Contractor Talk - Professional Construction and Remodeling Forum banner

1 - 20 of 25 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
I'm trying to accomplish this rounded return but I must be cutting my angles wrong? All my cuts are set at 22.5 except the one against the wall which is a straight cut. I can't make the last piece longer without making the bottom too thick or changing the angle... What am I doing wrong?

ETA - I know the overall length of the crown is too long, I'm trying to figure out the return before I cut it to size...
 

Attachments

·
KemoSabe
Joined
·
14,233 Posts
It looks to me that your spring angle is off. The top needs to be closer to the wall.

Without changing the spring angle, you can nest the crown in the box and kick the bevel over a degree or so to lengthen the top of the return. I'd make that adjustment to a longer piece until you're happy, then set the bevel back to zero to miter the return.
 

·
Ciaos mitigator
Joined
·
1,943 Posts
What Riz said.
Couple things to check:
are you cutting it nested? if so make sure the saw is cutting square cause if the vertical cut is off it will throw off your angles just enough to have that problem. i had a Hitachi 12" cms that would go out of plumb/ square constantly and caused me too many problems before i would think to check the set ups on it.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #4 ·
You guys were right, the spring angle was off. I tore it down and started again. However, I notice when assembling everything on the bench that even my 90 degree corners don't line up (see picture).

I am cutting the crown nested. I checked the fence and deck with my digital protractor and it indicates 90 degrees. I checked the vertical blade angle with the protractor and it indicates 89.6. Any thoughts what's causing my cut to have this kind of deviation?
 

Attachments

·
Ciaos mitigator
Joined
·
1,943 Posts
It's the bevel on the saw. The detent is either wore or just off. Although the tiny amount your talking about shouldn't make a difference.
 

·
Registered
Joined
·
136 Posts
22.5 is correct
Is your blade sharp? If the blade is even a slight bit dull it will pull the work and throw off the angle. I always use a newly sharpened blade when I cut details like that.
 

·
Registered
Joined
·
3,011 Posts
Correct me if I'm wrong, but shouldn't you be cutting 30's instead of 22.5's to complete that return?
Since it's a total of a 90 deg turn to complete the corner, you just divide 90 by the number of cuts. Example:
90/2 = 45's
90/4 = 22.5's.

My guess is the cuts aren't being indexed on the saw table exactly the same each time. Since the spring angle is determined by the back cut on the crown, & they can vary a lot. We always nested the crown in the saw, & made pencil lines to hold the crown while cutting, so the spring angle was constant. As long as the saw scale is zero'd in the cuts will always match up.

If your nesting each piece independently, you can get the problem you have. Not all crown is backcut the same, because they can come from different runs on the molder, with different grinds on the knives.
Joe
 

·
Registered
Joined
·
3,011 Posts
The easiest way to zero in the saw miter scales is to do a 90' cut, & check cut from opposite sides. Before you do anything, check to make sure the fence is flat left to right.
It goes something like this:

Check flatness of fence with straight edge.
Check blade runout. Spin it up, lightly hold cut to blade, look for varience in tension against blade while blade is slowing down.
Then cut a 1x4 (or bigger) on a 90 cut. The board has to be perfectly straight to be accurate.
Flip board to opposite side of fence, seat to fence, & lightly seat against blade. If different, 90 will be at 1/2 of the runout. If the scale is off, you have to zero the fence in to the 90' cut setting.

If a compound saw, you do the same thing, only vertically.
Basically, you do 90 cuts, & flip cut to opposite side to check runnouts.
Joe
 

·
Maker of fine kindling
Joined
·
6,199 Posts
I agree that the crown is probably not being nested the same every time.

Are you using any type of crown stops?

I find that a simple site made jig like this works great.



image-527715768.jpg



image-406072148.jpg
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #17 · (Edited)
It appears you're correct. I've been trying to determine the issue and discovered that the deck on the right hand side is 3/4" shorter than the left hand side. This makes the crown on the right hand side rest on the stop instead of the deck (see pic). The stop moves up and down almost 1/4" depending on the pressure I apply...

I don't see how they can advertise that this miter saw will work with 6-5/8" nested crown moulding considering how short the deck is on the right hand side; works fine on the left hand side.
 

Attachments

·
diplomat
Joined
·
5,292 Posts
For what it's worth, half a degree is generally a lot when it comes to precise cuts.
 

·
Maker of fine kindling
Joined
·
6,199 Posts
Isailer said:
It appears you're correct. I've been trying to determine the issue and discovered that the deck on the right hand side is 3/4" shorter than the left hand side. This makes the crown on the right hand side rest on the stop instead of the deck (see pic). The stop moves up and down almost 1/4" depending on the pressure I apply... I don't see how they can advertise that this miter saw will work with 6-5/8" nested crown moulding considering how short the deck is on the right hand side; works fine on the left hand side.
That is one reason I like the jig I showed. It gives you a nice flat deck and a continuous fence. The fence allows you to work with much shorter pieces as well.

Another reason, and possibly the most important one, is the kerf in the fence to align your cut mark to. Aligning a fine pencil mark or a slight knife mark with the kerf is very fast and extremely accurate. I find that MDF on the fence works the best. It seems to behave better than veneer core plywood for this purpose.

As others have said, your saw needs to be accurate. Without that you will continue to be frustrated with the quality of your work.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #20 ·
For what it's worth, half a degree is generally a lot when it comes to precise cuts.
I agree and have already solved that issue. The deviation in the corners was 3+ degrees so I was trying to locate the primary issue and work my way down...

Now I need to decide if I should simply return this saw or build a jig like Gus.
 
1 - 20 of 25 Posts
Top