Need Your Help: Need to Design a Saw with SUPER LOW KERF LOSS

Hi, Everyone. I have a small business that makes expensive guitar picks. One of the materials we use is called DuPont Vespel (pictured below). It is one of the most expensive plastics in the world.

https://i.imgur.com/Jp6JZSF.jpg

The problem? Let's say I make a guitar pick that is 1.0 mm (.040") thick. I am losing as much in the kerf as I am in the pick. There are some slicing services I've found that can get this down to about .020" (.50 mm) kerf loss per pick, but at $10 a throw it's way too expensive. CNC is also too expensive.

There are small HSS saw blades that go down to .020" or thereabouts, but I need to find a way to mount a blade and do the cut. I thought something like this design, adapted to my specific needs, might work.

https://i.imgur.com/bJnwO9u.jpg

I'll figure it out cuz I HAVE to do, but would love to hear your ideas.

Thanks,
EG

Maybe a rock saw with a .020” diamond blade, they have vices like in the photo. Highland Park and Covington are two leading brands.

Machinists regularly use slitting saws; they can be had in thicknesses as small as six thousandths...

https://www.mcmaster.com/slitting-saws

Now I understand your process - your raw material comes in rods, not in sheets. Ignore my previous comment about using a scroll saw - that was written when I thought your material came in sheets.

I have no idea how hard or brittle the plastic is, but I wonder if a deli meat slicer might work. It is just an idea I had.
If the plastic was not too hard and had a little bit of flex in thin slices the meat blade might be able to take a 1 mm slice off it. Usually thickness setting 2 is 1 mm. If you had to put a fine saw blade on the slicer instead of the knife blade meat slicers usually have an automated powered feed on the table that you might have to turn off and push the table past the blade manually so you don't feed the plastic into the blade too fast. The advance mechanism for moving the meat for the thickness of the slice is not normally affected by this.

What method do you use currently for cutting?
Possibly you will have problems with melting if you use a friction method to cut it. Even a saw might generate enough heat if run too fast.
Or just charge more for the finished product. Plenty of items that are $pendy because manufacture/waste is the price driver

Their's no way around cutting the material and not ending up with some waste. You just minimize the waste as much as possible. If I was selling the picks for good money, I would buy the material in sheet form. If you already have the material in bar stock, you could try a very thin slitting saw blade like mklotz suggested. In my experience working with engineered plastics, the very thin slices may bow or curl due to heat from cutting and internal stresses in the material.

вот что я могу посоветовать, есть у меня такие круги, наружный диаметр 258 мм. внутрений диаметр 100 мм. толщина режущей кромки 02 мм, вот его краткое описание " Алмазные отрезные круги с внутренней режущей кромкой (сокращенно АКВР). Они применяются при резке сапфира, граната, кварца, керамики, стекла, арсенида галлия, кремния и других полупроводниковых материалов. Круги предназначены для работы на станках резки Алмаз-6, Алмаз-12, TS-23 и других аналогичных станках.
Круги АКВР представляют собой тонкие кольцевые диски из нержавеющей стальной ленты толщиной от 0,1 до 0,2 мм. По периметру внутреннего рабочего отверстия нанесен алмазный (алмазоносный) слой."
куда этот круг крепить и привод придется решать, но мне кажется это было бы хорошим решением.Attachment 30285Attachment 30286

have you looked into water-jet?
might be able to do the profile then slice it off to thickness
Ray

Just to put a number to exactly how expensive Vespel is, and why kerf size is so important here:

https://s3-us-west-1.amazonaws.com/h...espel_cost.jpg

Folks, sorry, haven't been getting notifications.

FYI, sheet stock is FAR more expensive, not even close. A 10" x 10" x .25" is $1100(!) -- yikes.

Meat slicer -- great idea!

Will respond more later. Thank you!

What makes this material so desirable as a guitar pick? If it is so much better than other materials for some reason then the price becomes irrelevant. People will pay for a premium product

Actually, it makes the MOST INCREDIBLE pick in the world. We're in business four years, and there is such demand for what we do that our typical lead times run three times run three to four weeks -- and people pay IN FULL ahead of time.

A long story on the materials, but in acoustic instruments the holy grail for centuries has been tortoise shell. However, tortoise was outlawed in the seventies along with ivory, and for the last forty years the guitar world has been looking for a suitable replacement. This stuff comes very close, but we use six different materials that do different things with tone and again, demand for our stuff outstrips our ability to make it fast enough. Crazy, I know.

Not in sales pitch mode here, but this is our website, just to get a sense of what we do: https://www.charmedlifepicks.com/online-store

Thanks Very Much,

Scott

Fascinating. Can you get Vespel in very thin sheets and then just pick punch it?

Jon: No, and no. The thinnest they make it is 1/4" (I kid you not), and because of the different way the sheets are extruded it is much more expensive -- as in, $1100 for a sheet 10" x 10". And you get very little discount off that price unless your name is Boeing, Lockheed or Northrup. Occasionally you can score a random piece online, but still ridiculous.

Crazy.

The good news? There are more than a hundred (100) other engineering thermoplastics that have never been made into guitar picks by anyone on the planet. We're just starting to test one, and have two more on the docket. And they're ALL far less expensive than Vespel -- like half, or less.

scott

I found thinner stuff in sheet form (1/32" - .031") The price was still about what you stated though 10" x 10" $1009.09

I am wondering if a press mold cold not be made heated to somewhere in the 550 to 600° f range. then a small pellet of the material be placed in the shaped mold cavity the punch of the same shape be pressed down on the heated pellet to a high enough pressure to for the desired product.
It seems that vespel can be injection molded with very little chemical alteration

I had bad results trying to cut hardwood with about the same size cross section as a guitar pick, cutting along the grain using a 3-1/2” diameter 0.020” slitting saw.

Quote:

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Originally Posted by high-side

I found thinner stuff in sheet form (1/32" - .031") The price was still about what you stated though 10" x 10" $1009.09

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Yeah, ridiculous, huh?

What I found out in research is that Vespel was the first in a series of plastics called polyimides. Because they were first, all the DOD and milspec aircraft folks spec'd specifically Vespel into their blueprints. Since that time everyone and their brother has knocked off Vespel, but because it was first the engineers always insist on using it. Being DOD, they have more money than God, they have no reason to change, even though many of the competitors are less than half the price.

DuPont has only three master distributors in the U.S. It's all locked up. All pricing must be approved by DuPont. A few years back one of the largest plastics distributors in the country -- a huge master distributor for them -- was caught offering unauthorized discounts. They cut them off. That's how they play ball.

EG

That's correct. When I first started out, I had a CNC house trying to cut this stuff. They blew up three jewelry blades within a half hour. I'd settle for a .040" (1 mm) loss for now, but keep looking. However, the coolest thing is the 3D printing thing is coming on like gangbusters. Within ten years (probably much sooner), they will be 3D printing this stuff. All the sudden, no material loss. In the next couple decades 3D printing will revolutionize the metals and plastics industries. It's already happening.

thanks,
EG

Quote:

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Originally Posted by Frank S

I am wondering if a press mold cold not be made heated to somewhere in the 550 to 600° f range. then a small pellet of the material be placed in the shaped mold cavity the punch of the same shape be pressed down on the heated pellet to a high enough pressure to for the desired product.
It seems that vespel can be injection molded with very little chemical alteration

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Frank, interesting thought. But good luck getting DuPont to sell you that pellet. The better bet is to wait for 3D printing, which will be here sooner than anyone thinks.

EG

E G you might think about Torlon® or Flourosint® as alternatives probably not any more readily available

Quote:

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Originally Posted by Frank S

E G you might think about Torlon® or Flourosint® as alternatives probably not any more readily available

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I'm actually aware of those two materials. The cool thing is there are literally more than a hundred industrial plastics that have never been made into guitar picks by ANYONE.

thanks!