get your perspective right!!!!!!!!!!!!!!!!!!!!

Update

Ok, since I’m a fan of prototyping and a person, who has to see, how things appear in their environment, I’ve build a “rapid” prototype of my table in a couple of hours. I can recommend this approach, because you get a real impression, how your final table will look like and how it will fit into your room or whatever. I spent not more than maybe 20 Euro for the material and some time, but I think it’s worth it.

Here are some pics of the building process and the final prototype:

Workplace #1

Keep your eyes peeled! My dirty little helper, hehe

The bottom has just been finished…

...and here’s the rest

Now the framework will get decorated

I used black construction paper for the sides and large sheets of white paper for the top.

Finished prototype in his prospective environment - part 1

Finished prototype in his prospective environment - part 2

Now I know, that my table will be large, but not too large

Moreover I spent some more hours on research and desired setup would look like this (the measurements will remain unaltered):

- Acryl: EndLighten XXL (or will XL be enough? XXL is 10 mm (~0,4 inch) and XL is 8 mm (~0,31 inch)
- Protection/Projection Layer: PLEXIGLAS 7D006
- Projector: Toshiba TDP-EW25 (as I already asked - is there any difference between TDP-EW25U (name in USA) and TDP-EW25 (name in Germany)? Maybe the “U” is for US? Dunno)
- LEDs: Osram SFH-485P (or perhabs SFH-485?)
- Camera: PS3Eye (do I really need two of it? Can’t I go the same way back throug the mirror as the projected picture?)
- Mirror: dunno yet - have to check

The remaining components I have to check like retainers for the LEDs etc.

Maybe I can get some more hints, if this setup would work?

No way back now!

I’m a bit excited at the moment. Today my diploma officialy started and for this occasion I fortunately found a very good offer for my favoured projector, the Toshiba TDP-EW25.

The German online-shop xitra.de sells it for the bottom price of 1140,43 Euro INCLUDING a additional lamp, whose price alone is already 300 Euro. On the bottom line one pays round about 850 Euro for the projector, which is an unbeatable price! I already safed my instance.

Here’s the hyperlink for the offer. Watch out for the article number - it has to be “TDPEW25EU/KIT”. Since it’s seems to be a special sale, the shop won’t have a high number of items, so be quick.

Unfortunately they only ship to Germany and some other European countries.

I also started a blog about my project today: Touch it! - Just another multi-touch-blog

a few posts back you have asked for the U in the toshiba projector name.

i guess it stands for USA. i have got a panasonic pt ax 200e and ... surprise ... the e stands for Europe. there is as well a panasonic pt ax 200u…

your projector has very nice attributes. anxious to hear how everything works!

Hey,

yes, it seems like the U stands for USA and the EU for Europe. The projectors have exactly the same specs.

I’m also very tensed, if everything will work the way I want it :D

I updated some items and the measures of the table.

At the moment I’m looking for a (first surface) mirror, but I don’t get along with the “Projection Diagram Tool”. Maybe someone can help me?

My projector has the following facts:

Width: 337 mm
Height: 118 mm
Depth: 265 mm
Lens Offset: I don’t know exactly...I assumed the proposed 50
Throw Ratio: 0.59

Does this tool calculates with mm or inch? I assume mm…
I don’t really get how large my mirror has to be and in which angle and distance to place it :(

i don’t like that projection tool very much.

one guy from sensory minds (for which i made this project) uses to fold paper models of the projection channel. that means that you cut out a paper triangle that corresponds to the projection channel of the projector. the target is to have a projection where you do not have to apply any keystone correction from the projection as this will render the antialising of thin lines looking shitty.

in one corner of the paper triangle you can imagine the projector and on the the line opposite to the projector’s corner you will have your projection plane. from the attributes of the projector you can calculate the angle of the corner where the projector is. then you have to make the projection line as big as the surface of your table. but be warned: short throw projectors often have aspheric lenses. this means that on top of the projector’s lens the projection goes straight and on the bottom of the lens there is a high angle. this means also that you often have to mount this projector head up in your table.

as soon as you have got such a paper model you can fold it in a way that the projection channel fits inside of your table and that the projection on top is plain (as the surface of yout table is plain as well). in the places where you folded the paper you have your mirrors.

sounds pretty complicated but it is a hell of useful.

Hey,

maybe you’ll have to explain that again to me in German we’ll see :D
But thanks for the hint!

Update:

Ok, I wrote a few mails with the customer services at Evonik/Röhm and they told me, that 8 mm thickness for the EndLighten XL should also be enough for my size (110 x 72,5 cm with a seating of 5 cm on each side, therefore 100 x 62,5 cm “floating” plexiglas).

What are your guys experiences with 8 mm thickness at that size of the acrylic?
Will 8 mm really be enough or will the sheet bend on pressure?
Please consider, that a sheet of Plexiglas 7D006 will be laid on top of the EndLighten, which hopefully also does it’s part for the stability.

i think it will bend a little in the middle but it should not be bothering.

hey cdog there maybe slight bending in the middle like lagerkoller said, so rather than using an plexiglass overlay i’d change that with glass since glass is more rigid. even if you decide to go with the plexiglass overlay you shouldn’t have too much of an issue…

Taha - 23 March 2009 12:07 PM

even if you decide to go with the plexiglass overlay you shouldn’t have too much of an issue…

Thanks Taha. That’s what I wanted to hear, because the plexiglas overlay (7D006) is already on it’s way to me

If there are no too different opinions on that by tomorrow, I’ll order the EndLighten XL 8 mm…

hi, how are you proceeding?

Hey,

there were a lot of updates, but only at my blog at the moment
I don’t get around yet to write them all down.

Yesterday I did the soldering, but I will add some more LEDs, so the frame hasn’t been finished yet.

I hope, I’ll find some time to update my blog and this thread in the next days.

I’m still alive, but I’ve been very busy with my table and some other things. A lot has happened within the last week. I hope I can update the blog so detailed as is usual. The news in brief:

* Projector has arrived and I did some tests
* Found a useful and cheap frame for my LEDs in a DIY market
* LEDs including resistors and power supply unit have arrived
* Protection & projection layer “7D006″ has arrived
* NIR optical filter has arrived
* Soldering of the LEDs is almost done
* Lens mount respectively cam for disassembling has arrived
* Fans and cables for cooling have arrived and are running
* Box has been ordered at a local joiner respectively furniture-designer
* EndLighten has been polished by a local plastics-speccialist
* Second surface mirror and stuff for a DIY FS mirror has been bought

Many updates are online in my blog now, if you’re interested

year nice and very nice hardware components