Hedgeapple, at the end of the day, mostly just the amount of offset. Helical jigs will have a twist in them though, to account for the wrap around the arrow.
Dustybaer, usually I take off the front piece - it's really quick, especially if I didn't have a 3 foot bolt on it
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. But if you made the front holes a little bigger, you could just pull them out. If I were to make another one, I would make the front hole bigger (which I could still do now
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) and I would consider a method of putting some pressure on the clamps to get better, more consistent feather / shaft contact. That said, this one works really well and I've been happy with my scrap heap fletcher.