When I started to flange the holes on some of my recently made CH-601 rear ribs, I soon realized that it takes too long and too much physical effort (I was squeezing a set of dies between two 2X6 using a bolt and a wrench).

I found a hydraulic press design in the Zenair Newsletter no. 44 (January 1988).  While I could have built that design, I was hesitant because my dies are made of wood and they require equal pressure on all their surface. I had problems flanging using 2X4 instead of 2X6.  What happened was that the flange was more accentuated on one side.

So I made a rugged 6-ton hydraulic press:

In the design shown above, I utilized:

	3 2X8X8  (the pressure area is 12.5-inch wide). Actually, the middle mobile section is made of 2X6's.
	16 5-1/2 X 1/2 bolts, with nuts and washers
	20 3 X 5/16 wood screws (in hexagonal head)
	some pieces of 1/2 plywood  and 3/4 oak for the surfaces
	1 6-ton hydraulic jack
	4 5-inch by 7/16 springs
	8 hooks for the springs

The total cost is 80$ Canadian.  That is about 53$ of real dollars.  Being quite slow, it took me 4 hours to build it (I designed as I built).

Note that the parts in the middle horizontal section need to be spaced a bit (to allow for free movement along the vertical sections.  I started by sanding down the vertical 2X8. Then, I thought about just inserting small pieces of scap aluminum (0.025") between the 2X8 pieces... works great!

The jack area is approximately 8-inch high.  The pressure area is approximately 4.5-inch high.  To go faster and better, I but a 2X8 piece over the die when I use it.

While it took me about four hours to build, I only needed half an hour to flange 10 ribs (what was remaining in my lot).  Still, I will use it for the other 8 rear-ribs that have to be made, 20 front ribs and also for the spar.
 

Prior to making it with 2X8, I had built a model with 2X6's.  It was working well until it broke.  That press originally had a 2-ton jack.  I found that jack not to be powerful enough.  Because of this, ribs were "popping" once flanged.  These are pictures of that model: