I need help with my Hard Drive Scanner!

[pseudonyms]

Hello everyone, I would just like to say that I love you guys and you've all been huge helps to me recently.  But on to my Issue.

I've been needing some help in the past few days after attempting to DIY a HDD scanner using Wummi's method.

For Better Explanation, Please watch the video I made:
http://www.youtube.com/watch?v=UOjENYnHAfQ
[media]http://www.youtube.com/watch?v=UOjENYnHAfQ[/media]
People keep complaining I say Umm A lot.  My bad.


Any questions, just ask. I used rubber bands to help make the arms return to their original positions.

Using The program HeathCliff.

My Driver Delay settings are:
5"Step:200
10"Step:200
40"Step:500
Max. Edges:100

Will someone explain to me what these mean?

If you need any more of my settings or have any comments, please leave a comment! I want to see this work so badly!


Thank you all so much for your recent help, and I would love it if someone could help remedy my problem!

Also, For a permanent Lab Laser solution I am going to buy http://www.aixiz.com/shop/product_info.php?cPath=1_23&products_id=94  

I just had the little marker on hand, because the laser I'm using currently Isn't in a nice heatsink, which I am working on.
UPDATE!

New video Showing that I did what bionic-badger reccomended.  I am in a rut, people!

[media]http://www.youtube.com/watch?v=VZHLeDndXks[/media]
Everyone who sees this, at least give your 2 cents! A project grade for a class I am in is riding on this!

 

[Clickey]

I think your motors are spinning the wrong way...

 

[pseudonyms]

Alright, well, Tell me how to remedy it ;D

 

[Bionic-Badger]

I don't think you're using motors at all right?  Just the voice coils on the hard drives.

I haven't made one myself, but what I would start with is calibrating along a single axis  first (set one axis to not move, the other to full)), and then the other.  After you're sure you can horizontal and vertical lines, you should move onto getting the phase correct by using diagonal line patterns and ovals to get the phase right.

The "hyperbolic" square you have there most likely implies that the signal is out of phase by 180 degrees, in which case you can probably change the phase of the signals to get them in tune.  Again, I'd calibrate on a few known geometries first.

 

[pseudonyms]

I have done that with simple lines and small triangles Programmed myself into heathcliff. It seems to work fine enough until I move on to other shapes. Also I realize it isn't motors, I was just anxious for a solution.

Do you think it could be possible I have the wrong wires in the wrong places? My hard drives are in the exact same layout as wummi's. Right channel controlling X, left controlling Y.

 

[Bionic-Badger]

Did you try triangles at all angles/corners and such? Some patterns don't reveal all the problems of the aparatus, and you should be able to render an asymmetric triangle at all angles.

The wires might be off, but if they are you'd probably just see some anti-symmetric patterns which would be revealed in test patterns.

 

[pseudonyms]

Such as that weird, messed up triangle you saw in the beginning?

 

[Bionic-Badger]

Yes, but do them at different angles and such.  They don't even have to be triangles.  Just you want to have patterns that show you that the aparatus can correctly angle the light at certain positions.  Patterns like this may be useful:

+---+ 
 \  | 
  \ | 
   \| 
    ' 

+---+ 
|  /
| /
|/
'    
    .
   /|
  / |
 /  |
+---+ 

.    
|\   
| \  
|  \ 
+---+

What those do is allow you to see if it can correctly map to corners. Then you can adjust the settings until the patterns are correctly rendered. The patterns won't be straight-lined like that, but they should at least be able to render the quadrant-shape of the triangle. If there are any weird problems like it being mirrored, or not quite reaching its full width at the edges, you can see which axis is causing the problems and adjust accordingly.

 

[pseudonyms]

Okay, I get what you're saying. I'll try and do this and report back, in the mean time, does anyone else have any suggestions or experience on their belt that could help me? It would be much appreciated.

 

[pseudonyms]

Updated OP with new video. Give it a minute to process through youtube, send me more suggestions, a class grade is riding on this project!

 

[Bionic-Badger]

So on your video the shapes look awfully flat.  Does one of the axes have a lower maximum amplitude?  This can be tested by zeroing one axis and maximizing another (horizontal or vertical lines respectively).  When you have those amplitudes equalized, take a piece of paper and tape it to the ceiling (or whatever target), and mark the full range of the output.  So that you can see what corresponds to the vertical and horizontal axis of your "screen" as well as the maximum bounds.  This will help give a clearer picture of what is being projected where.  You could also tip the projector on its side (if possible) so it shows on a wall.

After those amplitudes are equalized, try diagonal line. This will test the "slope" synchronization of the two axes.  If it doesn't show a diagonal line, mess with the phase and timing values until you get one.  If I have time, I'll try making a program that mimics the motion of such a system.

Another thing to try:  can you slow the motion down extremely low, to perhaps a 1Hz operation so you can actually see the laser beam moving along the path?  This will allow you to see how the voice coils are timed with respect to each other.  For example in a quadrant-1 triangle, drawn clockwise, the motion of the two coils should move in a pattern such as (assuming 0,0 is lower left):

^    .    
|    |\   
h  1 | \ 2
|    |  \ 
v    +---+ 
 (0,0) 3
     <-w->

Segment	| H-coil	| V-coil
1	| 0	| 0 -> h
2	| 0 -> w	| h -> 0
3	| w -> 0	| 0

You will want w = h, but more importantly, you want the change in motion from 0 -> w, or 0 -> h, with respect to time, for each axis to be the same, that way it actually draws the shape, not just makes it from point to point as fast as possible. You can time and synchronize the motion with a slower moving coil frequency and then speed it up as you go along.