two 9volt batteries in a small plastic box with foam to hold in place,
and velcro'd it onto my DIY steadycam rig and it kept the rig more stable than without. I thought it would be too small to have any effect, but, it worked a little bit.
I got the idea from this very article or "ible".
Thanks.
You can use just a couple of small electric motors, cheapo units that are bigger than two fingers, it will work.
lavmal3 years ago
Great what you "invented"/discovered yourself. Would be great, if you can transfer images right to the HD:D
southa4 years ago
The Kenyon stabilisers work differently to this - see the original patent: http://www.google.com/patents?id=VI9NAAAAEBAJ A gyroscope on its own just turns a force in one direction into movement in another. I'm guessing that the gimbals shown in the patent are important.
arikyeo4 years ago
 use a car battery?! that removes the portability! maybe use a few batteries with a step-up transformer?
BobS (author)  arikyeo4 years ago

You know, when taking it into the field for a few times, these things come into consideration. Right now, I'm quite happy to put this small scooter battery in my inseparable shoulder bag. When still doing experiments, the last thing one wants is to have to go back home because the power source ran out of juice! A rechargable NiCd battery in decent shape could be substituted.

For video, or when going on a long trip, I think this is still one of the better solutions.

For urban use your suggestion seems excellent. I think a cell phone battery (Li-ion) would be the best candidate.
Patman27 BobS4 years ago
I just finished wiring up 12 D-size batteries, but they don't seem to provide enough amperage to start the spindle. When I tested mine (granted, much more massive spindle due to more platters), the motor drew a peak of a bit over an amp! What to do about the power supply??
dave9504 years ago
You bet me too it, I was going to do this. Where else can you find something that spins at high RPM and is balanced?
bazeemuth4 years ago
Do you notice much difference in the behavior of your one- and two-gyro models?  According to what I remember from physics, two gyros should act the same as one gyro, with the two gyros adding up to the effect of a single gyro oriented at 45 degrees (halfway) between the two.
BobS (author)  bazeemuth4 years ago
Could very well be! Now spring is coming, I hope to take the camera +rig out and find out...
amclaussen4 years ago
Excellent Instructable  Bob!
I cannot add any suggestion at this moment to improve it. Reading about your comment on your difficulty of holding your camerasteady when shutting, I remembered an Idea that I use to train people onhow to properly hold as camera and softly press the shutter button, itis by using a laser pointer temporarily attached to the camera to showhow much movement is done when pushing the shutter button down. Keep practicing until the laser dot projected onto a wall lookssteady.  The tool-like lasers like the Black and Decker can projecta pair of lines at 90 degrees, which helps in developing a sense ofhorizontality to properly level the camera too.

Finally, practice placing your finger laying on the camera body top, andusing ONLY the fingertip to SLOWLY squeeze the shutter,avoiding pushing the whole camera when operating the shutter.  Theold rule of thumb in 35 mm photography was to select a shutter speedreciprocal of the lens focal distance; that is, if using a 135 mm shorttelephoto, one should use at least 1/125 second exposure with hand heldexposures.  But with modern image stabilized lens or sensor, anaverage two stops can be saved (that would be 1/30 sec.) Now, using yourHard disk stabilizer can add at least one more stop. This is anexcellent idea and I truly commend you for your approach. Keep-up thegoog work!
amclaussen, Mexico City.
hmm -- never thought about it ... but its a bit like firing a gun. (the laser technique is used there too...). i wonder if breathing could help too?
BobS (author)  amclaussen4 years ago

Thank you for the laser suggestion!!! I think this is the best way of training to be a good photographer.
sintaks4 years ago
I'm  not sure if this will help or not. but there are these new 4 wheel drive mini remote control cars I seen on TV that have a super charge that make them go faster so they can make it over a steeper hill etc..

These cars are super small and the charge up in like 5 mins.
I dont know if this info helped at all.

These would be alot smaller to carry around than a HD and it charges super fast. But they may be way to light for a big camera.

abizar4 years ago
Hi Bob, just pulled a couple of VCR drum heads with integral motor, they are more compact than HDD's (about 2" dia by 2" height with the attachment plate), and I think the power supply issue should be simpler. Just wondering if anyone has info on how to drive these motors? Thanks again for the instructable.
BobS (author)  abizar4 years ago
VCR drum heads seem to be brushless motors, just like the HDD spindle motor.
It might be possible to use as is, or rewinding could be necessary. It needs a controller as used in RC planes. Some folks make their own controller: letsmakerobots.com/node/2898
Bob,
Did you give any thought to hacking into the hard drive so you couldwire the 12v directly to the motor and bypass the drive electronicscompletely? If possible, that'd eliminate the need for the 5v section ofyour power pack.


Hard, but not impossible. The motor in the HDD is a stepper type, so itneeds controller hardware to run. This will most likely run of 5V andthe motor itself of 12V, so hacking the driver chip to keep it onconstantly (shorting the enable pin to 12V with a series reisistor, etc)or keeping the board as one piece and using something as simple as a7805 to get 5V from the 12V, the car chargers would be eliminated.

James
BobS (author)  jamwaffles4 years ago

Wouldn't that be great!! I would love to see an instructable about how to wire a HDD motor, with or without the board. It would allow to eliminate the arm and reading heads. This way, the spacers between the platters could be replaced by platters salvaged from other HDDs.  (Today, I was at the town waste disposal, to get rid of nasty bramble clippings (ouch, $%##@&^*!!!!), and during the 15 minutes of unloading, I saw 5 old computers being thrown out, most likely with their HDDs still in it.  So easy to get components- and other great stuff, like a perfectly working petroleum heater for my recently finished greenhouse!!!
jamwaffles BobS4 years ago
well, the hard disk motor is a bipolar stepper type, and a quick search on google turns up:

http://www.tigoe.net/pcomp/code/category/arduinowiring/51

it is for arduino, but its not hard to modify. Basically all you need is a bipolar stepper driver chip, or a dual H-Bridge and some way of pulsing the input signal pins (Microcontroller? let me know if youve had any experience in uC stuff). the stepper driver chip will probably be a modified dual h-bridge anyway lol

The motor will run on 12V and the chip 5V, so a simple 5V linear regulator for chip (/micro) and the 12v from the battery would probably suffice.
Ignore the above comment lol and read the one by zapro - he's righterer than me :P
Well the motor is not a stepper type, it's a three phase brushless motor with star connection, and then it has three or four connections. It will not run without it's fairly complicated motor controller. You could possibly use a speed controller meant for RC planes that use three phase brushless motors.
I do appologise lol im not too experienced in motor technology so thanks very much for the heads up.
Its also a sound sampler for linux :P
BobS (author)  BobS4 years ago
Sorry, something went wrong with the layout..... Cannot edit the comment!
jamwaffles BobS4 years ago
edit what comment and what went wrong with the layout lol

james
BobS (author)  jamwaffles4 years ago
The one of 2 minutes before Oct 17, 2009. 7:56 AM, with the small print (how did I do that???)  (almost like the time when I cleaned the keyboard while the computer was on- it took more than a day to get that one straight...)
jamwaffles BobS4 years ago
OHH to the first bit and ouch to the second. Are you on Linux?

As im 15 and i have a mother with a stupidly mad clean-freak obsession, she randomly comes past and cleans my keyboard sometimes and i hate it. Thankfully i've never had to spend 2 days fixing it lol

regards
BobS - don't forget 'Freecycle.com' as you can get all the free computers you'd probably ever want...cheers,
I really need to start using freecycle :P
Just one correction, motors in HDDs are not stepper type, they are plain DC motors. 
They have four wires, so surely they are steppers?

If it was a DC motor it would only have 2. Or maybe the other two are for speed reference?

I dont think so on second thoughts, because with the stepper the speed can be controlled very precisely with no sensor delay at all.

James
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