Mylar film vendors

[FI marco]

Hello to all,

My name is Marco, and I own a small company in the Netherlands that produces gauges and other components for simulation, both for the 'hobby' and professional market. We have a KA350 sim (with 2DOF motion) for demo purposes and are currently in the process of upgrading the visual system from direct projection (via a spherical mirror) to a collimated display system. As you can see in the picture below we have a polystyrene vacuum chamber(lightweight so the motion system can handle it) The polystyrene chamer is made by a company that specializes in large polystyrene shapes (CNC milled)


7599



The 'backscreen' will also be from polystyrene, and 3 Full HD beamers will be used for front projection.

7600

The only thing is that we're having a realy hard time to find a supplier for the Mylar mirror film, so here's my question: does anyone here know where to find 0.5 mil Mylar with a minimum height of 55"? Any help is much appreciated!

Marco

[FI marco]

Thanks for all your potential help ;), but it I have found the right material overhere in Holland. If anyone needs Mylar in europe I can give you the info.

Marco

[geneb]

Marko, great job!

You have one tiny, little problem however.

See those curved bits at the end of each side of the mirror cell? That's a patented feature. Unless you've taken out a license from Rockwell-Collins, I strongly suspect they're going to turn you into a smoking hole in the ground as soon as you try to sell one. :(

Here's a copy of the patent:
https://docs.google.com/a/google.com/viewer?url=www.google.com/patents/US6050692.pdf

Good luck!

g.

[FI marco]

Hi Geneb,

Thanks, I just had a look at your project(s): simply wonderul! Our 'hardware' seems very much alike, but we had the luxury that we only needed to design it and had someone made it for us. That's because it had to be lightweight.

As far as the patented feature you're right, thanks for pointing it out for me. As our project will not become a commercial 'product' in our range but is only intended for use on our own sim I quess there will be no problems. We were not planning to offer it as a product because it's not good enough for certification (to small anyway) and too expensive for the hobbymarket. We use our sim for demonstrating our gauges and controls (that is our core business) and also use it as a testing platform. And also for fun of course;-)

Here's a video of our sim as it currently is (no collimmated visual yet): Flight Illusion Turboprop full sim setup - YouTube (http://youtu.be/fIPiyNB-YZY)

I'll be followingg your next project with great interest!

Thanks,
Marco

[kermit]

Hi marco ,
Can you give me the Adress for the mylar?
also can I have a copy of the drawing for making the cell,
or the adres

do you have the measurements in and outside
greetz vriendelijke groet
Henk

[FI marco]

Hi Geneb,

Thanks for the info, I didn't know that the 'ears' are a patented feature. As our system was not intended nor is designed to become a commercial product I believe there won't be any problems with Rockwell-Collins. We're only going to use it for our own sim. We use our sim as a testing & demonstration platform for our gauges and controls. And for fun of course ;-)

We considerd turning the design into a sellable product but realized it's not good enough to get certified and too expensive for the hobby market.

I just had a look at your collimated display system: amazing job! Must have been a lot of work to build it? (we had the luxury of only having to design it) I'll be following your next project (the big mirror) with great interest!

Thanks,
Marco

[FI marco]

Hi Henk,

Here's the adress for the Mylar is hififilm.com (HiFi Industrial Film Ltd)They have a salesoffice in Holland (in Hoorn) and sell metalized Mylar with a gauge of 0.5 mill and a (roll) height of 140 cm. Remember that we haven't tested the Mylar yet so I can't garanty 100% it is the right stuff.

I'm not sure if I can give you the drawing because that's against company policy, but I talk to my colleagues. I can tell you the mirror radius is 240 cm and the maximum outside (width) of the mirrorcell is 260 cm.

Marco

[FI marco]

Hi Henk,

I tried to send you a PM, I'm not sure it worked...

Best regards,
Marco

[FI marco]

Sorry for the double replies, it took a while for the first replies to get approved (because there are web adresses in it?) Patience is not my strongest point ;)

Marco

[geneb]

Excellent job on your sim cab! I love the engine gauges. Those dot matrix displays are very nice. I just wish they had one that could fit 5 digits in the same space.

I strongly suspect that by the time the patent expires (another four years I think), projector systems will make them a no-brainer buy for the people that have the room for them.

How was yours constructed?

What are you using to manage the mirror shape?

g.

[FI marco]

Thanks!

I think there are many applications like e.g. car driving simulators (they are used in Holland for driving lessons) or some types of gaming that could use a ‘low cost’ collimated display solution. The only systems that are available at the moment are the very big & expensive ones. That probably has to do with patents as you mentioned…

Our mirrorcell was first designed in Solidworks (CAD), we did some calculations regarding the virtual image size, eyepoints, minimal mirror radius, backscreen radius etc. We also did a raytrace simulation in 3D studio Max to see if the image generated by the mirror was as we expected it to be.
The next step was to have the mirror cell cnc milled by a company that specializes in making large objects from Styrofoam. Our mirrorchamber was produced out of high density Styrofoam. We coated it to make it airtight.

As we haven’t received our Mylar yet, and still need to construct the projection screen etc. we’re not 100% sure if our system is going to work or not…
We are planning to use a differential pressure sensor toc ontrol our mirrorshape. We’ll be using one of our own I/O modules to control the sensor and vacuumpump.

Marco

[Roland]

Hi Marco,

The styrofoam screen looks like a nice way to get lightweight complex dimensions.

With good tools and guides, styrofoam (or the denser variant like roofmate) can be heat-cut with thicker steel wire shapes, to get hollow spherical shapes.

I had been thinking about a small (single seater) collimated setup for my 3DoF cockpit:
Maybe a stupid idea, but if you would have this spherical (or parabolic) hollow shape cut into the stryrofoam structure, would it be possible to make the mylar screen from many strips of mylar, glued into the spherical hollow shape? If done neatly, I think you could end up with a decent mirror, without needing the vacuum system.

Just an idea...

[FI marco]

Hi Roland,

I'm not sure if that would work. When you apply mylar (or any other type of mirrorfoil) directly onto a surface, I think that would only work if that surface is absolutely 100% smooth. Even the smallest dust particle between the mylar and the surface would create a considerable deformation on the image. It would also be very hard to apply the mylar without any wrinkles in it. One of the advantages of using a vacuum behind the mirrorfoil is that it smoothes out all the wrinkles.

So, if you can create a 'mirror' smooth surface to apply the mylar onto that would be great, but it's very hard to do...

Gr,
Marco

[geneb]

Marco is being polite. It's _impossible_ to do. Mirrors of the optical quality REQUIRED by collimated display systems must have an accuracy measured in *angstroms*.

I understand you guys want to avoid the hassle of building a mirror cell and doing the whole vacuum thing, but you need to understand that you cannot do it by coating a surface with mylar. You'd have to be half blind and currently suffering from a concussion in order for it to look right. The kind of perfection a vacuum formed mirror can achieve is right up there with multi-million dollar machine ground telescope mirrors.

Marco, I really, really hope that styrofoam is insanely strong stuff. I say this because if it's not, you're going to collapse it as soon as you draw the Mylar into position. If I remember correctly, Wayne calculated a compressive force of about 3500lbs along the top edge of the display we built, which is about half the size of yours.

g.

[FI marco]

I always try to be polite ;-), but I must say I have to agree wih your explanation.

We still have to test the styrofoam mirrorcell but we are waiting for the Mylar to arrive. We did however test it with cheap mirror foil that was about 2 mil thick and put a fair amount of vacuum behind it (yes, 2 mil is too much thickness and very hard to apply) The styrofoam seemed to hold ok. As the mirrorcell is high density styrofoam it is very 'shape consistent' and pretty strong. We also reinforced the upper and lower edges with an extra 'ring' made out of wood. Lets hope it is enough...

Gr,
Marco

[geneb]

Wayne & I used 1mil and it works great. I worry that the .5mil you've ordered may be too delicate to work with. The commercial outfits use 1mil as well.

I think it's insanely cool that you've got a monolithic mirror cell like that. Awesome job. :)

g.

[Roland]

Thanks guys,

Always good to reflect an idea with the experts. I was half expecting this answer. So getting a decent collimated display really needs the mylar vacuum thing.

Adding this on top of a moving platform will make things even more complex, and I really doubt the tensioned mylar mirror construction can withstand the accelerations of a fast moving platform, as it would require an extremely rigid construction.

I guess the 2-DoF platform action that Marco shows in his video maybe just OK, as it does not produce very fast heave movements of touch-down and turbulence.

Even the commercial 737 6DoF I experienced, I did not really feel the fast G's that my little 3DoF motion cockpit is generating. Maybe on purpose to avoid tearing the mylar mirror?

[FI marco]

@ Roland: you're right, it never hurts to ask. At least you got a clear answer ;-) If you could heat-cut styrofoam very precise it maybe is possible to make a small vacuum mirror chamber for your system. The biggest problem with a fast moving motion system like you have would be the construction that holds the beamers & folding mirrors etc. because of the obvious mass and height of the system...

@ Geneb: You might be right about the Mylar thickness, 0.5 mil is very very thin (and delicate) It will be a challenge to get it placed... The advantage might be that if we get it applied right there's less vacuum needed to form the right shape I hope. Good thing is that we didn't run over our 'experiment' budget yet, so we can always try the 1 mil version later if 0.5 doesn't work. I'll try to post some pics here with the results when we got the Mylar in.

Thanks,
Marco

[max2770]

I'm curious as to what is the black part of your design made of, as it requires air to pass through.

[crashdog]

Hi Marco,
seco-sign.de (http://www.seco-sign.de/) could have what you're looking for. I can't see the thickness of their mirror foil. But the sizes are up to 9m X1.80m
I'm gonna start building a collimated visual for my MD80 MD80 Flight simulator (http://www.md80.ch)simulator soon. Your approach looks quite good. I could be interested to know more about how you build it.

Regards,

Gery

[FI marco]

Hi Max2770,

The black part of the vacuum chamber is the same polystyrene but it is coated with a special paint that makes the polystyrene airtight. In the center is a small tube that we'll use to suck the air out.

Hi Gery,

Thanks for that link, that's a nice height of mirror foil. We have only mamaged to get foil with a maximum height of 1.50m (just about enough for our project) I have to say we've tried different (and expensive!) mirror foils but until now only Mylar seems to have the right 'stretchability' and properties for this application...

Our Mylar foil should be delivered tomorrow (monday) so we can finally test our mirror if all goes well.

Thanks,
Marco

[FI marco]

Yesterday we have finally put the mirror foil on the vacuumchamber and it seems to work great. In the picture below it looks all 'wrinkly' but that's mainly the reflections from the edges you see in the mirror & the fact the vacuum hasn't been adjusted yet.

7726

The advantage of using the very thin 0.5 mil Mylar seems to be there's little vacuum needed to get it into the right shape! We've experimented with a small projection screen and we can see it's collimating so it works perfect.

The only big disadvantage we discovered (and suspected before) is that a mirror with a diameter this small (2.50 meter) is only suitable for a single seater. Once you take position off-centre to the left or right the image gets distorted. For us that is bad news because we planned this system to be used on our Kingair sim... So now it's clear why the high end sims all have these enormous mirrors.

Marco

[kermit]

Hi Marco, When I click on Attachm. 7725,
I get this;
Invalid Attachment specified. If you followed a valid link, please notify the administrator (http://www.mycockpit.org/forums/sendmessage.php)
Can`t see anything
greetz Henk

[FI marco]

Hi Henk,

I uploaded the picture again, I can see the pic here now so hopefully it works.

Gr,
Marco

[kermit]

Hi Marco,
I can see it now, I have to agree with you
its no good,
note
when can I pick it up , I will throw it away at no charge :)
greetz Henk

[FI marco]

Hi Henk,

I'll consider your kind offer to pick it up ;)

Gr,
Marco