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Thanks for the thoughts! > Can an equivalent length of available-size blades be welded together (maybe trimming the ends first, if they lack teeth)? I don't t

by aconz2 4y ago

Thanks for the thoughts! > Can an equivalent length of available-size blades be welded together (maybe trimming the ends first, if they lack teeth)? I don't think so, these blades are very narrow and thin -- 0.2mm x 0.3mm cross section at the spine -- and I'm pretty sure a weld would not hold and if it did, you'd still have to grind it down flush. And I'd guess the joint would also fatigue which is an issue since the blade needs to get wound/unwound repeatedly during cutting. Also, I think the heat of the weld would probably effect the already hardened steel. > I wonder what the required blade tension would be The tension on existing scroll saws is 10 - 20 lbs for blades of this size. > how machine will maintain tension on the blade The blade gets unwound off a spool which maintains the tension through a torque motor. > I wonder why the blade needs to be so long. Minimum usable length is ~10m, but I figure if you can make 10, you can make 50. The longer the blade, the longer you can cut before you have to rewind. And the longer the blade lasts before the teeth are dull and needing to be replaced

floxy 4y ago
>you'd still have to grind it down flush Not if it was a fillerless weld. >I'm pretty sure a weld would not hold ...thoughts on why a full-penetration weld not be as strong as the parent material? >I'd guess the joint would also fatigue This is based off of previous experiments? Conversations with a metallurgist? Other? >The longer the blade, the longer you can cut before you have to rewind. Any particular reason the reciprocating action of a normal scroll saw doesn't work for your application?
- aconz2 4y ago
  Idk, not a welding expert, maybe you're trying to tell me it is a-okay? What about the heat affected zone? What welding process are you thinking? > Any particular reason the reciprocating action of a normal scroll saw doesn't work for your application? It works... just not well. Reciprocating is only 50% time efficient (only cutting on the down stroke!), wears out the blades by rubbing on the up stroke, and the very small length wears out quickly so they have to get changed often
  - moistly 4y ago
    Japanese pull saws have the kerf you seek and cut on both strokes. What they lack is the narrow depth that would allow for tight radius turns. Regardless, the tooth pattern for a scroll saw that cuts in both directions exists.
  - floxy 4y ago
    >What welding process are you thinking? A pulse of GTAW. You can set your welder to just give a short duration weld pulse, and you'd have it set so that a single pulse would complete the weld on the saw blades without using filler material. Search on youtube for people welding razor blades together to get an idea.

by aconz2 4y ago

floxy 4y ago

>you'd still have to grind it down flush Not if it was a fillerless weld. >I'm pretty sure a weld would not hold ...thoughts on why a full-penetration weld not be as strong as the parent material? >I'd guess the joint would also fatigue This is based off of previous experiments? Conversations with a metallurgist? Other? >The longer the blade, the longer you can cut before you have to rewind. Any particular reason the reciprocating action of a normal scroll saw doesn't work for your application?

aconz2 4y ago
Idk, not a welding expert, maybe you're trying to tell me it is a-okay? What about the heat affected zone? What welding process are you thinking? > Any particular reason the reciprocating action of a normal scroll saw doesn't work for your application? It works... just not well. Reciprocating is only 50% time efficient (only cutting on the down stroke!), wears out the blades by rubbing on the up stroke, and the very small length wears out quickly so they have to get changed often
- moistly 4y ago
  Japanese pull saws have the kerf you seek and cut on both strokes. What they lack is the narrow depth that would allow for tight radius turns. Regardless, the tooth pattern for a scroll saw that cuts in both directions exists.
- floxy 4y ago
  >What welding process are you thinking? A pulse of GTAW. You can set your welder to just give a short duration weld pulse, and you'd have it set so that a single pulse would complete the weld on the saw blades without using filler material. Search on youtube for people welding razor blades together to get an idea.