DIY solutions for a Lens mount - Page 2

I waiting for a used U15 Panamorph I bought to turn up. I don't want to have it permenantly left out as it isn't a dedicated theater room, so I need to work out a way of having a quick detachable fitting for the new lens. I watch a couple of 16:9 HD TV programmes midweek on the PJ and usually watch a film or two over the weekend that typically are 2.35/2.40:1 so I'd only need to pop the lens on at the weekend.

I'm thinking slightly latterally in that I thought about making a flat plate out of MDF or similar that the PJ stands on. Then screwed to the shelf shown in my attached picture and having two drawer sides that pull forwards with a bar of MDF to allow the lens mounting bracket to fix onto, using some 'thumbscrew' type nuts to tighten it. This pull out shelf can be pushed back under the PJ when the lens is not in use. Any other suggestions gratefully received.

Slightly off topic, is anyone using a U15 with an AE2000 ( or AE1000)? I know it isn't a very high quality lens from reading up on the AVS archive forums, but I hoping it will work OK as I use a very long throw to minimise the lens area in use. I can't use a HE lens as I've calculated the image will be too wide for my screen, but if the U15 proves too soft, maybe a newer U85 might turn up in the future and this would be a striaght swop. I only paid £90 for the U15 so it's no biggy.

EDIT: I picked up a pair of heavy duty drawer slides from B&Q (UK equivalent to Home Depot I believe). They fit nicely onto the underside of the shelf, now I need the Lens for measurement purposes. I can add a small piece of Black anodised aluminum angle to the front edge which will hide the shinny ends of the slides and provide a strong surface to fix the lens bracket onto. I also bought some 'wing' nuts that I intend to use as the quick release mechanism to unscrew the lens bracket from my slide. I guess a picture will make things much clearer, so I'll post back once it is completed, incase it proves useful to someone else.

I finally got around to mounting mine today and used this model. It took us a little bit to get it situated right on the slide because we were using the holes that were already there instead of drilling a new one, but it's up now and it's a nice, simple mechanism.

Of course, we mounted the stupid slide a little "crooked" on the ceiling, but an easy turn of the dowel and the lens is square. As long as folks don't look too closely they won't notice...or maybe they will because it's pretty obvious but at this point I really don't care; they need to be focusing on the image that now covers the entire wall .

I'm getting ready to build my slide and I know almost nothing about drawer hardware so I wanted to ask - would something like this be a decent choice for a DIY?

http://www.thehardwarehouse.com/prod...roducts_id=368

I'm thinking I'll do two parallel with a chunk of 1x3.5 poplar I have left over from building my frame.

thanks.

Looks very similar to what I used. I also ended up going with 2 in parallel to add more stability.

yeah having never actually seen one of these 2-prism lenses in person before, I didn't really know what to expect when it came but having held it in my hands, I'd much rather have the added stability of two tracks. this thing is pretty solid and heavier than I thought it would be.

that one is 10 inches long. I assume that should be more than enough room right?

That depends on the PJ and your lens/sled design. You want to have enough lateral movement to make sure the lens can be moved completely out of the way, not blocking any air flow vents, etc.

That is almost exactly like the slides I used and yes I did use two. you can see the pics of mine on the preceding page of posts or check out my theater in my signature line.
it is very stable. I have a UH380 lens.

I've always thought these would make a good automated lens slide

So I ordered an htb lens and I am almost finished building my slide for it.

I have a bulk head just above and barely in front of my projector lens so I attached two drawer slides horizontally to the bulk head. I screwed a piece of wood vertically to the drawer slides and then at the bottom I have another piece of wood attached horizontally to attach the lens.

The problem I have is that when I slide the lens out away from my projector, because the center of gravity for my setup is not in line with the vertical piece of wood it starts to torque. So I need to add a counterweight at the back.

Any ideas as to what is fairly cheap, is smaller than 9in x 5in, and would weigh about 5lbs.

Thanks

John

Drawer slides are not good for the reasons you state. Here's an alternative solution.

http://www.avsforum.com/avs-vb/showthread.php?t=1035479

Here is my lens setup. Not completed yet but close. Need to paint or cover my lens slide to make it look pretty.

Check the strength of the drawer slide to hold the lens. Normally drawer slides a mounted vertically rather than horizontally. Horizontal position exerts more pressure on the slide in comparison to the vertical position.

Hi GetGray,

The CE rules, regs & of course fines; are they only in play if one is using RF type remote control ? I had read on a IR remote company's web site where they stated IR controlled electronics were not subject to those rules, is that true ? Just wondering in case I ever invent something that needs wireless control. Thanks for sharing your experiences with us!

John

John:

No, unfortunately they apply to anything with a microprocessor in them. It dosen't even have to be a fast microprocessor. And they have thought of every loophole. You can't even make "modules" if they are to be assembled as an end product. The FCC and CE RF lab charges for the CineSlide testing approached $15,000. The CE testing was the most expensive one since there are many more tests you have to pass. And that's just the start. Then you have to create a "technical file" and a Declaration of Conformity (CE). Nothing would have made me happier to not have to pay that just to be "legal". And I tried hard to find a way around it. There wasn't one. It's a brick wall for many entrepeneurs. In the US the FCC allows a tiny loophole, but it dosen't help if anyone is selling a thing. They allow one to make up to 5, for personal use, without the tests. But not sell them.

For the FCC, for unintentional radiators, see their "Part 15" rules.
For CE, it's a long list of EU directives. Which change all the time apparently.

Has anybody ever considered the possibility to swing up the lens instead of sliding to a side?

"GetGray",

Thanks for enlightening me. WOW ! A small company would have to sell a lot of product to pay off that kind
of testing investment. But it pays to be legal.

So, if a person came up with a way to use relays & switches w/o the use of microprocessors, you could still use IR or RF remote controls to control a system w/o going to the huge expense of all the testing & regs ? Just as long as you use no microprecessors... just wondering.

John

Well... the IR and RF receivers take microprocessors to deal with either incoming signal so the question isn't really valid. Ditto for the transmitter. For example the IR remote on the CineSlide is a digital signal, produced by a uP, sent out on a modulated 40MHz optical IR carrier. And I believe technically it's not necessarily that a uP that is the trigger, but an oscillating circuit, which all uP's (I know of) use to shift their program clocks.

Thanks for the info !

Can someone please post a link to the relay needed to connect to a 12v trigger output so it controls the actuator? Thanks.

No easy button links but some advise... 12v triggers aren't designed to drive ("power") anything, including relays. Most trigger inputs/receivers are high impedance sensors that simply look to tell if there is, or is not a (12v) signal present. Some devices will source 10mA, occasionally more. But some will only do microcurrent and connecting even a small relay might look like a dead short to them.

So, check the specs on whatever you are going to use to source the 12v trigger output. Then, either use a transistor to switch a relay, or possibly a miniature, low current relay to trigger a larger one, like a reed relay. See www.digikey.com for relays.

Practically all of these slides (which look great BTW) have their lenses screwed to a base so that there is no possibility to adjust the lens left or right. How do you deal with this need? I'm looking at using a lockable ball joint with 360 degree manipulation. I'll then attach that to a slide.

You will find that as much as you can isolate the degrees of freedom the lens has simultaneously, the easier it will be to properly adjust. Ideally, independent pitch, yaw, and roll at a minimum, altitude and left-right. A ball joint would be a real pain to align properly.

Still holding strong after 2 years. No sign of wear yet and we move the lens multiple times a day.

Wow! Looks like a replica of mine. Exact same drawer slides and wooden mount. The only difference is that I've screwed it directly into the ceiling and have then used wooden blocks between the slides and the lens mount to adjust for height.