Didn't want to start a new thread for this, so here goes:

Anyone know how to put a small hole in a piece of glass without breaking it?
I got a piece of 3.5" circular glass from a $1 picture frame and I want to try making a glass version of the spinning CD adapter.
The hole should be no bigger than the shaft of a CD motor.

I don't have any precision equipment here. (No diamond drill bits, etc...) I do have a template printed from Photoshop that I will lay the glass over to find out the exact center point. I understand this is a slow process, but I am willing to do it. I want to do this before I grind it because I'd hate to break it after spending all that time on it.

Any ideas?

Thanks!

[QUOTE=Frank Ladner]Anyone know how to put a small hole in a piece of glass without breaking it?QUOTE]
I already did this couple of months before. And I have four glasses with hole to attach on harddrive motor (silmilar to CD holder). I can send it, but its 800 grit. Maybe its to much for you. Im from Europe, so if someone wants, I can send it.

Dan: hey Dan... ignoring me ?

Daves: Are you talking about sending a pre-made ground glass? I appreciate the offer, if so. I'm actually going to grind with a larger grit in an effort to get a more even image w/ no hotspot. Since it will be spinning, the grain won't be a problem.

Can you tell me a little more about how you did it? Thanks, Daves!

I did not. I order it to be done for me. They made me 4 pieces, but I do not use them anymore. Since its useless for me, I can send it to you. But I do no know if its enough big for you. I think it have 8cm in diameter, 2cm center hole. Or so. Thickness is 2 or 3mm. Its ready to use, you do not need anything to do with, until you do not want to make grain finer. Now its sanded by 800.

Hrm..... 8 cm is about 3.15 inches. The one I have now is 3 & 1/2 inches, and that's cutting it close...so I think the 3.15 would be too small to work with the motor and condensors I have. I'd hate for you to go through the trouble and it be too small. I appreciate the offer to send it!

I was thinking about it and maybe I won't have to drill. I could possibly mount something to the glass surface to attach to the shaft. I started thinking of using something flexible so that when the glass spins, it would automatically spin straight (with no z - motion). However, I wonder how well this would work when the camera moves quickly.

So... Dan, whats up... Tell us !

Hey guys!

For those of you looking for an adapter housing, here's one possible solution:

I got my hands on an old hard drive and removed the internal mechanisms (read/write arm, magnets, platters, etc...) until all that remained was the aluminum box with the metal cover.

At the moment, I'm working on a 3.5 inch spinning glass CD and this fits perfectly into the housing...even giving a little room for wobble (because a glass CD spinning quickly and hitting the inside of the housing just might break :-) )

All I have to do is put the holes through both sides.

These drive housings are durable and not all that heavy once the inner workings are removed. I think it's a good solution for an adapter housing.

Once I get the thing finished (including holes, wiring, lens mount, etc...) I'll try and post some pictures.

I took a couple of pictures of the drive housing as-is. They are located here:

http://70.147.193.182/mwtest/

(The images are named harddrive_for_housing_[ 01 & 02 ].jpg )

I like the idea with the harddrive. It sounds way better than using plastic. Keep us on the up and up!

A hard drive spins WAY faster than a CD player. CD players spin at around 500-750 rpm depending on whether the read head is closer to the center or to the outside. Hard drives of course spin 5400 or 7200 rpm.

That means the speed at the outer edge of a 5.25" circular piece of plastic (blank CD, ground glass, etc), with a CD motor is about 8 to 11 miles per hour (circumference times rotations per minute = distance travelled). With a 5400 rpm drive, it jumps to around 84 mph! That is a HUGE increase, especially in terms of dynamic imbalance as well as simple stability. With a 10x speed increase, centrifugal force is increased 100x. That means any instability, even if it is "invisible" at CD motor rpms, will be really apparent at hard drive rpm's.

I would not want to be at a tangent to a piece of plastic or glass spinning that fast. I guess if you have it inside a metal housing it would be one thing but even so, I wouldn't want shards bouncing into my camcorder or my 35mm lens.

Just my two cents' worth, from a guy who has been around a fabrication shop and machine shop environment for years. Wouldn't want to see anybody's soft parts, or lenses, get hurt.

Hey Bill!

Thank you for the input - and I agree with what you say. However, I won't be using the motor from the hard drive - just the case/housing. I'm still using a regular motor from a portable CD player. I'll rig this with a variable resistor (potentiometer) to adjust speed. (ie. to be able to increase speed in lower light to reduce grain)

Just in case you may have missed the post about Universal Focus Gear for SLR lenses, I do offer them from my site (under construction)

The MPIC will be available before the end of the year offering a few options in terms of different quality parts (filters, screens, motors and adjustable amplitude of motion). You could buy the entry level and upgrade later to higher quality parts. I am still working on pricing it, but I want to make it as affordable as possible. I will list it on the same page:
http://dandiaconu.com/available_products.htm
as soon as I have prices for all parts so you can order it. Thank you all for your sustained interest in this project.

I am taking orders now for MPIC and a few other items.

I couldn't find it on your available products page.

You're right. Sorry.....
Very long hous.... looks like it was not uploaded. I'll do it by this evening. Thank you.

How much?
 

How much are you planning to charge for them after the promotional period?

It looks amazing, especially in terms of size and efficiency, but I would want to see independent tests and reviews before putting down that kind of cash.