Uneven cut when cutting off box tops

  • Advertise with us

« back to Joinery forum

Forum topic by SiRiC posted 08-17-2017 10:19 AM 866 views 0 times favorited 15 replies Add to Favorites Watch
View SiRiC's profile


4 posts in 1955 days

08-17-2017 10:19 AM

Topic tags/keywords: box


I make boxes and cut off the tops on the saw. I use the method of cutting just shy of the wall thickness so that there is a sliver to hold the top until the process is complete.

What I find however, is that when I make the second cut, it tends to be off by a tiny fraction giving a slight lip between the two sides.

I have tried cutting the sides sequentially, tried cutting opposite sides but it really does not make a difference.

Would appreciate any insight into solving this.



-- Measure twice...ummm.. i forget the rest!!

15 replies so far

View Andy McCormick's profile

Andy McCormick

31 posts in 3529 days

#1 posted 08-17-2017 10:57 AM

Your bottom of the box is not flat. If it’s not flat it will transfer the unevenness to the cut.

-- Andy, Liberty,Indiana,

View dhazelton's profile


2722 posts in 2230 days

#2 posted 08-17-2017 11:02 AM

I’d say your blade is not at 90 or the fence moved on you.

View Gene Howe's profile

Gene Howe

10258 posts in 3362 days

#3 posted 08-17-2017 11:29 AM

To eliminate the problem, finish the cuts with a hand saw or sharp knife.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

View Aj2's profile


1309 posts in 1731 days

#4 posted 08-17-2017 12:37 PM

Bandsaw does a better job. Thinner Kerf one pass and it done.
With a table saw you have to keep rotating around the mismatch your seeing is how flat your bottom is.
Just as Andy Mc Cormick mentions.

-- Aj

View hotbyte's profile


991 posts in 2909 days

#5 posted 08-17-2017 12:46 PM

Could fence to blade alignment also have an impact on final cut alignment???

View jeffswildwood's profile


2928 posts in 1911 days

#6 posted 08-17-2017 01:06 PM

I think fence alignment would make a mis cut on all four corners. I go with bottom not flat. Just a little off will do this. I too have had this happen, It’s a bear to fix!

-- We all make mistakes, the trick is to fix it in a way that says "I meant to do that".

View Carloz's profile


1147 posts in 525 days

#7 posted 08-17-2017 01:09 PM

I have a question for you too. How do people manage to make 3 post on the forum in 5 years ?

View rwe2156's profile


2842 posts in 1414 days

#8 posted 08-17-2017 01:15 PM

There are a several factors but I doubt it is the saw.

If the reference face of the box against the fence isn’t 1) perfectly parallel, 2) or if the bottom is not perfectly flush, 3) the sides are not perfectly square to each other.

I would still double check the blade-to-fence for parallel.

-- Everything is a prototype thats why its one of a kind!!

View Dan's profile


662 posts in 1826 days

#9 posted 08-17-2017 01:25 PM

If the insert is not perfectly flush, or like rwe2156 says, “if the sides are not perfectly square” focus more on pushing box against fence while running through.

-- Dan

View Redoak49's profile


3133 posts in 1922 days

#10 posted 08-17-2017 01:35 PM

For a long time, I used the table saw to cut off box tops. I switched to use the bandsaw and it is much better. I use spray adhesive and attach a sheet of sand paper to 1/4” MDF. I use this for sanding the bandsaw cuts smooth. This method works much better for me.

View BurlyBob's profile


5304 posts in 2199 days

#11 posted 08-17-2017 01:50 PM

I use a piece of a wide sander belt – 24”, clamped to my table saw. I sand the bottom flat so the box sits with no rocking. Once I cut the lid I do the same thing to the lid and box. Makes for a nice fit.

View Ripper70's profile


893 posts in 842 days

#12 posted 08-17-2017 02:44 PM

Here are two methods that may work for you:

How to Saw Off a Box Top

Cutting a Lid from a Box

-- "You know, I'm such a great driver, it's incomprehensible that they took my license away." --Vince Ricardo

View tmasondarnell's profile


79 posts in 1723 days

#13 posted 08-17-2017 05:17 PM


I was having the same issue and found that it was caused by two problems already identified:

1. The bottom of the box was not flat.

2. I was not keeping the box tight to fence—particularly on the short cut.

View SiRiC's profile


4 posts in 1955 days

#14 posted 08-17-2017 05:37 PM

Thanks for all of the responses!!

I make sure to keep the box tight to the fence, so it is most probably the flatness of the box.

Had tried the band saw and it was easier but the teeth marks afterwards kind of deterred me – will try again though as it easier to sand the marks than having to correct the incorrect cut from the tablesaw.

@Carloz, did not realise that I was an offender for not posting regularly!!

Thanks again,


-- Measure twice...ummm.. i forget the rest!!

View Jim Finn's profile

Jim Finn

2641 posts in 2856 days

#15 posted 08-18-2017 08:49 PM

”.....Had tried the band saw and it was easier but the teeth marks afterwards kind of deterred me ….”

Thanks again,

In the past 9 years I have made, and sold, well over 2000 boxes and I cut the tops off with a band saw. I then lightly sand the cut, with a random orbital sander, to remove the saw marks and move on to the next box.

-- No PHD, but I have a GED and my DD 214

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics