Hi, I made a simple one for hickory and bamboo backed longbows/selfbows using the shrink wrap method with a 2x4's and two c clamps using t-88 epoxy. Got the plan from 3 Rivers Archery, Rudderbows publishes the small booklet. Was worth the 8 bucks. Now for fiberglass... have not messed with it yet.
68 inch 2x4, two three inch cuts, two 1.5 inch cuts, glue and screw three inchers on ends (straight up) and 1.5 inchers in middle section about three inches apart. Handle sits there (duh), clamp about 1/3 of way down from string nock area. Just get the booklet if interested.