Splice

I didn't add quite as much back set as I'd wanted and that's meant theres a small gap in the tip of the splice on the back of the bow (top of the splice on the last pic). I'll fill this with epoxy and Osage dust just to stop moisture getting in, it won't add any real extra strength.
I'm not entirely happy, but we'll see if it holds once it's a bow.

Splicing Osage

Blimey, getting the splices to mate up nicely was hard work, it took a lot of fiddling and fettling as there seemed to be big gaps when I held it up to the light. I ended up opening up the V cuts to become flat bottomed and sawing the tips off the points which fit in the Vs.
It was easier to get a fine rasp in there. I tried all the tricks like assembling the joint with a piece of sandpaper in there and the pulling it out to remove any high spots. Eventually with plenty of patience and a several goes at it I got the slice to fit together reasonably well. A pice of flat steel from an old saw blade with sandpaper wrapped around it was useful for getting down to the bottom of the Vs.

I decided to try Resintite adhesive as it's realtively cheap and easilly available and has some gap filling properties, it was going to be that or Araldite precision.
The Resintite is a very fine powder which you mix with water, my wife didn't like me using the kitchen scales as the stuff is a bit toxic I think, so she banished me and the scales to the garage...just as well as I did spill a bit.
I bound the joint with wide rubber strapping (cut from a car innertube, or EPDM roofing sheet)
To apply pressure longitudinally I jammed the bow between a wall and the leg of my shelving, with some scraps of wood as spacers, leaving the middle slightly raised. By pressing down firmly on the middle it forced the joint together. I left it with the middle raised by about 2" which is the back set (a bit like reflex).
I'll take the rubber strapping off tomorrow and post a pic of the joint, you'll be able to see how it has been opened up compared with the pic in the previous post.

Splicing the Osage

I cut a splice on a scrap of 2x1 pine just to test the theory. The Osage however isn't straight! I layed it out slightly S shaped with a straight line (taut string) passing from tip to tip through the centre of the handle area. This meant the area for the splice didn't line up quite right.
I'd originally marked it up with the two ends of the billets butted up together, but once spliced they actually overlap, so having sawed one splice I readjusted my marking out on the other billet to get it all in line.
It was a bit nerve wracking sawing it, and you can see the splice needs some work with a fine rasp or file to make it fit snugly before glueing.
I'm not sure what glue to use, I don't have any of the generally accepted glues, but I suspect a good quality epoxy will do (after all it's holding my Asiatic Recurve together!)
If necessary I can take out some of the bend and twist on the tips later if necessary.
That's about it for today, although I may tidy it up to see if I can get a snug fit.
As it's the first time I've used Osage, I shall pretty much follow the 'recipe' in the Traditional Bowyers Bible vol 1.
I shall put my own twist on it by putting a bit of back set on the limbs when I glue it up.

Osage Orange

Osage grows in much of the USA and I was luck to be offered a pair of billets by one of the guys on the Primitive Archer website (from Texas). I sent hime a short Yew stave in exchange (Taxus to Texas!), but I got the best of the deal as the Yew is much lighter and the postage was less, I'll try and send him a stave suitable for a longbow later in the year.
The Osage feels very different to the Yew, much harder but not elbow jarringly so, and it cuts quite crisply, on the end grain shot I'll work it down so the first thick dark ring becomes the back of the bow (the pale wood to the left of that ring is sapwood). The other pic shows some Yew for comparison, The Osage is almost day-glo yellow, but it ages to a deep brown.
I'll be splicing the two billets of Osage, I've not done that before, so I'll try it on some scrap, I'll post pics of course.

What an Idiot!

I couldn't understand why my force draw machine gave a lovely big vertical deflection when calibrating it on the dial spring balance, but when I tested it with a bow the deflection wasn't the same!!?? In fact it was about half what it should be!
Had the bows mysteriously lost weight?
I investigated carefully by attaching the balance to a bow so I was pulling both at once, then the penny dropped.
I wasn't a factor of 2 out, it was more like 2.2
Have you twigged yet? Yes I was reading Killograms instead of pounds when testing with the dial balance.
I shall add another pulley to get more vertical deflection.
What an idiot!

Force Draw Plotter Working

The video is a bit brief and shows a spurious line plotted as I let the bow down, this is because the return spring on the vertical pen travel and the horizontal slide are both a bit slow.
This next video shows the movements separately.

Base Plate and Vertical Travel

You probably can't quite see how it works yet, I have enough trouble visualising it myself!
The horizontal section is now mounted to the base plate, free to slide up and down on two steel tubes. The only thing holding it down (other than gravity) is the spring from the spring balance.
As the bow is drawn the spring will stretch and the horizontal section will lift slightly, this lift will be linked to the pen to draw the vertical displacement onto the graph.
If you don't follow that, just trust me I'm an engineer! If you look closely at the first pic you'll see the spring has come off it's lower mounting (whoops).