I found a wonderful iPad app called Camera Lucida (http://www.cameralucidaapp.com/) after watching a fascinating documentary called "Tim's Vermeer". The problem I ran into was that I did not have a repeatable, reliable, and most importantly, comfortable way to hold the iPad over a drawing surface so I could work. Having scraps of PVC from another project, and some spare MDF laying around, I decided to build a stand. After all was completed I spent less than $10, but I think buying new, you could complete this for less than $20. The bonus is that I can also use the iPad to take top-down photos of varying sizes of objects.
Step 1: Materials Required
- Something to cut with
- Ruler or tape measure
- PVC Cement
- 1/2" PVC tubing
- (4) four 90 degree elbows
- (1) one Tee fitting
- (1) one Coupling
- 1/2" MDF for the drawing/photographing board (sanded smooth if you're using scrap like I did)
- 13/16" drill bit (I used 3/4" and sanded the mounting hole with a Dremel)
- 2" wood screw
- Drill bit slightly smaller than the width of the screw
Step 2: Step 1: Making the Arms
The iPad measures about 8"x10" (20cm x 25cm). I wanted the set up to be able to re-center the camera for larger pictures. The first arms I made were (2) two 8" (approx 20cm) pieces. The elbows are press fit onto the pipe so they can be used for longer arms.
Step 3: Step 2: Armature
The armature is the piece at the top to hold the iPad/Tablet above the work surface. In order to give maximum support width without interfering with the camera, I determined it needed to be about 6" (15cm) wide. The tee and two 90 degree angles came to 6.25" which was close enough. If it sits a little off-center, it won't bother me.
The pipe press fits into the fittings about 3/4" (just under 2cm). Cut (2) two 1-1/2" (3.8cm) pieces of pipe. Prime and put cement on the pipes and the tee, and fit them into place.
For the arm mounts, use (2) 90 degree angle fittings. Using a longer piece in the bottom of the tee and the coupling for accuracy, press fit the corner fittings and get them aligned to your liking. I made the bracket perpendicular, which was a bit of a mistake. The weight of the iPad does tend to sag the stand pipe a bit. So, cheat it a little larger than 90 degrees if you can. (You may still need to prop the iPad/tablet up on a dowel across the arms to make it level.) If you're satisfied, make registration marks on the tee and the corner brackets (so you can line them back up once you put the glue on). Prime the pipe ends and one side of the arm bracket fittings and glue them into place.
Step 4: Step 3: Mounting Bracket
Since I knew that the pipe fit 3/4" (2cm) into the fittings, and I have 1/2" (1.25cm) MDF for my drawing surface, I cut a piece of pipe to 1-1/4". Prime one side of the coupling and the pipe... glue... you know the drill.
Speaking of drills (how's that for a segue-way?), It's time to put a hole in your board. My board is slightly larger than 16"x20" since that is a standard US picture frame size, and I didn't want to go much larger in the beginning. Since I am right handed, I wanted the stand pipe to be on my left side if I had the board in portrait orientation. Find the midpoint of the wide length of your board and mark it. Take half the height of your tablet (10"/2 = 5" or about 12.5cm in my case) and measure over that distance. You want the camera to be centered, not the tablet. Measure in about 1" plus 1/2 the diameter of your pipe. Drill a hole all the way through.
Once the hole is drilled, you may need to use a file, or Dremel to make it slightly larger to accommodate the outside diameter of the pipe. The coupling will rest directly on the board. From the edge of the board, drill a pilot hole into the board and through the PVC pipe. Secure it with a long deck screw or wood screw.
Step 5: Step 4: Stand Pipe
I intentionally left the stand pipe loose from the armature and the mounting bracket for two reasons. #1 - Storage: The whole thing comes apart and sits nice and flat. #2 - Picture size: I want to be able to move the iPad closer to the board since I won't always need all 16"x20". Now, I had to figure out what my sizes were.
The aspect ration of the iPad's screen is 4:3. So, if my width was 20" (5*4), my height would be 15" (5*3)... (D'oh! So close.) The problem was figuring out how that translated into distance from the camera. I cut a piece of paper to exactly 4"x3", and raised the iPad above it until the paper barely filled the entire screen. Then, I measured the height to the bottom of the iPad where the camera was located. It was almost exactly 5". Using these numbers, I could generate some rough sizes for stand height.
Using whole increments for the height, you can get an approximate size. Since anything below about 10" or longer than 20 would be cumbersome, I eliminated everything in yellow. For an 8x10 (about the size of letter, A-size, or A4 paper), it looked like it would be around 13". Take the shorter dimension, divide by 3, and multiply by 5 to get your height ((8/3)*5=13.33). You can multiply by 4 to get the total width, also. The other way would be to divide by 4 and multiply by 5 if you wanted to constrain it by the larger dimension. (I built an Excel sheet to calculate it for me.)
After finding the total height, subtract the height of the coupling and the armature (they impact the total height, too). Then, add back in the depth which the pipe goes into the fittings (2*3/4"=1-1/2" in my case). Measure and cut your stand pipe.
Step 6: Step 5: Using Your New Stand
Force fit the stand pipe into the base, and place the armature on top.
Set the tablet gently onto it's new stand. Turn on the camera and looking at the screen, mark your corners. If they're not perfectly rectangular (more of a trapezoid), the device isn't level and you may need a small dowel toward the ends of the arms to raise the edge up a bit.
I also added a small hook to the armature to hold the power cable out of the way. Future enhancements may be a small set of LED lights mounted to the bottom of the armature to illuminate the work surface better.