Wednesday 25 July 2018

X-Y Table


My cheapo Chinese x-y table turned up and I gave it a quick try out of the box using an 8mm ball nosed mill which I'd bought from RDG Tools.
It worked very well on a bit of old Walnut table top and managed to cut Ali' too. There is a fair amount of backlash and it was all a bit loose, with the x travel vibrating round as I wound in the y travel.
Irritatingly the mounting slots are closer together than the slots on the pillar drill table, but I bolted it down on the diagonal with just 2 bolts for a quick try
The actual tables/ beds are aluminium extrusions and the carriages are also Ali' with brass gib strips to take up the play, so, not heavy duty!

I stripped it down and fettled it to tighten it all up. The lead screws are just M10 threaded rod with the nut being a bit of brass rod of 15mm diameter drilled and tapped and rather sloppy. To take out some of the slop I dug out my old soldering iron and soldered into the last few threads at one end of the nut. I then took an M10 coach bolt and filed 3 grooves into it like a tap and took the tops off the threads with a file. Using that I cleaned the soldered threads, which resulted in a much snugger fit, I did that for both x and y travel.
On re-assembly I tightened the gib strips and also tightened the retaining nut on the end of the lead screws, which incidentally have ball bearings at either end


It now feels much smoother and tighter with much less backlash. It's fine for use on wood and Ali' and I dare say it would cut mild steel if taking fine cuts.
It is what it is and I dare say that the whole thing would wear rapidly if worked hard, but for light occasional use it is much better and less dangerous than feeding material under a mill my hand!
I recon I've had about fifteen quids worth of fun out of it already!

Tuesday 24 July 2018

Tinkering with stuff

I'm afraid I've had a spell of clicking "Buy" on E-Bay! Bought some more clamps that open up to a full 6" only £5.35 each. Bought a jeweller's loupe with x10 and x20 magnification so I can see the tips of my lathe tool... blimey it needs sharpening the tip looks like the corner of a battered old brick, a quick touch up with an oil stone and it looks much better.
I ordered some milling bits and an x-y table to go under the pillar drill (drill press) that will allow me to do some light milling of Ali' and wood for the ongoing crossbow project.

The milling Ali' thing kicked off when I modified the upper blade guide of the bandsaw to give me some extra room for cutting thick stuff. I put a rotary rasp bit in the pillar drill and fed the Ali' extrusion carefully against it to enlarge a slot down to the black line in the pic. That allows me to raise the blade guide up about another inch.

Meanwhile back at the bows, I've had a couple of people get in touch, my cousin is asking about a bow for his adult son who is getting into archery, who will be phoning me some time.
My nephew will be visiting in a few weeks with his kids and I don't have any bows light enough for kids... I found this out a while back when my niece was over with her son.
Anyhow to rectify this oversight I'm making a Bhutanese style bamboo bow light enough for kids even down to 9yrs old or so.
It's 49" nock to nock and about 6# @ 20"


Thursday 12 July 2018

A Bit of Courtesy

A while back I had a bloke want me to make him a longbow (ELB) which I did, he came to collect it in a bit of a rush as he was passing this way on business. Ideally I like people to collect a bow so I can see them shoot it.
I said to him to let me know how he got on with it taking great care to mention that as it's custom made for him I really do want to know in case it needs any tweaking.
Did I ever hear back? No...
It only takes an E-mail. Will I ever make that bloke another bow? Will I even respond to him if he does E-mail?

Compare and contrast with Ron who contacted me recently wanting a primitive. He was willing to wait a good while, but as I looked through my staves I just happened to have one that would suit his draw length. (See previous posts)
He lives a long way off so wanted the bow shipped, I don't like shipping bows, but I sent it UPS.
Within 30 minutes of him receiving it I got the following E-mail and attached a picture.

Bow arrived 30 minutes ago. Set nock. Warmed it up . Third end 20 yards on a 40 cm face. Beautiful bow shoots like a dream. Into the woods tomorrow and some 3ds. Many thanks Derek.
Cheers
Ron

I was really happy to feel my work was appreciated and being used. If in the future the bow needs any attention I'll make sure it gets it.

Some people "get it"... others must think I'm like a supermarket with stuff on the shelf.

Saturday 7 July 2018

Yew Primitive Finished

Well, not quite, needs a few wipes of Danish Oil, but I'll get some more arrows through it tomorrow.




Wednesday 4 July 2018

Final Stages

I'm looking for 40# at 26.5" ok, that's a bit too exact as the change from this summer heat to a cool autumn day will shift the weight by more than the equivalent of 1/2" of draw.
But that's not the point, it's good to have an exact target, however I seem to have a little more wood to remove yet. It's sometimes hard to know how to proceed for fear of spoiling the tiller, which is why video is so useful, I can sit here with my tea and toast watching it flex and ponder where to ease off the last few strokes of the rasp and scraper to bring it to the exact draw length and weight.
My normal practice is never to pull past the target weight, but in this case i wanted to check how it looked near full draw so I've gone a tad over to about 45# at 26".
The horn nock overlays have been done but not polished and the brace height is a tad low still.
I think I'll ease off the right tip a little to get that flexing a whisker more and get a string on it. Shooting 50 arrows or so will help it settle in and let me do some fine tuning and review the tiller.
I've got all the bark off the back and cleaned it up. On this stave the sap wood was thin enough to leave without de
crowning, so it has a lovely pristine back.
Ha! Never act in haste, I've just held a CD up to the full screen picture of the bow at full draw, that right limb looks damn near perfect, the left looks maybe a whisker stiff on the inner to middle 1/3.
I will take very little off, maybe a hint on the outer of the right and inner left. Overall the right could do to be a merest hint weaker.
 I'll prob' take a couple of light strokes of the cabinet rasp along the whole belly, or maybe it will be achieved by simply removing tool marks, rounding the edges and little scraping. It's very easy at this stage to remove too much and suddenly become underweight. Conversely it's easy to be too tentative and end up feeling that nothing is happening and be filled with trepidation and a sense of impending doom! That's why getting a string on it and shooting a few arrows is a good idea...
Oooh hoorah, string making... my fave', not... grrrr ;-)
Meanwhile tea and toast, while I leave it strung to see if it settles at all.

Interesting, having said all that, and had my tea and toast, I've gone back into the workshop and twisted up the string to get it to full brace and had a good look over the bow. Running my fingers over that upper (right) limb, I could feel a thick spot where it swells up right across the limb where there is a small plugged knot. I eased that down by rasping a little from the belly to make it feel all of nice even thickness. Putting it back on the tiller I've gained a bit more draw length, 40# at 25" so I'm pretty happy that it's just pretty much cleaning up to get me there now.
That thick spot was probably what I was seeing when I thought the right outer was stiff. It's all very subtle, and sometimes a bit of checking with calipers can pin point the problem.


Monday 2 July 2018

Highs Lows and Senior Moments

I went out on Sunday to sight up the crossbow at 30,40,50 yards, it was a 25 minute drive, I got there, unpacked the target... no crossbow.
Calm calm... drive home, tea and toast and try again.
After all that messing about, the performance was disappointing. Having sighted it at 30 yards reasonably, I went up to 40, same again, not great but just about ok.
Found I couldn't get out to 50 yards as the elevation meant the scope was looking at the bow mount, must admit I was thinking the trajectory was a bit soft and I felt that was cocking the bow rather easy.
I went back down to 40... ok... ish. Went to 30 and it was shooting 6" low, also shooting right! What's going on? It was grouping ok, but low and right.
Anyhow back home I was checking for slop and vertical movement in the sight elevation mechanism, but also thinking that the bow was tiring rapidly in use and that I should check it on the tiller.
I demounted the bow bolted it to the test plate, got it on the tiller and could hardly believe my eyes... about 75# Waaaaa!???
That was 120# when it started! No wonder it was feeling easier to cock (and there was me thinking I must be getting fitter!).
As a crosscheck I put the original repaired boo/Yew prod on there and that gave me a bit over 80#.
(Note:- I'd shortened the draw on the cross bow a little since the early measurements)
The conclusion is that I've pushed the materials as far as I can, although some of the losses are possibly in it breaking down at the mounting. I may make a glass/wood/glass prod at some point, but I'll give it a rest until I fancy it but I've already put in motion the buying of some glass back and belly lams.

But by way of a contrast, a high, my mate John Turton won the ILAA Mary Rose Shoot which is a two day event.
He was helped by the performance of Il Bastardo the short Yew ELB flight bow which was the subject of much attention. It got some Oooohs, Aahs and WTFs when shot, because you simply couldn't see the arrows go! Its apparently got some of the other bowyers plotting shorter longbows for next year!
The hot weather wasn't helping the distances achieved, but Il Bastardo trounced the other bows by a good margin achieving 301 and 320yards in a two way shoot, where the others weren't much over 250 yards.

Meanwhile the Yew primitive is back to 40# at 24", so very nearly there... time to do the horn tip overlays, shaping the grip a bit more, cleaning the back further (all the bark is off now)