Here it is after glue up against a straight length of timber so you can see the glued in deflex. The grip area is too thick at the moment. When the Bamboo back is planed up it will get glued on and the assembly pulled into reflex for the last half of each limb, I may pull in a hint more deflex.
The Bamboo will be held on with rubber strapping, bow will be supported under the grip against a baulk of timber (as in the pic), with additional spacers if needed, (back uppermost) the mid point of the limbs will be strapped down and the tips pushed up into reflex by supporting blocks. Anyhow it will make sense when I do it, don't know when that will be as it's all getting a bit busy here. I expect I'll manage to sneak away and do a little here and there, which is the best way to get the bamboo backing planed up anyway. I can't see me getting it glued this week though.
It doesn't look much like a longbow at the moment because I've left it too wide and the riser section too deep, rest assured it will look more like a longbow when finished. The draw weight is the thing that's worrying me, but hopefully the Bamboo will make a big difference.
The pic shows the deflex, if you imagine the tips sweeping to the right by about the same as the width of that baulk of timber, that is sort of how it will look during the next glue up.
Update:-
I couldn't resist a quick clamp up to see the general shape. The reflex bend seems to be all mid limb, but that's because the limbs don't have much thickness taper and they don't have the full width taper yet either. There will be extra thickness taper in the bamboo backing and I will probably strap the limbs down nearer the tips too.
Tuesday, 26 August 2014
Monday, 25 August 2014
Heat Treating the Belly Billets
I glued up the belly billets and then clamped the spliced area in the vice while I pulled back the tips to feel the weight. I thought it felt quite stiff until I did the same test with a 36# bow. You can see they have some natural deflex/reflex shape.
That convinced me to heat treat the belly. The guy next door has been clearing out his garage and throwing tons of stuff into a skip, I salvaged an old Black and Decker Workmate and a nice length of hardwood which I trimmed up into two nice slats to clamp along
side the bow limbs to direct the heat along the limb.
The Workmate needs new handles, but it's V handy to have two when heat treating a bow, it's much easier to work my way along the limb.
I did it one limb at a time taking care to mask off the glued splice area with an off-cut scrap of so it wouldn't get any heat (see pic). I had the kitchen timer set to 4 minutes 30 seconds and ended up moving it along the limb in 10 bursts, that shows what a laborious slow process it is. 45 mins per limb, mind I made use of the time by giving the car a wash and tidying the garage. You can see I haven't gone mad, there is a slight colour change showing that the heat has actually done something. The big mistake with heat treating is to get it too hot, too close, too quick, all that does is char the outer surface. If it doesn't take about 30-45mins per limb, you aren't doing it right!
The next step is to make a riser block for the grip area, I'll probably make it about 18" long tapered gently at the ends and with some curve so it will pull in a slight deflex as it's glued to the belly. I'll heat treat it just to get a nice colour match in the wood. Hopefully get that done today. All this work and washing the car has helped loosen my back, but it's still sore if I sit for too long. Not looking forward to the desk job tomorrow, I might take in the kitchen timer and set it to alarm every 15 minutes so I can get up and stretch regularly.
Update:- Got the riser and a thin 'Power lamination' glued on. The 'power lamination is just a thin lamination to help blend in from riser to main limb, it's more relevant in laminated bows, but I thought a bit of extra belly thickness wouldn't do any harm, it can always be rasped off, but it would be hard to add it in after the event.
It's clamped up with a hint of deflex (the riser section was shaped with a slight curve.
Pics tomorrow if it stops raining.
That convinced me to heat treat the belly. The guy next door has been clearing out his garage and throwing tons of stuff into a skip, I salvaged an old Black and Decker Workmate and a nice length of hardwood which I trimmed up into two nice slats to clamp along
side the bow limbs to direct the heat along the limb.
The Workmate needs new handles, but it's V handy to have two when heat treating a bow, it's much easier to work my way along the limb.
I did it one limb at a time taking care to mask off the glued splice area with an off-cut scrap of so it wouldn't get any heat (see pic). I had the kitchen timer set to 4 minutes 30 seconds and ended up moving it along the limb in 10 bursts, that shows what a laborious slow process it is. 45 mins per limb, mind I made use of the time by giving the car a wash and tidying the garage. You can see I haven't gone mad, there is a slight colour change showing that the heat has actually done something. The big mistake with heat treating is to get it too hot, too close, too quick, all that does is char the outer surface. If it doesn't take about 30-45mins per limb, you aren't doing it right!
The next step is to make a riser block for the grip area, I'll probably make it about 18" long tapered gently at the ends and with some curve so it will pull in a slight deflex as it's glued to the belly. I'll heat treat it just to get a nice colour match in the wood. Hopefully get that done today. All this work and washing the car has helped loosen my back, but it's still sore if I sit for too long. Not looking forward to the desk job tomorrow, I might take in the kitchen timer and set it to alarm every 15 minutes so I can get up and stretch regularly.
Update:- Got the riser and a thin 'Power lamination' glued on. The 'power lamination is just a thin lamination to help blend in from riser to main limb, it's more relevant in laminated bows, but I thought a bit of extra belly thickness wouldn't do any harm, it can always be rasped off, but it would be hard to add it in after the event.
It's clamped up with a hint of deflex (the riser section was shaped with a slight curve.
Pics tomorrow if it stops raining.
Saturday, 23 August 2014
Good Days Work
I pressed on with the belly billets, clamping them side by side and using a spokeshave to take off any high spots and even them up. I then evened out the thickness taper.
There was less thickness than I'd ideally like and the taper was only about 1mm every 7.5". Normally I'd taper at about 1.5mm every 6" but I can gain some extra taper by tapering the Bamboo back.
Talking of which my Bamboo slats are only 73" long, but with care I can use the full length and maybe splice on a tiny bit at each end which will eventually disappear under the horn nock. I'll keep it as long as I sensibly can. The question of heat treat or nay, is still tormenting me, but no need to worry about that yet.
There was less thickness than I'd ideally like and the taper was only about 1mm every 7.5". Normally I'd taper at about 1.5mm every 6" but I can gain some extra taper by tapering the Bamboo back.
Talking of which my Bamboo slats are only 73" long, but with care I can use the full length and maybe splice on a tiny bit at each end which will eventually disappear under the horn nock. I'll keep it as long as I sensibly can. The question of heat treat or nay, is still tormenting me, but no need to worry about that yet.
I've cut the splice, a Z splice, this can be cut by taping the two billets together and cutting then in one go. It's one of those topological things that is hard to visualise, in fact it's so tricky to see how it works I checked it on a thin off cut of Yew first. It gives a perfectly fitting splice with aligned limbs, easy to do on thin flat limbs or laminations, almost impossible to do on normal self wood billets for an ELB as they are so thick compared to their width it's tricky to line 'em up and clamp them.
One of the only things to watch out for is the ends of the Vs, the female V has a flat bottom due to the width of the saw blade whereas the male can be cut to a really sharp point. The sharp point has to be sawn off to match into the flat bottomed V, because of this I measured out 4 1/4 " to get a 4" long slice. If you look at the close up you'll see what I mean.
Meanwhile I've been making my cider, I've got three 5L Demijohns and a 2L one too. I freaked out when I looked at the picture... what's the pretty lady doing in the top left! Ghost picture Arrrrghhhh! I had to go into the garage to check. It's a fancy carrier bag from the shop "Monsoon" which had some plastic bottles in it. Not some ravishingly beautiful ghost lady waiting to seduce me in the garage. Hey, can't win 'em all.
The cider is still V cloudy, but the first lot I did last week is already bubbling away.
I could only find 2 airlocks so I used a vinyl glove over one of them and fingers cut off a vinyl glove on the 2L and plastic bottle. I'll buy another demijohn and some more airlocks tomorrow. I'll rack off the cider into a clean demijohn after a few weeks, that should help get rid of the sediment. The whole process has been much more efficient this year, with the reinforced press and improvements to the scratter I think I'm getting about twice the amount of juice.
Friday, 22 August 2014
Better Belly Billets
I sawed these out yesterday evening from a long half log of Yew with scruffy discoloured sapwood. I've used wood from the same batch to make a ladies bow a few weeks back so I'm happy the wood is sound once the rough stuff is trimmed off (see chunks to the left of the billets).
The sharp eyed amongst you will notice the central pith is visible in the right billet, this will only be present in the grip area of the bow when finished. Once sawn the two billets did move slightly as the internal stresses in the wood were released. E.G if I put 'em back together they touch at the tips but there's a 1/4" gap in the centre. I'll spend some time today cleaning them up to an even thickness taper and so the match nicely for thickness.
It was touch and go if I could cut the two matched billets from the one piece. I carefully planed up one edge so it would run clean and true through the bandsaw. I marked a pencil line down the middle by eye, it was pretty tight in places with no wood to spare. Hopefully the billets will be thick enough. I've been drawing out deflex reflex shapes too, it's hard to know how much will pull out during tillering, but I'm planning on going for 1" of deflex which then sweeps back to about 4" of total reflex (e.g 1" gets back to the centerline level with the grip and then 3" beyond that) . I anticipate maybe loosing 2" of reflex during tillering. That would leave the tips 1" beyond the back of the bow before the bow is braced. I can't be bothered to draw a pic... all will be revealed in the fullness of time.
All this shows how hard it is to answer the question "how long does it take to make a bow?"... well I've already sorted through loads of my Yew and roughed out 5 limb billets not to mention the time getting the wood in the first place... just as well I love doing this stuff!
I'm struggling a bit as I pulled a muscle in my lower back over a week ago, it was easing off nicely, but two days sitting at a desk at work has set it off again. It's ok if I keep moving, worse things happen so I shouldn't grumble (wouldn't get any sympathy anyhow!).
The sharp eyed amongst you will notice the central pith is visible in the right billet, this will only be present in the grip area of the bow when finished. Once sawn the two billets did move slightly as the internal stresses in the wood were released. E.G if I put 'em back together they touch at the tips but there's a 1/4" gap in the centre. I'll spend some time today cleaning them up to an even thickness taper and so the match nicely for thickness.
It was touch and go if I could cut the two matched billets from the one piece. I carefully planed up one edge so it would run clean and true through the bandsaw. I marked a pencil line down the middle by eye, it was pretty tight in places with no wood to spare. Hopefully the billets will be thick enough. I've been drawing out deflex reflex shapes too, it's hard to know how much will pull out during tillering, but I'm planning on going for 1" of deflex which then sweeps back to about 4" of total reflex (e.g 1" gets back to the centerline level with the grip and then 3" beyond that) . I anticipate maybe loosing 2" of reflex during tillering. That would leave the tips 1" beyond the back of the bow before the bow is braced. I can't be bothered to draw a pic... all will be revealed in the fullness of time.
All this shows how hard it is to answer the question "how long does it take to make a bow?"... well I've already sorted through loads of my Yew and roughed out 5 limb billets not to mention the time getting the wood in the first place... just as well I love doing this stuff!
I'm struggling a bit as I pulled a muscle in my lower back over a week ago, it was easing off nicely, but two days sitting at a desk at work has set it off again. It's ok if I keep moving, worse things happen so I shouldn't grumble (wouldn't get any sympathy anyhow!).
Thursday, 21 August 2014
An Interesting Commission
I got a message from one of the guys on an archery forum asking if I could make him an ELB (English Longbow). The interesting thing is he wants it for target use mostly so wants it fast and not too high a draw weight, 40# max at 28.5" draw. He's also had bows by some of the top names, so I'll be interested to see if I can make a bow which can hold it's head up in such company. He's a good shot too and one of the people on the forum who talks sense. All in all a good challenge.
To get a fast bow, I'll push the definition of longbow as far as I dare, I'm looking at 75" Victorian style tiller with some deflex at the grip and a long sweeping reflex out to the tips, but not so much that the string touches the limb anywhere other than the nocks. I'll keep a flattish belly and take it close to the 5/8 thickness/width ratio.
I'm going for Yew belly from spliced billets with a continuous Bamboo back for strength.
I've been busy cutting belly billets from assorted bits of Yew.
The first (on the right) was from a stave that I'd hoped to be a Warbow, but it had some awful knots at one end, unfortunately the curve in the stave resulted in sapwood showing on the left edge/side of the billet (you can see my pencil markings laying out the bow limb). I cut two more, from billets taken from the same tree over a year ago. One has a lot of curve fore and aft, but that doesn't really matter as I can heat bend it to shape before glue up, or that can become some of the reflex and the other limb steam/heat bent to match.
I'm also contemplating heat treating the Yew belly for extra performance. The problem with that is once glued up I can't heat treat as it would break down the glue, so I have to get it roughly tillered and heat treated before glue up... not an easy task on individual belly billets, basically I'll make sure I have a good even thickness taper.
Of course all this is just rough planning in my head, I haven't done a timescale or a powerpoint presentation ;-)
I have some other Yew with manky sapwood which may yield some nice heartwood belly billets, I'll have a try with that first before choosing the final pair. The pieces I don't use will bet set aside for experimental bows etc.
The blog may be a bit quiet over the next week as we have a family wedding coming up and I'm doing stuff like decorating cakes and stuff.
To get a fast bow, I'll push the definition of longbow as far as I dare, I'm looking at 75" Victorian style tiller with some deflex at the grip and a long sweeping reflex out to the tips, but not so much that the string touches the limb anywhere other than the nocks. I'll keep a flattish belly and take it close to the 5/8 thickness/width ratio.
I'm going for Yew belly from spliced billets with a continuous Bamboo back for strength.
I've been busy cutting belly billets from assorted bits of Yew.
The first (on the right) was from a stave that I'd hoped to be a Warbow, but it had some awful knots at one end, unfortunately the curve in the stave resulted in sapwood showing on the left edge/side of the billet (you can see my pencil markings laying out the bow limb). I cut two more, from billets taken from the same tree over a year ago. One has a lot of curve fore and aft, but that doesn't really matter as I can heat bend it to shape before glue up, or that can become some of the reflex and the other limb steam/heat bent to match.
I'm also contemplating heat treating the Yew belly for extra performance. The problem with that is once glued up I can't heat treat as it would break down the glue, so I have to get it roughly tillered and heat treated before glue up... not an easy task on individual belly billets, basically I'll make sure I have a good even thickness taper.
Of course all this is just rough planning in my head, I haven't done a timescale or a powerpoint presentation ;-)
I have some other Yew with manky sapwood which may yield some nice heartwood belly billets, I'll have a try with that first before choosing the final pair. The pieces I don't use will bet set aside for experimental bows etc.
The blog may be a bit quiet over the next week as we have a family wedding coming up and I'm doing stuff like decorating cakes and stuff.
Saturday, 16 August 2014
Serendipity
I was driving out to the club to test the spliced Yew 70# longbow for distance. It's about a 20 minute journey each way and a bit of a pain when I only really wanted to lob a few arrows.
As I drove out of town on the dual carriageway, I noticed the big long meadow between the road and the river (part of the flood plain) had been mowed. At the far end there is a single track road which goes down to a ford. I turned in there and parked, the field is perfect for flight shooting when mowed being bordered by river and dual carriageway, it's over quarter of a mile long and a couple of hundred yards wide. It's not full of dog walkers like a lot of fields as there is no right of way through it. There is also only one access point...perfect. I strung the bow stood just inside the field loosed off three arrows and packed away the bow. I then paced out across the field to collect the arrows at about 200 -210 yards, pretty much as expected, but nice to use the bow for a full shot. Most of the year that field is flooded or the grass is too long or it has sheep in it. I'll have to remember it for a brief window of opportunity next year.
Getting back to the car, I noticed a few apple trees in the hedgerow, they were a bit scruffy where the farmer had gone down the hedgerow with a flail to trim back the hedges. I collected half a carrier bag of apples for my cider making (I always keep an old carrier bag or two in the back of the car).
Great, I'd tried the bow, collected some apples and saved some time and petrol on the journey. I thought I'd visit one of my favourite apple trees on the way back, I parked up and walked along the tow path of the River Stort, a lovely sunny day, dragon flies darting about, people on their narrow boats giving me a cheery 'Good morning' I got to the tree and could hardly believe it, barely an apple to be seen, none on the ground either! Funny how some trees will do well while others will have a barren year. That tree was my ace in the hole, a guaranteed 3 carrier bags full tree!
Never mind it was still an enjoyable stroll, and I noticed the blackberries are coming along nicely.
Getting home I did some work reinforcing the wooden frame of my cider press with some "Dexion" so that I can exert more force when pressing the apples. I'll pick some more tomorrow from the place on the cycle track where I went yesterday. I'd seen a fox there then, it was so used to humans it just sauntered off nonchalantly a lovely deep reddish brown with a bright white tip to it's tail, nice to see wild life, but depressing to see the amount of litter people leave. Again, at that location, one of the early fruiting trees was virtually barren while some of the others were fine, a nice lot of Elder berries and Sloes in the hedgerow too.
I'm looking forward to doing a pressing of apples.
As I drove out of town on the dual carriageway, I noticed the big long meadow between the road and the river (part of the flood plain) had been mowed. At the far end there is a single track road which goes down to a ford. I turned in there and parked, the field is perfect for flight shooting when mowed being bordered by river and dual carriageway, it's over quarter of a mile long and a couple of hundred yards wide. It's not full of dog walkers like a lot of fields as there is no right of way through it. There is also only one access point...perfect. I strung the bow stood just inside the field loosed off three arrows and packed away the bow. I then paced out across the field to collect the arrows at about 200 -210 yards, pretty much as expected, but nice to use the bow for a full shot. Most of the year that field is flooded or the grass is too long or it has sheep in it. I'll have to remember it for a brief window of opportunity next year.
Getting back to the car, I noticed a few apple trees in the hedgerow, they were a bit scruffy where the farmer had gone down the hedgerow with a flail to trim back the hedges. I collected half a carrier bag of apples for my cider making (I always keep an old carrier bag or two in the back of the car).
Great, I'd tried the bow, collected some apples and saved some time and petrol on the journey. I thought I'd visit one of my favourite apple trees on the way back, I parked up and walked along the tow path of the River Stort, a lovely sunny day, dragon flies darting about, people on their narrow boats giving me a cheery 'Good morning' I got to the tree and could hardly believe it, barely an apple to be seen, none on the ground either! Funny how some trees will do well while others will have a barren year. That tree was my ace in the hole, a guaranteed 3 carrier bags full tree!
Never mind it was still an enjoyable stroll, and I noticed the blackberries are coming along nicely.
Getting home I did some work reinforcing the wooden frame of my cider press with some "Dexion" so that I can exert more force when pressing the apples. I'll pick some more tomorrow from the place on the cycle track where I went yesterday. I'd seen a fox there then, it was so used to humans it just sauntered off nonchalantly a lovely deep reddish brown with a bright white tip to it's tail, nice to see wild life, but depressing to see the amount of litter people leave. Again, at that location, one of the early fruiting trees was virtually barren while some of the others were fine, a nice lot of Elder berries and Sloes in the hedgerow too.
I'm looking forward to doing a pressing of apples.
Thursday, 14 August 2014
Monkey Bow Lever Detail
I've made a new string to sit nicely in the shaped levers. there isn't enough wood on the tip of the lever to carve a monkey paw, so I gave up on that idea.
I've shot a few arrows and he seems to shoot really sweet and smooth, I've not checked the draw weight or speed yet...
I haven't finished off the other lever yet. I'll tidy up the whole bow and keep it for a show bow mostly. I'm not sure if it would qualify as a 'primitive' at an NFAS shoot, it certainly is primitive, but they are supposed to be loosely based on some primitive design, and I'm not really sure this is!
There is thunder rumbling around at the moment, maybe I'll get into the garage and check the weight and speed later, mind I need a good tidy up to get ready for the cider making season.
Here's a full draw shot... well very nearly full draw.
I've shot a few arrows and he seems to shoot really sweet and smooth, I've not checked the draw weight or speed yet...
I haven't finished off the other lever yet. I'll tidy up the whole bow and keep it for a show bow mostly. I'm not sure if it would qualify as a 'primitive' at an NFAS shoot, it certainly is primitive, but they are supposed to be loosely based on some primitive design, and I'm not really sure this is!
There is thunder rumbling around at the moment, maybe I'll get into the garage and check the weight and speed later, mind I need a good tidy up to get ready for the cider making season.
Here's a full draw shot... well very nearly full draw.
Monday, 11 August 2014
Monkey Bow Lives Again!
Hoorah! He's now got a 28" draw, the draw weight is prob' pretty low, I haven't measured it yet.
The levers need shaping in but I wanted to test it to see if it was ok. I'm thinking of removing the temporary tip overlay on the top limb and making it into a Monkey paw, not sure if I will, I'll do some sketches to see if its feasible. I did have some Pear wood ages ago which is good for carving, but it's prob' long since lost, I do have some Cherry which may be suitable
.
The whipping is thin linen thread onto which I dripped low viscosity super glue. The glue soaks in and spreads quickly giving a quick hard finish.
Any how here are the pics. sorry no full draw shot yet!
I walked up the town today and noticed some apples are ripe, I'll have a good tidy of the garage and prepare for my cider making.
I'm really pleased Monkey bow survived, he's a great crowd pleaser when shooting whistling arrows, if only I could make an arrow that went Ooooh Ah Ah Ah!
Update:- I've been tidying the levers and I noticed I hadn't cut one down to length before adding the temporary nock, it was only an inch too long! I've trimmed it off and glued on a fresh chunk of Ash for the temporary nock. Hopefully it will still be good for the 28" draw, whilst lifting the draw weight a tad.
The levers need shaping in but I wanted to test it to see if it was ok. I'm thinking of removing the temporary tip overlay on the top limb and making it into a Monkey paw, not sure if I will, I'll do some sketches to see if its feasible. I did have some Pear wood ages ago which is good for carving, but it's prob' long since lost, I do have some Cherry which may be suitable
.
The whipping is thin linen thread onto which I dripped low viscosity super glue. The glue soaks in and spreads quickly giving a quick hard finish.
Any how here are the pics. sorry no full draw shot yet!
I walked up the town today and noticed some apples are ripe, I'll have a good tidy of the garage and prepare for my cider making.
I'm really pleased Monkey bow survived, he's a great crowd pleaser when shooting whistling arrows, if only I could make an arrow that went Ooooh Ah Ah Ah!
Update:- I've been tidying the levers and I noticed I hadn't cut one down to length before adding the temporary nock, it was only an inch too long! I've trimmed it off and glued on a fresh chunk of Ash for the temporary nock. Hopefully it will still be good for the 28" draw, whilst lifting the draw weight a tad.
Sunday, 10 August 2014
Stupidity in the Higher Primates
It absolutely stonked down with rain so I resigned myself to improving my Chrono' set up and testing the Spliced Yew bow.
I made a cardboard light shield which directs the light directly over the sensors of the chrono' . I also moved the ceiling hook nearer to the centre of the garage to give an easier shot.
Time to test it, I thought I'd use a short slowish bow for initial tests (a very long bow can foul on the ceiling). I picked up Monkey Bow but forgot it's only tillered to 26"... BANG the tip of the upper limb sheared off when I took it to the full 28".
I may well repair it as it's such a fun show piece, Maybe I'll do slightly longer levers so it can be drawn to 28".
Anyhow, on to test the Yew bow, the chrono' works much better giving very clean reproducible results. I probably need to pick up the lower edge of the arrow netting and drape it over the wire to give extra thickness to catch the arrows. They drop to the floor having hit the netting, which is better than having a target there and risking them smashing each other.
With the 11/32" shafts I got 170 fps and you can see with the 5/16" shafts I got 173.7 fps, slightly faster but less comfortable on the bow hand.
This compares well with 178fps for my refurbished Yew bow which was heat treated and is substantially shorter.
I think I'd probably get a slightly higher speed with a better loose, the prob' is I have to splay my legs out to avoid hitting the ceiling. I'll update this if I get a better result.
Here we are, a couple of higher results. Note in the 184fps the left wooden spill I use as a marker indicating where to shoot has been shot off, this indicates the arrow was probably flexing wildly (or I can't shoot straight!) and may not have gone cleanly through both gates of the chrono, thus giving a false result. It is prudent to discard any suspicious readings as spurious. I am willing to believe the 178.3 as it was a nice clean snatch loose as I'd use if flight shooting and both spills are still in place. It's safest to take the average reproducible reading. No point in claiming optimistic freak results.
The chrono actually comes with steel rods, but they don't survive very well! they are fine if you are shooting an air pistol or a fire arm. The spills are from an old split cane roller blind and are very hand for all sorts of things like mixing epoxy.
Update:-
Monkey Bow will rise again (Oooooh Ah Ah Ah!).
I've started work on making new levers to splice onto the tips. The limbs have been cut to the same length.
The re worked bow will be about 3.5" longer, hopefully that will get me to 28" draw. All just a bit of fun experimentation, but it will be nice if he can shoot again. Ideally I'd use Ash with curved grain to follow the curve of the levers but I don't have any suitable (I'll keep my eye out for any curved limbs that fall over Winter for future use). Anyhow, I'll play it by ear and may add a slim belly or back patch to add extra support to the splice, or maybe just a binding of linen thread soaked in epoxy, that will prob' be simplest. This is really just random tinkering, but that's how we learn and discover stuff... maybe I'll discover a new antibiotic during the process? or perhaps I'll stumble on time travel? Although I'm not sure time machines are generally of wooden construction....
Sorry I'm getting hungry and wandering off into flights of fancy.
I made a cardboard light shield which directs the light directly over the sensors of the chrono' . I also moved the ceiling hook nearer to the centre of the garage to give an easier shot.
Time to test it, I thought I'd use a short slowish bow for initial tests (a very long bow can foul on the ceiling). I picked up Monkey Bow but forgot it's only tillered to 26"... BANG the tip of the upper limb sheared off when I took it to the full 28".
I may well repair it as it's such a fun show piece, Maybe I'll do slightly longer levers so it can be drawn to 28".
Anyhow, on to test the Yew bow, the chrono' works much better giving very clean reproducible results. I probably need to pick up the lower edge of the arrow netting and drape it over the wire to give extra thickness to catch the arrows. They drop to the floor having hit the netting, which is better than having a target there and risking them smashing each other.
With the 11/32" shafts I got 170 fps and you can see with the 5/16" shafts I got 173.7 fps, slightly faster but less comfortable on the bow hand.
This compares well with 178fps for my refurbished Yew bow which was heat treated and is substantially shorter.
I think I'd probably get a slightly higher speed with a better loose, the prob' is I have to splay my legs out to avoid hitting the ceiling. I'll update this if I get a better result.
Here we are, a couple of higher results. Note in the 184fps the left wooden spill I use as a marker indicating where to shoot has been shot off, this indicates the arrow was probably flexing wildly (or I can't shoot straight!) and may not have gone cleanly through both gates of the chrono, thus giving a false result. It is prudent to discard any suspicious readings as spurious. I am willing to believe the 178.3 as it was a nice clean snatch loose as I'd use if flight shooting and both spills are still in place. It's safest to take the average reproducible reading. No point in claiming optimistic freak results.
The chrono actually comes with steel rods, but they don't survive very well! they are fine if you are shooting an air pistol or a fire arm. The spills are from an old split cane roller blind and are very hand for all sorts of things like mixing epoxy.
Update:-
Monkey Bow will rise again (Oooooh Ah Ah Ah!).
I've started work on making new levers to splice onto the tips. The limbs have been cut to the same length.
The re worked bow will be about 3.5" longer, hopefully that will get me to 28" draw. All just a bit of fun experimentation, but it will be nice if he can shoot again. Ideally I'd use Ash with curved grain to follow the curve of the levers but I don't have any suitable (I'll keep my eye out for any curved limbs that fall over Winter for future use). Anyhow, I'll play it by ear and may add a slim belly or back patch to add extra support to the splice, or maybe just a binding of linen thread soaked in epoxy, that will prob' be simplest. This is really just random tinkering, but that's how we learn and discover stuff... maybe I'll discover a new antibiotic during the process? or perhaps I'll stumble on time travel? Although I'm not sure time machines are generally of wooden construction....
Sorry I'm getting hungry and wandering off into flights of fancy.
Saturday, 9 August 2014
Gripping Yarns
The spliced Yew bow now has a Mother of Pearl arrow plate a leather grip and a nocking point.
Wow! What a difference a little detail makes!
I'd been shooting it in and the grip was uncomfortable especially with the 70# draw weight and the disparate arrows I'd been shooting, the 5/16" 100gn point arrows are maybe a tad light, the 11/32" 100gn are smoother to shoot. I'd noticed the base of my left thumb was a little tender one evening and it took a while to work out it was the shooting that had caused it.I took a good deal of time to add some leather to the back and round it off nicely before adding the grip. The addition of the arrow plate and nocking point mean I was getting a consistent arrow and hand position. Blimey, what a difference, she's smooth, hard hitting and accurate now, I started clattering the arrows into each other. You can see from the pic that there are two groups, the lower are all 11/32" the main group are the 5/16" with a couple of 11/32" Bear in mind I was actually "aiming" as such just really shooting the bow in whilst focusing on the square of paper.
The other pics show the leather work and the back of one of the limbs to illustrate my take on following a ring with Yew, you'll see I've generally got it with any ring boundaries running along the bow.
If the weather is ok on Sunday, I'll get to shoot it. Failing that, I'll set up the chrono' and see how fast it is.
I'm really pleased with the bow, it's for a guy who has been after a 70# for a while, one previous attempt exploded on the tiller, and another was ok but full of patches and no faster than the 60# I'd made him a couple of years ago, so I kept it as a demo' bow. I think this one has been worth the wait!
Wow! What a difference a little detail makes!
I'd been shooting it in and the grip was uncomfortable especially with the 70# draw weight and the disparate arrows I'd been shooting, the 5/16" 100gn point arrows are maybe a tad light, the 11/32" 100gn are smoother to shoot. I'd noticed the base of my left thumb was a little tender one evening and it took a while to work out it was the shooting that had caused it.I took a good deal of time to add some leather to the back and round it off nicely before adding the grip. The addition of the arrow plate and nocking point mean I was getting a consistent arrow and hand position. Blimey, what a difference, she's smooth, hard hitting and accurate now, I started clattering the arrows into each other. You can see from the pic that there are two groups, the lower are all 11/32" the main group are the 5/16" with a couple of 11/32" Bear in mind I was actually "aiming" as such just really shooting the bow in whilst focusing on the square of paper.
The other pics show the leather work and the back of one of the limbs to illustrate my take on following a ring with Yew, you'll see I've generally got it with any ring boundaries running along the bow.
If the weather is ok on Sunday, I'll get to shoot it. Failing that, I'll set up the chrono' and see how fast it is.
I'm really pleased with the bow, it's for a guy who has been after a 70# for a while, one previous attempt exploded on the tiller, and another was ok but full of patches and no faster than the 60# I'd made him a couple of years ago, so I kept it as a demo' bow. I think this one has been worth the wait!
Monday, 4 August 2014
Spliced Yew Shoots
I've got the horn nocks on and a new string. There is still a hint of the S shape to the bow so I'll fettle the nocks a tad just to fine tune the string line. You can see the pencil markon the nock nearest the camera indicating where I'll shift the centre line across a whisker, similarly at the other end, the odd mm or two can make a big difference in the look of a bow. (The string is the long tillering string with it's adjuster on it in that pic) The nocks aren't finished or polished yet and the back needs some careful cleaning up along with removing some tool marks.
You can see it on the tiller at full draw, actually it's about 1/2" overdrawn as I didn't adjust the scale to allow for the extra thick handle section, but that's neither here nor there in the grand scheme of things. The limb tips look a bit asymmetric, but that reflects how they are in the unbraced state.
I shot 3 of my 11/32" arrows and they seemed to go away nicely fast and hard. I'll tune the arrow pass a bit and get the bracing height back (it dropped 1/2" as the string settled) I'll try it through the chrono' when it's all finished and shot in. Hopefully I'll get a chance to shoot it up the club next weekend.
You can see it on the tiller at full draw, actually it's about 1/2" overdrawn as I didn't adjust the scale to allow for the extra thick handle section, but that's neither here nor there in the grand scheme of things. The limb tips look a bit asymmetric, but that reflects how they are in the unbraced state.
I shot 3 of my 11/32" arrows and they seemed to go away nicely fast and hard. I'll tune the arrow pass a bit and get the bracing height back (it dropped 1/2" as the string settled) I'll try it through the chrono' when it's all finished and shot in. Hopefully I'll get a chance to shoot it up the club next weekend.
Sunday, 3 August 2014
Decisions Decisions
I've got the bow back to about 70# at 28" the tiller is much better and it still has some reflex.
This interpolates to 88# at 32" and I'm reluctant to press on to 32" anyway.
I just feel it's working nicely now and I don't want to push my luck. A guy who had a 60# off me ages ago has been wanting a 70#, so I'll see if he's interested, otherwise I might just finish it for myself and see what it does. A few people have been asking after a bow, so maybe someone will try it and fancy it. I'm not fussed, the fun is in making the bow and testing it to see what it will do, but I'd rather it was getting used than standing unused in the garage.
I'll press on getting the tiller how I want it and see what the draw weight comes out like. It still has the temporary nocks at the moment, but the picture of the back shows it now looks like a bow.
It's all a bit frustrating really. I contacted the chap at the club who wanted the 90# and he agreed he'd rather see a working bow than have me push it to breaking point.
There are a couple of features that make me reluctant to take it to 32".
1. The stiff handle.
2. The amount of reflex.
3. A filled knot on the edge 11" down from one tip, which is a rather vulnerable area.
4. A pink blush on the belly at one point where there was some growth damage.
On the plus side one diagonal knot on the belly near one tip has all but disappeared.
This interpolates to 88# at 32" and I'm reluctant to press on to 32" anyway.
I just feel it's working nicely now and I don't want to push my luck. A guy who had a 60# off me ages ago has been wanting a 70#, so I'll see if he's interested, otherwise I might just finish it for myself and see what it does. A few people have been asking after a bow, so maybe someone will try it and fancy it. I'm not fussed, the fun is in making the bow and testing it to see what it will do, but I'd rather it was getting used than standing unused in the garage.
I'll press on getting the tiller how I want it and see what the draw weight comes out like. It still has the temporary nocks at the moment, but the picture of the back shows it now looks like a bow.
It's all a bit frustrating really. I contacted the chap at the club who wanted the 90# and he agreed he'd rather see a working bow than have me push it to breaking point.
There are a couple of features that make me reluctant to take it to 32".
1. The stiff handle.
2. The amount of reflex.
3. A filled knot on the edge 11" down from one tip, which is a rather vulnerable area.
4. A pink blush on the belly at one point where there was some growth damage.
On the plus side one diagonal knot on the belly near one tip has all but disappeared.
Saturday, 2 August 2014
Spliced Yew on the Tiller
This post is at start of play today. That's an important point, always check where you are before setting to work on a bow.
I've got it on the tiller on a taut string (but not braced) I've clamped a block in front of the bow to stop it flipping over. I took some video watching it flex and slowly worked it up to how it's shown in the second picture. The right limb was beginning to look a bit hingey on it's inner third so I didn't take it any further, (there is a dark mark on the belly at that point which makes it look like a thin point on the limb) the left looks pretty good.
It has the look of a beginners attempt at tillering, what I call square tillering, but it's early days yet.
The outer half of each limb needs to work a lot harder now. It's just my style of tillering, but I like to get the middle of the bow moving just about enough and then bring the ends round, plenty of people do it the other way. My view is that as long as I don't get the middle flexing any more than it will in the finished bow that's fine, what you don't want is to get full draw with the tiller wrong, or more deflection at any point than it will have in the finished bow. It could be argued that, seeing as how I started with a load of reflex near the grip I've already passed that point... well maybe I have, time will tell.
Without this check I may well have taken more wood off those inner limbs. I shall put on the tea and toast and pencil a big "LLL" (for leave... leave...leave well alone) on that inner limb before doing anything else.
You can see the tips are now back 10" so it could be braced.
There was a good discussion on Primitive Archer about longstring vs short string tillering and a couple of guys had worked out empirically that a slightly long string actually gave good weight/draw figures. E.G If we look at the second picture here it's pulling about 80# at 23" and they have found that when braced it turns out to be a similar figure.
Personally I go by tip deflection, then I brace and work from there. It will be interesting to see what figure I get when I brace it.
Update:- I've braced it and it was trying to bend sideways, with each limb going a different way... so, on average it was fine ;-) . This is why the tips are left wide!
I removed a little from the side of each tip to move the nock across away from the side it was trying to bend to, (it tries to bend towards the weaker side. I also removed a little from the belly on the sronger side to help balance it up. Back to brace and it looked much better, still a slight S shape but within acceptable limits It's mostly just cosmetic and some judicious tidying up as tillering progresses will leave it looking fine.
It's this stage of initial brace is critical, if problems aren't correct they will just get worse and I'd have ended up with a completely twisted bow. Correcting sideways bend and twist needs a careful approach, it's easy to get it wrong and make matters worth.
Just about done for the day, it's at 5" brace and pulling to 70# at 25" which extrapolates to about 95# at 32"
so you see I haven't actually got much poundage to play with to get to target weight & draw. I might ahve to use my ace in the hole and heat treat that right limb which seems weaker than the left, it's thicker but seems 'softer'.
Note the bow is stiff handled to take strain off the splice.
I've got it on the tiller on a taut string (but not braced) I've clamped a block in front of the bow to stop it flipping over. I took some video watching it flex and slowly worked it up to how it's shown in the second picture. The right limb was beginning to look a bit hingey on it's inner third so I didn't take it any further, (there is a dark mark on the belly at that point which makes it look like a thin point on the limb) the left looks pretty good.
It has the look of a beginners attempt at tillering, what I call square tillering, but it's early days yet.
The outer half of each limb needs to work a lot harder now. It's just my style of tillering, but I like to get the middle of the bow moving just about enough and then bring the ends round, plenty of people do it the other way. My view is that as long as I don't get the middle flexing any more than it will in the finished bow that's fine, what you don't want is to get full draw with the tiller wrong, or more deflection at any point than it will have in the finished bow. It could be argued that, seeing as how I started with a load of reflex near the grip I've already passed that point... well maybe I have, time will tell.
Without this check I may well have taken more wood off those inner limbs. I shall put on the tea and toast and pencil a big "LLL" (for leave... leave...leave well alone) on that inner limb before doing anything else.
You can see the tips are now back 10" so it could be braced.
There was a good discussion on Primitive Archer about longstring vs short string tillering and a couple of guys had worked out empirically that a slightly long string actually gave good weight/draw figures. E.G If we look at the second picture here it's pulling about 80# at 23" and they have found that when braced it turns out to be a similar figure.
Personally I go by tip deflection, then I brace and work from there. It will be interesting to see what figure I get when I brace it.
Update:- I've braced it and it was trying to bend sideways, with each limb going a different way... so, on average it was fine ;-) . This is why the tips are left wide!
I removed a little from the side of each tip to move the nock across away from the side it was trying to bend to, (it tries to bend towards the weaker side. I also removed a little from the belly on the sronger side to help balance it up. Back to brace and it looked much better, still a slight S shape but within acceptable limits It's mostly just cosmetic and some judicious tidying up as tillering progresses will leave it looking fine.
It's this stage of initial brace is critical, if problems aren't correct they will just get worse and I'd have ended up with a completely twisted bow. Correcting sideways bend and twist needs a careful approach, it's easy to get it wrong and make matters worth.
Just about done for the day, it's at 5" brace and pulling to 70# at 25" which extrapolates to about 95# at 32"
so you see I haven't actually got much poundage to play with to get to target weight & draw. I might ahve to use my ace in the hole and heat treat that right limb which seems weaker than the left, it's thicker but seems 'softer'.
Note the bow is stiff handled to take strain off the splice.
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