Wednesday, 28 December 2016

Funny Old Year 2016

Ha! I've got the archer automaton fished:-
https://www.youtube.com/watch?v=UajIxPdUZVE

Been a funny old year even ignoring world politics (which I try to do here).
I've made some decent bows, a 150# Warbow being my heaviest yet, an Osage flight bow that stretched my PB out a few yards to 310 yards. not to mention the hickory flight bow that was a bit dodgy with it's arrow snapping, 'shoot through' window.
The wonky hazel was fun and there were other primitives too, not all of which survived! A half of the Yew heartwood primitive which I ended up destruction testing became a mini bow which I shipped to the states for the Marshall  Primitive Archery Rendezvous mini bow challenge.

At a personal level, my funny turn at the start of the year made me wonder about the nature of memory and self, having lost my memory for several hours. We lost a pet cat and got another (rescue cat) I've retired and had plenty of visitors both old and new friends. I've harvested some Yew with friends and kept pretty busy. Retiring in September has given me more time to ejoy making bows and doing other stuff on my 'want to do' list.

The archer automaton has been engrosing and has been well received on Youtube, as have the two video series of making a Warbow and an ELB.
At times I get a bit jaded (especially after a breakage) and take a rest from making bows, but they always call me back. I'm still making a few to commission, but I'm getting more inclined to only make them for friends or those who are close at hand, that way I can maintain them... it's worth noting that having Warnbow shooting friends is an education in itself and the bows do need some care attention and maintenance to maximise their life.
Anyhow enough blethering on, all the best to all who read this and those I see at shoots I wish you all good fortune good health and good shooting for 2017.

Monday, 19 December 2016

Chasing a Mirage

Ah! The automaton is a bit like a mirage which vanishes just when it appears to be within your grasp. Fortunately I like problem solving!

At one point he was catching onto the string nicely but as it drew back all the force was bending the upper bow limb and the string became slack below his hand and came off the lower nock. It took a while to work out what was going on.
There are so many changing angles and variables in timing and position between the two movements. Even when it works successfully, there is no guarantee it will work right next time.

I'm slowly taking the slop out of the mechanism and designing in stuff to make it work correctly. Firsly I've made the bow pivot in the bow hand which ensures even tension on the string both above and below the hand. (Yes that's yet another bow...)
The control rods are being uprated again to steel cut from sheet, fortunately the bandsaw will manage thin mild steel (not finished yet). I'll be improving all the pivots by drilling tighter tollerance holes with a nice set of drills which I've got Santa to order from Axmister tools . I've also ordered some tiny self tapping screws (size 0, from E-bay), the plan is to remove the slop and then make the hand that catches the string adjustable so that it can be set in the correct position to reliably catch the string.

I'm pretty sure I'll get there in the end, and I've made one more crucial piece... the nock on the string which the hand catches onto was made of linen thread with superglue soaked ito it, which I'd then tried to file into a conical shape. The conical shape allows the hand to slip past it in one direction and then snag on it as it pulls back. Now I'm sure you can imagine that trying to file something like that is nigh on impossible, so, I thought I'd turn a cone on my little lathe, but from what material?
Trying to drill a 1mm hole in something hard is tricky, then I thought maybe horn, then, even better antler!... it turned brilliantly and even parted off cleanly, it was fine up to the point when I dropped it on the floor never to be seen again! Oh well the lathe was still set up and the antler still in the chuck so I just made another. I haven't tried it yet, but I've threaded it onto some of the linen thread I use as the bow string.

I'm enjoying this and it will give me something to tinker with over the holiday period. No pics now, I'll save 'em (and hopefully a working video) for my end of year review.

Talking of which, I looked at last years review and what I had planned for 2016 I was a bit optimistic when it cam to flight shooting, but I did gain a few yards!

Friday, 16 December 2016

Mk II Automaton Getting Close


I've got all the basics done on the automaton, but the fiddling, fettling and fine detail is a nightmare.
I've spent all day adjusting the control rods that run up his back and getting his hand to snag onto the bow string. It's been V difficult to get a consistent action and I've had to add small modification to take up slack and slop.
Just getting a smooth mesh on the gears took an age. I bet a pound to a penny once it's finished someone will ask if I have plans for it, not realising that plans are no good for this sort of thing, it's working from an idea followed by loads of trial and error.
I'd made about 3 versions of the control rods out of ply before realising that they clashed into each other and I ended up making them out of copper from a bit of 15mm pipe sawed in half down the length and hammered flat. That makes them thin enough to overlap each other.
I've had a furry helper looking down from up above the work bench!
Here's a few pics including the nock of the arrow, to give an idea of scale, the string is a single strand of linen thread and to open out the nock to get a good fit I had to make a makeshift saw by filing some teeth into a bit of thin tin plate. The arrow itself is a wooden kebab skewer.
The next big step is to get the release action to loose the arrow, that can wait as I'm knackered.
There is a big tied nocking point below the arrow, it's linen thread with a tiny spot of superglue, it provides something for the hand to catch onto so it can draw the string back.



Saturday, 10 December 2016

Automaton Evolution

As I've improved the various bits of the automaton and built them up on the prototype I realised that I didn't want to keep remaking parts. Unfortunately the right arm is fixed to a cranked shaft which goes through the body to the operating lever. The parts are too small to be easily threaded or fixed together in some way that can be taken apart, I'd been mulling over this for some time when the solution struck me. I have sawed through the shoulder pivot point then screwed it back together and re-drilled the bearing hole, this way it can be taken apart much like a main bearing on the crankshaft of a car engine. I've also made a mount for the bow which allows me to adjust it, the previous bow was just stuck in place and had no adjustment.
The new bow is made of the Cherry I cut a few days ago and seems to bend nicely with much better tiller, seasoning isn't a problem with such a thin sliver of wood.
The drawing hand has been cut from tin plate and seems to line up and catch the string quite well. there is a lot of trial and error and adjustment, slowly improving each part. The biggest change is the canting of the bow across the body in a much more realistic manner which also gives it a bit more of a 3D look.
Note, the full draw pic looks a bit off due to the canting of the bow and the camera angle. (It makes the bottom limb look too short).For each problem I solve another appears, the canted bow looks better and allows the fingers to hook onto the string better, but the lower limb goes behind the archer when the bow arm is down and clashes with the control rods which will operate the arms. For now I'm getting the geometry of each arm individually and working out clearances, I'll then have to implement both arms at once. Lots of fiddling and fettling I'll probably have to bend the operating rods all over the place to get it right.


Wednesday, 7 December 2016

More Work on the Automaton

The automaton video on Youtube has had a very good reception, (mind I've touted it around quite a few forums being a bit of an interweb tart!).
I've started on the next iteration, I trimmed about 6" inches off a seasoned Hazel stave and cut it up on the bandsaw into suitable sizes. I've machined on bit using the pillar drill (drill press) with a 10mm end mill, that I bought a while back, in the chuck. The Hazel machines nicely and is so much better that the first rough pine parts (see pic for comparison)
I found a nice free program on t'web for drawing out gears to be cut from plywood:-
https://woodgears.ca/gear_cutting/template.html
The scaling feature didn't seem to work properly, but I could find a way round that if necessary (the 150mm scale line came out as 120mm. I entered 120 into the scale correction box and printed again... just the same).
Anyhow the mkII is slowly progressing, here's a pic of some of the bits.

Monday, 5 December 2016

Tinkering

I've been messing about trying to get an archer automaton mechanism working, just a realistic draw and loose initially. I started with some tin from an old biscuit tin and then moved onto plywood. The draw isn't too difficult but the loose is tricky. I'm following my engineering of simplicity, simplicity and trial and error.
Any how here's a video of it:-
https://www.youtube.com/watch?v=udnK4SXUtBY

I've been doing some online research too and they mention Basswood as being good for carving, I though... "Oh, I'll have to get some of that"... them I thought, "Don't be a twonk, I have all sorts of wood that's good for carving already!" Hazel, Cherry, Lemon wood is prob' good too. Any how, I split some cherry that has been outside for over a year from when trimmed on of the Cherry trees. That led to more work like cleaning out the dust extractor and changing bandsaw blades.The cherry is too wet to use now, but it's been cut down to useful sized pieces. I have some already seasoned lying about and I've been planning the next stage of the automaton. I want it to grab on to the string automatically, I don't mind having to manually load the arrow tho'.
There are some incredible Japanese ones on youtube, but I think they were made by a skilled automaton maker rather than an archer as the bow drawing action is all wrong! That is to say the draw is all accomplished by pushing the bow hand forward and there is no drawing back of the string. They are still fantastic works of skill and artistry though.

Thursday, 1 December 2016

The Sun is Shining

Ha, I've cheered up a bit after the bow explosion, I got a nice E-mail from the guy for whom I was making it.
I've tidied up the garage and cleared out a load of mess from the summer house job. I had a quick shufti at my staves too, there is some good stuff which will be ready for next summer.
I might have a bit of a tinker with a project I've been thinking about, making an archer automaton... it's a bit chilly in the garage, but I might have a little try out with some tin plate from old biscuit tins etc (I keep all that stuff as it's great material) and a soldering iron. If it warms up a bit I may sort the staves.... a stave falling on your head in clod weather just hurts too much!