Primitive Archer
Main Discussion Area => Bows => Topic started by: TimmyDeNorCal on December 29, 2021, 12:26:46 am
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After witnessing D97 dig into some of string grooves, I have finally accepted that I should use tip overlays...and I have now actually come to appreciate them for both their function & their added beauty.
But I cannot seem to make ‘em clean enough to where they pop. Yeah, they are functionally adequate - as in they keep the dern string on the bow without cutting into the bow wood...but they just don’t look all that clean.
Can anyone guide me as to the best tool(s) and/or method(s) for this job? I start with a round file and mostly use that same file - in slightly different sizes - while also alternating between the files and sandpaper. But I am having a hell of a time achieving that smooth angled transition between the grooves in the sides of the bow and the continued angled groove on the top of the overlay.
Also - I have only used hardwoods for the tip overlays (because that is the only material that I have had access to so far...).
Any & all help will be greatly appreciated!
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A few, pointers:-
A half round file used curved side down is good for blending in, (see sketch).
You can make the tip very narrow so that you only need a groove on the back of the bow, cut into the overlay (no groove on the side). This allows the sring to move smoothly without snagging on the groove in the side of the bow.
Some masking tape or even a bit of thin tin plate placed over the bow limb can help you rough down the tip without cutting into the limb.
Basically it's practice, I'm sure we all notice our detail work getting better over time.
Del
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Ok so to start with your would be advised to find a picture of a bow with what you class as 'perfect' nocks :)
Aim to copy that bow.
Then simply practise, practise and more practise.
If you really want the practise. Make some pretend bow limbs to practise on.
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Here you go; cut the groove across the back and string your bow at full brace, pencil in where the string lies and use the lines on both side of the string to cut your transition lines. I cut my grooves before I do the final shaping of the overlay.
(https://i.imgur.com/uOwODvM.jpg)
After I cut the side lines I stand my bow up with the belly facing me and use my chainsaw file to sweep the side lines evenly to the middle of the belly.
(https://i.imgur.com/7WSCPVK.jpg)
Your string nocks will look much better is you cut the glue pad at an angle toward the belly then glue on your overlay on. This will let the nock make a smooth transition to the limb and not be a big lump on the back of your bow.
(https://i.imgur.com/eRjoBeS.jpg)
I just went out to the shop and took the last two pictures of a bow I am working on. The extra groove is for a simple parachute cord bow stringer. On the bottom limb I widen the string nock slightly to hold the string and the stringer loop.
I am not completely done shaping the above pictured nock. It will look like this when I am finished. The one above is still too fat in the front between the groove and the limb.
(https://i.imgur.com/XgB7h03.jpg)
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I don’t cut string groves past about have the thickness of the tips unless the bow is a recurve.
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Whoops
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I coat the overlays with superglue to harden them up
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I make my tips narrow but thick because wood is 7 times stronger in thickness than width.
This looks like it would break off but it has a lot of thickness to make it strong. It is probably at least 1/2" thick, the overlay is osage burl which is as hard and dense as a rock.
In all my bowmaking for the last 25 years I have never had a bow tip break from normal use. I have had a couple of overlays pop off, examination showed that I clamped them on too tight and starved the glue joint.
I soak the groove with superglue as well to strengthen the overlay
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But I cannot seem to make ‘em clean enough to where they pop. Yeah, they are functionally adequate - as in they keep the dern string on the bow without cutting into the bow wood...but they just don’t look all that clean.
Can anyone guide me as to the best tool(s) and/or method(s) for this job?
Quality advice so far from some very experienced craftsmen. Do you have examples of what you mean by a 'clean' nock?
I use a carbide grit rod saw blade to start the grooves, then follow with a small diameter (5/32" maybe?) chainsaw file, then finish with sandpaper wrapped around the file.
An example of the rod saw: https://www.amazon.ca/RemGrit-E0406180-100-Carbide-Blade/dp/B001FAY5OG/ref=sr_1_12?crid=XZISBS5235Z3&keywords=carbide+tile+hacksaw+blade&qid=1640792996&sprefix=carbide+tile+hacksaw+blade%2Caps%2C180&sr=8-12
It can be used in a hacksaw frame or loose. It is stiff enough I use it loose for the most part. It cuts faster than the file to get started and leaves a narrower kerf so the file cleans everything up nicely. I start by cutting the groove across the back of the overlay, then slowly work it around the corner down to the sides. Del's recommendation to make the nocks narrow and have no side groove works well for me.
A couple examples of narrow nocks:
(https://i.imgur.com/sOslwD5.jpg)
(https://i.imgur.com/SjhoQBx.jpg)
Both of these are 5/16" wide and the string just wraps over the back and then can slide loose on the sides of the nock.
Mark
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So I make most of my overlays with Buffalo horn - I like the way it looks, polishes and finishes and is also really easy to work. For $10 you can get enough horn from any pet store to make a dozen plus overlays. I rough cut it to size with a hacksaw and then usually flatten it on a belt sander. Often I will make the wedge transition on the belt sander as well. From there I flatten the bows surface and use thick CA and clamp it for a minute or two. I do all shaping with a farrier’s rasp. I use either a hack saw across the back for the string grove to start it or use the edge of a half round cabinet file. Once started I use a chainsaw file to shape it out.
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Thank you all for your responses.
As for an example of a nice, clean nock, the examples posted by you guys above all qualify to me. The issue I was specifically referring to is that super clean transition between the grooves on the sides of the bow tips into the top groove on the actual tip overlay. You can see how the two materials - bow wood & tip overlay material - are so cleanly jointed to the point whereby the angled groove is perfectly harmonious & continuous...
...and that perfect unison/angled marriage is what I am striving for. And so far I just cannot seem to make mine all that clean.
But you guys have provided me with some solid ideas, tool suggestions, and methods for me to try.
Again, thank you all for your responses!
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There are some good examples. Easy just do ten of them. Ten bows with the help you get around here and you got it. Or not. 😬😬😬😬
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The thing to avoid is not widening the groove on the bellyside. Wears your string much quicker than one that is done properly. Remember that the string is in one position at brace and another at full draw :) This needs to be accounted for on the bellyside. It is one of the most common 'mistakes' I see.
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For finalizing smoothness in groove I use a 1/4" wide fine emery cloth twisted into a cord.Clamp the bows tip into a vise and give the groove a shoe shine action finish.
All other work prior done by pre beveling a short amount on the approach for string loop before glueing on.Grooving done with chain saw file.Shaping with no. 50 nicholson file then to finer file.Then to sand paper going down to 220 grit,and if you want going to 0000 steel wool for the extra shine.
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This information is priceless. Can I assume that the overlay doesn't add any strength to the limb tip unless it was several inches long? Just trying to understand how thin the limb tip can be when using an overlay?
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I usually leave my tips a bit wider than I need them from the start and use side grooves for tillering. When I get to the final few inches of tillering I will add the overlay and then narrow the tip to its final size. That gives me a fresh side to cut in new nocks. Cutting in the nocks again is a lot cleaner than adding an overlay and trying to carve the nock in the overlay to match the sides.
Doug, the wood at the tips can be quite thin without compromising strength. I usually keep the last few inches of the tip the same thickness though. Overlays are more for aesthetic or function than strength.
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Ryan we are all a bit different. I finish the back of my bows put the overlays on floor tiller and then tiller. Do the handle then final sand and the finish. All methods work I guess. Arvin
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Absolutely Arvin. A lot of ways to skin the cat on this one.
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Main thing for me is to get them to match.Taking your time.Except for a rounded bottom tip look sometimes.