Blade Ping

[EIEIO]

I'm new to scroll sawing and I'm impressed with the quality of the output I've seen so far. There was a post on this site about "Vertical Cuts" and a recommendation to make sure the blade tension is right - that it "pings". I have an electronic guitar tuner that is used to set tension in guitar strings. Does anyone know about what note it should hear when the scroll saw blade is plucked? I don't expect an exact value, just a ballpark.

[scotti158]

I really don't think a guitar tuner is the way to go. If your shooting for a "E" you could be an octave low from the "E" that you want. Normally I tighten the blade until it "pings", not a "thunk". On Steve Good's blog, he had tones you could download for a reference, but I think practice on a scrollsaw is the best teacher. Too loose and the blade will wander, too tight and it breaks.

[Keefie]

If you go to this site http://scrollsawworkshop.blogspot.co.uk/ and scroll down there is a "free software" box on the left side near the Jigsaw Puzzle Pattern Book. it plays the note for tensioning the blade.
hope that helps,

Keith.

[Toneman]

I think if you play a "c" chord on the quitar, you will be close.

Tony,aka,Toneman

[king310]

I'm tone deaf except for when I'm in the shower.My method is to shot my bb gun and hit the weather vien rooster in the backside and if it goes "ping" I know my saw is set right.
They say that is a high C but I like juicy juice.

Welcome EIEIO

[IBMer]

Idea Copyright by IBMer,  January 18 2013
"What the Scroll Saw world really needs is a dedicated Machinist's Dial Indicator to measure blade travel.  Something to attach to your saw, or maybe build into new saws.   The dial would measure the precise amount of blade defection based on the amount of pressure applied to the blade by a weight.    

For example, the dial could swing down and clamp against the blade.   Then you would allow a weight to rest against the opposite side of the blade.  Measure the amount of defection as you tighten or loosen the tension screw, and adjust to zero out the dial."    

If anyone wants to use my idea, just be sure I get the proper royalties, or at least a free finished product ;-)


Hey, this person had the same idea, but for a Bandsaw..      http://woodgears.ca/bandsaw/tension.html

[crupiea]

No need to really over think this.

If it cuts under control, its basically the right tension.

If the blades are breaking right away the tension is off.

You will be able to tell right away if its too little tension because it will start drifting on you and be tough to control.

[Old Crow]

High C

[UHMNL]

Old crow is righjt. High C.
Or the blades should not move sideways more than 1/8" and that almost to much.
Also have good speed and low feed rate. Let the bade do the cutting, they say.
FD Mike

[geneVG]

I tried with my guitar tuner andit just don't work the same.  The best way is to get the tension on the blade and you will know when it goes "ping".

gene

[EIEIO]

I ran Steve's "Ping" into a spectrum analyzer and get a fundamental of 1335 Hz and a second at 2670 Hz. 1330 is close to high E (40th white key on the piano is at 1318.5 Hz). My guitar tuner said it was an E but not which E (low, middle, high). But it was sensitive (changed a lot) when turning the tightening knob on the saw.

I understand that you tighten it until it seems to work OK, but more consistent tuning might lead to more consistent cutting. A cheaper version of the guitar tuner that sits on the saw and just indicates that one 1335 Hz tone might be a nice electronic or even mechanical project.   

[Mainewoods]

Don't get too worried about the actual note!     It's a good starting point, but you'll soon get a feel for it and you'll just know when it's right!  With some experience, you'll know as soon as your saw starts....it will just sound/feel off.   

[IBMer]

I found a Band Saw blade tension tester.  Basically clamps onto the blade, and you apply X amount of pressure while a defection dial checks how much it moves.   And for a Mere $350, you can own one too...    Yikes...

My problem is often with applying too much tension to my blades.   They seem to slip or pull out of the blade set screws, or break right off.  It's a bit of a balancing game between being too loose and poor cutting, or too tight and easy to break.   

Like others have said, over time you set it based more on experience than anything else.    What would be very cool is a blade clamp that sets the perfect tension every time.   It shouldn't be so hard to make.   If the blades are all exactly 5 inches long, you could have a guide stop to put the top and bottom of the blade up against, and the machine sets the tension based on this.   

J.

[dgman]

Don't get too worried about the actual note!     It's a good starting point, but you'll soon get a feel for it and you'll just know when it's right!  With some experience, you'll know as soon as your saw starts....it will just sound/feel off.   

EXACTLY!!! Once you get a feel for your saw, it will become second nature. The ping is just a starting point. As I tension my saw, I know when it's just right by the feel of the tension lever.

[Billy in Va]

Agree Dan!!!   I bet I can set the tension 99/100 without even looking and when its not right, I can "feel" in th the tension lever.  A good friend told me a while back    " You will develop eyes in your fingers after scrolling for a while"  He was right!