HEMNES Multitouch Table

I had been thinking of my Touch Table project for a long time. My research on existing solutions was a bit disappointing: mostly insanely expensive, large, or platform locked, they did not fit my vision of a [Android or Linux-powered] ‘desktop’ that would allow me to fit it into my existing workflow, rather than hope that applications would support it (like the Microsoft Surface).

First I tried to draw out what I wanted on paper, but it turns out that even the 11×17 paper I borrowed from work wasn’t quite enough space to work with. Then I looked for a free, web-based CAD program to sketch out a 3D design. I was pleasantly surprised when I found TinkerCAD, which worked beautifully with Chrome.

The IKEA HEMNES table seemed ideal for my purposes. Initially I was going to use the LACK, but the wood of the HEMNES seemed more amenable to shaping with conventional tools. Also, I think the HEMNES matched my existing décor.

Purchasing the components was a planning process in itself. I was able to get almost everything from Amazon, eBay, or IKEA. The bare essentials are:

– IKEA HEMNES coffee table (white)

– Krylon 11 oz Low Odor Clear Matte Finish Aerosol Spray

– CRC All Purpose Enamel Spray Paint, 10 oz, Gloss White

– Stencils (for decoration)

– 12 packets of black Sugru

Tech stuff:

– Dell P2314T multitouch monitor

– Intel NUC small form factor computer (D54250WYK1)

– Monoprice Mini DisplayPort to DisplayPort

– Leap Motion controller

– Logitech K830 wireless keyboard

– USB DVD drive

– Various USB and HDMI cables

Tools used for this:

– Jig saw (IKEA FIXA) (…I regretted using this)

– Rotary tool (Dremel or similar)

– Power drill

– Screwdriver

I am not a carpenter. Thankfully IKEA furniture is inexpensive enough and ubiquitous on Craigslist, so messing up is not catastrophic.

Nonetheless, measurements were important. I measured the dimensions of the monitor (57 cm wide by 34 cm tall) and centered this on the table, with a slight bias toward more space on the “south” side (closest to intended seating). I upturned the monitor to trace it in pencil. (Contrary to habit, I actually made it slightly larger, since I was going to fill the edge with Sugru.)

I did the same for the Leap Motion controller. I decided to skip other features in the above TinkerCAD design for the moment, with the idea that I could add them later as needed.

Step 0: Identify a place (work bench, some old boxes, etc.) to place the IKEA HEMNES parts for working and cutting.

Step 1: drill two (2) holes at the corners of the monitor area. If they are close enough together, it should be easy to create a space for the jigsaw blade. These should match up enough to pop out the cutout.

Step 2: Do the same for the Leap Motion controller. This is a smaller version of the monitor step. Some creativity with the jigsaw can make it a 3 minute job.

Step 3: Use the rotary tool to sand and shape each of the holes. This is time consuming and messy, but necessary. Edges should be smooth, corners should be close to 90 degrees without creating a sharp angle. The monitor corners are more square than it might first seem. Carefully try to pass the monitor through the hole, sanding and shaping more as necessary. The monitor should pass through completely, but just barely. Keep in mind the power and menu buttons.

Step 4: Wipe it down to get rid of all the sawdust.

Step 5: Cut out two support segments from the monitor cutout. They should be approximately 4 cm wide, and long enough to span the gap north to south. If the width of the cutout is approximately 57 cm, this should span the 34 cm gap, with 4-6 cm additional on either end to attach it. I also used some spare pieces as spacers to account for the depth of the monitor. The table thickness is a bit over 2 cm, which was more than adequate for the depth of the monitor below the table surface.

Step 6: Insert a small drill bit (1/32 inch) into the power drill, taking care to insert it so that the amount extended will pass through the support segments, the spacers, and part of the table itself, without breaking the surface. Placing all the pieces correctly for alignment purposes, drill a small hole through the support segments, the spacers, and some of the table, without going through. Screw a 1/16 inch screw of appropriate length (5 cm/2 in?) into the hole. Repeat for all four attachment points.

Step 7: Wipe it all down again to get rid of sawdust.

Step 8: Assemble the IKEA HEMNES according to the directions. Leave the bottom wood platform out for now.

Step 9: Use Sugru or some other silicone product to line the holes. I also used Sugru to create rubber pads for the monitor to rest on, so that it was at the right height (roughly the table surface). I used 12 packets of Sugru in total, though this may vary depending on one’s skill with it.

Step 10: Wait for Sugru to cure (12 hours). Make sure the monitor still fits. Shave Sugru or add more as necessary.

Step 11: Wipe down the table again. Tape off Sugru area and use white enamel spray paint to cover any woodworking errors. After 2+ hours, use stencils (if so desired) for table design. After another hour, coat with a spray-on clear coat. Wait another 2 hours.

Step 12: Bring table inside and install monitor and bottom wood platform. The monitor was a tight fit for me, but seems to work just fine. I had to connect some of the cables before dropping it in. The computer (NUC) is currently resting on the wood platform, though it has a VESA mount and I may use it to screw into the table. I also used a USB 3.0 hub designed to clamp onto Mac monitors to instead clamp onto the HEMNES table.

The computer installation I’ll leave as an exercise to the reader, and according to preferences. I used Ubuntu-GNOME 15.04, which has reasonable multitouch gesture support. The Leap Motion controller was a perhaps a playful extra, but it’s pretty neat to control Google Earth just by waving my hands. There are ways to integrate it into basic window management and desktop control, but it tends to interfere with the touchscreen if you use both at the same time.

I used the computer’s mini-DP port for the table monitor because I also connected my TV via HDMI. Linux supports extended workspaces and multiple monitors in a pretty flexible manner, meaning I can drag windows “onto the wall” or “onto the table” as I see fit.

I did most of the woodwork in a weekend, the painting/stencil/clear coat over two days, and the computer stuff in a night. It was a hit at a party.

~ Brian Merrell