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Discussion Starter · #1 ·
Hi, Folks!


As I've mentioned in other threads, I'm going to try to design my own remote-controlled mechanism for switching the ISCO 3 lens in and out of the optical path of my Sony Qualia. To pull this off, I'm starting off by gathering information about the different components that'll be used. Unfortunately, I can't find the dimensions of the ISCO 3 lens itself! I've perused ISCO's site, and the only specs they reveal are for the smaller ISCO 2 lens. Does anyone know the actual size of the ISCO 3 lens?


The reason that this is important is that I'm trying to determine the precise travel distance that will be necessary to activate or deactivate the lens. This will then determine the minimum enclosure size, which will then allow me to figure out how to come up with a general enclosure design that'll hopefully look decent in front of the Qualia.


Even if ISCO doesn't have exact specs, I'll take anything I can get in terms of rough dimensions. Can anyone help? Thank you very much!


Have Fun!

MarkF
 

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Found this for the ISCO II:


Manfred is an Engineer with ISCO Optics in Germany


Posted by: Manfred Hettwer


I was asked for the dimensions of the Video Attachment II:


Length: 103 (min) - 125mm (max)

Front diameter:~125mm

back diameter:~64mm

Weight ~1500g w/o stand


Take a look at:

http://www.iscooptic.de/isco_new_e/home_cinema_e.html


Drawings Home Cinema Projection Unit / Frontview

Drawings Home Cinema Projection Unit / Sideview

Drawings Home Cinema Projection Unit / Topview


Shows the exact dimensions of the housing that ISCO uses for the II and III

(I think that is the case - very strangely organized website) Should give you

a good idea of the space needed. Strange that the specifications of their lenses

are not on their website.
 

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Discussion Starter · #3 ·
Hi, UsualSuspects!


Thank you very much for the links! I'd seen these, but the reason that I'm searching hard for the exact ISCO 3 dimensions is because I'm contemplating a rather different sort of system. Personally, I find the ISCO remote housing rather ugly. So I started off thinking about ways to make the housing more attractive. In the process, I realized that the basic problem was that any Left/Right shift mechanism would presumably need to be asymmetrical, which would look bad in and of itself, in my opinion.


As a result, I've actually been contemplating a vertical lens motion system, where the lens would move over the projector when it's not in use - perhaps I should actually refer to this as a vertical-axis, circular motion system! Though this is mechanically far more difficult than a horizontal motion system, I think it would look really cool if I can get the mechanics to do what I'd like them to do. In other words, we'd start off with the ISCO 3 in front of the Qualia, and after retraction, the lens would remain parallel to, and horizontally centered on the projector's optical axis, but the lens would actually rest on top of the projector, about 1-2" back from the front of the machine.


The primary challenge is that this requires a parallelogram-type mounting system that would have to rotate through nearly 180 degrees, based on the sketches that I've done so far. However, I haven't yet been able to come up with anything else that could potentially look as good. Given the gorgeous design of the Qualia, it seems worthwhile to me to try to find something that doesn't detract from this clean appearance.


Perhaps this background may help clarify why I'm seeking to understand the exact dimensions of the ISCO 3?


Thanks again!

MarkF
 

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Hmm... how about this - retraction - first flip the lens 90 degrees so that the lens from face points at the ceiling - then retract straight back on top of the projector - much easier to engineer?
 

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Discussion Starter · #5 ·
Hi, U.S.!


Yup, that's a possibility I considered. In fact, it's quite a bit easier, since there's no need for the parallelogram system - a simple circular motion of a single-beam mount would be close enough. There are two disadvantages. First, it'd lead to more dust collecting on the front lens surface, and second, I don't think it would look as good (this would also need a greater vertical clearance to the ceiling, but that's probably a minor issue, given my guess of the lens size).


If I can pull off the constant-horizontal lens position, that'd be preferable, but if I can't, I may well use this "rotating" mount as a reasonable compromise.


Good thinking!

MarkF
 

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mark-


I've been reading the 2.35 posts, and I noticed your post about the remote-controlled lens.


I actually liked the idea of the lens rotating up over the PJ when not in use. A dust cover (part of the remote housing) would solve the dust problem.


My thinking is that you have a motor behind the mechanism, belt-drive the rotating arm that holds the lens, and have limit switches at the in/out extremes.


It may be possible to machine a bracket that actually bolts to the PJ mount.


Total cost for this would be about $150. in parts. NRE would be maybe $200.


Just thought I'd throw my two cents in.


Don
 

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Discussion Starter · #7 ·
Hi, Don!


You've definitely got the right idea! I'm not sure if I'm going to need a belt drive or not, but the rest is spot on (thus far, I've been looking at surplus ~6 RPM gearhead DC motors). That, along with a DPDT relay, the remote control PCB, and a 12V power supply will just about do it. Coincidentally, we just got a new 4-axis CNC/prototype system up and running today at work, and it got me thinking about what kind of housing I could try to come up with to make the whole thing look good. It's definitely a challenge in that regard: the Qualia's so pretty that it's tough to match its style! :)


Since that's now two suggestions that the lens would look better vertically when it's stowed, I'll spend a bit more time thinking about how I could make this look good. Who knows, we may yet give that approach a shot!


Thank you very much for the feedback! By the way, I definitely plan on complementing this with your masking and draping systems! Expect a PM from me before too long...


Have Fun!

MarkF
 

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Mark-


Check out allelectronics.com for the 6 RPM motor. Plenty of torque. I gave this a little more thought, and you're right, you could attach the swing arm directly to the motor shaft.


I can supply you with the motor control electronics and IR remote. PM me if you want.


Don
 

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Saw your room shots in the 2:35 screen picture thread. What is above your ceiling? Could you cut a hole in the ceiling and have the lens come straight down for 2.35, then retract all the way into the ceiling and close a little trap door for 16:9 – that would be cool. Makes it a little painful if you decide to move the projector….
 

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Discussion Starter · #10 ·
Hi, Gang!


Don: While I've already got a remote system and the relay, I must admit that I'm intrigued by the possibility of having the same remote control both the lens and the masking system. In an ideal world, your IR controller would offer three positions for the masking system: 2.35:1, 1.85:1, and 16:9 (a fourth position for 4:3 wouldn't be bad, but I wouldn't use it much). In that same ideal world, the lens would automatically retract when the aspect ratio is set to 16:9. How might this work in the real world with your IR controller?


Thanks for the pointer to allelectronics - that's the exact motor I've been thinking of using!


UsualSuspects: I think you may have me confused with BillS2K? My Qualia won't arrive until next Thursday. Actually, I do have empty space between the ceiling joists, so this could be made to work. It would have the advantage of looking great when the lens was retracted, but then we'd have supports hanging down from the ceiling when the lens was active. It's a possibility, though!


Personally, I just think the motion of a parallelogram-type mount looks really cool, so perhaps that's why I'm still biased towards using one. ;) As I flesh this out with an enclosure, though, it may well lead to one of the other alternatives. We'll see what happens!


Have Fun!

MarkF
 

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Wouldn't it be simpler just to have an L-shaped perspex mount that was hinged above the PJ - as per the rather crude drawings attached here - raising and lowering of the mount by simple pulley. Because it is perspex it will be cheap to make and still look good.

 

FrontViewLensDown.pdf 69.375k . file

 

FrontViewLensUp.pdf 60.3056640625k . file
 

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Discussion Starter · #12 ·
Hi, JKennedy!


Hey - that's a very good idea! While the curved upper surface of the Qualia would be a minor irritant, there's no question that this could work quite well! [For other New-World Rebels like me, that's plexiglass]


Far from being crude, I like your models! May I ask what CAD package you used to create them?


Thank you very much for taking the time to put these together!


Have Fun!

MarkF
 

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Discussion Starter · #14 ·
Hi, Folks!


I keep going back and forth on the different approaches, and what keeps haunting me is the mechanical stability of the mount. The ISCO 3 will be my fifth anamorphic adapter, and one thing that I've learned over the years is that peak image quality requires very precise optical alignment. Of the mounting types we've discussed, the best in this regard is still the horizontally sliding lens mount, and then it's probably a tie between John's plexiglass mount (assuming a "magic" solution for mounting the lens to the plexiglass) and the parallelogram mount. Arguably, the least mechanically stable designs are the single-arm rotating mount, and the retract-into-the-ceiling mount (OK, this last one could be made strong enough, but the stronger it is, the worse it'll look).


John, while your plexiglass approach is appealing, I can't think of way to hide the pulley, etc. In the absence of a better solution, I'm back to either the horizontal sliding mount or the parallelogram mount. Does anyone have any other thoughts or ideas before I just give up and start building one of these? Either way, thank you very much, guys, for the very cool ideas!


Cheers!

MarkF
 

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Discussion Starter · #15 ·
Hi, Guys!


OK, I'm now starting to take a good look at the (tiny) mechanical drawing in the owner's manual to see how these might fit the Qualia. It looks as though the best mechanical attachment point would be to the front two bolts that attach the projector to the bottom mounting plate. These two bolts are about 4" apart, about 5" back from the front of the projector. Unfortunately, using them will require cutting back the plastic shroud to clear whatever attachment is used. The thought, though, of cutting into any part of a $30K machine... ugh!


In addition, I hadn't realized until now that the top-front of the projector in that exact region is the air intake! That will just about rule out the plexiglass approach, because to get enough clearance for the air intake and still maintain strength, the hinge point would have to be so high that the lens would hit the ceiling in my installation. Drat!


This isn't going to be easy...


Cheers!

MarkF
 

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Discussion Starter · #16 ·
Howdy!


Hmmm. I just had another thought. It appears that it might be possible to use the projector's front two feet as the mounting point. These are about 15" apart, and are roughly 5" back from the front of the projector. The really good news about this approach is that it appears that the feet would clear the plastic shroud without any problem. This might even make it possible to come up with a simple two-bolt anamorphic add-on assembly (and maybe even a good looking version for those that use a fixed ISCO lens, too). No projector mods is a good thing! The investigation continues...


Have Fun!

MarkF
 

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Discussion Starter · #17 ·
Hi, Don!


Well, the 6 RPM Gearhead Motor arrived from AllElectronics, and it looks pretty good! The primary concern is torque: this is a tiny little motor!


I've written ISCO tech support to ask for the actual size and weight of their "Anamorphic Attachment III", but don't yet have an answer. Assuming that it's similar in weight to the "ISCO 2" / Anamorphic Attachment II, the lens plus the movable components of the mounting mechanism will probably weigh about four pounds. Using the parallelogram-style mount, the length of the lever arm will be ~5-6 inches, meaning that the motor will need to deliver perhaps 25 inch-pounds of torque during lens retraction. That's a lot of oomph!


I guess that we'll just have to wait and see if it'll work once the mount's been built, since we're working with a surplus motor that doesn't have a spec sheet. If all else fails, I may have to look into some funky coil or compression springs to help reduce the torque required for retraction. Time will tell...


Have Fun!

MarkF
 

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Mark-


Being that these are 6 RPM suggests to me that these are high-torque motors. But, not knowing the weight and arm distance exactly, we are just guessing about the torque needed for your system.



One other alternative is to buy the window motor from them, which has enough torque to pull a train. One caveat here: it is rated at I think 100 RPM, which is way too fast. One way to slow it down is through a motor controller bridge, which uses a PWM drive pulse to determine motor speed. With a PWM duty cycle of say 10%, you can get the RPM and torque needed to drive your system. Just remember, the longer your arm, the more torque you're gonna need to move your lens.


Hope this helps.


Don
 

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Mark-


Just another thought, but you could use a winch and guide rails to move the lens up and down. The guide rails could even be drawer guides.


Allelectronics has right-angle motors, which you could attach a pulley to. Mount it so that the pulley is centered between the two guide rails, above the lens, and raise and lower the lens with a cable.


This will require much less torque.


Don
 

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Discussion Starter · #20 ·
Hi, Don!


Thanks for the good suggestions! If, indeed, this approach will wind up needing a motor that's unreasonably large, you've got some great ideas! The winch approach would have the downside of not having the mount stability (with the lens on a cable, if I'm understanding you), but it's definitely more energy efficient! Then a second motor would pull the lens back. The two motors would have to be sequenced, because this approach would require that the winch run to let the anamorphic lens clear the projector lens before the slide rail motor could pull the lens back (or it might be possible to use a cam and some gearing to run everything off one motor). Do I have this right? Thank you again!


On other topics, ISCO sent me detailed mechanical dimensions for the Anamorphic Attachment III - yeah! There was a bit of bad news and good news in their response. The bad news is that they forgot to mention the weight, so we're making another pass at that information. The good news was a bit surprising. I sent my request to "TecSupport", but received the response back from the VP Sales & Marketing for their Digital Projectors division! In a nutshell, they're obviously curious about my little project, and are even asking about whether this might be available for worldwide sales! Let's see how this goes, first! :)


Have Fun!

MarkF
 
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