# Trying to cut boards to equal length



## [email protected] (Jan 30, 2012)

Hello, I am rather new to woodworking, and I am building a large dobsonian telescope mount. The mirror box needs to be four panels of 1/2" Appleply or similar hardwood. the dimensions of each need to be near exact at 17 and 3/4" by 15 3/4". I cut all the pieces from a board on my table saw ,pushing each one tight against the fence, but somehow, each of the boards is something like 1/8" different from the others. Now I am thinking about how I can make them equal to each other, without taking too much wood from any of them. Any suggestions appreciated. I was thinking about running them all through the table saw at the same time, and on the left side of the table, clamping a 2x4 piece of wood, sort of as a left sided fence, and squeeze all the boards together so there is no change for error.
in general, how does one get exacting cuts, with larger boards? I found information on smaller pieces of wood, but not larger. thanks!


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## cabinetman (Jul 5, 2007)

Use only your saw fence set at the dimension, cut all the pieces for the same measurement, individually at that saw set up. When ready for the next size, set the fence and cut each piece one at a time. IOW, each size hasn't changed from one to the other (for the same dimension).

Don't try to cut pieces that are ganged up...like on top of each other.











 







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## [email protected] (Jan 30, 2012)

ok, but on the second setup, how do I make sure they are all the same size? It seems like your just telling me to plop down the boards (which are different lengths, and cut the against the fence? yeah, and? How do I make sure they all end up same size?


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## ccrow (Jan 14, 2010)

theoretically if the fence doesn't move and you don't change anything other than the board to be cut, each one should be the same.

Anther option would be to use a table saw sled and use a stop block on one end and cut the other end off.


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## [email protected] (Jan 30, 2012)

I notice that the boards can move around a little during the cuts though, maybe undulating a little against the fence.


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## joesbucketorust (Dec 13, 2011)

[email protected] said:


> I notice that the boards can move around a little during the cuts though, maybe undulating a little against the fence.


What kind of fence are you using? If you set the fence and use the miter gauge in the slot on the same side of the blade as the fence to provide support behind the board, then there shouldn't be any moving. 

If that is outside the ability of your tablesaw, you can try a jobsite route that works for 2x4 gang-cutting - stack all the pieces, clamp together, clamp a square down as a guide and cut them all at once with a circular saw.


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## yocalif (Nov 11, 2010)

I take it you are crosscutting? If so are you only using a miter gauge without any thing else to guide the cross cut?

1st make sure your blade and miter slot are aligned perfectly and miter gauge set at 90º, then the rip fence to the blade.

If you are not using any attachment (fence) to your miter gauge that effectively widens the gauge so your piece of wood is stabler, then add either a piece of wood that is perfect flat and parallel as per the image below.









You can even add a jig to size the cut perfectly to the wood fence. The pic above shows using the left miter slot, most use the right, depending on where the most support on your table saw is you can either.


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## [email protected] (Jan 30, 2012)

I do not have a miter gauge, this is an older craftman table, with a new blade, and I have this little portable miter handheld guage, and I like the idea of making a simple jig as above, I just need to re-read the instrutions.
I also have a miter saw with laser guide. Problem is of course that miter saw is really a chop saw and only gets one pass. Was thinking how much I like that laser. Could I use the miter saw for a couple of passes on each piece, by that I mean, I would make my first chop, re-set the wood, once or twice, so it would take a few times on each wood piece, but that laser makes me confident about where the blade will go.
thanks!


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## Foresta Design (Dec 26, 2011)

One thing you have to watch with the laser on your miter saw is that the laser is true. The line can look right but if you put you blade down it can really be off. As with any tool make sure your laser is true. Trust me I learned the hard way.


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## ctwiggs1 (Mar 30, 2011)

If you're ripping using the fence and getting different widths every time, it's either operator error or a bad fence. I also have an older craftsmen, and I have to measure BOTH sides of the blade (front and back) because the fence sucks.

Even 1/32 inch will make a big difference from board to board, so you have to make sure that thing is dead on. Don't trust the tape on the fence... Use a tape measure. And along those lines -- use the same tape measure for the entire project.

ctwiggs1


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## AlWood (Apr 18, 2010)

Chironic, I presume you work with a table saw, and your fence is by now well set and stable. I was dealing with the problem like yours many times, and -- again other than fence -- what is greatly important, is that you provide a strong holding pressure on the side of a piece that goes into the blade. Two things: 

(1) use a good feather-board, with the front feather coming close to the blade (and preferably, the full contact length of the feather-board long enough -- close to the length of your piece);

(2) you need a strong holding pressure on your piece as it comes out behind the blade. Of course, you can use another feather-board, but in my experience the best is a good, well-springing splitter. On most of the saws, a splitter is essentially, a part of protector assembly, but I use my own splitters (have made a set of them, using a mild steel, with the thickness slightly smaller than a blade kerf); make sure that the right side of the splitter is flash with the right plane of the blade). 

This way, your piece is guided not by the fence alone (which in no way provides good precision), but also by your "left handlers", so that it rides in a well defined channeling structure, and doesn't not depend on operator's errors like unsteady hand, etc. But with all these holding things -- be CAREFUL: use a good pusher that not only pushes your piece, but also hold it down at a sufficient length; try to not put your hand on the piece... 

Good luck.


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## [email protected] (Jan 30, 2012)

*"pulling da trigger"*

so, what I have done, and I guess it's kind of "ganging up"
is I have leveled out/squared the stack to cut the height of my mirror box
for my dobsonian telescope 

http://www.obsessiontelescopes.com/publications/index.php

so I have four 1/2" boards. all I have is my table saw 10" blade (rip blade w fewer teeth). But it was late by the time I got set up, and as I decided to save the setup for tomorrow. please look at the pictures and tell me im not crazy.


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## [email protected] (Jan 30, 2012)

I see the pic I tried to post didn't make it into the thread.
I took my four boards, roughly 16 x 18", leveled/squared em at the bottom; wood screwed em twice, measured the table saw, and saved the setup for tommorow to push all the wood thru in one fell swoop. I have my fence and a little push stick I made. It seems like a lot of stock to put through at once, bu then again, shouldn't a medium sized table saw accommodate 2" of hardwood?


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## BernieL (Oct 28, 2011)

I'd like to help here, but I'm a bit confused. By equal length and your cuts being 1/8th off, are you trying to cut the width or the length? Both fence and miters have been mentioned here and they just don't mix. 

If you're trying to cut equal width, use only the fence. Make sure your stock has a true edge by placing it on a true flat surface and a light source behind it. If you see light sneaking out from under the board, your edge is not true. Now you need a jointer or add another true edge on top of the opposite side to use while creating a true edge. I know some folks understand what I'm saying here, so if you don't understand, ask.
Once you have a "true" edge, make sure your fence is square and recut using the true edge against the fence

If you're trying to cut equal length boards, using a miter, using a fence could be very dangerous to you. you cut off boards could bind and be ejected at a very rapid speed (kick-back). Best case scenario, your cut off snag a bit causing them to be of unequal length and not get ejected. The solution to cutting equal length pieces using a fence and a miter is for you to clamp a piece of wood to your fence BEFORE the blade. That way you can butt the clamped wood and cut without the snag. Again, I know some folks already on this forum know what I'm talking about... so ask. 

Good luck and welcome to the world of woodworking. It's another great hobby like astronomy.


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## [email protected] (Jan 30, 2012)

Thanks bernie,
So, what I am trying to do here, and if there is a way for me to post pics on the thread from my hardrive, please let me know -- my boards now are all about 18" by 16". so when you ask if I am cutting to width or length, are you asking because of the way the wood grains are oriented?
please picture this, which is my current set-up, and ready for cut tomorrow: four 1/2" pieces of Appleply hardwood, wood screwed together with two 2 " bolts; a craftsman 10 " table saw, blade straight up w. no bevel, a standard rip fence, and a small push stick I made. The table has not miter gauge. I have used my large angle carpenters angle to measure the exact distance from the edge of the blade, to the fence. Clamped the fence, oriented the wood; and now just need to wait for the right time to turn on the machine, and push the wood in, using my right hand to push the stock against the fence, and my left hand manipulate the push stick, and my heart and mind to see me through. I have no miter gauges, sleds, or other than I have mentioned. Though I might change my mind and tomorrow just bolt and feed to boards at a time, which seems to me a little more sane. The old man I bought the table saw though, he is sort of a wood guru, told me I could do it this way. Just not sure that's all there is to it. that is why I am posting here.


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## [email protected] (Jan 30, 2012)

oh and to answer if I will be cutting to width or length, well, both, in different sessions. The first cut will be to height. most of the stock is at about 17 3/4" height, squared on the bottom, and clamped, then bolted together. So the first feed will be the length, wherein I will be trimming width wise. The width of the boards are at about 15 3/4 "; but again, they all vary by as much as 1/8" or 1/4". I would be essentially trimming width wise so everything is equal width. 
Then I will unscrew the stock, and level again, and feed the width, again trimming about 1/8" to each one, all at the same time.

Any better suggestons with common wood cutting equiment?
I also have a good circular saw, a jig saw, miter saw, and a router. but how better to go about making all pieces equivalent then using a table saw?


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## BaldEagle2012 (Jan 25, 2012)

If you use your miter saw, measure from the blade to the length that you need and clamp a stop block there, then put your boards on the table and cut them to length. They should all be the same when you finish. MEASURE TWICE, CUT ONCE.


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## MNsawyergp (Jan 31, 2012)

I just read your conversation and I am wondering how accurate your saw is set up. If your blade isn't exactly parallel to your fence, the board will pinch or pull away from the fence as you push it through. Either will give you a different measurement end to end. To fix, raise the blade all the way, lock your fence a few inches away, then measure from the edge of the blade to the fence at the front of the blade and the back of the blade. This measurement will tell if your fence is parallel to the blade or not. To adjust, there should be some bolts on your fence to loosen the clamping mechanism part and the rail part of the fence. Slightly loosen those bolts so the rail moves at the back end of the table. Move the fence into parallel position and re-tighten the bolts. The next thing you need to check is whether you have true 90 degree corners. Checking that requires an accurate framing square. Most framing squares are not square. Test the square by putting the square in position with one blade against a wide panel and drawing a line along the blade that is on the panel face. Then, flip the blade that was against the edge to the other side of the line and line the blade you drew the line against up to the line you drew. It should match exactly. If not you have a worthless square. Now, back to your panels...you will be chasing your tail until you work with accurate tools. If you had a jointer, you could trim from zero to 1/64th or 1/32nd off the incorrect side and make your panels exact. You could also use a router with a pattern bearing straight bit that will follow a pattern and make exact copies in the piece you attach to the pattern. You could pick your best piece as the pattern and trim the others to fit it with this method. These are some options, but accuracy is only as good as the tool set up.


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## cabinetman (Jul 5, 2007)

[email protected] said:


> ok, but on the second setup, how do I make sure they are all the same size? It seems like your just telling me to plop down the boards (which are different lengths, and cut the against the fence? yeah, and? How do I make sure they all end up same size?


If you don't understand a suggestion, it will be explained. If you set the fence one time and cut each piece against it, each piece will be the same (as per the fence setting). Is that clear enough?










 







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## [email protected] (Jan 30, 2012)

Yes your post is clear, thanks. what I did not do the first time is use both hands to feed, and I think that is what went wrong.


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## woodnthings (Jan 24, 2009)

*Yipes...No!*



[email protected] said:


> Yes your post is clear, thanks. what I did not do the first time is use both hands to feed, and I think that is what went wrong.


OK the basics are that the blade and the fence are parallel or should be.
A workpiece, *held firmly against the fence* and moved into and across the blade will be a given size...what ever the distance from the fence to the blade is...everytime.!
*Two hands are not required for this*, just downward, forward and inward pressure toward the fence.
You can use a push block that does that, or your hand depending on the size of the piece to be placed between the blade and the fence. Here's how to do it..the correct way and the wrong way:






This is called ripping, and uses the "rip" fence. It's usually a cut down the length of the board, and with the grain of the piece.
Cross cutting is done using a miter gauge or a sled that fits in the miter slots and...is usually a cut across the width of the board and across grain of the piece.

Cross cutting, across the width of a board, to a certain length does not and should not involve using the "rip" fence. To cross cut pieces to an exact length, a stop block can be clamped well in front of the blade to the saw table or to an extended miter gauge surface ...sorta' like a fence, but don't confuse it with the "rip" fence. :no:

This is real basic stuff and should be covered in an owner/operators manual for any table saw. You can download one from Grizzly. 

BTW Plywood has the grain running down it's 96" length, so when ripping plywood down it's length you use the "rip" fence. 
Crosscutting plywood may be restricted to the maximum width by the limitation of the miter gauge or you can use the rip fence if there is enough edge to bear against the fence and maintain control, usually at least 12", more is better.
You can use a combination of the miter gauge and the fence with practice and with them both properly squared and adjusted. This is somewhat controversial, so expect warnings from those who have never done it, but it helps keep the work piece from rotating off the fence as in the Video, and prevents kickback. The best "kick back" preventer is the splitter and every saw should have one. They do not permit stopped or partial cuts, so they come off for those... and sometimes never get put back on.
Plywood is one of those "either/or" situations because it is a lamination of grains that cross internally. I've had plywood pieces rotate off the fence and come back at me with lots of speed and force so you must hold a constant pressure against the fence, especially on pieces under 12" wide. Most miter gauges will allow a cross cut of 14" or so, if your table is the standard 27" deep. 
The splitter also prevents the work,when it's lumber from a tree, not plywood, from closing back on the rear of the moving saw blade, pinching it, and then launching forward toward the operator. It keeps the saw kerf open so that doesn't happen.


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## [email protected] (Jan 30, 2012)

That is a terrific video! 
So essentially kickback occurs when the not enuogh pressure is applied against the stock into the fence, as the stco passes the midline of the blade, that back part of the blade is not pushing the stock into the table, but up and toward the user.
So manual force needs to be applied the entire way through the cut. Is this correct? anything else I should know?

How do I know what is a safe amount of stock to feed through a rip or cross cut? 
My job entails a 2" deep rip cut, then a 2" deep cross cut, across an amount of stock between 15" and 18".

So my concern is the size of the job.
Should I clamp an additional piece of wood parallel to the fence also to prevent the stock from binding? 
anything else I should know about the job I describe?
your information is invaluable to me, and if there were a way for me to pay you here I would, because I really need this job done, safely, and accurately.
thanks again!


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## [email protected] (Jan 30, 2012)

sorry I just re read your post, and it says that cross cuts should use a miter, and not the fence?
why is that?


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## [email protected] (Jan 30, 2012)

also, I am cutting plywood of several layers. it seems like the orientation of the grain is not so much a factor then, because only the top veneer has the growth rings?


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## cabinetman (Jul 5, 2007)

[email protected] said:


> sorry I just re read your post, and it says that cross cuts should use a miter, and not the fence?
> why is that?





[email protected] said:


> also, I am cutting plywood of several layers. it seems like the orientation of the grain is not so much a factor then, because only the top veneer has the growth rings?


There is more to cutting on the table saw than just the "rip" or "crosscut" terminology, as it's more of a theory that you decide on. It's not always a grain direction decision. It's a decision you make on the size and shape of what you are cutting. 

With plywoods, grain direction is not an issue, but rather the shape and the cut you will make. This can apply to lumber also. 

Here is an example:

Lets say you have a 24"x24" piece of plywood, and you want to cut it in half...winding up with 12"x24". You may want the grain to run the 24" length. With this cut, it is neither a crosscut, or a rip. Once the one cut is made you now have two pieces 12"x 24". Going further with the theory, if you now want to cut one piece at 10", giving you a 10"x 14", that would be a cross cut because it is longer than what will ride on the fence. Because it's narrow and long, it's harder to control keeping the edge on the fence. So, with this example, using a miter gauge, or a sled would be a safer cut.

Now, going to lumber, the same holds true, if the piece is long and the edge riding on the fence is narrow, it also is a cross cut. "Ripping", would refer to having a long board and cutting "sections" off one edge...hence...ripping off an edge. 

So, the "rip" and "crosscut" theory is one that you make decisions on for which way to orient the board/stock to be a safer cut.

NOTE: The sizes for the cuts were general not figuring a saw kerf.










 







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## [email protected] (Jan 30, 2012)

thanks again for the clarification, on "theory."
So, I did take some time today to go to a woodworking shop where I watched an old hand do some cutting. He has this machine that cuts would like butter, and it's less noise than a kitchen blender. And I am thinking, I got this old craftsman 10". Are these table saws Craftsman make really worth even having in the garage. I mean, this other machine I saw really put mine to shame.


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## BaldEagle2012 (Jan 25, 2012)

The posts I am reading from Chironik, appear to be confusing. 

Chironik, my first suggestion is to go to the library get a book on basic table saw use. Paying particular attention to the RIPPING, and CROSSCUT explanations. 

My second suggestion is to purchase a quality miter gauge for your table saw. I use the INCRA 1000 SE. It is a very good miter gauge, and comes with a stop on the left side that is adjustable along the length of the miter gauge. It also has an adjustable length incorporated to accept different lengths and for multiple crosscutting of boards to the same length. 
http://www.rockler.com/product.cfm?page=16842&filter=incra miter gauge

I use this miter gauge daily in my shop and I get consistent results every time. It is adjustable to make sure it is accurate, and I recommend that you make sure it is tuned up correctly. 

I never use the table saw fence when crosscutting, it is far to dangerous and not worth getting hurt. 

Also when I use the fence for ripping I use two push sticks, one in the center of the piece I am ripping and one on the left rear corner of the piece to keep it stable against the fence thru the entire cut. 

I have a Craftsman contractors Table saw I bought in 1995, it has a very reliable fence, similar to the Unifence, and is also adjustable and works quite well. 

I hope that this information is helpful.. 

Wayne


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## TomC (Oct 27, 2008)

BaldEagle2012 said:


> The posts I am reading from Chironik, appear to be confusing.
> 
> Chironik, my first suggestion is to go to the library get a book on basic table saw use. Paying particular attention to the RIPPING, and CROSSCUT explanations.
> 
> ...


I agree with the above statement. I would also suggest if you have a friend or relative that is an experienced woodworker have them go over the basics of table saw operation. Also, you could check with a local community college to see if they offer a basic woodworking course. I took two classes when I got back into woodworking after not doing any for several years.
Tom


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## [email protected] (Jan 30, 2012)

Thanks, I have acquired books on the subject. but actually, Can anyone recommend some dvd's or videos of good quality to learn from.


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## BernieL (Oct 28, 2011)

Sorry I got busy... life is always happening around me (Ye Ha). But I must admit... I'm still a bit confused although yo do have lots of excellent advise - #1 being what I originally tried to warn you about; miters are dangerous when used with a fence. As suggested, go to your library or return to that workshop (with the silent saw) and learn the basics. Once you know the basics you can re-post questions so we can all be on the same page. I belong to a few woodworking sites on the net, but I keep coming back to this one because of the folks. All sites have good advise, but some seem to be hijacked by a few. Here you get good across the board advise. Woodworking is an adventure and depending on your personal experience, it gets described in different ways, all being correct. When you see different responses, you just need to pick the one that works best for you. Good luck and keep all of us posted,


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## [email protected] (Jan 30, 2012)

BernieL said:


> Sorry I got busy... life is always happening around me (Ye Ha). But I must admit... I'm still a bit confused although yo do have lots of excellent advise - #1 being what I originally tried to warn you about; miters are dangerous when used with a fence. As suggested, go to your library or return to that workshop (with the silent saw) and learn the basics. Once you know the basics you can re-post questions so we can all be on the same page. I belong to a few woodworking sites on the net, but I keep coming back to this one because of the folks. All sites have good advise, but some seem to be hijacked by a few. Here you get good across the board advise. Woodworking is an adventure and depending on your personal experience, it gets described in different ways, all being correct. When you see different responses, you just need to pick the one that works best for you. Good luck and keep all of us posted,



I am not sure what it is that I said was confusing, or maybe I changed the topic a little?
But I gather you expect a certain amount of "proficiency" to have a conversation here. Ok, it's gotta be worth your time.


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## woodnthings (Jan 24, 2009)

*thintz has videos*

it's called NewWoodworker.com on You Tube:

He does some tool reviews and how to's:

http://www.youtube.com/user/thintz12?blend=1&ob=0


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## BernieL (Oct 28, 2011)

Chironik... please excuse me for the way I said what I said. It was a bad choice of words or at least I didn't say what I meant to say. I certainly do not have a right to ask for a certain level of proficiency to use this forum. By all means, new woodworkers should be encouraged to ask questions.

I guess the problem I'm having here is not understanding what you are trying to do and the problem is not necessarily you. But I'm afraid to mislead you or anybody else and then read a post about a serious injury I could blame myself for. Woodworking is a great hobby many of us like. And it's great to share our interests. But it's also a very dangerous hobby if the tools we are using are not understood. Every time I buy a tool, I read the manual and they all say "understand your tool before using...".

It scares me to read that you are trying to cut equal "length" pieces with the use of a fence. Fences are for the width of boards. And if you try to cut a wobbly board, that can cause kick backs. 

Please forgive me for the way I said what I'm trying to say here. Don't give up because of what I said. I'll just step back from this post at the moment and let other folks who understand your problem take over here. Good luck!


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## [email protected] (Jan 30, 2012)

thanks for your reply!

I have been learning a lot this last week, as I acquired this moderate sized craftsman table saw, without a miter gauge, I was trying to cross-cut using the fence, and I had a couple of sketchy incidents. Fortunately I made sure to stand to the side of the table, so that when kick-back did occur, (which occurred in fractional seconds and caused my heart to jump about one hundred rhythms), the kick-back missed me. So I have purchased a book on table saws and also I purchased a DVD which I have studied. I also purchased a new rip fence (the one I had was bent) and a miter gauge. I hope to not have any more kick-back incidents, not any other sketchy incidents. I have been able to cut boards now of equal length, by measuring very carefully the distances on all points of the rip fence to miter slots.
I would like to make a sled. So if anyone could give me some ideas on how to make the miter slot runners, I would be very obliged. The DVD I have kind of ran through that topic too quickly.


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