Noobish Question Ever...

[mackmack]

So I have never been tought so much as to cut a piece of wood with a hand saw, never was able to take shop class in highschool...though I did take Latin..lot of good that did me.

Anyways, I have a simple question "How do you cut wood accurately"?

I usually measure three times, and then use a very sharp pencil to make a line on the wood. I then line it up on my table saw and cut. I would say I get an accurate cut 50% of the time. When I'm off its by 1 or 2 16ths of an inch.

Should I use pencil to mark then cut? Do I cut to the inside, outside, or center of the line that I make?

It suck having to measure 3 times and cut 5 to get 1 or 2 good pieces that fit perfect.

Oh, and the table saw is fine...it is set and accurate...It's just me. WHat am I doing wrong and what shouldnt I be doing?? THanks so much for any help.

[Ken Weaver]

Simple question Mack, not a simple answer though. Several things to consider (assuming you're trying to do a cross cut).

When you use a pencil and a square, you will throw off your cut by the width of the pencil lead if you make the cut on the wrong side of the mark. For example, measure 3 3/4" on a piece of scrap - make your mark. Use your square to make the line all the way across the board. The only place where you get a true 3 3/4" is on the side of the line next to the square. Assuming you were measuring from the left side of the work, and placed the square head to the left of the mark, you would have to cut to the inside of the line to be accurate. This would be true if your were using a TS or CMS.

When ripping the most common problem is forgetting to allow for the width of the blade in measuring from the fence.

Taking your time and practice are the best ways, but it still doesn't protect you from brain cramps (see my earlier post). You'll get there, keep the faith.

[LCHIEN]

So I have never been tought so much as to cut a piece of wood with a hand saw, never was able to take shop class in highschool...though I did take Latin..lot of good that did me.

Anyways, I have a simple question "How do you cut wood accurately"?

I usually measure three times, and then use a very sharp pencil to make a line on the wood. I then line it up on my table saw and cut. I would say I get an accurate cut 50% of the time. When I'm off its by 1 or 2 16ths of an inch.

Should I use pencil to mark then cut? Do I cut to the inside, outside, or center of the line that I make?

It suck having to measure 3 times and cut 5 to get 1 or 2 good pieces that fit perfect.

Oh, and the table saw is fine...it is set and accurate...It's just me. WHat am I doing wrong and what shouldnt I be doing?? THanks so much for any help.

Several areas where you can go wrong, and add up to 1/16th of an inch.

1. Make sure your ruler has a zero reference, that is, a hook ruler, or a combination square where one end hooks to the existing end of the wood, otherwise you will have parallelax and error of matching the end of the wood to the ruler at that end. A tape measure has a hook, but generally I don't trust tape measures that much. for smaller cuts.
2. make sure you make a pencil allowance, when using a combination square and I want 6", I make sure the 6" line is just under the square part rather than showing. Then I butt the square to the end of the wood, and mark across the end of the rule. I also tilt the pencil so as to mark close to the rule end as I can. Then I take the square and put it crossways to the cut direction. Rest the pencil point on the little short line, slide the square rule up to the pencil so it will mark on the same line, and mark the width coincident to the mark I made. I use a 0.5mm mechanical pencil so the pencil lead width is always constant and not dependent upon how sharp the pencil is at that moment.
3. Make some hash marks on the waste side of the wood just as a reminder.
4. When you cut, the edge of the blade should be up against the line! Not centered. The blade should take out the kerf (3/32 to 1/8" depending upon blade thickness) on the waste side you marked. To do this you may have to bend down and sight along the blade and the line, and make the first little cut a tiny nibble so you can see if your cut is right at the line. You want the edge of the blade to split the pencil mark with the rest of the blade on the waste side.

Make sure nothing is slipping - some people line the face of their SMT fence with fine sandpaper glued to the face to provide a non-slip surface for holding wood during crosscuts.
I can make extremely accurate cuts.

If you are measureing 3 to 5 times and coming up with different lines then your measuring and marking technique needs work. You should be able to mark the same line repeatedly. I only double check my work to make sure I didn't mark 5-3/8" by accident when I meant to mark 5-3/16" (misreading the scale). My marks are always on the first time.

If your marks match repeatedly, then your your cut technique is probably not hitting the cut line correctly.

All this will be better with more practice!

[JR]

You can frequently overcome accuracy problems by assuring similar cuts are exactly the same. If they're off by 1/16" it's ok, because they're all off by the same amount.

Study your plans for this kind of opportunity. Rip cuts of rails and shelves that need to be the same width should all be done with one setting of the rip fence.

Whe using the SMT for cross cuts, set up a stop block at the correct distance from the blade. Then cut all your legs or stiles or whatever using that same setting.

Many times the problem isn't so much one of accuracy, but rather it's about symmetry.

good luck,
JR

[SARGE..g-47]

You've gotten some excellent advice, mack-mack. If you're new to this, I would go back and start at ground zero though. Use a machinist square if you have one (most squares aren't square anymore) and make sure the blade is sitting 90 degrees to the table.

Then make sure your mitre fence is dead on 90 degrees to that blade. Place one side of the square against the fence and have the other L slightly touch the front tooth kerf of the blade (with saw un-plugged of course). Now, move the slider forward till the leading edge of the L gets to the back of the blade tooth. Rotate the saw blade and see if a kerf tooth touches slightly as it did on the front and rear. If so.... you are square.

I don't make a pencil line all the way across. Make sure you use the same measuring device and I simply make a "tick" with an old sharpend ice pick at the front of the stock. Then I take a sharp pencil and insert the point slightly to leave the dark graphite for a better visual.

Then I place the stock on the mitre fence and align the outside of the keft tooth just outside the "tick". Secure the stock to the fence and the square you derived at from the 90 degree angle of mitre fence to blade will take care of the rest. As the guys metioned, you are cutting from the outside edge of that tooth keft. The blade is either 1/16" or slightly smaller using a thin kerf. Put it in the wrong place on that line and you get pot luck!

I use a corrected large framing square when making a rip cut. FS from fence to front inside tooth kerf of blade. Then reverse the square and fence to rear inside tooth kerf of blade. And as mentioned, if they are all off the same amount, you just made a slight adjustment in design plan but still have square. :>)

SARGE.. g-47

[RayintheUK]

If your table saw is set up accurately, then rather than "lining up" the workpiece on your saw, the only measurement you shoud need to make is the distance of the fence from the blade for ripping (All the following points assume that you're cutting conventionally, with the rip fence to the right of the blade when viewed from the front).

If I want to rip a piece "x" wide, then I measure from the fence to the inside of the teeth and check twice that it's exactly "x" - second check is done after the fence is locked down. This measurement can be done with a steel rule or a good-quality steel tape. Butt the end against the fence, then run the rule through the gap in the blade between teeth. Look down from immediately above the blade and adjust the fence until the mark on the measure exactly co-incides with the inside (right-hand side) of the saw blade tooth. After that, just lock the fence, re-check and rip it. If the saw's right, then the cut will be too.

When cross-cutting, then if you need to make a cut on a line you've drawn on the timber, err a little on the strong side when setting the board on the saw, then you can "creep up" on the cut if it's still too strong - this applies to both table saws and miter saws equally.

You don't say which table saw you've got, but if you're using one with a sliding table or miter gauge, then the use of a stop block (as JR mentions above) is the way to get repeat cuts. Once the measurement from the stop block to the inside of the teeth is correct, away you go.

The point Ken Weaver makes about allowing for the width of the teeth (the "kerf") only applies if the "good" piece of stock is to be the cut-off - i.e. the part of the timber that runs to the left of the blade when ripping or cross-cutting. HTH Nil carborundum!

Ray.

[mackmack]

Wow, great info and fast like always guys. I appreciate it. I will be putting as much of what you have given me into practice today. Thanks again!

[Tom Hintz]

For most people, accuracy seems to be an acquired skill that benefits a bunch from practice.
I have a story on Accuracy with some things I have found to be true in my shop. There may be some bits of info there that will be of help to you along the way. see the link below.

http://www.newwoodworker.com/accurcy.html

[Jeffrey Schronce]

For most people, accuracy seems to be an acquired skill that benefits a bunch from practice.
I have a story on Accuracy with some things I have found to be true in my shop. There may be some bits of info there that will be of help to you along the way. see the link below.

http://www.newwoodworker.com/accurcy.html

Great article Tom!
Does anyone have any detailed information on the REAL LIFE use of these devices. Example in your article you have a photo of the magnetic base with the indicator dial. Well those things don't come with directions for measuring arbor runout or whatever you are doing with it to those jointer blades. And yes, I have read a bunch of TS books and they suggest all kinds of things but never explain how to do them.
Anyone have a great reference on these precision tools?

[SARGE..g-47]

Ray in the UK...

Not on subject here, but do you use the long fence or the Euro short rip fence? Just curious as I built a short fence years ago on advice from an English WW that did custom furniture in Houston, Texas. Richard Jones has since moved back to England and teaches at one of the WW colleges now in northern UK. He occasionally has an article printed in Furniture and Cabinet-making (UK) and Wood (US) mag.

Once I got used to that short fence, there was no looking back over my shoulder!

Cheers...

SARGE..g-47

[Pappy]

Something I didn't see mentioned. Most blades have alternating teeth. Usually every third tooth will be to one side of the blade body, another set to the opposite side. Make sure you measure to a tooth facing the fence or stop block when you set up the cut. Measuring to the wrong tooth will introduce a slight error.

[RayintheUK]

Ray in the UK...

Not on subject here, but do you use the long fence or the Euro short rip fence?

My BT3000 doesn't give me the options of fence usage like a cabinet saw would, but if ever I need a short fence, then a long stop block works just as well, provided it's correctly attached to the rip fence using the T-nut slot.

Ray.

[gary]

I'm not sure I have to be extremely accurate; I am sure I need to be consistant.

When I cut table legs; do they all need to be exactly 29"? No

When I cut table legs, do they all have to be the same length? Yes

So I'm planning my cuts so I can make as many cuts as possible once I get set up for a given measurement. I also use stop blocks so every cut will be identical?

It's consistency that counts!

[scorrpio]

Some thoughts:
1. Pieces you cut do not need to be certain size - they have to fit with other pieces. Which means that if some pieces are already cut, you might want to use them to setup your subsequent cuts.

2. Things come out crooked when parts are different size. Try to plan to cut all parts that should be same size on the same setup.

3. Speaking of setups. It is generally a good idea to not mark the piece of wood, but to setup your saw. Need to rip a piece to width? Set the rip fence that far away from blade teeth. Need to trim to length? Clamp a stop block to miter fence. Need to cutoff a specific length off a longer piece? Clamp a stop block of known thickness to rip fence in front of the blade, and set rip fence needed distance plus block thickness from blade. Trying to align blade teeth to pencil marks is never a good idea.

4. Far as pencils go, they are good for crude things. A marking knife is a better tool - provided this is not the finish surface.

5. Always be conscious as to on what side of blade is the waste piece. And always do setups from the other side - that way you don't have to account for the kerf.

[jabe]

Ray & pappy got it right, measure to the tooth of the blade that faces the fence or stop block. For crosscutting on the SMT do as Ray describes. For ripping just measure to the blade tooth facing the fence b4 & after locking the fence down and measure to a tooth facing the fence at the back of the blade to be sure the fence is parallel. Not understanding that the kerf of the blade does remove material will cause the frustration you're having.