Metal cutting - oxyfuel cutting, plasma cutting, machining, grinding, and other preparatory work.
Measuring blade tension on band saw
Post Reply
User avatar
  • Posts:
  • Joined:
    Sat Aug 01, 2015 8:38 am
  • Location:
    The Land Down Under

Hey all.

The refurbishment of my ancient McPherson and Sons 14" band saw is going even better than expected and I now honestly don't know how I got by without it - I use it constantly for cutting aluminium.

I have fitted new urethane tyres and have set up the tracking nicely. I have also made up brushes that keep the aluminium chips off the tyres. I have been using the old, used blades that came with the machine, but I have new blades on order and I'm looking forward to using something fresh and sharp.

Question: how do I properly set blade tension? Thus far I have been eyeballing it and have never had a disaster. I see that band saw tension gauges are pretty expensive. Anything wrong with just continuing with my guess-o-metric approach, or am I asking for trouble?


Kym
Top
Artie F. Emm
  • Posts:
  • Joined:
    Thu Jul 24, 2014 7:53 am

I saw a website that tensions the blade according to the sound it makes when you twang it. The site had recordings of blades at various tensions. Let me take a look, see if I can find it again.
Dave
aka "RTFM"
Top
User avatar
  • Posts:
  • Joined:
    Sat Aug 01, 2015 8:38 am
  • Location:
    The Land Down Under

Artie F. Emm wrote:I saw a website that tensions the blade according to the sound it makes when you twang it. The site had recordings of blades at various tensions. Let me take a look, see if I can find it again.

Interesting!

I can only assume that the sound would vary according to blade width and possibly pitch, too. Good info, especially considering the price of tension gauges. Seeing as the saw cost me nothing, it wouldn't seem right to spend heaps on a gauge!



Kym
Top
Artie F. Emm
  • Posts:
  • Joined:
    Thu Jul 24, 2014 7:53 am

Sorry, got caught up and forgot to look into this. I think this is the site:
jpthien.com/tg.htm

You enter parameters (blade width, length, thickness, etc) and the calculator gives the frequency associated with those parameters. Then play the frequency so you know your target tone, and adjust the saw. Pretty cool.
Dave
aka "RTFM"
Top
User avatar
  • Posts:
  • Joined:
    Sat Aug 01, 2015 8:38 am
  • Location:
    The Land Down Under

Hey that IS cool!

Thanks Artie. I'll take a look at the site and do some twanging.


Kym
Top
User avatar
  • Posts:
  • Joined:
    Thu Jan 06, 2011 11:40 pm
  • Location:
    Near New Orleans

That's great! I always tensioned mine by ear, but without a reference... I just tensioned until it went from a "buzz" to a clear tone, then tightened it about one note up the octave, and called it good.

Steve S
Top
ex framie
  • Posts:
  • Joined:
    Sun Aug 09, 2015 1:09 am
  • Location:
    Brisbane QLD Land of oz

being both tone deaf and having worked on aircraft flight lines before they brought in real hearing protection I've always just tightened mine up until it no longer slips and a couple more turns.
Seems to work for me.
Pete

God gave man 2 heads and only enough blood to run 1 at a time. Who said God didn't have a sense of humour.....
Top
User avatar
  • Posts:
  • Joined:
    Sat Aug 01, 2015 8:38 am
  • Location:
    The Land Down Under

ex framie wrote:being both tone deaf and having worked on aircraft flight lines before they brought in real hearing protection I've always just tightened mine up until it no longer slips and a couple more turns.
Seems to work for me.

Yeah, I've not had anything go badly wrong thus far doing 'by feel'.

Maybe reading about how all the hardcore band saw guys go about it has spooked me a bit. Mind you, they de-tension their blades after every cutting session so that the blade doesn't 'take a set', too...



Kym
Top
Post Reply

Return to “Metal Cutting”