Alright guys, I'm going to apologize straight off in advance incase this has already been discussed to death.

Come to find out my uncle is an Electrical Engineer and he also knows a few Mechanical Engineers. So I wanted to ask, does anyone here know in brief or in detail what you have to go through in order to get the Diffuser to vibrate properly? A link possibly? That would be freaking fantastic if you guys could help out.

RH.

The vibration is done with a motor with an offset weight, like the ones used in pagers or cellular phones. Here's a picture of one from a Nokia:

http://www.druckerzubehoer.de/shop/images/products/612893_popup.gif

The Letus uses rubber parts from syringes, to make the vibration within a specific range. Unfortunately I can't find the Letus guide anymore (had it as a .pdf).

http://bellaire.homestead.com/files/MediaFiles/Vibrating_GG_DOF_Adaptor_2.pdf

The cylindrical motors with an offset weight can be quite noisy. I am personally using a small disc motor, which is quite silent once enclosed. If I am not mistaken, this is also what is now used in the Letus.

Last item on the page:

http://www.solarbotics.com/products/index.php?scdfa-250100084-viewCategory-categoryzq37=true&frm=sbsb

They are a bit tricky to solder though.

http://bellaire.homestead.com/files/MediaFiles/Vibrating_GG_DOF_Adaptor_2.pdf

That is so cool Quyen! I can't believe you still distribute your older plans. Obviously they've changed and improved, but I think it's great that you still do that. What a gentleman.

Francois, how would one go about using such a motor? Do you have any pictures of the way you have it mounted? I'm interested in making a vibrating GG but don't know much about motors and such. Very eager to learn though.

No pics yet, however, it looks a lot like what you see in the tutorial, except I have three posts instead of four and the disc motor is glued to the GG support plate.

Soldering the wires to the disc motor is the tricky part. The best way to do it, IMO, is to glue the disk motor and wires (cut at the right length) to the support plate before you solder.

I think you will find a lot of tips in the initial thread by Quyen.

BTW, I also thank Quyen for sharing his great ideas.

I looked more closely through Quyen's instruction file and it does seem pretty straight forward. I'll get things assembled in a static manner first and then see about adding a motor soon after. Looks really cool though. How much power does one of those little disc motors take? I'm no electrical engineer, that's for sure.

This file is not mine. I believe Craig made this pdf file. I am glad that you can build it yourself. I only sell to people that don't have the necessary skill or time to put it together. My current unit uses coin motor and has most of the parts done by CNC at a local machine shop plus all the updates, so the unit in the guide and my unit now is quite different. Hope you enjoy building it if you choose to do so. Also please keep in mind that my address and phone number on this file is out dated, thanks.

Quyen

Anyone know if this motor would work? Not very much info on that page though... But for all of us living in EU and Europe it would be preferable to buy as much stuff "locally".

http://cgi.ebay.co.uk/Vibrating-Disk_W0QQitemZ5827450863QQcategoryZ50423QQcmdZViewItem

Man, thanks a lot guys...you really helped me out. I have a question for you Quyen if you don't mind, you don't have to answer, but I heard back in some other forums you chaned that type of sticks to vibrate the glass. Do you mind sharing? If you don't want to, that's completely cool, I know you have your business to run. I'm going to run this past my uncle and see what he can do. I'm going to look around for some custom fiber glass places to shape exaclty what I'm looking for. I'll see what I can come up with.

RH.

My sticks now made of aluminum. I have machine shop machined it for me at exact length so I can have the same spacing between GG and mount. There is nothing to hide here really but it will depend on what you will use for your mount holding and the distance between GG and that holder. Some testing will give you optimum vibrating GG plane. Plastic sticks still work OK, thanks.

Quyen

how those cellular motors have been behave by long usage? Somebody got to replace it already?

what happened to the .pdf?

I was running out of space on my servers and hadn't seen anyone using the file in a while... I'll see if I still have it some where... Sorry

http://bellaire.homestead.com/files/Vibrating_GG_DOF_Adaptor_2.pdf

My suggestion would be to glue the GG unto the face of a 55mm Wheel Bearing with a large inner bore, the largest you'll find is about 40mm inner diameter. Slide the wheel bearing inside the tube and spin it by a rubber wheel attached to a small battery powered motor. The rubber wheel would rotate the inner bearing from the opposite side to about 12,000 rpms. I'm in the process of working on this idea as we speak, waiting for my wheel bearing to come in. Has anybody considered working on this type of spnning the GG?

Yes,
Nick Bartleet ( http://www.pixelloft.com/ ) designed this method over a year ago and has been using it ever since on his adapter.

http://www.sysmicfilms.com/wayne/PB050176.JPG

Only thing that bugs me, is that in theory the dead centre of the GG does not spin, and the spinning gets slower towards the centre of GG. You need very fine grit GG for this method to work.

What about GG artifacts near axis of rotation?

Frank,
Yes this is what I was trying to explain. You need a very fine GG. Nick works with the FX-1 in HD, had his work is on MTV alot, no problems.

Only thing that bugs me, is that in theory the dead centre of the GG does not spin, and the spinning gets slower towards the centre of GG. You need very fine grit GG for this method to work.

Yes, i'm sorry i missed that. btw how micro35 is designed. How far is rotating axis from viewable area.

Cant speak for the m2, but the SGpro's rotational axis is around 28.7mm from the centre of the frame. I think this is getting off topic.

Exactly what I was referring too! The only thing is that my adapter will have the tiny motor inside the tube with a rubber wheel wheel that will spin the inner wheel of the bearing. It will eliminate extra metal parts and thereby weight. I found a bearing that will fit inside the tube and the inner diameter is 40mm, giving me more focus plane unto the GG. I am considering using the motor of a CPU fan for the project. Tnanks for the image.

isn't 40mm too small for a 36x24mm image, or are you aiming for 18x24?

Wayne,

The largest inner bore diameter wheel bearing that I found is about 40mm, and outer diameter that will be 55mm that I needed. Unless somebody can point me in the right direction where I could find a much bigger inner bore that will accommodate either a 55mm or 58mm outer diameter tube.

If you are still going this route, perhaps forget about the wheel bearing and examine the bearing which carries the pulley/clutch assembly on automotive airconditioners, particularly GM products circa 1990 or thereabouts.

These have a wide centre hole, a narrow race and a narrower outer diameter than a wheel bearing.

I think you will find this route a dead-end as have other developers done and abandoned early in the research phase.

An old bearing will run free but will be noisy. A new bearing will be too tight and kill off any lightweight motor and battery unless you remove the seals and dissolve the grease out with solvent and replace it with light oil.

All of these options are almost the exact opposite of operating mechanicals near optics which must be kept clean and grease free.

Bob,

Thanks for the feedback on the bearing. I found out that bearings can be ordered to either accept grease or oil, so I think an oil bearing would diminish the noise issue. But I can see the oil conntaminating the inside of the tube. Thanks for sharing this info.

P+S technik was using the rotation with dead center on their forst model.
they stopped it due to complaints about the "vortex effect" it caused while looking at video.
I had made such design (with 55mm inner circle) for my first mini35, but never take the time to put the stuff into rotation.
I think the vibrating glass got more success.
The idea vwould be to glue an ultrasonic transducer on the glse so you can clean dust just by activating it.(same as done on some digital SLR camera).

Thanks for your in depth reply. At least I know that I should consider another route that could yeild better results.

Two narrow race ball bearings, preferably twinrow races, one able to fit inside the inner diameter of the other with about 6mm clearance, then an eccentric sleeve to fit the inner bearing outer ring snugly inside the inner ring of the outer bearing would do the job with about a 3mm excursion available by the time you leave some metal on the thinnest portion of the eccentric sleeve.

The outer rim of the outer bearing is fixed to the housing of the device. The inner rim containing the groundglass also remains fixed from spinning but free to move in an orbital motion. The outer rim of the inner bearing, the eccentric bush and innner ring of the outer bearing move as one. this provides the orbital motion.

This is a design I have examined but abandoned due to sourcing difficulties with suitable bearings. The inner and outer bearings would have to be custom made with free balls working in the races.

For the loadings a GG would impose, something like silversteel, hardened after machining would probably suffice for making the custom races. The eccentric bush could be eliminated in favour of having an integrated inside/outside facing race with offset centres.

The intention was to machine small belt pulleys onto the outer rim of the eccentric section and also around the rim of the GG frame.

The belt around the GG rim is only there to stop the spinning of the GG and to have enough stretch to allow the GG to orbit. It replaces a sliding key channel and pin which would wear and get noisy.

Except for the machining of two x two rows of bearing tracks and the frustration of trying to get all those tiny bearing balls to obey and stay put during assembly, it would be a simpler solution than the three-crank or four-crank orbiting systems.

The eccentric sleeve, if made slightly thicker could be drilled to provide partial counter-balancing.

The CD disk system although bulky, remains the simplest and most reliable for low budget home builds.