Woodworking Talk banner

Making a 50° cut on a table saw

18K views 63 replies 15 participants last post by  FrankC  
#1 ·
I’m trying to help a guy on one of my other forums.

He’s trying to cut a 50° angle on a table saw.

My first thought was to set the blade to 40° use a sacrificial fence and stand the ply on edge, but I know first hand that doing it this way can be dicey.

You guys always come up with stuff I hadn’t thought of. Any ideas for this?
 
#2 ·
Seems to me without actually making this cut, If you set the blade to 40 degrees that will result in a 50 degree angle on the workpiece. 90 minus 40 = 50.
No need to go "vertical" just lay it flat on the table.
What confuses most folks is the angle indicator plate on the front of the saw is always the setting "from 90 degrees", which is "0" or vertical.

Same with the miter gauge, the "0" setting is 90 degrees:
Image


 
  • Like
Reactions: Pandday kuno
#21 ·
Seems to me without actually making this cut, If you set the blade to 40 degrees that will result in a 50 degree angle on the workpiece. 90 minus 40 = 50.
No need to go "vertical" just lay it flat on the table.
What confuses most folks is the angle indicator plate on the front of the saw is always the setting "from 90 degrees", which is "0" or vertical.

Same with the miter gauge, the "0" setting is 90 degrees:
View attachment 448623

I agree..... no matter what thickness the board will be and the cut is on the left side of the table saw the upper angle cut of the board will be 40 degrees and the lower angle will be 50 degrees ... that is if the question is about bevel cut on the board...
 
#11 ·
The OP's post is ambiguous, is there a wish to move scale past 45 to 50 degrees, or is an actual 50 degree cut necessary. As the later is possible we have to assume it is a wish to have a 50 degree movement on the scale. Simply put is desired result more or less than 45 degrees.
This is not that easy to explain so I hope there is no need for mansplaining in any replies.
 
#15 ·
He’s trying to cut a 50° angle on a table saw.
If he wants a 50 degree angle on the workpiece? That means tilt the saw to 40 degrees on the indicator plate, 90 - 40 = 50.

If he wants a 50 angle on the blade, the saw won't tilt that far, only 45 or 46 degrees.
 
#20 · (Edited)
If he wants a 50 degree angle on the workpiece? That means tilt the saw to 40 degrees on the indicator plate, 90 - 40 = 50.
If he wants a 50 angle on the blade, the saw won't tilt that far, only 45 or 46 degrees.
No, posts 4 and 17 are correct. 😁
The saw won't tilt to 50 degrees. PERIOD.
However, a setup can be made to bevel a panel in angles less than 25 degrees as shown in the video.
BUT, that is not a 50 degree angle with the panel held vertically, his blade is at 15 degrees:



A 50 degree angle is cut by tilting the saw to 40 degrees on the indicator plate BUT which measured with a digital gauge will read 50 degrees.
This is the common confusion between "saw settings" VS actual angles I pointed out in this thread because all the "settings" are "from 90 degrees":

See how the miter gauge is set to 30 degrees but the actual angle is 60 degrees:
Image



Sorry If I am belaboring this point, but you can't argue with the math.
 
#29 · (Edited)
I think what you’re saying is use the complimentary angle? Or flip the board over and you’re reading the complimentary angle?

Angles are always relative to a reference face. Gotta think about this !🤯🤯

View attachment 448650
The ? degree angle will be a straight line drawn perpendicular to the blade in the bottom angle of the board touching the blade....WNT is correct... the angle you've drawn is not 30 degrees... it is more than 30 dergrees.... and for us to know the degree of the bottom angle we will need the width of that board and apply Trigonometric function which I learned 60 years ago ...
 
#24 · (Edited)
Based on your red line on the board, that is NOT a 30 degree angle, most certainly an obtuse angle like 90 + 30 or 120 degrees.
See what I mean about the "confusion"? All because the settings are not the resultant angles on the workpiece, rather than "subtracted from 90 degrees". The "reference edge" in this example is against the face of the gauge. This concept is just common knowledge by framers and those who use a Speed square and miter saws.

With all due respect, take a few minutes and go to the shop, set your miter gauge to 30 and make a cut. Measure the cut angle with a protractor and see what you get. If you set the gauge to 0 and make a cut, the angle is 90 degrees to the edge of the board, so the settings are subtracted from 90 degrees! Your 45, 30, and 60 triangles from drafting are good visual examples to keep in mind.

Here's an excerpt from my post titled "Angles and settings on the Miter Saw":
If it weren't for my buddy coming over this AM I never would have thought about this, He's a rough carpenter/framer. I tell him about our discussion settings vs angles. He pulls out his speed square and goes " No problem, This is the same as the miter saw." I go HUH?? He goes "YAH, I always think away from 90 since 90 is plumb/vertical." I go HUH? What are all these other nos on this thing for? He goes "These are the angles if you pivot it, on the corner, marked "pivot" it gives you angles or roof pitches etc.."
I go "Let me see that thing!" Of course I've used one before, but only to cut square ends, so I never paid any attention to the rest of the numbers. He says "Yah, you get a book with it and it tells you all about it." I go " Mine never came with a book!" "I'm still a dummy on this thing!"

:eek:AH HA! What I finally realized was this:
I come from a drafting/architectural/ cabinet maker, woodshop, background.
He comes from a rough carpenter/ framing background, but he's a great cabinet maker too.
So, it's the way I learned vs the way he learned.
I always worked with drafting triangles, 30 degrees and 45 degreees,and a protractor, so everything was always measured in terms of the included angle.
He worked with that "speed square" which measures away from 90 degrees, like a miter saw, and has the roof pitch values on it . A 7/12 roof pitch is the same as a 30 degree angle. So, it was second nature to him to cut angles on the miter saw.
So, back to my original reason for posting, and I do appreciate your comments Mikey, for those starting out with some of these tools to immediately grasp the concepts behind them might take some 'splainin Lucy. Regards back to you! bill
 
#26 ·
Based on your red line on the board, that is NOT a 30 degree angle, most certainly an obtuse angle like 90 + 30 or 120 degrees.
See what I mean about the "confusion"? All because the settings are not the resultant angles on the workpiece, rather than "subtracted from 90 degrees". The "reference edge" in this example is against the face of the gauge. This concept is just common knowledge by framers and those who use a Speed square and miter saws.

With all due respect, take a few minutes and go to the shop, set your miter gauge to 30 and make a cut. Measure the cut angle with a protractor and see what you get. If you set the gauge to 0 and make a cut, the angle is 90 degrees to the edge of the board, so the settings are subtracted from 90 degrees! Your 45, 30, and 60 triangles from drafting are good visual examples to keep in mind.
You’re right WNT. But if it were set to the other 30 I would have been right.

I know I’m right about one thing - it’s totally dependent on the edge you reference off.

in your example
1. Referencing from the edge furthest from the fence the cut edge is actually 30, not 60
3. But referencing off the edge against fence it’s 60.

On the miter gauge angles to the left of 0 are obtuse, to the right of 0 are acute. Kind of like -30° vs +30°. OK gotta stop my heads about to explode and we’ve lost Rebel entirely.

Geomentry can be obtuse, even for an acutely ignorant college educated dumba$$ like me. And to think I aced geometry, oh that was 50 years ago.

50 YEARS?? 🤯🤯
 
#28 ·
I’m not lost, just the question..

Reminds me of cutting the notch for a fence picket topic. Some complicated answers for such a simple task…

More time is spent analyzing each others post, than answering the actual question..
 
#33 ·
All this math is making my head spin. How about a non-math way?

Take a piece of wood that is the same width and length as the miter slot. Make it protrude from the miter slot, it might take some experimentation. Run the board that you are trying to cut on the wood sticking out of the miter slot and try to have it stick up enough to get at least a 5 degree angle on it when the blade is at 90 degrees. Doesn’t have to be exact, you can decrease the angle of the tablesaw from 45 degrees to compensate and get your 50 degree angle.

Only possible downsides are narrow boards that aren’t wide enough to reach the miter slot, or too wide of boards that rise up above the fence.
 
#34 · (Edited)
All this math is making my head spin. How about a non-math way?

Take a piece of wood that is the same width and length as the miter slot. Make it protrude from the miter slot, it might take some experimentation. Run the board that you are trying to cut on the wood sticking out of the miter slot and try to have it stick up enough to get at least a 5 degree angle on it when the blade is at 90 degrees. Doesn’t have to be exact, you can decrease the angle of the tablesaw from 45 degrees to compensate and get your 50 degree angle.

Only possible downsides are narrow boards that aren’t wide enough to reach the miter slot, or too wide of boards that rise up above the fence.
Without going to the shop, I think if you set the miter gauge to 40 degrees it would result in a cut that is at a 50 degree angle.


Yep, just what I thought. The angle is 50 degrees, No Math.
Image


Image


Image
 
#35 ·
I dont know which way he wants the 40*
If he wants it on the edge,Just set the blade @ 40* off vertical and the underside will be at 50* or am I misunderstanding because I am not at my saw right now
Just reverse the numbers in Post #7
 
#37 ·
I don't know which way he wants the 40*
If he wants it on the edge,Just set the blade @ 40* off vertical and the underside will be at 50* or am I misunderstanding because I am not at my saw right now
Just reverse the numbers in Post #7
Tony, it doesn't matter if the cut is a miter or a bevel, the "setting" on either the saw or the gauge is 40 degrees which will result in a 50 degree angle on the work piece.

Now 40 degrees is a new number, so that is a change from the first post:
I’m trying to help a guy on one of my other forums.
He’s trying to cut a 50° angle on a table saw.
 
#39 ·
The OP wrote that he knows he could stand the piece up and cut it, which implies that he needs 50° on the edge. The blade is normally used at 90°to the table, so he just needs to set the blade angle to 50° and position the piece so the acute angle is near the correct surface.

I'm not sure why anyone mentioned setting the blade to 40° when that's not possible on almost all saws-
 
#40 ·
The OP wrote that he knows he could stand the piece up and cut it, which implies that he needs 50° on the edge. The blade is normally used at 90°to the table, so he just needs to set the blade angle to 50° and position the piece so the acute angle is near the correct surface.

I'm not sure why anyone mentioned setting the blade to 40° when that's not possible on almost all saws-
If you've the thread carefully, you'd know that the setting of 40 degrees on the face plate is actually 50 degrees on the blade.
Because 90, or zero degrees from vertical, minus 40 equals 50.
Image
 
#45 ·
#46 ·
YUP, the same idea to make those cuts you need an "auxillary fence" to get those acute angles, a 45 degree block like this:

Image


The flag boxes a lot of folks make need this set up to make 22.5 degree cuts on the miter saw: