# Fine tuning a mitre box that doesn't cut vertically correctly



## kevinw (Feb 29, 2008)

Hoping someone here can help me figure something out. I use an old mitre box a lot (not a chop saw) and I cannot seem to get a square vertical cut on it. I have shimmed the wooden base and when I check it with a square to the blade it is square. But when I make a cut it is never quite vertical

See this pix for better explanation:

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https://flic.kr/p/7570623874

The top view on the 45 degree angle is fine:

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https://flic.kr/p/7570629684

Any suggestions?


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## MonteCristo (May 29, 2012)

Maybe it's the saw ? If the teeth on one side are damaged it will likely go off course despite your best efforts.


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## TedW (May 6, 2012)

It probably has to do with the wood moving while cutting it. Maybe try clamping the wood so it cannot move.


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## ajosephg (Aug 25, 2008)

No expert on these machines, but I'd guess the saw isn't set correctly -i.e one side has more set than the other resulting in the blade wandering.


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## thedude50 (Aug 13, 2011)

Is this a hand saw miter box do you have a full sized photo of the box does it have rods that are supposed to keep the saw aligned I am thinking this is what your talking about but want to know before I waste my time on the wrong saw


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## patron (Apr 2, 2009)

could be your stance too
like your eye is over the cut
and your shoulder to the side
making for a slightly 'pulled over' stroke

the guides may be worn too
from years of service
or like the dude says
the posts got tired
and are sagging to the right


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## kevinw (Feb 29, 2008)

Here is a couple of pix of the saw for "thedude50"


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https://flic.kr/p/7574449102


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https://flic.kr/p/7574455066


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## Sawkerf (Dec 31, 2009)

I haven't used one of those for years, but wonder if the saw guides are in good contact with the saw blade on both sides. They need to be close enough to eliminate blade "wobble", but loose enough to allow the blade to travel without binding up..

If they're worn enough they may not work right.


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## kevinw (Feb 29, 2008)

In case everyone wonders why I don't use a chop saw, the answer is that I make lots of very small boxes (2" x 4" for instance), and it just doesn't feel safe to me to use a power tool. Have messed around with limited success making jigs for my table saw as well as they are either not accurate enough or feel unsafe at these small sizes.


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## thedude50 (Aug 13, 2011)

first off looks nice ok i am of the theory that the bushings in the sled are worn or the guides are too loose I think you should check that the rods are plumb as well also critical is the work surface must be level .///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////


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## Smitty_Cabinetshop (Mar 26, 2011)

Doesn't look like those rods are adjustable as older ones are via set and adjusting screws. Might be some play in the steel saw guides as well, that bending can cliose up. May have to start looking for an older box, too, that can address these problems


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## thedude50 (Aug 13, 2011)

did this problem ever get resolved did you look at what i recommended


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## kevinw (Feb 29, 2008)

I haven't resolved it. As a temp fix made a old fashioned wooden u shaped mitre box and getting good results with that with same back saw, so feel that eliminates questions about stance, saw sharpening, etc.

Bed is level and saw is square to bed. Hard to tell if rods are plumb as not a good surface to test off of, but they seem to be plumb as best I can tell. If they are not, how would I adjust them? I don't see any way to do so other than maybe shimming somehow.

Not sure it has bushings. Where would they be located?


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## thedude50 (Aug 13, 2011)

the rods on my box are held in brass bushings. if they are loose your cuts will be bad. if the rods are bent the same thing. try to take the rods out and roll them on your table saw. if they aren't flat you will see them wobble, after you try this let me know what you find.


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## Loren (May 30, 2008)

You might want to invest in a Lion or similar miter trimmer - 
the cuts you get are dead-on. In the old days mitering
with a saw was unreliable and end grain would routinely
be squared using various forms of miter trimmers and 
shooting boards.


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## Johnnyblot (Mar 2, 2012)

Following on from Loren's comments which I agree with: -
My approach, to get the accuracy you are looking for, would be to saw (as you are doing) to a knife line, cutting just shy of the line in the waste side. Then with a shooting board and plane sneek up onto the knife line.

I know this will take longer but the accuracy you can achieve is much better IMHO.

The great thing about gauge and knife lines is that they leave behind a mark or "polished track" that you can see easily.

I hope this is of some help.

Cheers
John


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## thedude50 (Aug 13, 2011)

I also agree with Loren a a shooting board is how i do all my cuts, but the saw should still cut pretty close to true. I would get the saw as close to true as I can and ten go to the shooting board. I like my 62 on the shooting board with a hot dog. Rob Cosman uses a no6 on his and that's what he likes. One thing for sure your Iron must be very sharp to the extreme, to cut end grain well. If you don't know how to do this on a shooting board you can go to my website and click on the rob cosman banner ad then sign up for your free month. He shows how to use a shooting board correctly on his site. I am currently working on several videos on the topic and will be putting up my own videos soon free of charge. But for now if you don't know how to make or use a shooting board robs power and hand tool class is a great resource. I recommend it highly. Like I said you get 30 days free from my site, but if you want to learn a load of hand tool stuff and some power tool stuff join and watch them all.


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## kevinw (Feb 29, 2008)

Finally Figured this out. Below where the posts screw on there is a threaded screw with a nut to lock it. This allows you to kick the base of the rod in or out. 30 minutes of fiddling and it cuts nice and square!


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## roman (Sep 28, 2007)

a finely tuned tool

yummy : ))


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## kevinw (Feb 29, 2008)

Here is a photo to show it better.


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https://flic.kr/p/8041813343


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## dewhite (Feb 17, 2013)

I just had the same problem out of nowhere. Not sure if it was sharpening the saw or what. After reading posts I stoned the sides to remove excess set. No success. Adjusted and readjusted everything. Then I replaced the board with a much thicker piece. I also plumbed the blade of the saw rather than the guides. It seems to cut well for now. I think the big problem was the baseboard because I noticed that after cutting as I let up pressure on the saw the top of the cut piece moved away from the saw rather than staying flush with the saw. It seemed that the base was flexing during the cut and throwing it off. Hopefully you are still not having this problem but if so, maybe this will help.


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