Years ago, I cobbled together a ski tuning rig using a couple of old clamping work tables. It looked like this:
Yep, butt ugly and these economy clamping tables are not exactly high quality precision instruments. Anyway, I just joined the tables with some 1x2 scrap lumber. Then I made some ski supports out of scraps, figuring out the heights by trial and error with some skis. The tops of the supports have strips of wide home insulation tape stapled in place (on top of duct tape strips). The insulation tape is slightly tacky, so ski topsheets stay put on it. The rig let me move the supports (& clamp 'em in place) where needed to accommodate different length skis.
I used the above rig for years. It was cheap, as I got the work tables on sale at Harbor Freight for like $9 bucks each. It's truly a hokey looking setup, but it worked just fine for waxing and light tuning.
For heavy duty setting of side edges, I made a simple add-on jig with a couple of 3ft 1x12s, some 1/2x1/2 aluminum angles and some toggle clamps. Jig is placed sideways (vertically) in the clamping tables & clamped down. Toggle clamps hold the skis in place (vertically) with half the base exposed to accommodate a file guide.
Anyway, over the years I've drawn up numerous plans to build a real homebrew ski tuning bench. All the designs were just too complicated or way too expensive. No matter what I came up with, the designs were not that much more useful than the old rig since the clamping tables add a big versatility factor.
So, I decided to just improve the design of the old rig. Here's what I came up with:
The key feature of this design is seen on the back clamping boards: two bolts go through the 6' clamping board and through the center of the table clamp board below. The bolts actually act as bearings. This allows both the table clamp below to articulate AND the 6' clamp board to articulate, giving more clamping adjustment options. Note: by design, only the back half of Harbor Freight's clamping tables articulate, thus the front clamping board is always fixed.
My add-on clamping boards are actually made up of 6' 1x4s and 6' 1x8s. A 1x4 is laminated to a 1x8 to give a thicker clamping edge and to give some clearance for operating the table clamp handles. Note: the Harbor Freight work table top clamps are 4" wide.
The ski tip rest is attached to a couple 2x4s - which are attached to just the front clamping board. The front clamping board assembly is fixed, only the back clamping board assembly articulates. So, basically, the ski tip rest "floats" over the clamping board.
For the center support I have two choices now: a boot dummy (shown) or a simpler support that the ski rests on. In either case, I use a simple woodworking clamp on the center support to keep it secure.
The new rig lets me quickly adjust the supports as needed & clamp 'em in place. Supports skis solidly - especially if I use the boot dummy. The 6' length can handle skis up to 185cm or so - maybe longer.
At the end of the season, the rig is easily dismantled and stored in a corner of my workshop.