2 Place Collimated Display

[jthiani]

Awesome project. Im in awe !!! I will be embarking on a similar project and any help is much appreciated. Castle, i tried to pm you about coming to see your setup., not sure if it sent though

[castle]

It has been a long, long time since my last post. Finally got around to reskinning the mirror. Lots of folks, friends and neighbors, wanted to come over and fly and kept putting of the job. Took best part of 3 days; one to tear it down and prep and 2 to position and attach the mylar. Just about perfect The pics tell the tale..

Will take a moment to pass along some "lessons learned"

Gene: if and when you throw together a kit or set of plans, lose the spider arms, you need to provide a scheme to position and suspend the screen for two reasons; first for the 16' system you need a minimum of 4 projectors and the arms get in the way, and second, you need to position and drape the mylar sheet over the top prior to taping. After I had the projection screen attached, calculated the CG of the structure, defined the suspensions points, and once that was done removed the arms. The rigging allows for adjusting, as needed.

Reduce the weight of the screen by reducing rib weight and use ceconite fabric and a thin slurry to cover the material once it is attached and heat treated. That will also allow for a lighter frame.

As you work your way around the frame attaching the mylar you can use blue painters tape attached to the front side of the mylar to hold the mylar away from the glue as you remove the covering from the tape. Work from bottom to top in 3 inch sections ( the width of tape ). Do not stretch the material, just keep it taut. At the ends position the tape sections vertically.

Still need to attach the clamping pieces.

Cheers
John

[wledzian]

Castle, that looks spectacular. Glad to hear that this skinning went so well. Did you draw a line around the edge on the last one to monitor slippage? I know mine looked beautifully pleated like that until the first drawdown, but has always had just a little bit of stretch ever since. The marker line hasn't budged, so I know it hasn't slipped. Yours has seen much more usage than mine, however. I've finally got mine running again, and am hoping that slippage doesn't become an issue.

Jthiani, looking forward to demoing for you this weekend.

[castle]

[QUOTE=wledzian;158180]Castle, that looks spectacular. Glad to hear that this skinning went so well. Did you draw a line around the edge on the last one to monitor slippage? I know mine looked beautifully pleated like that until the first drawdown, but has always had just a little bit of stretch ever since. The marker line hasn't budged, so I know it hasn't slipped. Yours has seen much more usage than mine, however. I've finally got mine running again, and am hoping that slippage doesn't become an issue.

Yes, I drew a line and that was the main reason for the reskin. Just a small section at the rear of the top left edge had slipped and when drawn the mylar was contacting the rib. The rest of the mirror was holding fine. Turns out that was a portion that was exposed to direct sunlight through a shop window at sunrise over a two week period a while back. Tried to do a repair with two "ugly" schemes, first used a heat gun to shrink the mylar in that area and that helped and since it was on the far left rear quadrant did not impact the rest of the visuals but the glue was still losing after a couple of weeks so stuck a large piece of mylar (about a foot square) over the area but that also proved futile in the long run.

On this job, also used a paint roller to apply pressure to the tape prior to attaching the mylar and repeated the action after the mylar was attached. Will be doing the same with the clamping layer. Thinking of using two applications of the tape, one section onto the mylar, roll press it to the mylar, than a second layer onto the clamping sections. Roll press those parts, and then remove the cover sheet on both, attach to the frame, roll press again, and finally apply the screws to the clamping mask. And blocked the sunrise illumination with curtains and blinds.

One thing you might notice in the pics, the mylar attached to the collar is very smooth maximizing the surface contact between the mylar, glue, and collar. This is a result of the procedure to first fully drape the mylar over the entire and using the blue tape to hold the mylar away from the glue as the cover sheet is removed from the glue, section by section.

This is 1 mil mylar. If I do this again might consider using 1/2 mil stuff, although I have enough 1 mil for about 2 or 3 more reskins.

John

PS, say hello to Joe for me.

[geneb]

Agreed on the support arms. It was my first ginormous mirror cell design. What can I say?

An ink brayer would work as a good replacement for a paint roller I think.

g.

[jthiani]

looks great John ..... i must make another trip there and stay a bit longer. Tomorrow i leave for seattle and i really look forward to meeting Wayne and Gene and seeing there setup. Im also just about ready to embark on my build. Been working on the motion base thus far and just about done with it

[fsaviator]

I happen to be in Colorado Springs for a few days and so I swung by to see "Castle" and the progress on the collimated display. All I can say is... Wow. Bottom line, I didn't take pictures as they do not do it justice (really I was too stunned to remember).


I've seen pretty much every type of display possible in our little sim world and I will say that without a doubt, short of buying a Level D sim, you will not beat this collimated display.

I'm still speechless. I felt as I could reach through the windows and touch the clouds. I was able to take off, fly a circuit and land on the runway, visual, without crabbing, with the same view from both seats.


Just had to share.

[jthiani]

I happen to be in Colorado Springs for a few days and so I swung by to see "Castle" and the progress on the collimated display. All I can say is... Wow. Bottom line, I didn't take pictures as they do not do it justice (really I was too stunned to remember).


I've seen pretty much every type of display possible in our little sim world and I will say that without a doubt, short of buying a Level D sim, you will not beat this collimated display.

I'm still speechless. I felt as I could reach through the windows and touch the clouds. I was able to take off, fly a circuit and land on the runway, visual, without crabbing, with the same view from both seats.


Just had to share.

I must completely agree here .... i had the very same reaction when i saw this display last year. It is nothing short of the real thing !!!!!

[castle]

Hi,

Away from the project for several months; other pressing matters and priorities. Finishing up some software I started last year. Have been using Immersive Pro for creating the warp mesh. A nice program and reasonably priced, but a little limited for working with compound curved projection screens. One aspect I did not like was having to move individual control points to adjust for the unique radius of the screen at each control point. It was a PITA and tough to get uniform gradations from point to point as the radius changed.

Since the geometry the screen and mirror are uniform and can be expressed mathematically, it was just a question of developing an algorithm to crunch the numbers. The program produces a nice mesh that can be adjusted by varying the input parameters in real time that describe the geometry of the system. You do NOT move control points manually. The resultant control points are saved in an .xml file that can be imported into Immersive Pro for final "tweaking" and edge blending.

Would be interested in user feedback as to whether or not such a program is useful, so if anyone would care to play with it, send me a request via PM and I'll send you the file along with instructions and commands for use.

On another note, might be moving the sim to Denver this summer. More later as the plans firm up.

Cheers
John

[jthiani]

Nice to see you back here John ..... was wondering where you disappeared to lol ... I am about to start my display build and would be interested in trying this out. Im still working on the motion base and getting it finalized