HACKER Q&A
📣 aconz2

Can you make me a 50 meter scroll saw blade?


I'm turning to HN as a semi-last resort in my attempts at finding a manufacturer for a 50 meter long scroll saw blade (0.2mm thickness, 0.6mm width, approx 12 TPI, hard high carbon steel like 1065).

I'm hoping for both a) direct responses if you can make this (ideally with price tag!) and b) meta responses on where else to look, how else to look, how anybody finds others willing to take on projects that are slightly "out there", etc.

These blades exist on today's market as size "2/0 scroll saw blade" (google-able) and are about 5 inches. I've been looking for the past several months to create the same thing, but with teeth for a continuous 50 meter length. I would use these blades in a manner like a bandsaw, but without being in a closed loop. I previously worked on a "CNC scrollsaw" (google-able) and this new blade would power that machine's successor.

I've brainstormed and refined many ideas on in-house (DIY) manufacturing, outsourcing, and some combination.

So far, I've tried contacting:

* The 3 well known manufacturers of these blades: 1 got a prototype to me before saying no (the prototype had teeth, then gap with no teeth, then teeth, etc). 1 said no. 1 had no response

* A reseller of these blades who then asked one of the same manufacturers, but got the same response

* Umpteen companies on Alibaba, few leads, no winners

* Multiple manufacturers that do punch & die work, varying levels of no or no response

* A manufacturer that does reel to reel etching, still in discussion, but seems unlikely

* Multiple manufacturers that do custom CBN form wheels for grinders. skeptical responses and I would need a good spindle to run them

* A manufacturer that makes a fairly similar product to what I'm looking for, just in slightly larger size, but they said no

* A discord of machinists, who had some helpful tips, but no leads

* Steel suppliers for the raw material (flat wire/ribbon is likely the best), but obtaining small (ie < 1 ton) amounts has not been fruitful

I think the DIY approach is not impossible for someone with more skills and better space+equipment than me. A 50m length has about 25,000 teeth, so whatever process it is (milling, punching, grinding, ), it needs to be repeatable. The best idea I've had is a purpose built CNC grinder with computer vision for wear compensation and alignment, but a major hurdle with grinding is the corner radius would ideally be <150 um (300 um tooth height, so that leaves half the height as flat). I could ramble about more specifics, but maybe that gives a bit of flavor and intrigue if someone is interested in working on this.

Thanks!


  👤 Someone Accepted Answer ✓
It’s not what you ask for, but one thing you can buy is diamond wire used for cutting large blocks of stone. For example https://www.dexpan.com/collections/diamond-wire has 100ft wires, and they sell a hydraulic crimper. To me that suggests it is possible to connect two of these to get that 50m length.

That is a lot thicker than what you ask for (about 1 cm², compared to your 0.0012 cm², so about 800 times as thick) and more flexible.

Unless you’re cutting a very weak material, I would think that thickness is as good as unavoidable. If you pull at one end of a 50m saw, and, say, 25m of it grips the thing being cut, would the fairly small pin through the end of the blade that you pull on be strong enough to not break? Or are you going to move the blade very slowly through the thing being cut? Alternatively, maybe you want fewer teeth, to decrease the maximum force needed to pull this blade through whatever you’re trying to cut?


👤 entrepy123
Can an equivalent length of available-size blades be welded together (maybe trimming the ends first, if they lack teeth)? A person welds a band saw blade together at 2:50 in https://www.youtube.com/watch?v=yJV0yV5lHXE and it does not look so impossible.

At that length, you would need a jig or straight edge to keep it linear, not to mention a large space. But it does not seem impossible.

Maybe ask a number of machine shops or even a general contractors to assemble it for you, suggesting this method, especially if you bring the supplies? I would try a small prototype first.

The punch and die shops probably focus on their specific type of product (punches, dies), so I would look broader.

Or maybe put the project on the Handy app? (A hungry person may be happy to do it for you, not thinking more than twice about how unusual it sounds.)

Asides: I wonder what the required blade tension would be and how machine will maintain tension on the blade. Also I wonder why the blade needs to be so long.


👤 floxy
What about welding the small blades together end to end? Bandsaw blades are welded, so I wouldn't think there would be a big concern about hurting the heat treat on the blades. Is this a one-off/prototype-type project? GTAW/TIG welders are getting to be really inexpensive these days. I could see it just being a single pulse at the joint between blades.

👤 zzz345345
Band-saw blade manufacturers should be able to do it?

https://www.youtube.com/watch?v=zlqEn4Wmfpg&t=1m05s


👤 moistly
Have you considered using a water jet?