I want to say a bit THANK YOU to everyone on the forum who has given me advice with this project - my first proper medieval crossbow. It's hardly an original work more an act of plagiarism as I've borrowed ideas from everyone I could find! The main inspiration was Todd's Working Man's Medieval (thanks Todd).
The only option I have for shooting is with the NFAS and true medieval bows don't really fit their rules: the bow must have a bolt clip, a working safety and a full trigger guard. You can see how I've dealt with that in the pics.
Prod is a standard fiberglass 150lbs, with 3.25" brace and 9" power stroke. I think that's a bit shorter than these bows are built for but the weight goes off my 100lbs limit bow scale about 3" short of the nut so it can't be far short of the full weight.
Tiller is a piece of american oak finished with Danish oil and wax (needs a bit more work), with a but plate of ipe, a thin layer of lemon wood and some black fibreboard spacers left over from a knife making project. The tickler, trigger guard and stirrup are mild steel given a bit of blue by heating them on the gas stove in the kitchen. I had a real tussle bending and shaping them cold without a proper bench or vice. I quite like the tickler guard - it means you can't bump the tiller by accident when spanning. The nut is delrin with an M8 bolt sear inserted.
The safety is a wedge of ipe which goes between the tiller and tickler. Copied this from from a video on youtube of a German guy who runs a medieval crossbow gallery at historic fayres and uses one of these as an idiot proof safety for the public. The wedge isn't a very pretty solution but it is effective and can easily be removed when not required.
Its taken me about 4 months to do this (a lot of looking round for materials, learning to use new tools and thinking time was needed.
Only had a limited test in the garage so far but looking good.
Advice and feedback welcome