wixey digital angle gauge inaccurate?

[fredhargis]

I'm trying to follow, but it seems like Derek and Wxman are saying the same thing (?). Did I get this correctly (and I agree with what they suggested, at least as I understand it).

[mound]

4.  Without moving the blade at all, I moved the gauge itself by rotating it some while on the blade.



5.  Simply by changing the orientation of the gauge as shown in Picture 4, I have induced a significant error in the reading on the gauge.



Hope this helps.

I'm very confused by this.. So you really have to pay close attention to exactly how the gauge is attached to the blade?

[mound]

I'm trying to follow, but it seems like Derek and Wxman are saying the same thing (?). Did I get this correctly (and I agree with what they suggested, at least as I understand it).

I'm confused by what they're saying but will go play with the thing and see for myself..

[Handplanesandmore]

https://youtu.be/QanSL2AfdUw?t=44

Simon

[R Clark]

I'm trying to follow, but it seems like Derek and Wxman are saying the same thing (?). Did I get this correctly (and I agree with what they suggested, at least as I understand it).

Yes, Derek and I are in agreement.

I wish I could explain it better; I can't, and that's why I posted the pics.

I didn't pay a great deal of attention to Mr. Braz in 10th grade geometry 46 years ago.  That might have had something to do with the miniskirts that were fashionable back then.  

[Handplanesandmore]

That might have had something to do with the miniskirts that were fashionable back then.  

Boys will be boys.


Simon

[barryvabeach]

I'm confused by what they're saying but will go play with the thing and see for myself..

Not to confuse you further,  but this link is to lombard st in San Francisco,  famous for the way it criss crosses back and forth  https://www.pinterest.com/pin/331507222550475917/

So if you look at the hill, and were going straight up, the angle would be a certain angle, and quite steep  ( checked and the slope of the hill is 27 degrees ) .  Instead, the road goes from left to right, then crosses back   So each leg is much less than 27 degrees.   

If you had the gauge set exactly in line to  the axis of the arbor that turns the blade,  ( so that if you drew a line through the gauge, it went straight from the hole in the center of the blade to the highest tooth ) it might be 45 degrees.  Assume you placed a mark on that tooth using a magic marker, and then turned the blade a few inches so the mark rotated towards the front of the saw.  If you kept the gauge aligned so that the imaginary line went from the hole in the center of the blade to the marked tooth, the angle will be less because you are now measuring the angle to start to criss cross to get to the top of the blade, which is located further back and is higher.   Hope that didn't muddy it further.

[Derek Cohen]

This is a video in which Chris Schwarz describes how to calculate the resultant angle of a chair leg. We are into compound angles, but Chris makes this more understandable ...

https://www.pbs.org/video/woodwrights-sh...furniture/

If you get this, you will understand that there is a predictable difference in readings when moving the position of an angle gauge. Vertical and off-vertical are not the same. Use the Wixey correctly (in the correct plane) and you will have correct results.

Regards from Perth

Derek

[mound]

This is a video in which Chris Schwarz describes how to calculate the resultant angle of a chair leg. We are into compound angles, but Chris makes this more understandable ...

https://www.pbs.org/video/woodwrights-sh...furniture/

If you get this, you will understand that there is a predictable difference in readings when moving the position of an angle gauge. Vertical and off-vertical are not the same. Use the Wixey correctly (in the correct plane) and you will have correct results.

Regards from Perth

Derek

Thanks, now I see.

So ultimately you can't just attach the thing to the blade - you have to very carefully and accurately place it so it's oriented "straight up the hill" so to speak - inline with the arbor of the TS in this case. 

Was very surprised to watch the displayed value change as I "rotated" the gauge away from and toward me.  I definitely paid no attention to it's rotation relative to the arbor when I tried it first on the TS. I "get it" now but I still think that is very unintuitive for most folks who just want to dial in the angle of their blade, especially given it came with no instructions.


But doesn't that then require some new method to ensure accurate placement? I suppose I could zero it on the tablesaw top, and then attach it to the blade that I know is at 90* and then "rotate" the wixey to bring it inline with the arbor such that it reads 90*, and then adjust my blade to the desired angle.

[TDKPE]

Can you just slide it down so it's back edge is flat to the insert?  That would put it at 90 degrees to the top in that plane, and whatever angle the blade is.

Alternatively, put it on the blade, with the bottom flat to the insert, then tilt the blade to the desired angle.

If you know your blade goes to 45 degrees accurately, you can also tilt to 45 deg. and check the Wixie and adjust if necessary, then tilt back up to the desired angle.

OR, stick it to the blade, tilt to the desired angle, and rotate the blade a little while watching the Wixie display - the highest number (or the lowest; I don't know which way it works) will occur when it's oriented correctly, even if it's off-center, and will also be the actual angle of the blade to the table, assuming it was calibrated to the table top.