Little bit of Slo-Mo

I need to get more lighting and careful set up to improve the quality of the slo-mo. It will be interesting to see how it is in natural light filming a real archer.
The shooting machine works, but think the loose is too perfect and virtually instant.
More next year ;-)

Looking Over the Year

It's been my first full year of retirement and  I've had fun with warbows, the cross bow, primitives, flight bows,  building the shooting machine and re-working some bows including Twister.
My stand out warbows have been Wonky which was a tad extreme, and the 3 RPI (ring per inch) fast grown English Yew which disproved some of the myths and prejudices about yew.

February and the spring was somewhat tied up with looking after Emily Cat who went missing for 3 days and came back injured, fortunately she recovered and is back to her bonkers best but without her tail now..
The ILAA Popinjay shoot was great fun and I consider it a "must do" for this year.
My two fave' bows were the 3 RPI warbow and the pretty Boo, Purpleheart and Yew trilam...
Over the year I've improved my tools collection with a load of G clamps and improvements to the arrow tapering jig and the thicknesser.

In the spring I made up a spliced yew flight bow from some dodgy random billets which performed quite well and has given me food for thought for 2018's flight bow, and of course the arrows, because self evidently, one the arrow has left the string... it's all about the arrow. Hopefully the shooting machine and my new camera should help in achieving a little more distance this year. I'll be making a flight longbow/warbow to be used by my trusty test pilot and chum JT in the summer.

Failures included the exploding take-down ELB, a big Yew log with no decent wood in it and a Laburnum heartwood primitive which eventually was destruction tested.
The ongoing crossbow project was a bit like the curate's egg, good in parts, the trigger mechanism was good, but the prods varied from just about acceptable to failures, mind I am trying for an impressive performance with a lot of self imposed constraints. Maybe I'll persevere with the natural materials or maybe I'll make up a prod with fibre glass or carbon laminations over a wooden core.

Bliss, just got out of the house for a couple of hours harvesting some Hazel with a couple of mates. We cut a few poles and split two of 'em. I'll quick season one of the poorer staves... so we can start some bow making at the start of February. I'll be helping JT through the process and hopefully he'll end up having made a shootable ELB.
Here's an early try out with the camera, using my crossbow pistol.

All the best to friends old and new for 2018

First Test Shots!

I've tried the shooting machine with a 30# bow from a fixed 27" draw.
I've lightened the back of the stock a bit so it balances better and screwed a chunk of aluminium in front of the trigger mechanism as a fixed stop to hold it at 27" draw.
It shoots nicely, but with a weak bow slightly under drawn, the arrows are a bit stiff and kicking left. The basic design has certainly been proved, but I don't trust the trigger mechanism for anything much heavier.
Over the holiday period I should get some interesting video and work on a more robust version of the trigger and the sliding release.
Lovely tiller on that little 30# Hazel, it's one of my best bows, it was the one that Ruth Goodman shot on the TV program.
Update:- I've tried with the sliding release, cocked and loaded the bow at about 20" and then pulled the trigger mechanism back using a makeshift handle made from a wire coat hanger. As it gets back to 27" the trigger gets lifted by a block that I'd screwed in place.
It was rather awkward to operate but released ok. I was V close to the target and the arrow struck home whilst it was still flexing and flying at an angle, so it embedded 2" into the target and snapped off the shaft. It will be interesting to see it in slo-mo once I have the fancy camera.
Updated update:-
I've just shot "twister" from outside the garage, so that's 10 yards. Perfect shot, lined up pretty true and struck the target square, just shows that with the right arrow and bow it shoot correctly :)
Cant wait to get some video but I'm not allowed to open the camera until Christmas!

Sliding Trigger Mechanism

I managed to sneak a few minutes in the garage away from making mince pies and sausage rolls to get the sliding rails done for the trigger mechanism. It's pretty smooth! Mind I did wipe it over with beeswax polish first as aluminium can be a bit of a poor sliding surface.

I'd been pondering how to do it for some time, then I remembered some aluminium angle that I'd been given a while back. I knew it would come in handy.
Just about ready for testing, just got to work out a peg arrangement to trip the trigger and some way of pulling it back along the track. Got to be aware of the recoil when it looses, don't want it hurtling back and whacking the operator!
Another minor problem is the balance. The main horizontal arm that has the bow on one end and the trigger mechanism on t'other is a bit back heavy. I can move the pivot point a few inches, but I'll probably give it a try out first.
It'll all be over by Christmas!

Prototype Trigger Mechanism

I've got the prototype trigger mechanism almost finished.
It's basically the standard 2 part mechanism, a rotating nut and a trigger. The juxtaposition of the two parts is such that the trigger protrudes horizontally from the back. The entire mechanism will slide back along the stock of the shooting machine between two rails. As it draws back to the desired draw length, the trigger will lift on a sloping peg inserted into the stock giving an automatic loose.

Alternatively the mechanism can be clamped in a fixed position, the string drawn onto it and the the trigger manually lifted to loose.
The nut and trigger are made of plywood and will only probably be only strong enough for light bows. Of course plywood is no good for the working parts so these have been faced with bits of hacksaw blade epoxied into place.

I've made the fingers of the nut approximate to an archer's fingers, and being wood, I can easilly shape them as needed. The final version will have aluminium fingers and a steel centre section and trigger.

The sheet steel sides of the mechanism are held apart by two aluminium spacers with 3mm steel rivets going through the whole assembly.

The sketch shows the approximate layout and illustrates the easiest way to get a smooth trigger action. If you draw lines from the release point where trigger and nut meet back to the centre of the two pivots (red) and arrange these lines to meet at 90 degrees this gives a line of force directly back into the pivot rather than a force which try and make the trigger either slip or jam. The trigger will pull without forcing the nut to rotate back against the pull of the string. So you just sketch roughly where you want the two pivots and then get a set square or the corner of a sheet of paper and move it around to find the required position for the sear to give the magic 90 degree angle (or do it by eye). You don't need this 90 degree angle, it's just an easy way to get it right.

Hopefully I'll get the rails built soon and try it out, mind I have mince pies and sausage rolls to make too!
Soon be time for my round up of the year, but it would be nice to get this done before then. Hoping for some Hazel harvesting over the holiday too, good excuse to get out of the house and have a pint with some chums.

More on the Shooting Machine

I've done some more to the shooting machine including a minor modification to allow more room for a movable trigger mechanism that slides back, automatically releasing at the desired draw length. The plan is to have about 22" minimum draw, with the string and arrow hooked onto the release mechanism at that distance. The mechanism is then pulled back by handles (or rope?) and it releases at the pre-set draw length.

You can see in the pic, I've mounted a bow in it and it looks good.
I'm now working on a prototype trigger mechanism just made out of plywood to prove the geometry and concept. It should be strong enough to shoot my lighter weight bows. The"bent" (the face where the trigger sear bears) is formed by inserting a bit of hacksaw blade into a slot cut into the plywood. The nails are just for reinforcement and the excess will be cut off.
In the actual final part will be rivets through the aluminium and steel assembly.

Just realized I've made a bit of a schoolboy error! the release mechanism has to be above the grip for the bow! But that's the joy of working with wood, just glue another length along the top, saw a bit off here, bish, bash, bosh, job's a good 'un!

Awkward Yew Stave

Andy, the guy for whom I'd shortened the bow collected it this morning and was very pleased with it, we had a quick try out and he could feel the extra draw weight. We also shot the Chinese repeater and another couple of bows.
I've done some more heat work on the tricky Yew stave and it's beginning to look more like a bow, it's been a bit of a pain, but it will hopefully be a handsome bow eventually. Here's a pic of it at about 65# at 24" so it's coming along.
I took some video to show what I'd done:- https://youtu.be/8-Fk_YIYew4
The deflex dip just right of the grip makes it look weak there and the left limb is stiffer than it appears, as it has some natural deflex near the tip. There's a bit of a kink 2/3 of the way along the righ limb... other than that it's ramrod straight ;-)