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Digital Gaming Table

A collection of posts, images and links that relate to my attempts to create a digital touch enabled gaming table.

All my gaming table related posts (in reverse chronological order)

Digital Gaming Table Software -

Virtual Table Top -

Multitouch Links -

Gallery 4/11/2011 -

Here are the first shots of what I'm building.  This is a 'general idea' prototype and I've already got ideas on how I'd make it better, sometimes I just wing things without full blown plans and this is one of them.   The first thing I'll do on Mark 2 is make the bottom smaller than the top so it slopes upwards this will give more room for feet.

It's going to stick up through this table leaving an extended shelf along with the chip trays and drink cups and etc.

The reason I build this in sections like this rather than framing it out is that I had thoughts on making it able to be taken apart and stored away when it wasn't needed but after playing with MDF for the first time I realized that there's just no way you can do that.  I've seen them use MDF so often on DIY 'makeover' shows as in "Let's build you some cabinets out of MDF" that I assumed it was a valid option for building.  It's not.

But I've already bought the sheets so I went ahead with it and it just strengthened my thoughts on making this the Mark 1 build so make it functional rather than good.   I am going overkill on the supports using full 2x4's and screwing every 2 inches on top of using glue.

The reason for the gap in one of the supports is that's the side the projector will be placed on and I wanted as much room for cables as possible as the projector needs to essentially sit on the floor of the box aimed upwards to allow it to fit in the 33" of vertical space and get me the projection size I want.

The final interior dimensions are 28 x 44.   Today I'm going to finish the sides and then put framing on the outside of 1x4's for both strength and visual appeal.

I'm going to make a doughnut if you will around the top out of 1x6's that will expand outwards that will give the acrylic more support, my plan is 1.5" of support all around to help prevent sag.   I went with .25" acrylic as it was easy to get and will put a diffusion layer on the bottom, either Vellum or frosted window sheeting, I'll try both.   This doughnut will be removable as I want to keep the hole in the tabletop that this box will fit in as small as possible so to put it together the box will be placed inside the legs of the table frame and then the table top lowered over it and then doughnut support frame dropped on top of that.

Either way I'll be using some form of Diffused Surface Illumination as long term I'd love to work with Fiducials in some fashion even if it's just control pieces.  And FTIR doesn't support Fiducials even if it's arguably the better reactive surface.

Gallery 4/12/2011 -

I've added the fourth wall as you can see and then I trimmed it out with 1x4's, the cheap crap wood but this is the Mark 1 prototype after all, why waste good wood?

It's gotten it's first rough sanding to knock down the bumps.  My original thought was to paint it black so it hides in the shadows under the table but then I started thinking, it's going to get kicked, scuffed and have chair rollers knocking into it so paint may not be the best option there.  I'm not a fan of the 'distressed' look, why people pay a premium to have someone hit their furniture with chains and run a sander over it after it's finished is beyond me.  I guess I was ahead of my time, I grew up with distressed furniture, we just called it hand me downs back then.

So now I think I'm going to stain it instead, a nice dark stain which should help to hide smaller dings.

I'm going to hit the trim work with a router tomorrow to round the edges down as well as move the top and leg frame of the table out to the garage so I can start the surgery on those.

The big square doughnut looking thing is the cap that goes over the top of the base that provides a place to hold the display, it's made to be removable.  The base will go in the game room, the leg frame will go around that, then the game table top will slide down on top of the base which will protrude through a cutout in the center and then cap will slide down on top of that.  Then I'll add some filler panels on the tabletop to fill the gap and call it done for now.

Still waiting on my projector to show up, apparently Fed-ex is screwing up (again) as it was ordered next day air on Friday, was in Fed-Ex's hands by Monday morning and yet I still don't have it.  Per the tracking number it's still in New Jersey where it entered Fed-Ex's system on Monday with a "Scan Error" code on it.   W.T.F...

Gallery 4/13/2011

Today (so far) the table has been routed and sanded, holes filled with putty and sanded again.  Unfortunatley I jacked up my oribital sander, the sanding disk came off at some point and I didn't notice and when I went to use it again I fried the velcro disk that holds the pads to the sander.  $%*!**!%&!

I cut out the non-projector side as an access hole and trimmed the cutout with 1x2's for appearances sake.

Next I cut the acrylic to fit.  Fairly simple to cut, just used my circular saw with a 40 tooth carbide blade, cut without any problems at all, no cracks or tearout and the edge is fairly smooth, I was happily surprised.

I'm just using quarter inch acrylic, nothing fancy but it has less flex than I was thinking it would.  I can deflect it by about an 1/8th with heavy pressure, far beyond what I would hope to need to blob detection.

Not pictured is the first coat of stain.   It doesn't look good to be honest.  MDF soaks up anything you put on it like a gd sponge and it's impossible to get an even surface out of it.  Add in the soft crap wood I'm using for trim and it's splotchy as all hell.   But at least it's protected a bit from scuffs.

I painted the inside white, well I attempted to, I used spray paint and two cans later it's still not fully covered due to, again, the MDF soaking up anything you put on it.  I can't stress enough, don't use MDF.   Get yourself some 1/2"  furniture grade plywood, hell you can get birch or oak ply at Lowe's or Home Depot for about $50 a sheet and you only need two.   MDF is simply too soft and frangibile.

As you can see in one of the shots my projector has shown up, finally.  Yay!

Still to do -

  • another coat of stain and poly on everything
  • more white spray paint to get the inside "silky smooth"
  • install 120mm fans for ventilation and PC power supply to run them
  • wire access holes
  • cut a protective sheet of mdf or hard board to go on the top when it's not in use as a projector
  • figure out how to mount the projector (reminder get a tap and die set)
  • Test projective surfaces using frosted window liner, tracing paper, vellum, frosted window spray


Gallery 4/14/2011

Faux finished the table, then cut out the opening for it, moved the bracing on the legs structure so the box would fit, cut out an assload of mdf to make filler plates for the gap between the outer shelf and the box, covered the mdf with some green felt that I had laying around because I didn't have any more paint. Moved everything inside the house and put it all together.  Added a rope light I had laying around to add some direct lighting for papers that people might be looking at.   I probably will replace them with some micro florescent or some other kind of small strip lighting to add enough work lighting for reading things easily.

Wired up 2 intake and 1 outflow fans inside (reminder need to order some more fans) that I stole out of door of my server closet.  I thought I had more 120mm fans but all I could find are 80mm's.

All in all a decent day's work all things considered.


Gallery 4/15-16/2011

Added the projector to the table and spent some time trying to get front side illumination to work without any joy.  Tried all kinds of tricks and surfaces but simply cannot get defined finger tip blobs that don't also include the palm and hovering forearm.  Not sure what the deal is with it.   Then I made a couple of IR pens to use with the system but the FOV of the camera is killing me as its cutting off a good 8" of the displayable image which is still a couple of inches short of where I want it to be.

Finally caved in and ordered a modified PS3 Eye camera from Peau Productions.  I know at one time there was talk of a change in the PS3's that made them difficult to modify and decided to just order one already modified to filter IR and with the wider angle lens on it.

I also ordered a right angle VGA and power cable for the projector which should let me drop it down by at least an inch closer to the base of the table which should kick the width and depth of the project image enough to fill the table top.

Used the projector to try out running maptools with a second copy running as a Player piped through the projector.  Worked well as was expected really.  No surprises there.

Added a couple more pictures to the bottom of the gallery.

Update 4/21/2010 -

Received my PS3 camera with m12 2.5mm lens and 850 nm IR filter as well as a 25 LED module string of IR lights and a roll of Vellum from Dick Blick Arts.   The vellum provides a pretty nice projection surface although of course it's going to be prone to picking up finger oils and dirt but it's certainly cheap enough to replace as you need to.

Unfortunately I didn't get the touch working.  I tried putting the string of IR lights about 12" down from the top aimed out and that didn't work, I angled them up and that worked better but the slightest bend in the acrylic from pressure causes the lights to show up as blobs.   I then as a quick experiment tried using regular paper as diffusers over placed above the LED's which did help to eliminate the pressure blobs but regular blobs didn't work that well.  Stability was a major issue with the blobs flickering like mad and getting it down to just finger tips was very difficult.

So I pulled the LED's off the wall and trailed them on the floor of the box aimed up and was back to the least pressure caused the LED's to pop up as blobs as the angle of the acrylic changed minutely.

At that point I called it a night and played some Portal 2.   I'll go back to it tonight.  My current thought is to put the LED's higher up, next to the acrylic aimed across and put diffusers below them to block them from directly shining into the camera.  I'm also going to try moving the camera higher up so it's not reading the sides of the box so much.

Update 4/23/2011

Still no joy with getting stable usable finger blobs.  I can get hand blobs fairly well but who cares right?  I can get my IR pens to work very well but using IR pens with the existing mouse drivers is next to impossible.  Frankly the mouse drivers lack more than a little bit of features in terms of making multi touch useful.  I'm resizing my drive now to open up some space for a windows 7 installation to see if that works any better.

I can use small white paper squares and get really good blobs although they fade out about 6" from the edges and corners all around which makes it seem very likely that I simply don't have an enough IR light in the box.    As a cheap way to test that I've ordered a couple of 48 IR LED security lights from Deal Extreme in the right IR frequency (850nm). At $15 each with free shipping it seems like pretty cheap way to check that theory.   I know there will probably be issues with hot spots as the led's are very focused but for testing they should work.  I can try bouncing the light around the walls or using come kind of diffuser material.

So now we wait for the flood lights to show up as I've pretty much exhausted all the possibilities with placement for the current IR's I have.




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