Decrease blade tension on an Excalibur saw?

[xocd]

I have a new-to-me Excalibur 30 (the green one).  It was a great Craigslist find.  I am wondering if there is a way to control the blade tension other than introducing slack on the blade when installing it.  I am wondering if I am missing something.

I am cutting marquetry packets using 2/0 blades.  If I install a blade following the manual, the blade snaps: i.e., if I tighten the holders with the tension lever to the front and then push the lever back.  After some research I have found two ways to fix this. The first is to introduce slack on the blade before tightening the blade holders (see link to youtube video below).  The second is to tighten the blade holders starting with the tension lever more or less vertical.  I imagine that one could re-shape the tension lever to reduce the tension on the blade, but I have not tried that yet.

In other saws (Dewalt, Hegner, RBI Hawk) one has fine control of the tension.  I am surprised that this is not possible with the Excalibur.

Thanks,

xocd

 

 

 

[Roberta Moreton]

I move the knob in the back just a tiny bit to lower the front just a tiny bit. If it’s still not quite where I want it I move the knob until it is. Sometimes breaking the rules is actually OK

Edited July 5, 2021 by Roberta Moreton

[TAIrving]

I have a Pegas saw and also find that 2/0 blades sometimes break when I tension them.  So, as you mention, I introduce a little bit of slack when installing the blade.  Works just fine for me.  

I prefer to not adjust the inherent tension of the machine as it is good for all the other blades.  

[Denny Knappen]

I had the same problem and switched to #0.  But you do marquetry and need the smallest blade.  I would not recommend using the black knob on the back as this is for maintaining the upper arm parallel to the table.  The suggestion of a little slack before tightening might work. 

[Roberta Moreton]

On 7/5/2021 at 11:13 AM, Denny Knappen said:

I had the same problem and switched to #0.  But you do marquetry and need the smallest blade.  I would not recommend using the black knob on the back as this is for maintaining the upper arm parallel to the table.  The suggestion of a little slack before tightening might work. 

I realize this is true. However, my EX 21 lived it’s first several years with the white mark on the knob at about “one O’Clock. Then I had problems. I did the Hold it with a rubber band thing. Ok for a while. Now the knob likes to be close to 10:30. I can’t explain it. As long as it is working, I’m not complaining. 

[xocd]

(OP) I have noticed something that is fixing the blade breakage issue I was having: when attaching the blade, make sure to move the tension lever as forward and down as possible. This seems to stretch the blade by the correct amount.

Moving the tension lever back moves the top holder up, and results in the largest distance between upper and lower blade holders. Assuming no slack, the blade is stretched by the difference in the distance between the holders when the blade was attached and the distance between them when the lever is thrown back. I noticed that the minimum distance between the holders does not occur when the tension lever is completely forward and down;  it happens when the lever is a bit higher than that.  I was attaching the blade at this (minimum distance) position, which stretches the blade too much (at least for the 2/0 blades I am using).

 

Thanks!

xocd