Removable Onlay Scales

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Xplorer
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Re: Removable Onlay Scales

#21

Post by Xplorer »

^What a great way to increase the value of a knife :p

That handle is looking great!
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RustyIron
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Re: Removable Onlay Scales

#22

Post by RustyIron »

Very nice tutorial. A couple of your techniques I'll be stashing away in my few remaining brain cells, for future use.
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Re: Removable Onlay Scales

#23

Post by Bolster »

RustyIron wrote:
Wed May 26, 2021 4:17 pm
Very nice tutorial. A couple of your techniques I'll be stashing away in my few remaining brain cells, for future use.

Thanks! I hope you at least remember the centrality of beer to any useage of power cutting tools or flammable materials.
Alexander135
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Re: Removable Onlay Scales

#24

Post by Alexander135 »

Thanks for the info.
I'm messing with 3d printed mule scales right now. I wonder if I can make something lighter than 0.3 oz per scale. :p

Unfortunately my skills with wood are very novice and I have no power tools aside from a drill so it may be awhile before I'm able to make nice wood scales.
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Re: Removable Onlay Scales

#25

Post by Bolster »

Looking for a rabbet set like this, but with the bearings fitting on the shaft side of the cutter...can't find...

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Might have to make my own set out of a hinge mortise bit like this, using aftermarket bearings:

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Re: Removable Onlay Scales

#26

Post by Bolster »

The hunt for pattern bits (to date) has revealed that most bits with standoff bearings ride on a 3/16 shaft at the tip of the bit (regardless of the shank size, whether 1/4 or 1/2"). So I'm resigning myself to routing smaller-than-pattern pieces using the same method as shown above, with the pattern on top and the cut piece somewhat "hidden" beneath it. That method works OK, it's just that you can't see what's happening as well.

There are a few 1/4" shaft bearings out there but I've not been able to locate a whole graduated set of different sized bearings. (Finding a graduated set is easy if you are shopping 3/16 tip-style bearings.) I suspect the reason that bearing-on-shaft is rare, is because the router bit itself would be a little odd if the bearing is on the shaft: for the latter you'd need a skinny shaft (1/4") and a large diameter cutting bit, which is backwards from a strength standpoint.
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Re: Removable Onlay Scales

#27

Post by Bolster »

Who in his right mind would make scales out of white pine? Nobody--in his right mind. But that leaves me free to do it. The strength to weight ratio for pine is really remarkable, it's a superlite wood. Not balsa light, but still really light. Not a pretty wood either. The walnut scales I made previously were 0.6 oz (both). I was able to drop the weight of these scales (yes, both left and right together) to a mere 0.2 ounces. I submit this knife as a low-weight Mule contender at 2.8 ounces as pictured. That's lighter than a Sage Lightweight.

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Only one coat of BLO as pictured, so these should be looking better in a week. Hoping that the BLO will give it a "case hardened" protection.

I'm calling the grip pattern "golf ball grip." Like the wood, it's not particularly attractive. Felt I needed a spaced-out pattern for pine, given it's not a strong wood and small, fine features would be vulnerable to wear. Feels great though: an interesting hand experience to it, where it feels neither very smooth nor very grippy. If you grip hard, your skin pushes into the divots, giving a firm grip. If you grip lightly, you don't feel much pattern at all. Maybe "panic grip" is a better term for it.
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Re: Removable Onlay Scales

#28

Post by Bolster »

Upgrade to step Nine and completely eliminates step Eleven...a much better way to skin the cat:

(In this example I'm using a 4-40 threaded barrel nut that's 3/16 in diameter and 1/4" in length. I think this is the same or similar hardware used by Halpern for their "flat" scales.)

Clamp one scale to the mule just as you want it to look when finished. Using a 3/16 mule tang hole as a guide, drill a 3/16 diameter recess with a flat-bottom end mill bit on the backside of the scale where you want your screws to be, but only approx .06-.07 deep. Blow out the dust. Now drop a 3/16 barrel nut through the tang & into the blind hole. It should fit snugly. Use that as a drill guide for a #42 drill. This guide hole will get drilled dead center, thanks to the barrel nut being in place. Be sure you drill into scrap wood beneath your scale, to avoid tearout on the outside of the scale. Now flip the scales over so you're drilling from the outside in (less chance of tearout that way), and drill with a #36 bit to widen the hole, so the screw will fit in. The best way to drill this hole centered is to hold the scales in your hands, and push the scales up into the rotating drill bit in the drill press! (Carefully so as not to drill your hand, obviously.) That way your #36 will follow the existing pilot hole as the path of least resistance. Now you have a dead-center hole of 4-40 screw-shank size that aligns perfectly with your 3/16 diameter recess for your barrel nut.

This kink saves a lot of time and hassle, and you don't have to buy a specialty countersink bit to do it.
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Re: Removable Onlay Scales

#29

Post by PBWilson »

That was a mighty entertaining read! Thanks for the laughs and for the really nice work you showed.

Gotta get an order in for those threaded barrels and screws and get making!
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Cherry

#30

Post by Bolster »

Image

Cherry...wonderful wood. Tight grained, relatively light, and beautiful to look at, with lovely chatoyance (using my new word here). This is a swell-centered set of scales; there is a modest palm swell between the two screws. That took some hand shaping, and instilled a new respect for those of you who rasp, file, and sand 3-D scales.

Again, just a simple BLO finish, about 7 coats so far, no stain used, and that super rich red-brown color comes shining through.
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Re: Removable Onlay Scales

#31

Post by defenestrate »

These are both entertaining and informative, Bolster! Thanks!
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Re: Removable Onlay Scales

#32

Post by Xplorer »

Really nice work here! Not only does that Cherry look nice, but how about that jimping work?!! The jimping is a nice custom touch that adds a look of refinement to this Mule. You should be quite proud of your custom Mule!
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Trouble

#33

Post by Bolster »

Why thank you, gentlemen. Now for a failure:

Wanted to make some scales out of mesquite wood I'd cut and dried (from a tree I planted!) for this M1 Backpacker, which is an odd and uncomfortable knife to hold if "naked" without scales. It has a long 1/4" slot cut into the tang (for weaving a paracord handle). So I purchased aluminum barrel nuts 1/4" diameter, and some 8-32 screws to match. Put the barrel nuts at either end of the slot so the scales are locked into place and can't scootch forward or backward.

But goodness sakes, it seems like everything fell apart on this project.

1) Mesquite is dark brown, dense, and looks like a cross between walnut and fir (LOL). When I put BLO on it, I got a whitewash look. Dunno what is going on with that...! The wood seems smooth and strong, so let that be...

2) I did not do an Illustrator model beforehand, just did what seemed reasonable. Was surprised to see the placement of the forward screw...so far forward! (Arrow B) It looks fragile, like there's not enough material around the front of the scale to be strong.

3) The 8-32 screws were...hunktankerously big! They overpowered the scales, and stuck out a fair altitude from the handle, even though I countersunk them. The fix was to chuck them in a drill and sand them down so now they are only small humps in the assembled knife. Fortunately the broaching for the Torx was deep, and there's plenty left for a good purchase when tightening.

4) If that wasn't enough, on the backside, my Pony spring-clamps let me down when locating the rear hole. They scootched, and I did not see it until after. (Arrow A) Lesson learned: Use double-sided tape PLUS the pony spring clamps. Now looking at a complex repair of rebuilding around the hole with epoxy and re-drilling...or just living with it. It makes my OCD act up, looking at it.

5) The scales themselves only add 0.2 oz, but the hardware, even though the barrel nuts are aluminum, add another 0.2, so I've heavied up my knife by a half ounce, when the point of this particular knife was light weight. I wish I'd used 4-40 hardware, but was unable to find 1/2" OD barrel nuts with a 4-40 thread. (Alternately would like to find 4-40 pan head titanium screws.)

More fails than successes on this one; hope some of you folks can learn from my mistakes.

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Counterbore without counterbore

#34

Post by Bolster »

How to counterbore without a counterbore?

You've seen counterbores for sale in the knife parts stores; they're nifty. They use a smaller (screw) hole to guide the dead-center drilling of a flat-bottomed larger hole (for the head of a screw). You have to find the correct combination of screw body size (guide) to screw head size (cutter). If you do the same size over and over, nothing beats a counterbore. If you are using different size heads and different size screw bodies, collecting all the counterbores you might need can be an expensive proposition.

Here's how you can counterbore with just a drill press (no mill needed).

1) Precisely drill for the screw body. If you use numbered drills rather than fractional, you'll get much closer tolerances. Measure the diameter of your screw body, then check the Starrett Drill Sizes sheet (http://www.starrett.com/docs/educationa ... n-1317.pdf) and choose a drill that's just a bit wider (maybe one number larger) than the screw body itself. But you don't have to. If you use the same size, you'll be essentially cutting tiny threads into your scales when you twist in the screw.

2) If you check your work at this point, you need to unclamp. That's OK, unclamp. We can re-clamp with precision.

3) Take the drill you used in step (1) and chuck it lightly (hand tight good enough) in your drill press upside down. Now use it as a locator for the hole(s) you drilled earlier. Just fit the upside down drill bit into the hole you drilled previously, lower everything onto the drill press table, and clamp your scales in place so they don't move.

4) Now you need to drill a square bottom hole on top of that. You'll want a (usually quite inexpensive) end mill bit that's the right size for the head of your screw. You can order those from MSC, McMaster-Carr, Shars, Little Machine Shop, Amazon, Homedepot.com, and on and on. I've found that 4-flute end mills work better than 2-flute end mills in wood. For wood, HSS is plenty good enough...no need to get carbide, cobalt, or coated.

That's all there is to it...!
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Re: Removable Onlay Scales

#35

Post by Bolster »

Bump for current discussion of removable onlay scales in other thread...
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Josh Crutchley
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Re: Removable Onlay Scales

#36

Post by Josh Crutchley »

I want to try this but not sure how highly figured wood will hold up. I'm afraid of it warping over time. This is the wood I got, ribbon Maple with some burl.
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Re: Removable Onlay Scales

#37

Post by JRinFL »

Josh Crutchley wrote:
Sat Jun 25, 2022 11:59 am
I want to try this but not sure how highly figured wood will hold up. I'm afraid of it warping over time. This is the wood I got, ribbon Maple with some burl.
Image
Maple burl has been used on knife scales for ages, however I do not know if those are glued down to prevent warping or if the nature of burl counteracts the warping.
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Re: Removable Onlay Scales

#38

Post by Josh Crutchley »

JRinFL wrote:
Tue Jun 28, 2022 11:48 am

Maple burl has been used on knife scales for ages, however I do not know if those are glued down to prevent warping or if the nature of burl counteracts the warping.
I wouldn't worry if it was glued down. I'm concerned with warping from humidity, if that's even a problem after stabilizing. I've never stabilized wood before and never made wood scales to actually last. I made a set of oak scales on a PD1 mule as practice but didn't keep them.
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Re: Removable Onlay Scales

#39

Post by JRinFL »

I would think properly stabilized Maple burl would have no problems with humidity, etc.

Anyway, looking forward to what you make from the block above.
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Re: Removable Onlay Scales

#40

Post by Bolster »

That's some stunning maple!

IF your wood is still green, and because of that it moves or warps a bit in a year or two, it's always possible to remove the scales, sand the tang-contact side flat, and reattach. If it's severe, and the sanding/flattening takes a significant amount off, you can always add a thin G10 spacer to add dimension back.

I've not had warpage problems. I make sure the wood is dry with a moisture tester, and when finished to shape, it gets "bathed" in linseed oil, to seal it up proper.
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