Monday, 22 August 2016

Wonky Hazel Finished

I had considered an arrow plate, or putting my bowyer's mark on it, but it's a primitive so I think I'll leave it unadorned, although I may brand in a dot to mark the arrow pass.
Back on the tiller to check the draw weight having shot in a few arrows bent it a tad at the grip and finished it off... midway between 40 and 45# at 28" perfect, I didn't really want 45# as I felt it was working rather hard.
I've taken some video of it actually being drawn to get realistic pictures, I've also tried to capture some of the character.
I'm pleased with the tiller, although maybe the tips could work more, but it's tricky due to the character in the limbs.
The lower limb looks stiffer, but if you hold a CD (other circular objects are also available) up to the picture and move it around to match the curve to the upper limb and then move it down to the lower limb they are very similar. The lower limb looks much shorter than the upper, in reality the upper is only 3/4" longer which is less than on many bows (see footnote), the top nock is a little longer due to the extra stringer groove which makes it look longer.
Click on the pics to bring 'em up full size.
The head on shot shows the wide limbs and the waggle nicely, also how canting a broad limbed bow allows a good view of the target.

 Footnote:- Traditionally/conventionally you have a 4" grip with the arrow pass 1" above the geometric centre. This means that 1" of the grip is above centre and 3" are below, making the lower limb 2" shorter than the upper.

Friday, 19 August 2016

Very Interesting!

The Wonky Hazel now has a string and it shoots where you point it...
But the arrows waggle viciously from side to side!?? (See pic, accurate, but arrows sticking in at odd angle.)
I increased the brace height and relieved the arrow pass a tad, no real difference.
I'd noticed that they flew smoother from a higher position where the grip swells back out towards the limb.
Maybe the arrow pass is too close to (or even beyond) centre shot?
In true scientific fashion, having formed a hypothesis we must test it.
I took a scrap of wood about 3/16" thick from the scrap pile and taped it onto the arrow pass with some masking tape. Perfect arrow flight! Hypothesis proved.
So what's the fix? As usual there are multiple possibilities.
1. Heat bend at the grip to correct the string line.
2. Glue on a sliver of Hazel to the side of the grip.
3. Add a thick chunk of Waterbuffalo horn as an arrow plate.
Well 2 and 3 are a rather poor last resort type fix, I'll jig it up for some steaming of the grip, same as last time (see pics) but a bit more.
Thinking about it, if I want to move the middle of the bow over by 3/16" then I need to move the tip over by twice that, 3/8" which is a fair shift when all the bend is at the relatively thick grip. I've jigged it up and filled the steamer right up with water so it's had about an hour steaming.I must resist the temptation to un-clamp it until tomorrow morning. Note:- In the pic above, once it had about half hour steam I tightened the clamp with the yellow jaws to pull the limb nearest the camera right across to the wooden jig.

Once again this illustrates the difference between a bow, and a good bow. Having had this minor set back it was nice to get an E-mail from a mate of mine for whom I'd made a new bamboo backed Yew longbow.
"...thank you for the bow which is without doubt the best I have ever owned.
It’s light to carry and being only 40lb at last I am anchoring properly but despite it lightness it’s as fast as  bows I have owned with heavier poundage."

Update:- When I unclamped the bow the tip had moved across about an inch and a half! Oh dear, have I over done it? No, give it an hour to relax and it's already moved back a good deal. I'll leave it all day and see where it finishes up. Heat bending can be V tricky, sometimes heat treating ( getting up to about 200 degrees C) will help fix a bend in place as it stiffens and hardens the wood.
Update 2:- 8 Hours later it seems to have stopped moving, I've strung and shot it, clean and true arrow flight.

Explain more... I'm not sure which bit, but I'll assume the arrow flight.
Without a high speed camera I can't be sure what's happening but I have my experience to go on, so I'll go through my thought process.
Here's the stuff I know

1. The string line was a bit to the left, known from having made the bow.
2. 45# @ 28" draw weight, length and brace height about 5".

3. experience tells me my arrows suit a bow of that draw weight, length and brace height so should fly straight.

Experience tells me that generally arrows waggle when they are too weak spine, the arrow pass is too far left (e.g The arrow has to bend a long way to get round the bow).
I normally find that moving the arrow pass towards the centre line and/or raising brace height improves things... it didn't this time.
I've found that over a lifetime in electronics design and in other things that sometimes the answer is in the opposite direction to what you expect! So I had the theory that the arrow pass was too close to centre rather than too far away. My experiment proved this to be the case.
But it begs the question how can it be too close? Surely centre shot is ideal? Well you'd think so, but modern target recurves have a pressure button to give fine adjustment and they are generally slightly less than centre shot.
Why? ... My guess is that as the string slips off the fingers and initiates some lateral movement the arrow is normally forced against the side of the bow, if it is cut away too far the arrow can come away from the side of the bow an there is no friction to damp out or constrain it's oscillation. Put simply, it has too much room to waggle!
This theory is supported by my observations with the flight bow a few weeks ago where I had two arrows smash during loose, the addition of some stiff bristles from a brush prevented it.

Hope that extra explanation is some help.

Thursday, 18 August 2016

Wonky Hazel Full Draw

I put the horn nocks on, slimming the tips and went over the belly with the scraper to take out the tool marks. Had it brought it back any further? Nope!
Hmmm, I'd got the tiller looking really good and was reluctant to do much more work, but I went over it again with my fingers and eyes looking for thick or stiff spots, I looked at the pictures and the tiller again. A little light rasping with a cabinet rasp here and there mostly on the wonky lower limb and it came back a bit more... but then the right limb needed easing off. Back on the tiller and now it's near as dammit, mind the tiller can maybe still have a tweak! (I think the lower limb is always going to look a bit odd due to the wonkiness)
I'll maybe ease it down a tad on more on the right limb to fine tune it and bring the weight down a whisker. The spec' was 40-45# and it's a bit over at the moment so I a tiny bit of room for fiddling and fettling.
I've tried the CD test against the pic and it looks pretty good, I think the extra white wood on the left limb draws the eye and makes the tiller look odd, there is also a hint of deflex on the left tip. (Feel free to comment)

Doubtless, I could have heaved it back to 28" a couple of days ago, but with a risk of chrysalling the belly, it still would have been a shoot-able bow and indeed there is nothing to say that after 100 arrows it won't suddenly chrysal. That reminds me of when I was at the Tennessee Classic, a guy (who shall remain nameless to spare is embarrassment) was showing me a gorgeous bow that he'd made and it was well shot in. He suddenly stopped dead... he'd seen some chrysals, that hadn't been there the day before. I really felt for him as it spoiled a bow of that quality... but if one of your first bows, don't worry, get a bit of shooting out of it. Better to make an under weight bow with some set or chrysals than not to have made a bow at all. And don't worry even the best have bows that go wrong. Another time a chap was showing me a bow he'd had made by a reputable bowyer... I spotted a chrysal, fortunately the bowyer replaced it with no fuss.

The nocks need polishing and I'll make a decent string. I'm booked into a field shoot in 10 days, I'll probably take it round and see how it performs, get some pics of it in action too.

Note:- anyone who is extremely sharp eyed may notice the rule beneath the tiller has been adjusted slightly, that's because the grip is quite deep and my draw length measurements were about 1/4 " out. Yes it's a bit obsessive, but it takes attention to detail to play this game.

Wednesday, 17 August 2016

Hazel on the Tiller

I've taken off a little more and put it on the tiller to review it. The tiller was good, but in reducing the weight by removing wood from the bally and adjusting the width here and there it shifts.
You have to constantly check it on the tiller and be hyper critical. Even if it's reasonable, keep a watch out for potential trouble spots. I'm going to leave the inner end of the left (lower limb). I'll have a look along that limb as I'm flexing it and see if it is twisting as it is drawn and I'll ease off the inner yyof the right limb a bit (mid and maybe inner? Not sure, I'll use my eyes and fingers to decide...).
One thing I need to do is compare it with the unbraced bow, some "faults" may just be features in the limb. This process is very much hare and tortoise... "A thousand Quatloos on the tortoise"!

I haven't actually seen a change in draw length this time, but I've not taken much off. It's very much a "little and often" approach with constant tiller checks. You have to spot the problems before they are obvious, and you have to check that your small changes are making matters better rather than worse. It's very easy to work on the wrong limb or get carried away. The easy mistake is to work on one limb, stop for the night, then pick it up in the morning and work again on the same limb. So always check on the tiller before and after any work.
The devil is in the detail, if you make your tiller rig easy to use, it's easier to check.
I've included an annotated pic showing how I see it.
Update:- Work on the right limb ( and a tad off the left) has evened up the tiller and brought me back another inch of draw, 25" at 45# The bow is taking a hint of set now which is ok, I'd rather have a hint of set than chrysals or a smashed bow. The set also shows where it is working hard and shows that I need to bring the tips round. That sounds like it's time to fit decent nocks and really slim those tips.
Before doing that I decided to steam the grip to adjust the string line by about 1/2" at the tip, it should make the whole thing better balanced and sweeter.
I did check, the lower limb is coming back without twisting, it's just that the back isn't uniform and also as the limb narrows it shows more white wood and less bark.
Explain more:- Not really sure what is needed, but try holding a CD up to the picture of the bow. If you move it back and forth you can match up the right limb to the curve of the CD, If you try it with the left limb, it shows the weak point bending too much, or if you match the curve to that area of the limb, then the outer doesn't match and loos stiff.

Tuesday, 16 August 2016

Back to the Hazel

The Hazel has had another week to season a tad more and the wood feels good and crisp uner the rasp.
It's really starting to move now, I've cleaned the upper limb, filled a couple of knots and waxed the back to encourage the bark to stay on.
The knots weren't very solid on the belly side but didn't go right through to the back else I'd have cleaned 'em out and left them as character holes. I filled them with Yew dust and epoxy to match better with their original colour.
The lower limb is a tad stiff and I'm now working on bringing that round a bit more, the brace height has now been increased to about the final height. There is still plenty of draw weight, but I'm not pulling it too hard until I've evened up the limbs a bit more.
I'm on the home stretch now, but taking it very carefully to avoid chrysalling a limb.
Cleaning up near the grip reveals some pretty but subtle figure round the central pith of the stave, I think it's beginning to get more elegant as it progresses.

I've rasped a whisker off the lower limb and put it up on the tiller 45# at 21" so getting close now. I'll probably have it to full draw by the weekend, although I'll also be apple hunting for my cider!
Update:_ teased it back a bit more 45# at 24"
Hope to post some pics or video tomorrow showing near full draw.

Monday, 15 August 2016

Whew What a Scorcher

Went to the Medieval Society roving marks shoot yesterday in Norbury park in Surrey. Beautiful setting great company and superbly organised shoot despite their catering equipment being stolen the night before. They managed to find replacements at short notice, kept calm and carried on.

I shot the 60 pounder Yew hunting longbow which served to finish its shooting in. It performed well, but was hard work by the end of the day... mind I should hardly complain when there were those shooting 100# and over.
The weather was pretty hot despite the forecast saying overcast so my forearms and face are a nice shade of red this morning and I have a pale stripe across my forehead from the reversed baseball cap!
The were some very tricky shots over distances from about 100 - 210 yards which were difficult to judge, I only scored on one mark where I was aiming near vertical, the arrow was in the air so long we had time for a drinks break before it landed.
Sorry no pics as I limited what I was carrying to keep the weight down.
I travelled with my mate JT, which was good as it kept the driving down... shattered by the time I got home but a quick shower and a roast dinner soon fixed me up. The shoulders were a bit sore, an asprin and an early night has left me remarkably bright and breezy this morning and feeling very limber.

It was great to meet up with old friends and particularly to have a chat with Chris Boyton and show him the Osage flight bow for comment. I said I might slim the tips a bit more and he commented " There's always wood to be removed from tips" which I rather liked. I also showed him some of the patches on bows (several of mine, and many of his, were being shot) particularly a belly patch on the 130# Warbow which was to protect a pinch. "I do that" was his response which I found very encouraging.
I'd recently seen a very disparaging remark from a bowyer who was criticising such work and proudly saying how he only uses perfect staves. He really needs to get out more! Some of Chris Boyton's bows were from superb staves, but there were also plenty of character bows incorporating dramatic knots missing from the side of the bow and roller coaster undulations.
So if you are trying your hand at making a bow and you meet a problem, don't just saw the bow into firewood, try to find a fix or a save, it's how we learn and don't be afraid of imperfect wood.
If you insist on waiting for the perfect Yew stave, you may never make a bow.

In the heat of the afternoon, I got drawn into a slightly heated discussion with a guy shooting a 100# bow who claimed it shot flat at 90 yards. I explained that an arrow drops about 8" over a 10 yard flight! After some explanation and order of magnitude maths, it transpired he meant the point blank range (point on distance) was 90 yards. He then started to explain to me what point blank range meant... I had to laugh and say I did actually understand this stuff. It ended in a good natured manner. But it does illustrate how careful we need to be our words else we end up with people who think modern target bows have paradox and point blank range is zero.

Thanks to all at Med' Soc' for a great day!
There, I've added a pic to cheer you all up... courgettes from the garden at last... yum!

Saturday, 13 August 2016

New Distance PB :-)

I made up a couple of flight arrows yesterday and tried 'em from the Osage flight bow in the evening, my first shots were a bit tentative, and the best was only 267 yards. I had another go with a much firmer left arm and a crisp loose as I drew the last inch. 307 yards as measured with a laser rangefinder.
I was really chuffed, mind to be fair there was a tail wind, but I think there is more to get from the bow. The arrows were 5/16 diameter cedar shafts of the highest spine I could buy which have been fairly heavily barrelled (266 and 325 grain ) If I can go smaller diameter and say 250 grain with reduced fletchings, I should get a bit more. The nocks where slightly tight too as it was all done in a rush.
The arrow flight was good, but I lost sight of them near the top, there was a hint of porpoising, but no visible waggle. Adjusting the nocking point should cure the porpoising.
Off to a roving marks shoot tomorrow with the Medieval Society, I'll be meeting up with some old friends so it should be fun.

The top pic shows how Osage ages to a darker colour from the bright Yellow when it is first worked. The bow on the right was used as a reference to give me some idea of dimensions. The little shorty was made from an offcut and makes a fun demo bow, showing how much power you can get from an apparently innocuous little stick.
The pic of the tips shows how those of the flight bow are much slimmer. The temporary Hickory nocks got tidied up and have remained.
Bottom pic shows the slight cut away and shelf lined with leather suede side out. The shelf may get enlarged, but it seems to give good arrow flight at the moment.