How Can I Create This Bevel?

[Scott Memmer]

Dear Moderator: I wasn't exactly sure where to put this thread. If it fits another subforum better, please move it there for me. I apologize for any inconvenience this may have caused you.

How, All. So I make high-end guitar picks. I am posting a few pics from one of my competitors who does a superb job on fit and finish. I realize that my question is perhaps a bit off-topic since I'm machining plastics and not wood, but the same machining properties should apply.

This vendor uses Arylic, which I do not use, but not the excellent beveled edge around the entire perimeter of the pick. This is not done through injection-molding (too expensive), so this has to be a machining process. What kind of machine would do this for me? I appreciate your insights and suggestions.

https://i.imgur.com/rW1xTJV.jpg

https://i.imgur.com/cgUubxB.jpg

[Jamie Buxton]

Chamfer bit with a guide bearing at the tip. Your pic is not clear about what angle of bevel you need. Here's a set of several chamfer bits with several angles. https://www.eagleamerica.com/product/m7685/chamfer-router-bits

[Jim Becker]

These may very well be cut with CNC and also appear to be laser engraved. But after engraving and a simple cutout with a laser, the edges could also be beveled by hand. It's hard to see the actual edges in those small photos. It would be interesting to know if the maker is doing their own lamination or starting out with multi-layer product such as Dibond.

[Scott Memmer]

Chamfer bit with a guide bearing at the tip. Your pic is not clear about what angle of bevel you need. Here's a set of several chamfer bits with several angles. https://www.eagleamerica.com/product/m7685/chamfer-router-bits

Jamie, thanks so much. Forgive my ignorance, but could those bits be used on a standard router, or are they for CNC? It's cool either way, as I have a Shapeoko CNC coming on line in the next month or two, which is the way I want to do it long-term.

Thanks Again,
Scott

[Mark e Kessler]

Whats the back side look like, is it perfectly smooth?

[Scott Memmer]

These may very well be cut with CNC and also appear to be laser engraved. But after engraving and a simple cutout with a laser, the edges could also be beveled by hand. It's hard to see the actual edges in those small photos. It would be interesting to know if the maker is doing their own lamination or starting out with multi-layer product such as Dibond.

Jim, hi, thanks for chiming in. I always enjoy your posts.

To elaborate a bit, I'm doing them by hand now and it's too slow and imprecise. We have huge opportunities in our industry now (we're six years in business) and we need to speed up our lead times.

The various hand beveling tools I've tried up on plastic edge (unless there's one I don't know about, in which case I'd interested in learning more) where they would probably glide over a wood bevel.

Looks like I need to get motivated to finish assembling my Shapeoko.

Thanks, Jim,
Scott

[Scott Memmer]

Whats the back side look like, is it perfectly smooth?

Mark, hi. The back side on all guitar picks, including these pictured and mine, is identical to the front side.

Thanks Very Much,
Scott

[Mark e Kessler]

The other thing i realized is they could be heating the acrylic pressing them into a mold/die, i am in the plastics industry and have seen it done on small scale items.

How many of these things are sold per year?

If they were injected molded you are right could be expensive, more than likely would be a hotrunner (more expensive than a cold runner) probably min 15-20k (but could be less - depends on size, number of parts per cycle) plus the mold. But they do make cheap ones for limited runs out of aluminum instead of SS, i have seen 3d printed molds as well.

if they were injected molded, they would need some hand finishing. They would have a small shallow divet from the ejection pin and gate mark (where the plastic is injected)

[Jim Becker]

Mark, hi. The back side on all guitar picks, including these pictured and mine, is identical to the front side.

Thanks Very Much,
Scott
This is where the challenge will come as that's a very flat bevel. My widest vee-bit is 120º and I'm not sure that would be enough for this application. It would also be a two sided operation which for a sheet of those puppies will be interesting. Some kind of vacuum hold-down might be the best bet because other common methods for keeping thin material down on the machine may interfere with being able to flip and cut the opposite side. (I'm just thinking here and quickly...)

[Scott Memmer]

Mark, hi again. Appreciate your expertise. You could be right on the acrylic pressing. However, the Acrylic boys make literally hundreds of different models and shapes; I would imagine that making all those molds would be ridiculously time-consuming. Does that make sense? In light of that, I'm putting my money on machining, probably CNC.

Another reason I say this, Mike, is that another big Acrylic house is also making picks from PEEK (as we do), and I don't think PEEK could use that mold/die process. Am I understanding this correctly. Here is the (very similar) bevel design from this other vendor: Same bevel design:
https://i.imgur.com/B4G6wPj.jpg

[Kurt Wyberanec]

Hi, I feel like I remember hearing Vinny say the v picks are hand polished but maybe that's different now or maybe wasn't accurate... that might have been a dozen years ago at namm

Then what does that mean....I could see some sort of molding process and perhaps some sort of automated buffer of sorts to remove the burr... don't know though plastics is not my thing

Shoot me a pm with your info, always curious to connect with another music industry fellow 😀

[Scott Memmer]

Hi, I feel like I remember hearing Vinny say the v picks are hand polished but maybe that's different now or maybe wasn't accurate... that might have been a dozen years ago at namm

Then what does that mean....I could see some sort of molding process and perhaps some sort of automated buffer of sorts to remove the burr... don't know though plastics is not my thing

Shoot me a pm with your info, always curious to connect with another music industry fellow 

Oh, hi, Kurt, I will indeed.

Vinny seems like a really cool guy, from my own brief interactions with him as well as what I've heard from others. He also does some beautiful work. I'm guessing (but could be wrong) that the "hand polishing" refers to the final buff and polish with a bench grinder (I often use a Dremel, for more accuracy and close up work).

I'll be in touch.

Thanks Much,
Scott

[Michael Schuch]

To me it seems like CNC cutting the picks would mean cutting half way though the material with a chamfer bit then turning the material over and doing the same on the back side? Seems like you would also need to leave some attachment points to the sheet to keep the picks from flying off the CNC table?

I do not see how those chamfers could be cut by a hand router with a guide bearing and being able to cut chamfers on both sides? It seems like there would not be enough edge for the bearing to ride on?

Interesting problem... I look forwards to see what you come up with.

[Jamie Buxton]

Jamie, thanks so much. Forgive my ignorance, but could those bits be used on a standard router, or are they for CNC? It's cool either way, as I have a Shapeoko CNC coming on line in the next month or two, which is the way I want to do it long-term.

Thanks Again,
Scott

Now that I understand the pic is of a guitar pick, those bits I suggested aren't going to work. They're much too big.

[Mark e Kessler]

Does this solve the mystery?

https://en.wikipedia.org/wiki/V-Picks_Guitar_Picks

“V-PICKS are made in Nashville, TN (https://en.m.wikipedia.org/wiki/Nashville,_TN). The company produces over 100,000 hand made picks per year, and supplies guitar picks to 101 countries in the world. Some models are originally cut out by laser from sheets of cast acrylic. Others start as raw materials poured into molds. Both styles are then hand ground on a bench grinder and hand trimmed with a razor knife. This creates the bevel, feel, and sound of the pick. Next, they are tempered (https://en.m.wikipedia.org/wiki/Tempered_glass) for strength with intense high heat, much like the process done on steel and glass. Then they are buffed with high heat flame for a smooth and slick playing edge and bevel.[4] (https://en.m.wikipedia.org/wiki/V-Picks_Guitar_Picks#cite_note-4)”

[Scott Memmer]

To me it seems like CNC cutting the picks would mean cutting half way though the material with a chamfer bit then turning the material over and doing the same on the back side? Seems like you would also need to leave some attachment points to the sheet to keep the picks from flying off the CNC table?

I do not see how those chamfers could be cut by a hand router with a guide bearing and being able to cut chamfers on both sides? It seems like there would not be enough edge for the bearing to ride on?

Interesting problem... I look forwards to see what you come up with.

Michael, thanks. What we will probably have to do is cut these individually, each pick, one by one. The reason for this is some of these industrial plastics we use are so expensive that it's much cheaper to buy it by the rod, then machine the shape of the pick from above and part it off. So I suspect I'm looking at creating a jig / holder thingie; and yes, I think you're right, it would need to be flipped 180 degrees to do the other side.

Thanks!
Scott

[Bradley Gray]

Ineresting. I have woodworking business and am also a mandolin player. I am having a hard time understanding this market. I have always used extra heavy picks and have made some picks. My experience has been that once the picks are thick enough to lose flex the do not work. The picks I have made I beveled free hand on fine abrasive.

[Prashun Patel]

My method would be to make a jig to hold them against a sanding belt or disc or slow speed grinder. But that’s only if I had to make small runs.

[Scott Memmer]

To me it seems like CNC cutting the picks would mean cutting half way though the material with a chamfer bit then turning the material over and doing the same on the back side? Seems like you would also need to leave some attachment points to the sheet to keep the picks from flying off the CNC table?

I do not see how those chamfers could be cut by a hand router with a guide bearing and being able to cut chamfers on both sides? It seems like there would not be enough edge for the bearing to ride on?

Interesting problem... I look forwards to see what you come up with.

Michael, what you're saying makes perfect sense. And I would think ultimately one could create a large jig where the whole sheet could flip over, perfectly aligned. Not impossible to do, over time. And I agree about leaving a small tab as well.

Stay tuned! Thanks, Michael.

All the Best,
Scott

[Scott Memmer]

Ineresting. I have woodworking business and am also a mandolin player. I am having a hard time understanding this market. I have always used extra heavy picks and have made some picks. My experience has been that once the picks are thick enough to lose flex the do not work. The picks I have made I beveled free hand on fine abrasive.

Brad, I don't like making money off my friends. If you wanna try one of our picks, I sell clean blems off at half price. What are you playing? Golden Gates? Dawgs? Dunlop?

PM me if interested. No big deal if you aren't. I'm not here to promote my business.

sm

[Maurice Mcmurry]

I am having trouble understanding this thread as well.

[Scott Memmer]

I am having trouble understanding this thread as well.

EDITED: See below.

[Maurice Mcmurry]

I guess I should have quoted "understanding this market"

[Scott Memmer]

I guess I should have quoted "understanding this market"

Maurice, forgive my misunderstanding. I want up just now and edited/deleted my response.

Yeah, it's a weird market. Actually, what's happened in the guitar industry in the last 15 years is that the economy has been very robust, so there are hundreds of thousands of guitar players who own guitars in the $5000-10,000. This, combined simultaneously with the rise of ecommerce and internet marketing, has caused the high-end accessories market to explode. This includes straps, strings, tuners, capos, pedals, cases, picks and dozens of other toys.

It's really crazy what people will buy.

I apologize for any misunderstanding I may have caused. Please let me know if you have any questions, and feel free to PM me if you feel like it.

Thanks, Maurice,
Scott

[Carl Beckett]

Another reason I say this, Mike, is that another big Acrylic house is also making picks from PEEK (as we do), and I don't think PEEK could use that mold/die process. Am I understanding this correctly. Here is the (very similar) bevel design from this other vendor: Same bevel design:


PEEK can be injection molded but high temperatures ($$ molds). Machining PEEK is tricky to get good finishes and it leaves burrs so a good deburring method is needed. The medical PEEK implants often CO2 blast for deburring.

I wonder... (random brainstorm) if a fixture that set into something like a knife sharpener would allow you to pass the edges through it and get the finish/angle you wanted. Worksharp has a small knife sharpener that simply holds the piece at an angle against a belt. But that is still one at a time...

Getting one side on a CNC could be done with a bit ground to the angle you want. Location indexing when flipped to the back side would be critical to pick up the edges accurately (several location pins needed), but that might be worth a try then the angled cut on the backside would also become the 'cutoff' where the part releases from the sheet. Could be tested with a standard angled bit.

[Rob Luter]

I think the challenge here will be workholding. It makes sense that the other picks on the market would be hand ground following laser cutting. I'm guessing a two stage process (grind then buff) perhaps followed by a bulk tumble polishing process. With decent workholding/fixturing you could do the hand work fairly quickly and consistently.

While very nice, Personally I've never understood the type of pick you manufacture. I suppose it would make sense if you were a single line sharpshooter type player. I bought a gross of these (below) 30 years ago and they've served me well. I expect these are die cut from sheet, tumbled, and hot stamped. That's how I'd make them anyway. Perhaps a bit pedestrian compared to the boutique nature of your product, but serviceable and economical to manufacture.

https://live.staticflickr.com/2600/4105860507_2372607f01_o.jpg

[Mark e Kessler]

A PEEK doesn’t necessary cost more because of the mold, but to design the mold and HotRunner properly a moldflow analysis should be done also because of the thin part very high pressures are needed to inject it which can add cost to the HotRunner a little because to cost of high pressure tips are needed (but really that doesn’t add much) additionally depending on how many drops in the mold (parts) you could need a fairly large tonnage machine.

Also a properly setup process can produce flash free parts that require no post processing, it’s done all the time - Epipens, Novopen comes to mind where a part with even the tiniest bit of flash can mean death for its user



PEEK can be injection molded but high temperatures ($$ molds). Machining PEEK is tricky to get good finishes and it leaves burrs so a good deburring method is needed. The medical PEEK implants often CO2 blast for deburring.

I wonder... (random brainstorm) if a fixture that set into something like a knife sharpener would allow you to pass the edges through it and get the finish/angle you wanted. Worksharp has a small knife sharpener that simply holds the piece at an angle against a belt. But that is still one at a time...

Getting one side on a CNC could be done with a bit ground to the angle you want. Location indexing when flipped to the back side would be critical to pick up the edges accurately (several location pins needed), but that might be worth a try then the angled cut on the backside would also become the 'cutoff' where the part releases from the sheet. Could be tested with a standard angled bit.

[Mark e Kessler]

Did anyone see my post on how the OP’s picks that he posted are made? Some are laser cut, some are cast and all are hand finished at least thats what the company that makes them claims it’s not rocket science…. Although they also claim that they sell 100k of them a year, can you imagine hand finishing all of them without some sort of process that involves fixtures/jigs of some sort?

[Jim Becker]

In case you haven't seen this thread, Dale occasionally does a short run of wood and brass picks.

https://sawmillcreek.org/showthread.php?296024-Wood-amp-Brass-Guitar-Picks&highlight=Guitar

[George Yetka]

Jamie, thanks so much. Forgive my ignorance, but could those bits be used on a standard router, or are they for CNC? It's cool either way, as I have a Shapeoko CNC coming on line in the next month or two, which is the way I want to do it long-term.

Thanks Again,
Scott

Generally speaking all CNC bits can be used on a router. But all router bits should not be used on a cnc. Basically if it comes down to safe plunging.