Hello everyone, my name is Garrett and I am 13 and want to build my own FTIR! I have been scanning through these post for weeks now and can’t wait to get started! I tried to draw up some designs tonight, but I am a terrible drawer! I can only draw 2d. Please let me know what you think of my sketch. I accept criticism good or bad. Sorry if I embed my pictures wrong, this is my first time to actually post something!

First I tried to do it without the ruler, that didn’t work

This one was done with a ruler and then later labeled in photoshop! I cant draw 3d, so the CPU/Laptop Storage and personal Storage are supposed to be out to the side not under the whole rig! Sorry if that didn’t make sense! Let me know what you think!

I will attach the pics incase I embedded wrong!

Thanks,
Garrett

I don’t know how you plan on getting the CPU storage on the side, but CPU’s are big, and would probably poke in too far and block the projection.  Maybe draw a top view, or try doing it in Sketchup.  Sketchup is really easy to learn and lets you make quick 3D drawings.  Also, what are the dimensions you are trying to get?

Good Luck!

Alex

Remember that light hitting a mirror will bounce off at the same angle. You’re also likely to get a fair ammount of keystoning with that setup. Try this calculator and play around with the positions. http://robertpriewasser.com/stuff_projects/programming/rearproject/shockwave/index.html

xelapond - 23 August 2008 09:19 AM

I don’t know how you plan on getting the CPU storage on the side, but CPU’s are big, and would probably poke in too far and block the projection.  Maybe draw a top view, or try doing it in Sketchup.  Sketchup is really easy to learn and lets you make quick 3D drawings.  Also, what are the dimensions you are trying to get?

Good Luck!

Alex

Ya, I am probably not going to build that. I will probably put a fold down shelf or something to put a laptop on though. Where can I get Sketchup? Does it cost money? Is it compatible with Mac OS X?

Thanks,
Garrett

spbogie - 23 August 2008 10:32 AM

Remember that light hitting a mirror will bounce off at the same angle. You’re also likely to get a fair ammount of keystoning with that setup. Try this calculator and play around with the positions. http://robertpriewasser.com/stuff_projects/programming/rearproject/shockwave/index.html

Thanks for pointing that out! I didn’t even notice it was rotated the wrong way. The calculator helped out a lot. The projector that I am going to be using has an option to adjust the keystone. Hopefully that will deal with any keystone problems that I would have. I am probably going to post some better sketches with sketchup soon, so check back some time!

Thanks,
Garrett

Found sketchup, will be posting soon!

Also, regarding the mirror.  You might need a bigger one on the left side, as the image constantly expands in accordance with its throw ratio.

Looking forward to seeing your sketchup,

Alex

Seems very interesting. Using a bit of physics I see (nothing like a night alone with sweet lady physics...)!!! Seems to me that having 2 mirrors will complicate things but if you do your math correctly and have a way to mount the mirrors and the projector in a way so that you can change the angles without much hassle you should be able to pull this off. As for the LED rails, refer to (forgot what the member’s name… Touchfactors Jim I think was his name. He’s got a colleague working with him as well) on using SMC IR LEDs. That will save you tons of time and problems. Though if you want to use the standard T1 (3/4) LEDs then you can look at what I did in my setup here:
http://nuigroup.com/forums/viewthread/724/

The real time saver in my design are the use of LED holders (or clips). I discovered that if I was to drill out the holes for the LEDs and try to let them sit in the holes that not all the holes were the same diameter which resulted in some LEDs fitting tight while others were exceeding loose. What kind of channel are you thinking about using? Make sure to leave yourself plenty of room to solder.

About your drawings, they seem to be fine for rough draft purposes. As you get older and draft more you’ll get exceedingly good and will be able to draft by hand as well as a computer can.  Are you intending on doing engineering as a career? Using mechanical pencils, a good eraser like Pink Pearl, a clear ruler and triangle, and for colored lines that you may need I use fine tipped permanent markers.  Don’t forget about a protractor and compass. Sketch Up seems to be a great for 3D modeling especially since it’s free! AutoDesk is expensive (unless your a university student, then it’s free) but powerful 3D modeling program capable of doing many things. Once you get used to the controls it’s easy to create 2D and 3D sketches.

Can someone please tell me if screen ration matters (like 4:3 or 16:9), if so which do I need for my FTIR? Hope that question makes since!

Either one works.  I find 16:9 makes for a more table-shaped table, but all that really matters is that you match your projector.  If your projector does both, then its all up to you.