thoughts on spinners

[seaner]

I'm going about constructing a spinner... has anyone had any luck using the encoders from a standard PC mouse on such a thing?
I've got the knob machined out of aluminum, and it looks snappy, just trying to figure out what to do about encoding.
My options are basically the following:
1. mount encoder wheel from mouse, keeping the photodiodes in the same locations on the original PCB.
2. print out a larger encoder wheel with custom spacing on laser printer transparency, sandwich between plexiglass discs, and remount the photodiodes (in pairs, since the gap spacing will have changed) on a new PCB.

Any thoughts?

http://www.beerbot.ca/mame  
if anyone cares to read more on my progress.

Cheers,
Sean

[ErikRuud]

Some people have used the encoder wheels from their mice.  I believe the Twisty-Grip plans use the encoders.

I cut my own encoder from a thin sheet of styrene.  I printed the encoder wheels from the Cheep Spinner plans and glued them to the styrene, and then cut the wheel out using an exacto knife.

[Brad Lee]

I bought the seperate parts(encoder wheel and optics) from Oscar's for a grand total of like 15bucks, including shipping
A little bit more than printing/making your own discs once you factor time into it, yet a heck of a lot more reasonable than getting a whole spinner rig, even the cheap ones from Oscar are what, 40bucks?
(I havent checked prices in a while)

[Justin]

Brad, where did you get these parts exactly?  

[rampy]

Brad, where did you get these parts exactly?  

I'm no brad.. but  he's referring to OSCAR from http://www.oscarcontrols.com

rampy

EDIT/PS  Have you checked out the usable suspects for great howto's on building your own spinner from scratch?  (i.e. cheep spinner, twistygrip, hardrive spinner, and uhm... one other...)  i've got the pdf plans to those somewhere if you need 'em... *Shrug*

[anthony691]

I am starting out a hard drive spinner, any advice?

[rampy]

I am starting out a hard drive spinner, any advice?

obligatory snotty comment "save yourself the trouble and buy an oscar spinner"

now that, that's out of the way... I'd research currently documented "home made" spinners regardless if they are HD based bearings or not... just to get different ideas... cheep spinner plans

twisty grip spinner plans

You see dhansens HD spinner site or the rollerblade bearing spinner hack page?

*Shrug* (I'm looking for a primo byoac forum thread for you also - although in retrospect wasn't primo but was interesting)

rampy

[anthony691]

Well rampy, I had meant that I have done the research, and even have the mouse apart on my table next to the hard drive bearing ripped from my drive. I will begin attempting the hack tonight (I hope it isn't too bad)

[rampy]

Well rampy, I had meant that I have done the research, and even have the mouse apart on my table next to the hard drive bearing ripped from my drive. I will begin attempting the hack tonight (I hope it isn't too bad)

uhh... never mind then =P Hopefully someone else could use those links...

  good luck!  (I'd still check out those threads anyway if you haven't seen 'em...)  

blah...  

rampy

[seaner]

Thanks for all the links guys.  
I've read most of it before.. just trolling for opinions =)
Obviously doing something like chopping every other spoke off a mouse encouder wheel is a bit crude sounding (one plan I read did this) in order to drop the resolution.  Since this screws up the phase shift of the waveforms, I was wondering about making larger wheels, and basically if anyone had worked out what would be the ideal size and shape of such a wheel in order to have it spin freely without backpedalling.

[OSCAR]

Truth be told, the type of optics used on the spinner have a greater influence on backspin than the size/spacing of the encoder wheel teeth.  Manipulating the tooth size/spacing is "fix" for reducing backspin, not necessarily the cause.

Mouse optics are notorious for inducing backspin.  A dual optic board such as mine and the Happ board effectively eliminate backspin regardless of the size of encoder wheel used with it.  Both my optic board and the Happ board may have difficulty reading a small mouse encoder wheel, however.

For example; you can take a standard 24T trackball encoder wheel and use it on a spinner.  If you use mouse optics with this encoder wheel, you can get backspin if you set the MAME Speed setting too high.  If you use my optic board or the Happ board, it is nearly impossible to get backspin.  I have also noticed that some mice optics are more prone to backspin then others.

[seaner]

Truth be told, the type of optics used on the spinner have a greater influence on backspin than the size/spacing of the encoder wheel teeth.  Manipulating the tooth size/spacing is "fix" for reducing backspin, not necessarily the cause.

It's the spacing between the optics in relation to the spacing of the gaps, right.  phase difference between the two pickups.
I was planning on using the mouse optics, but not in the way they are used in the mouse.. typical mouse optics mount two photodiodes in one package, hence to maintain phase difference, you need to maintain the same gap spacing.  I'm planning on using two such packages, and only tap one of the photodiodes in each, and set the spacing as I see fit.
Obviously using the mouse optics straight out of the box is a bad choice if building a custom disc.

[OSCAR]

It's the spacing between the optics in relation to the spacing of the gaps, right.  phase difference between the two pickups.
I was planning on using the mouse optics, but not in the way they are used in the mouse.. typical mouse optics mount two photodiodes in one package, hence to maintain phase difference, you need to maintain the same gap spacing.  I'm planning on using two such packages, and only tap one of the photodiodes in each, and set the spacing as I see fit.
Obviously using the mouse optics straight out of the box is a bad choice if building a custom disc.

This is correct.  However if you are setting the distance between the phototransistors, then only you will be able to determine the tooth size/spacing which you asked about in your previous post.  Not reading the original post closely enough, I assumed you were using a standard mouse optic pair and asking advice on what would be the correct size encoder wheel to use with them.  But since you are modifying the spacing between the optics, then it would be difficult for somebody else to tell you the correct size encoder wheel to use with it.

[seaner]

only you will be able to determine the tooth size/spacing which you asked about in your previous post.

That's very true..  perhaps a better question is what seems to be the norm in terms of pulses per revolution on these spinners?  This would determine the spacing relative to the size of my wheel.

Cheers,
Sean

[djsting]

Seriously guys, why would you want to reinvent the wheel?    Save yourself the time and effort and just buy the Oscar Pro from www.oscarcontrols.com it can be purchased with either a PS2 or USB cable making hookup to your PC extremely simple.

[seaner]

Seriously guys, why would you want to reinvent the wheel?    Save yourself the time and effort and just buy the Oscar Pro from www.oscarcontrols.com it can be purchased with either a PS2 or USB cable making hookup to your PC extremely simple.

Because I get enjoyment out of D-I-Y stuff, and it's only going to cost me about $3.  I've already built my own keyboard encoder, why not finish it all off homebrew
Who knows... I may never end up playing any games on this thing even.. but it sure has been fun to build.