looking for input on checkering mother of pearl

Awesome info Stacy! Thanks a heap! I ordered the pearl, including a B grade set to practice on.

You guys are awesome!

Bob
 
Got another question...Stacy. Okay, actually anybody that definitively knows; Can I use the carbide PCB drills at high speed on MOP for my gold wire holes? I have a Servo Micro Drill so I can run up to around 19k rpm.

Bob
 
Bob Ohlemann said:
Got another question...Stacy. Okay, actually anybody that definitively knows; Can I use the carbide PCB drills at high speed on MOP for my gold wire holes? I have a Servo Micro Drill so I can run up to around 19k rpm.

Bob
Click to expand...

I've never had any problem cutting pearl with any type of quality drill. Although alot of those import PCB drills have square tips, and may want to wander at the start of a cut, they're also weaker than shit, and break super easily with any lateral pressure. When you get real tiny carbide is nice for rigidity, but you may want something with a pointed tip, and a lot of those pcb drills have really aggressive fluting that mitigates the rigidity, for drilling circuit boards, maybe they need more chip clearance. Notched tip straight flute carbide drills are very rigid and start holes at a fine punch mark (pin prick with a carbide scribe in this case probably) pretty well, and you can get them in wire sizes. They have shit chip clearance, but pearl turns to powder anyway, and the high speed tends to "blow" the cut out. Now on the other hand, if you're talking about premium domestic angled tip PCB drills, they'll probably be great.

Just keep in mind that pearl is chippy, if you break one of those PCB drills in a cut, expect to have to scrap that piece of pearl, and give yourself some clean up room regardless, in case of minor edge chipping around a hole. I'd layout and drill all your holes first, make sure you can clean up past any issues, then layout your checkering.

Another thing to mention, any moisture or oil on a drill bit, when you're drilling pearl, and the flutes will load up, causing the hole to expand and the bit to dull really fast. Keep the tips clean, use alcohol if necessary and let it evaporate between cuts.

I use little high speed Grobet Optical Drill presses, that are similar to the servo micros, same 0.0002" TIR spindles, although mine only go up to 12 or 14k. They can't be beat for this kind of stuff. One of mine, the on spindle power switch is wired to the quill handle, as soon as you pull the handle down, the spindle starts turning. For this kind of work, this, or a foot switch, are INSANELY useful.


Another thing I'll recommend, I usually use a new drill bit for each set of scale holes I drill. With pearl, stag or ivory, I'll even use a new one for each scale (usually 3 holes, at 1/16"), pearl will dull a drill bit fast. You're going to be drilling a lot of holes. If you use solid carbide straight flute drills, you probably will get through a lot more of them, but you may want to do some experimenting to see how long they last. That's a big advantage of HSS here, you can buy a pack of 20 or more probably for the same cost of a couple of carbide ones.
 
Javan, you make a good point without actually saying it. If I ruin an expensive set of pearl scales because I tried to go cheap on the drills, I'm going to be pissed at myself. I use high quality USA made straight flute carbide drills for all my detent holes in my hardened blades. I've had very few failures but, those are #54 or#53. The #65 straight flute carbides are $15+ and tiny! I know it doesn't really matter in the scheme of things but I'll probably buy five or more and that adds up. I will also order a 12-pack of cobalt 135 degree twist drills which is $25. I'm going to do some testing on the extra set of scales I bought anyway.

That auto on feature on your Grobet sounds very cool. I might have to set up a foot switch for this job. Pretty sure I have a momentary switch hidden away in the shop somewhere.

Thanks

Bob
 
Bob Ohlemann said:
Javan, you make a good point without actually saying it. If I ruin an expensive set of pearl scales because I tried to go cheap on the drills, I'm going to be pissed at myself. I use high quality USA made straight flute carbide drills for all my detent holes in my hardened blades. I've had very few failures but, those are #54 or#53. The #65 straight flute carbides are $15+ and tiny! I know it doesn't really matter in the scheme of things but I'll probably buy five or more and that adds up. I will also order a 12-pack of cobalt 135 degree twist drills which is $25. I'm going to do some testing on the extra set of scales I bought anyway.

That auto on feature on your Grobet sounds very cool. I might have to set up a foot switch for this job. Pretty sure I have a momentary switch hidden away in the shop somewhere.

Thanks

Bob
Click to expand...


I will add, since you've got a nice drill; you really should be fine with high quality twist drills for pearl, running at high RPM (treat it like carbide, at this size, you can likely run at max RPM without a problem, but 8-10k sounds like a good spot to me) Unlike steel, you don't need any pressure to drill it, and thus, flex is less of a concern. Good USA, HSS, don't worry about whether it's cobalt or not, just make sure it's domestic of good quality, buy a couple packs of 20 (for about the cost of 1 straight flute carbide), and mic each one before you use it. Run it at high RPM, setup everything securely, and stop if you feel any resistance, and clean the flutes out. Also, in wire sizes, make sure and check them for "straightness", it's not totally uncommon for some of them to be warped at this size.

The rigidity of the carbide straight flute drills would probably be a huge boon for someone less experienced with small holes, on a less premium drill, and especially on heavily contoured stock where your drilling on top of a curve. If you're leaving the pearl flat, I wouldn't stress it.

If you're doing heavy contouring, I'd be inclined to drill them from the back flat out, like you would already glued up scales on liners of stag, ivory, or something already curved, using a template.

I'd make it out of G-10, lay out all of your holes and drill them, temp glue it with CA to the back side of the pearl, and then use it as a drill guide.
 
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I use Busch Tungsten-Vanadium twist drill bits. They have a 3/32" shank and come in sizes from .5mm up to 3mm. A six-pack of 0.9mm bits runs me $17.
 
Gesswein, Rio Grande, Stuller (wholesale only to professional jewelers and metal workers, but most any friendly jeweler will place an order for you). Better quality, lower prices, fast shipping. I get a lot of my finishing supplies, like 3M polishing papers, files, polishes, sandpapers, etc. from Stuller.
 
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