# Newbie Miters



## patlaw (Jan 4, 2010)

What do I need to do to make better miters? These were cut on a Kapex 120, so I must not have assembled them correctly.


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## Stick486 (Jan 4, 2013)

appears that the 45 is good but the vertical isn't 90° to the face by a fuzz...
tune the saw or use a shooting board...


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## Cherryville Chuck (Sep 28, 2010)

The first requirement is that opposing sides be exactly the same length. The only other requirement is that you cut 45* and vertical. 

It may not be something you can cure with the setup you have, primarily the blade you are using. I was getting horrible miters with a Makita chop saw that was properly set up and had a brand new (supposedly) good quality blade. Once I added blade stabilizers they started fitting properly. Blade Stiffeners - Lee Valley Tools


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## patlaw (Jan 4, 2010)

Cherryville Chuck said:


> The first requirement is that opposing sides be exactly the same length. The only other requirement is that you cut 45* and vertical.


As well as I can measure them, they are 45* and vertical. I have some extras I cut, so I'll measure those again to be sure. 



> It may not be something you can cure with the setup you have, primarily the blade you are using. I was getting horrible miters with a Makita chop saw that was properly set up and had a brand new (supposedly) good quality blade. Once I added blade stabilizers they started fitting properly.


They were cut on a new Kapex 120 with the stock blade. I was very careful to make sure that no sawdust was accumulating on the table to create a spacing problem. The wood is crappy off-the-shelf pine from Lowe's. I don't know if that makes any difference. It would be fun to do something like this with hardwood.


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## patlaw (Jan 4, 2010)

Stick486 said:


> Appears that the 45 is good but the vertical isn't 90° to the face by a fuzz. Tune the saw or use a shooting board.


It's a new KS120, and everything I've measured seems right although I haven't done the five-cut test, which is probably what I need to do. My son and I are going to a class on shooting boards on January 23.


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## Stick486 (Jan 4, 2013)

if the edge that is placed against the fence isn't flat, the face to edge isn't square the length of the piece, the piece has a ''twist'' to it or the piece isn't uniform thickness that could make a world of difference...

isn't flat... that will change the angle of the cut...
twisted... every cut will be slightly different..
edge to face isn't square... coplaner of cut is different for each cut...
the thickness.. premium miter fit is about impossible..


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## patlaw (Jan 4, 2010)

I used to own a picture framing shop. It was trivial to make custom frames with perfect miters every time (using a Morse chopper.) It almost seems like that was a dream since it was long ago. Picture frame stock and the Morse chopper must both be made with precision.

I did it then, and I should be able to do it now.


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## mjadams61 (Dec 24, 2015)

That cheap pine could do it since I ran into problems like that in the past. Get you a piece of baseboard and cut it at a 45 like you would a picture frame and see if you get the same results. If a better 45 comes of it then its the pine.


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## JIMMIEM (Apr 4, 2010)

You've got a very expensive saw. Did you test and adjust its alignment? What's the stock blade on a saw that expensive?


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## patlaw (Jan 4, 2010)

JIMMIEM said:


> You've got a very expensive saw. Did you test and adjust its alignment? What's the stock blade on a saw that expensive?


I've tested it to the best of my ability. The lasers are not correctly aligned from the factory, but I don't use them yet. The blade appears to be the Universal 60-Tooth Blade.


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## patlaw (Jan 4, 2010)

Cherryville Chuck said:


> The first requirement is that opposing sides be exactly the same length. The only other requirement is that you cut 45* and vertical.
> 
> It may not be something you can cure with the setup you have, primarily the blade you are using. I was getting horrible miters with a Makita chop saw that was properly set up and had a brand new (supposedly) good quality blade. Once I added blade stabilizers they started fitting properly. Blade Stiffeners - Lee Valley Tools


I wonder whether this blade flange (8.9) serves as a stiffener.


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## Nickp (Dec 4, 2012)

It's also possible that the wood moved (twisted) after cutting it down to smaller pieces...while the 1x's look nice straight when they're long, you may have gotten some twist after cutting...

Did you use anything like a strap/corners to clamp while assembling...? 
Feed rate when cutting...? (try slowing down how fast you cut)
Did any of the pieces rock at all when laid on a flat surface...? 
TPI of saw blade...?
Enough glue for end grains...?
Super precision on alignments...?
No play when cutting or sliding the saw...? (side to side)
Did you lock down the saw after setting the angle or bevel...?

Are you cutting the 45's with the wood vertical (saw set to 45) or flat (set at 0, beveled...?) If beveled, your pull should be on the same axis as the bevel rather than straight down (could indicate some play)


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## patlaw (Jan 4, 2010)

Nickp said:


> It's also possible that the wood moved (twisted) after cutting it down to smaller pieces...while the 1x's look nice straight when they're long, you may have gotten some twist after cutting.
> 
> Did you use anything like a strap/corners to clamp while assembling?


No



> Feed rate when cutting? (try slowing down how fast you cut)


The feed rate was rather slow and cautious.



> Did any of the pieces rock at all when laid on a flat surface?


Not a chance.



> TPI of saw blade?


We posted at the same time. The blade information is above your post.



> Enough glue for end grains?


Maybe not. I covered both ends, but there was no squeeze out. Why does the amount of glue matter to the alignment?



> Super precision on alignments?


As precisely as the KS 120 will cut. I did you my Wix digital gauge to make sure that the vertical angle is 90 degrees, which it is within 0.1 degrees, according to the Wix.



> No play when cutting or sliding the saw? (side to side)


Not that I could detect. 



> Did you lock down the saw after setting the angle or bevel?


Yes. It has positive stops that are supposed to be dead accurate.



> Are you cutting the 45's with the wood vertical (saw set to 45) or flat (set at 0, beveled?) If beveled, your pull should be on the same axis as the bevel rather than straight down (could indicate some play)


Wood vertical with the saw set to 45 degrees.

Thanks for taking the time to ask these questions. They are very helpful to define the troubleshooting process.


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## woodknots (Mar 7, 2012)

Mike
All good suggestions above.

Some have suggested that the verticals don't look "vertical". This could be caused by "perspective distortion" - common when shooting a subject at an angle. What did you use to take the picture; camera, phone?

Hard to tell from the photograph, but it looks to me like the only issue is the slight space in the miters.
What is *your* concern with the miters? You've called them newbie miters, but since you owned a picture framing shop, you're not a newbie.

As good as your Kapex is, it's still a chop saw - keep that in mind.
You said you used a Wixey to check the angle at 90 degrees - did you use it to check the 45 in relation to the fence?

As stated, the opposing sides need to be identical - did you use a stop block while cutting the lengths/miters?

It's been suggested that you use a strap/corner clamp during assembly - good idea. This might have tightened up the joints.


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## Nickp (Dec 4, 2012)

patlaw said:


> No
> 
> 
> Maybe not. I covered both ends, but there was no squeeze out. Why does the amount of glue matter to the alignment?


End grain sucks up more glue...if insufficient glue AND not clamped tightly it will separate some. Corners and strap will ensure less space but squeeze-out will ensure sufficient glue. You might also pre-glue the end grains and then apply a second coat to ensure the grain does not suck up all your glue...

...just another thing to try...may not be the only cause...


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## patlaw (Jan 4, 2010)

vchiarelli said:


> Mike
> All good suggestions above.
> 
> Some have suggested that the verticals don't look "vertical". This could be caused by "perspective distortion" - common when shooting a subject at an angle. What did you use to take the picture; camera, phone?


iPhone 6



> Hard to tell from the photograph, but it looks to me like the only issue is the slight space in the miters. What is *your* concern with the miters?


The only issue is only that they don't look as tight as they should be. 




> You've called them newbie miters, but since you owned a picture framing shop, you're not a newbie.


You're taking away my excuse. That was 30 years ago. Any knowledge obtained then has long since evaporated.[/quote]



> As good as your Kapex is, it's still a chop saw - keep that in mind. You said you used a Wixey to check the angle at 90 degrees - did you use it to check the 45 in relation to the fence?


I don't know how to do that. How would I use it to measure on the horizontal angle?



> It's been suggested that you use a strap/corner clamp during assembly - good idea. This might have tightened up the joints.


Maybe that's a lot of the problem. It will be good if that's the problem. I don't have a strap, but I'll get one.


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## woodknots (Mar 7, 2012)

patlaw said:


> iPhone 6
> 
> 
> 
> The only issue is only that they don't look as tight as they should be.


Thought so - a corner strap will help - they're inexpensive but well worth it




patlaw said:


> You're taking away my excuse. That was 30 years ago. Any knowledge obtained then has long since evaporated.


OK, sorry about that - not evaporated, just tucked away - it'll come back with practice



patlaw said:


> I don't know how to do that. How would I use it to measure on the horizontal angle?


I presume you've got a Wixey angle gauge?? Set it against the fence, then zero it out - then against the blade and check the angle.

Sorry - led you down the wrong path - I said "Wixey angle gauge" should have said "digital miter gauge"



patlaw said:


> Maybe that's a lot of the problem. It will be good if that's the problem. I don't have a strap, but I'll get one.


Good idea


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## TwoSkies57 (Feb 23, 2009)

Ahhhh the elusive tight miter. They WILL drive ya nuts!

3 out of 4 of the corners look crisp and clean (at least from above), the upper left looks tight in the center with gap above and below joint (possibly camera?) They just dont' appear tight. Is this the glue line were seeing or a physical gap? The gap/glue liine appears to run even along its entire width. What do the inside/outside corners look like? Are they tight?
couple things (mostly redundant) 
-As mentioned earlier, opposing sides have to be exactly the same length. 
-Miter angle has got to be dead on as well. Even a .1* (one tenth of a degree) degree error can be difficult to overcome when it comes to appearance. A phenomenon know as "compounded error" comes into play. On a 4 sided box, an error of .1* degree amounts to a total error of .8* or almost a full degree. (8 corners combined).
-The wider the miter the more pronounced this error becomes.
-The same scenario plays out on a vertical as well as a horizontal cut 
-Clamp down pieces prior to cutting...As the blade engages the wood, there can be enough pressure applied to the wood by the blade to push it ever so slightly one way or another..

At this stage of the game, you have got to start my making absolutely sure that the setup you are using is capable of achieving the results you are looking for. Take a small straight edge (little metal rules will do on something like this) check the flat of the miter length wise, is it perfectly flat? No rocking of the straight edge, no light weeping through? Use a square to check your vertical cut. You need to verify that your miter angle is spot on. Compare your findings one board to another. Are the errors the same if any? 

You got a premium saw there,,,top shelf no doubt, but I do not know if it is design or intended to give you the kinda accuracy your looking for. 

On dark woods you can get away with a dark drying glue ie. TBIII or the like. On lighter woods you want to look to something that dries a little lighter ie. a yellow PVA or Elmers. You may sacrifice a bit of holding power with the lighter drying glues. I always look to some kind of reinforcement with miters, splines are my first choice, having a framing background you are familiar with the staples etc. that are available..etc.etc...

You can always rough cut your material and then go to a disc sander for final fitting or even go with a well tuned shooting board: 
here's a link to mine:

http://www.routerforums.com/show-n-tell/27852-bench-hook-shooting-board.html

each present their own unique setup/usage characteristics that may need to be dealt with. All that said, I'm a big fan of the shooting boards.


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## patlaw (Jan 4, 2010)

There is a pencil line that makes one joint look worse than it is. Bill, I would love to have the impressive setup that you have. However, making jigs requires precision skills. It's chicken and egg: You make a precision shooting board so that you can make precision miters. That's why I have to buy my precision tools, like your Incra tools.

I have been told by a highly skilled woodworker (a medical doctor) that the Festool is accurate enough for picture framing. He makes frames on his all the time. However, it's possible that there are some calibration settings that he knows about that I don't know about yet. All in due time.

It helps to have these thoughts to know where to look next.


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## TwoSkies57 (Feb 23, 2009)

Mike.... to a large extent my shooting board may look impressive and I suppose to some extent it is, BUT...you can achieve the EXACT same results with one having far less
"makeup".. At their core, they are all pretty much the same. I take the opportunity when making my jigs to focus on precision. I carry over what I learn from them into my other woodworking adventures 

Very cool that you have someone who has the same setup, doing the same thing. if he is achieving the results that are up to your standards,,,by all means, pick the ole boys brain  It all starts with identifying where the problem lies. If you determine the cuts you are making are in fact straight and true, then I'd whole heartedly agree the problem may very well be in the calibration of the equipment...Hell, tweaking is a science in and of itself *L*


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## rwl7532 (Sep 8, 2011)

30 years ago...
I think you are on to part of the problem.


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## Ratbob (Apr 6, 2015)

patlaw said:


> What do I need to do to make better miters? These were cut on a Kapex 120, so I must not have assembled them correctly.


Looking at your assembled box, I'm wondering how the bottom is attached. Is it captured inside a dado running the full circumference of the inside perimeter? If so, and the bottom is cut an RCH big, that could prevent the miter faces from mating fully.

That's one fancy saw you've got there Mike!


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## patlaw (Jan 4, 2010)

Ratbob said:


> Looking at your assembled box, I'm wondering how the bottom is attached. Is it captured inside a dado running the full circumference of the inside perimeter? If so, and the bottom is cut an RCH big, that could prevent the miter faces from mating fully.


That's a good point, but I actually got that part right. There's 1/16" inch space around the bottom, which is captured inside a dado running the full circumference of the inside perimeter. 



> That's one fancy saw you've got there Mike!


It is, but to be quite honest, I'm not happy that the lasers are not aligned. When I bought the saw, I told the dealer that I'm a beginner, and I want a tool that is properly aligned. The table and fence seem to be perfect, but the lasers are not. (I know that tools require alignment, but it's reasonable to expect them to be aligned when new.)


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## Cherryville Chuck (Sep 28, 2010)

patlaw said:


> I wonder whether this blade flange (8.9) serves as a stiffener.


It does but it isn't wide enough depending on the blade. The problem comes from the fact that the growth rings in trees have a layer of soft early wood that forms in the spring and early summer and a denser layer of late wood that forms in late summer and early fall. This causes a blade to deflect back and forth on mitered cuts as the tension on the blade changes between the softer and harder layers. Blade grind can make a difference and the plate stiffness definitely makes a difference. You don't want a thin kerf on a cut off saw.

One thing you could try is to bevel the blade to 45* instead of angling the blade and see if that makes a difference. If you get a better fit that way then I would say the blade is the problem. BTW, I've had very few tools that were set up properly from the factory. Some of them way off. I used to assume the same as you but not anymore.


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## neville9999 (Jul 22, 2010)

A lot of good advice here, The more perfect the cut the better the join and most picture frame makers use a miter guillotine to do the cuts, I use a 120 tooth blade when I cut miters myself, and they come up very well straight off the saw, perfect miters really require a shooting board, this is mine, its the Stanley 50/51 combination and this set up is the best one ever made but hard to get these days since they have not been made since the 40's, shooting planes have an angled blade, Veritas sell one but its not cheap so a normal plane can be used and you you can make your own board and use a normal plane, for perfect miters then guillotines and shooting boards are the only ways, 120 teeth also helps, the plane in a shooting board must have a razor sharp blade, learning how to do that is a whole other story. Only a perfect join will give a perfect miter. N


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## Marco (Feb 21, 2009)

patlaw said:


> What do I need to do to make better miters? These were cut on a Kapex 120, so I must not have assembled them correctly.


I feel your pain when miters are a little off. The closest I have been is almost. I just ordered a Miter Trimmer. Shop our G1690 - Miter Trimmer at Grizzly.com with measuring attachment in hopes of solving the annoying problem. I looked at Incra's Miter express and Incra's 500 miter sled but didn't have enough information on them to take the Incra plunge. A shootin board looks to be a great solution but I don't trust my operator to master that. I have seen a Miter Trimmer in person and watched a video on it from Highlander 




If I can't get a perfect miter with a miter trimmer then..... I'll have to overhaul the operator!


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## Ray Newman (Mar 9, 2009)

Miters can be -- or are -- difficult. I usually cut my miters on either the Uni-saw or the ol’ Hitachi 10" SCMS. For real precise work, the shooting board or the miter trimmers are sometimes utilized.

Here's what I learned --and most of it the difficult way! FWIW:

-- Stock needs to be the same width, thickness, and length. Any variation can/will lead to problems.

-- If a dado/ groove is cut for a box lid or bottom, it must be uniform in depth. A “high spot” can keep the lid/bottom from fitting and closing the miter. As others posted, the lid/bottom must be accurately cut. Cutting the groove a bit deeper than needed helps close the miters.

-- Firmly clamp the stock in place when cutting – do not rely on hand-applied pressure. A stop block to keep the same length is a necessity. If utilizing a miter-dedicated table saw miter gauge, place adhesive-backed sand paper to a sub-fence to keep the work from moving. Same with the SCMS fence(s).

-- Check to 45 degree stops on the saw with an accurate protractor or combination square. Always make a test cut on scrap before cutting the stock. 

-- Initially cut the stock oversized in length. On one end, make a ”rough” 45 degree cut, then slightly shift the work to re-cut the miter. Repeat same on the opposite end. Sometimes a rough cut followed by a finish cut improves the accuracy of the miter.

-- On a SCMS, permit the blade come up the full steam before cutting.

--Cut longest miters first. If you make a mistake and cut it wrong, you could utilize it to cut the shorter mitered pieces.

A few years ago I made a shooting board and it works extremely well with my Lie-Nielson miter plane. Very simple to fabricate. The key to using a shooting board is a well-made board, securely held to the bench, and a heavy and sharp plane with its sides 90 degrees to the sole. Sharpness makes a fine, controlled, accurate cut and the weight adds momentum. Fine touch/cut is necessary --do not attempt to “hog off” the wood. If the sides and sole are not 90 degrees, the shooting board will not cut correctly. Trust me on this! If you find an old Stanley #7, that jointer plane will work due to mass, but make sure the sides and sole 90 degrees.

Besides lie-Nielson, VERITAS has a shooting board (or is chuting board??): 
https://www.lie-nielsen.com/product/joinery-planes/no.-51-shoot-board-plane-?node=4169
Veritas® Miter Plane - Lee Valley Tools
Fabricating a shooting board: Setting Up and Using a Shooting Board

Or as Marco posted, keep an eye out for the old and now-defunct Pootatuck Lion Miter trimmer, or one its “quality” import clones. Like a plane, the blade must be scalpel sharp. The ol’ Lion has adjustable fences for trimming different angles.


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## Herb Stoops (Aug 28, 2012)

When doing miters I found that if I cut 3 sides/pieces and they all are fitting like they are supposed to, I always physically mark the 3rd cut,that way it will fit no matter what.

And a jig can consist of the size of your project laid out on a sheet of plywood and 4 cleats nailed to the outline for you to assemble the project inside of them and holds them so you can clamp them. But it allows you also to dry fit them before you put any glue on them and fine tune the joints.

Just my 2 cents,

Herb


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