New PB For Distance!

Had a good time shooting on Sunday, mostly flight testing 4 new flight arrows. I tried 'em from my Osage flight bow first but struggled to reach full draw and they were going about 280 yards. I took the one that went the furthest and tried it from the shooting machine (26 3/4" draw) ... I didn't see it go, we walked up the field to pick up some other arrows and I couldn't find it, then I spotted it about 40 yards further on, obviously well past 300, I got out the laser rangefinder and sighted back to JT's landrover, then subracted 10 yards as we'd paced that far out onto the field  345yards! That smashed my previous best which was from the same bow at a 24" draw.
My mate JT then tried 'em out of the Yew ELB flight bow, but struggled to get a controlled full draw due to the short draw length not giving a convenient anchor as he's used to shooting 32" draw.
Back at home I've confirmed the draw weight at 26 3/4" to be about 80# so I should be able to mange that with a bit of practice.
I don't want to wear out the bows so I'll refurb' last years quick try out Yew flight bow for training purposes, I'll have to repair one of the flight arrows as the tip fractured just behind the pile.
The solid Ipe arrow was seemed to fly shorter than the footed arrows, but they all came off the bow fairly cleanly. Ideally I'd have tried then all from the shooting machine but there was a lot of other shooting going on and the lure of a pint and a bowl of chips at the Rainbow and Dove was hard to resist.
It was my arrow number two that subjectively seemed to fly best and made the 345yard shot.

A request for more arrow info :-
Arrows 1 and 2 seemed to fly furthest, they are lightest and have similar FOC balance point, they all have similar spine.

Diameters in mm

Belt Sander Fixed

I've got it rebuilt with the fully sealed bearings and it runs sweetly. I've vastly improved the dust collection and made it so I can change belts without using any tools (bliss!). I just lift the wooden catch, slide out the dust box and I can change the belt.
The metal tray that was fitted beneath the belt was held on with 4 fiddly little M4 screws and the dust extractor spigot was pointing down wards from that, virtually inaccessible.
The new arrangement seems to catch the dust better, although some overshoots, as the shield doesn't protrude above the level of the belt (that's another modification I made, allowing long items to run over the sander without fouling).
It's much more convenient having the on/off switch accessible too. (The pics are taken from the other side to the on off switch).

Meanwhile a friend asked if I could have a try at fixing a flight bow of his which has taken on some twist/ sideways bend when braced. I'ts by a reputable well known American Bowyer who has told him how to do the fix as shipping it back and forth to the US is impractical.
It's a very deep, narrow ELB flight bow, Hickory back Osage belly with some other core wood.
The technique suggested is to force the string over while braced and heat the side/belly (on the outside of the bend, see pics). This has needed a couple of 20 minute heat sessions, taking care not to get it too hot. After the first session it was back in line but crept back some way over night.
The friend in question has given me some carbon fibre tow which I will use wrapped round the nocks of the next crossbow prod... that should stop the bugger splitting!

The second session I got it a little hotter and pulled it another inch over. It seemed ok the next morning, but I'll leave it a few days before declaring it good.

My only reservations about the method are the ability of the Resorcinol glue to withstand the heat (but the glue line is for the most part, deep withing the limb).
Secondly, is heating it whilst braced going to introduce set? The bow did have some set to start with.
Anyhow, it's a no-lose scenario as the bow would become fire wood if it isn't fixed

Belt Sander Refurb

 

My cheapo belt sander has been getting sluggish recently so I stripped it down to find out why.
The bearings had pretty much seized up and one was rattling about on the shaft, having worn it down (e.g The shaft was rotating loose in the inner race of the bearing).
Fortunately the outer portion of the shaft is smaller diameter (11mm) where the pulley fits. The bearing inner diameter is 12mm and the shaft had worn down to a whisker over 11mm.
So I was able to turn the whole shaft down to 11mm , I then turned a bush with an inner bore of 11mm, pushed that over the shaft (with some epoxy for good measure) and then turned it down to 12mm.
That repair went well so I've ordered new bearings, good quality sealed ones, the old ones were "shielded" which keeps out big bits of crud but aren't good for dust. Mind I've cleaned out the old ones and they are ok, but for a few quid, I'm happier not to have to repeat the strip down every few years.
While I'm waiting for the bearings I thought I'd make some other improvements, like moving the on/off switch to an accessible location, improving the dust extraction and making belt changing easier.

Last pic shows work in progress, you can see where I've moved the power switch. I'll blank off the hole with some sheet aluminium or a bit of 1/8" ply.

Close But No Cigar

I'd had a good day helping my mate JT work on the Hazel longbow, the belly patch was worked down to blend in to the bow, but left a whisker plump, the horn nocks were roughed out enough to fit the string at a low brace and flex it, pulling it to 45# at about 22". It looked much better and the right limb which had chrysalled and gone weak now looked a hint stiff with the tiller restored to a reasonable shape. We quit there as we'd had a good session and didn't want to spoil the work by rushing.

By teatime I couldn't resist testing the crossbow and it worked nicely  201.1fps first shot, but then 200.5fps on the second and it then went on to loose about 2 fps of speed with each shot!
After 7 shots it was down to 188.8fps, I was just pushing it too hard, I'd taken a few turns out of the string to lower the brace height a whisker and take some strain off it to no avail.

Bang! The string cut deep into the nock on the left limb splitting down along the lower edge, this made the string slack and allowed the limbs to flex past their unbraced position splitting the belly lams away from the core.

If only I'd double served the loops or bound below the nock with linen thread soaked in superglue. Easy to be wise after the event, but even if I'd done those things, it may well have lost speed.
I've proved some aspects of the design, the bow mount, the Boo/Yew /Ipe combination, the 120# draw weight. The nock failure was at least different to the last one which virtually snapped off.
Am I down? Of course I'm not (well just a tad) I could buy a crossbow, but what would I learn from that. I'm hedging my bets, I've seen some nice maple slats on E-bay which I've ordered, these can be used with Boo/Ipe, or maybe I'll succumb to the lure of glassfibre laminations.
I'll probably have another go with the natural materials but with an extra inch on each limb, and better nock design. The belly lams will go right into the mounting/riser block this time so they won't simply split off if the bow flexes beyond it's rest position.

Frogs and Crossbow Progress

The frogs were just becoming active the other week when we had a week long big freeze, since then I've found 6 dead frogs and I was getting worried that the population had been badly effected. Last year it was they had spawned by March 5th.

Yesterday I was relieved to see one cluster of spawn and a couple of frogs. This morning, at least 4 pairs were writhing about and a good deal of spawn.
 All is well with my froggy friends!

Mean while I've pulled the crossbow prod back to about 14" at 120-130#. Its reaching the point where drawing it further will merely cause set in the bow rather than giving more weight. With this in mind I've taken 1/2" off the track and moved the bow mount back.
I've added horn nock overlays as reinforcement  and also added the string catchers (neither  polished up yet), these have been glued onto rubber sheet and that then glued onto the limbs, hopefully this will help absorb shock.
I'm currently making the string, (well typing this and drinking tea really). I may get to test it today, but I'm taking things easy having given my back a little tweak (groan). I was working on the floor mending our vacuum cleaner... the cable retract mechanism had managed to jam the cable such that you could only pull about 3/4 of it out. I was wrestling the damn thing on the floor to try and get it apart, I reached over for a screw driver and felt the back give a nasty twinge... not too bad if I keep moving, but not a great aid to a good night's kip.

Yet More Crossbow Prod Work

The Ipe from my mate Matt at Cambridge Longbows has come in very handy, as well as using it on flight arrows there was enough to make a pair of belly laminations for one of my crossbow prods. I have 2 prods on the go, the slowest one being used for experimentation. That one had a bamboo belly which I've taken off using my new draw knife and carefully taken down to the Yew core.

The Ipe was sawn on the bandsaw with some care to try and get nice clean parallel strips. It's not as simple as one might think, some careful set up and a suitable blade helps enormously. Contrary to what one might think, I've found a narrow blade seems to allow the wood to follow the guide best.
I'm using a 1/4" x 0.025" 4 tpi AS Hakansson Silko blade. (From Justbandsawblades)
That's a general purpose carbon steel blade, 4 teeth per inch Alternate Set. The alternate set cuts a slightly wider cut and helps avoid friction. Being a 1/4" blade it also allows you to follow quite tight curves, the down side is that it's not as rugged as a wider blade and you wouldn't rip down logs with it.

I still have the former from the last glue up of the prod, but the Ipe is too stiff to bend easily to shape without some heat bending first to get it about right. Once the Ipe was hot (using a hot air gun) I clamped it to the former to get the bend. As I heated the Ipe, it changed colour, going darker and tiny specs of oil came out of the wood. I have heard people suggesting that some oily woods be de-greased before glue up, but others suggest a fresh sanded surface is fine. I went for the fresh sanded surface. The Yew was lightly scored and all traces of the old glue removed. Glue up was with my usual Cascamite (Resintite) and plenty of clamps. (Picture shows starting to clamp it up starting near the centre to ensure it is nicely butted up against the centre riser block)

I've had the prod up on the tiller clamped up between two thick aluminium mounting plates, as it will be when mounted on the stock, to ensure it doesn't break at the shoot through cut out.
I've pulled it to about a 13" draw (measuring from the Aluminium mounting plate nearest the archer) and it's pulled about 125-130# I'm not sure if I dare pull it much further.
One consideration is that although the latch is at 14 1/4" one has to pull it beyond that to actually cock it and engage the latch, also because it is being pulled with two hands on the string that effectively shortens the string slightly pulling it even further.
I can always take 1/2" off the end of the stock to reduce the draw, I don't know yet, I'll proceed slowly.

Freezing Cold

I've not posted over the last week, mainly 'cos it's been too cold to do much out in the garage other than a few minutes here and there finishing some flight arrows for the 90# @ ~27" Yew longbow.
I've been a bit more thorough about noting dimensions etc and I've got 4 nice arrows with varying weights and centre of balance etc.
Two are rebuilt from the 26.5" arrows which had the tips broken off, these now have footings added to make 'em 28", that's allowing a little safety margin in length to remove the risk if sticking the point into the belly of bow at 27" draw.
Still too cold and wet to test 'em but maybe next weekend.

I've picked up the boo/Yew/boo crossbow prod which was slower than the original boo/Yew and I've taken the boo off the belly using my restored draw knife, it's a joy to use but too long to fit in my drawer. It's a bit lethal to leave it on the bench as the cutting edge is so long, so I'm making a leather wallet for it. I like working with leather and once it's all cut out and punched I can sit indoors in the warm to stitch it.
The game plan is to glue an Ipe belly onto the crossbow prod, it will all be guess work and may need 2 strips of Ipe side by side for each limb, as the stuff I have isn't that wide. If that fails I may have to resort to laminating a prod using glass or carbon fibre, not really my thing, but still an interesting project. It prob seems bonkers to some people that I'd be doing all that when I can but a reasonable crossbow for about £150. It's just the fun of it, to see what I can produce. Keeps me out of mischief too, mind I'm not sure how much mischief I could manage these days!
With the bit of snow we had I did manage to make a snow cat :-)

Oh, I've also noticed that the feedback tick boxes at the foot of each post seem to be working again, which is nice as I can see that I'm not boring everyone rigid... Google works in mysterious ways!

Been out in the garden, the ice covering pond is starting to thaw but I noticed 4 dead Rudd floating under the ice, these are descendants of fish that my brothers and I caught as kids. There should still be a reasonably healthy population. I expect Emily Cat will be trying to get 'em out when the ice finally clears.