40” Rear DI Multi Touch Table
Posted: 18 January 2014 03:20 PM   [ Ignore ]
Joined  2011-06-28
Total Posts:  3
New Member

Hello all!

I started building a multi-touch table a few years ago with the help of the community, but after many failed attempts I abandoned the project. I recently starting playing D&D again and now have a reason to finish it! It is very closely modeled after SpinalTom’s 42” Table. I really liked the design and presentation. That, and using 2x4s as a frame was brilliant! Saved money and time in the assembly process, plus added the much needed rigidity.

Without this community I would have been completely lost and I probably not have even thought of doing something like this, so I thank you all very much for your vast wisdom and suggestions.

Here’s the specs of the table:
Camera: PS3 Eye with 2.8mm lens and 850nm filter from Peau Productions. (Completely worth it. It was like going from VHS to Blu Ray when I removed the floppy disk and installed the 850nm filter.)
Surface/Diffuse: 30” x 30” x 1/4” acrylic with vellum sheet.
IR Lights:4 x 48IR LED illuminators 12V 0.5A 850nm
Mirror: 12” x 10” from ACE Hardware
Projector: Epson S4 (sometimes a Dell 3200MP)

I don’t have many pictures of the assembly process as that all happened a few years ago, but I can take pictures of what it looks like currently. Any suggestions are more than encourage as I still need some help here and there fine tuning it and getting it to perform how I would like.

The acrylic looks like it’s flexing but that is just the picture making it look that way. Very strange.
This one shows roughly where the mirror will go. I used to mount the project on the side wall, but have since started putting it on the ground. It has a very short throw so it all works out!

I’ve been using the compliant surface on the underside because when I have the vellum on top I get vicious hotspots that come back every time I touch the top. Is there a better way of fine tuning CCV to ignore them? I’ve thought about dynamic subtraction, but that doesn’t seem to work as well as I was hoping.

ReacTIVision settings:
Gradient: 17
Finger Size: 15
Finger Sensitivity: 200? (Not sure how much it affects the overall tracking)

CCV Screenshot:

Reactivision Camera Settings:
Source (vellum on top):
Tracking (vellum on top):
Source (vellum underneath):
Tracking (vellum underneath):

My blob detection is decent I suppose, but configuring ReacTIVision is nothing but easy.

I have some questions for the community too!
Would switching to 1/4” glass instead of acrylic be a better choice?

How can I reduce the glare when I have the vellum on top?  I’ve tried angling the lights, but every time the acrylic flexes it detects new blobs regardless of orientation. Putting vellum on the lights themselves doesn’t seem to diffuse the light as much as I was hoping either.

The box is not completely light-proof. Would taping up the joints, edges and gaps improve my readouts that much? Same with lining the inside. I’ve read mixed things about both, but nothing conclusive. I also recently found out my power supply is 12V 1.25A and not 2A. I ordered a 2A so hopefully the additional amperage to each illuminator will increase their output and improve tracking!

I cannot seam to get the Flash XML to work either. I always get dreaded “Could not bind or send TCP to Port 3000”. I made sure the global flash settings were correct and that I had the standalone flash projector. I load up CCV, calibrate it, return to menu by pressing x. I fire up a flash demo and then I go back to CCV and press F. Nothing.

Someone mentioned the mouse driver interfering, but I didn’t know how I could prevent that. Any help would be much appreciated.

Anthony Sciutto

Image Attachments
2014-01-18 12.38.11.jpg2014-01-18 13.06.50.jpg
Posted: 28 February 2014 04:15 PM   [ Ignore ]   [ # 1 ]
Joined  2014-02-28
Total Posts:  7
New Member

Hello, I too am building a table, also inspired by SpinalToms 42”.  I have my frame built and most of the things I need.  I am waiting on a larger mirror as the one I originally got was too small.  I just got the Acrylic in today though.  Here’s some pics of my frame right after I brought it home.  My daughter decided to pretend it was a house, lol.  I’ll get some pictures with my better camera later.  I had left it at work that day:


For a projector I picked up a used NEC 491VT(iirc, @work so can’t check) for $150.  Can’t beat that.  Guy had several for sale as well, he gets them at school auctions, makes sure they work, makes sure there is plenty of lamp life left and sells them.  Found on craigs list.  Great deal.
For my mirror, looking around online I found the best deal at this site: http://www.whittemoredurgin.com/ Being that they are stained glass supply I looked for stained glass supply shops in my local area and they were able to order me a piece even cheaper.
I picked up my camera from Peau Productions and used the light kit he recommends from environmental lights as well.
For Diffuser and Acrylic I also used Peau Productions recommendations in his video and ordered the Acrylite.

I got the Acrylite in today so will be messing with this some more as soon as I get home from work.  I still have the too small mirror, so I should be able to get a too small image and get it working tonight.  Once my mirror gets here next week I will work on mounting the projector on the side to get a longer throw distance and larger image.