Monday, 4 February 2013

Horn Nock Making Instructional (part 1)

I've noticed the page of this blog which gets the most hits is the nock fitting tool, I've also had quite a few questions on the topic.

So here's my guide to:-
Horn Nock Making.
Horn Nock Fitting.

Over the last few years I've honed my technique from starting with a vast chunk of horn and trying to shape it before gluing onto the bow.

Now I start with a much smaller piece and generally get both nocks for a bow from one bit of horn, (pic1) this saves on cost and also saves on a lot of rasping, it also gives nicely matched nocks when using the paler horn as I'm using here. The horn looks fairly dark at the moment but you can see the white centre on each bit, and once the scruffy outer layer is taken off and it's polished hopefully well see some nice coulour.
Note the drill I use has the shank cut down, this helps to keep it rigid and centred as some cheap wood bits wobble about like a drunkard and centre differently each time they are put in the chuck. The drill is just a 16mm flat wood bit (they are V cheap) the flat cutting face is ground away to make the shape in the pic. I used a grind wheel mounted in my pillar drill.

(Pic2) shows
the drill offered up to the end of the bow, note I've stuck masking tape onto the back of the bow and marked a line 6" from the nock. This allows me to cut the final nock groove in the horn in the same position as the temporary nock.
Pics 3 & 4 show the horn against the drill and the end of the bow limb, this is going to be the top nock which is slightly longer and fancier than the bottom nock which has to withstand more bumps and abuse as it contacts the ground.

Once the nock is drilled (see the video) the tip of the bow is rasped to a rough point. I rasp back and belly first to a sort of wedge, holding the drill up against it for comparison, then I rasp the sides which gives a squarish point, the corners are then rasped off and it's then ready for my 'pencil sharpener' style sanding tool.
This tool removes wood but more important indicates the area where more needs rasping off. So it's a repeated task of rasp, sand try the nock until a good fit which reaches the full depth of the hole is achieved. You can see in the final pics how a burr has been pushed up on the wood where i've put on the horn nock and twisted it back and forth to check the fit, this shows where I need to remove more wood. The  last pic shows a pencil line marking how far the horn pushes on compared with the drill, it shows the wood is getting right up into the full extent of the hole. The final operation in this part is to lightly score some lines along the very tip of the wood to help any air and excess glue squeeze out as the horn is glued on with 10minute epoxy (which of course take half an hour to cure).
I'll show where I go from here in part 2 which hopefully I'll post later today. the posts get rather ungainly when there are lots of pics and the editing is tricky as I can't get the pics to go where I want them!

Of course not everyone has a pillar drill, and if you are using a hand held drill it may be better to use a bigger bit of horn.

pics of the 'pencil sharpener ' style tool for shaping the tip of the limb is shown left. It's drilled into a block of Oak using the same drill that is used for drilling the horn nock, a slot is sawn to allow a bit of old sand belt or wet & dry paper to be slotted into it.


video

1 comment:

  1. excellent instructions Derek, nicely laid out page. An alternative method of ejecting air and glue from the tip-nock joint is illustrated on page 257, TBB v.4 (Hugh Soar), employing a "purging-hole" on the belly side of the nock. Such a small hole can be made in the horn by inserting a red hot needle to form a tiny hole, through which excess glue and air will escape. drilling a tiny hole is risky as a tiny drill bit is likely to snap off.

    ReplyDelete