The best way to MEASURE

[Craig Mitchell]

This is probably a silly question but...... what are some good techniques as far as measuring before cutting?


I've done simple wood projects for a long time now with basic tools but have recently upgraded to a rail system (EZ smart) which has made my cutting abilities about 100 times more accurate than they were.


Which in turn has made me realize that although I can cut extremely accurately now , I now need to make sure my measurements (and markings on the wood) are perfect too.


Having been essentially self taught, I've always used basic things like tape measures, rulers, and simple squares..... but if anyone has any special tips or measuring techniques they can share, I would be grateful..... and perhaps something that is obvious to you might be new to me.


My next big project is kitchen cabinets and I've realized I need to be in the sub 1/16ths of accuracy which is maybe the width of a pencil line or blade width.


And while I can now cut that with the rail system no problem, I'm still not 100% confident I getting that kind of accuracy in my initial measurements of markings. Thanks!

[Randal Stevenson]

Several basic things.........

1. Mechanical pencils. They have a much finer lead.
2 Marking knives (I don't like these as well, but some do)
3. There are rules like Incra, which have the slots for the mechanical pencils but
4. Make a template, and use that for all your pieces. Once you have got it measured for, you use it between the blade and the stop/fence, for your good pieces that aren't under the rail.

[Peter Quadarella]

The thing I am learning about measuring is to do it as little as possible. I will go out of my way to mark something based on the size of something else. For example, use a marking gage or combination square or something similar set to the size that you need, and mark your wood based on that.

I've heard people call this relative dimensioning. Also, when you are making marks, stay away from wide lead.

[JohnT Fitzgerald]

Ditto on the mechanical pencils.

Also, when scribing a line, be sure to get the lead right up against the ruler.

Another suggestion - once you get a machine set up to make a cut, make ALL the cuts that need to be the same length. If I'm making a chest that's 44" long, and ALL the pieces end up 44 1/32" long, then it might be OK. Along the same line.....using a stop block to make repeatable cuts is very helpful.

[Greg Cole]

Story sticks & marking knives will go a long way towards accuracy. Also a good brand of square for layouts.... or the plastic drafting squares
I tend to not fussy over measurements as long as things are indentical when need be. What it the width of that tenon I cut, I dunno exactly but it fits the mortise just fine... etc.
A pencil is good for roughing things to length, width etc, but the tip of a well sharpened marking knife is much more accurate when you are looking to split hairs. In all honesty, my fingers do alot of "measuring" when I am making multiples of something, stack em up and your fingers will feel the slightest difference. "The fingers can feel what the eyes can't see" (Nikki I believe coined that one?).
The one other thing that will help out your accuracy is to make sure the machinery you are using is tuned to the best of your ability. For example, I spent a few hours on a 2 year old jointer this winter and it's oh so much more of a treat to use now as the results are impeccable.
If you are one who likes to measure, make sure to use the same measuring device from start to finish. I work with another hobbyist WW'er who does our CAD stuff etc on the day job... and he'd drive me bonkers with dimensions & tolerances in my shop. Then again if I handed him my "prints" of nothing more than basic dimensions and no drawings etc, I'm sure he'd go nuts.:D

Greg

[Ben Rafael]

Depends.
If you are going to chisel something then a marking knife is ideal since a creates a place for the chisel edge.
I avoid rulers and other such measure tools except for rough measuring. Story sticks are ideal for me. In general consistency is important.
If I need, lets say, 10 pieces that are 12 1/8" long I will cut them so that they are all the same length although they may be off by a 1/16" from true 12 1/8".

[David DeCristoforo]

Sticks. Two of em' each a bit shorter than your "net" measurement. For example, say you need to cut a rail between two stiles. So you butt one stick against each stile and mark across the sticks. Then place the sticks together with the lines matched up and you have a "gauge" for setting whatever saw you are using. A small spring clamp will hold them together if you need. No numbers required. Just look down there on the floor next to your table saw to find the sticks. Many shops (mine included) lay out entire projects on sticks and then cut and fit without ever touching any other measuring device. This eliminates any variation that might exist between your tape, your ruler, your saw fence scale or whatever.

Disclaimer: This is not something I thought of myself!

DD

[jason lambert]

My bigest error I found out was the tools, no two tape measures where the same and my squairs where not squair. No I buy all good stuff and the same brand tape measures. Helped 1000%.

[Todd Miranda]

Depends.
In general consistency is important.
If I need, lets say, 10 pieces that are 12 1/8" long I will cut them so that they are all the same length although they may be off by a 1/16" from true 12 1/8".


I'm pretty new at this woodworking and have gathered quite abit of equipment in last 6 months, but this is the area I struggle in like no other. I have been working in the metal working industry for 20 years now and have become a extreme perfectionist when it comes to measuring. When making rip cuts and length cuts what is considered a good +/- range? 1/8, 1/16, 1/64. Seems everytime I rip several pieces I gravitate to using my calipers and getting frustrated when I vary 0.010" between 5 or 6 pieces of stock.

Todd

[Shawn Honeychurch]

My bigest error I found out was the tools, no two tape measures where the same and my squairs where not squair. No I buy all good stuff and the same brand tape measures. Helped 1000%.

I never thought of the issue of tape measures and such not being the same. I have at least 3 tape measures in my shop and have just grabbed which ever is the closest.

For awhile I have been noticing that even when I am sure I measured and cut correctly, some pieces do not match dimensionally, maybe this is why. I have a couple of cabinet doors to make, I will make one using the same tape measure, and one using all 3 and see what the results are but I think I already know.

Thanks for the insight.

Shawn

[Rod Sheridan]

Hi Craig, all good advice so far.

One item I'll comment is that since you are making kitchen cabinets, you may wind up using the metric system.

Modern cabinet design is often based upon the 32mm system for design, and fabrication.

I can tell you from experience, that's it's far easier, and more accurate to stay metric during the meausurment, design and fabrication stages than trying to covert particular measurements. (Plus there aren't any pesky fractions to deal with).

Regards, Rod.

[Craig Mitchell]

Thank you very much for all the replies! Lot of good info, please keep it coming!

[Mikail Khan]

When installing mouldings on cabinets I no longer use a measuring instrument. I cut the 45 deg on one side, fit the moulding on the cabinet and mark the cut position with a sharp pencil. This has given me very good results.

MK

[Craig Mitchell]

Does anyone have a source for what would be considered "very accurate" measuring sticks and large squares.

I have several Johnson metal measuring sticks in 3, 4, 5ft length and some smaller Empire Squares.... what would be the next step up?

Good suggestion about going metric as well for cabinets. Thanks!

[Bryan Parlor]

[QUOTE=Craig Mitchell;825505]This is probably a silly question but...... what are some good techniques as far as measuring before cutting?

Craig
The tape measure has been my biggest source of error (apart from occasional bouts of brain fog). I avoid using a tape a much as possible and instead use a steel ruler, a Lee Valley tools ruler stop and a 7mm mechanical pencil.

I use the ruler to make the first part and then set up a stop on the bench for all subsequent parts. That way all parts are identical (provided you don't get sawdust between the stop and workpiece).

The ruler and stop also allows multiple marks to be made using the same setting (sometimes useful).

I also use the ruler and stop as a guage to set the Ez rail parallel to a workpiece or fence (see picture).

Bryan

[Lee Schierer]

A sure fire measuring system is to measure with a micrometer, mark it with chalk and cut it with an axe......:D


I measure with a Stanley measuring tape or 12" scale. I use the same one for all measurements on a given project so I don't have to deal with tape errors. I make pencil marks with a .7 mm mechanical pencil (.5 mm lead is too thin and breaks too easily).

For duplicate parts I like to set stops on the cross cut guide to get all pieces exactly the same length.

[Glenn Clabo]

Craig,
I was taught and continue to live by the "If you don't measure it...you won't screw it up" rule. I just completed an entire bathroom...from total rip out...to custom vanity and closet doors...without using a measuring stick once. In place marking...templates...mockups work. Measuring devices don't.

[David DeCristoforo]

"...what would be considered "very accurate"...the next step up..."

http://catalog.starrett.com/catalog/catalog/groups.asp?groupid=703

For a caliper, this is my favorite:
http://www.woodcraft.com/family.aspx?FamilyID=4440
because it's steel, has a nice "fit and finish" and reads in 64ths instead of hundredths or thousandths.

[Greg Cole]

One item I'll comment is that since you are making kitchen cabinets, you may wind up using the metric system.
Modern cabinet design is often based upon the 32mm system for design, and fabrication. Regards, Rod.

To add to that, most sheet goods today are really measured in millimeters and converted to the next closest fraction. And milling boards you can mill to metric dimensions just as easily as imperial, least I can & do.
If you opt to use metric measurements, you might as well "slave" the tooling you buy to match. As in don't count on a design with a 12mm dado to be snug if you use a 1/2" dado stack etc etc etc. The conversions are close, but close doesn't mean good.
You can drive yourself bonkers on this subject. Don't get into tiny machinist measurements with wood, it was once alive and still moves after it's dead.;)

Cheers.
Greg

[J. Z. Guest]

As others have said, the most reliable way is if you dont have to measure, don't. In other words, mark according to what is existing, rather than measuring it and trying to measure again and cut again. This isn't always possible, because one has to start somewhere.

Lee Valley sells something called setup blocks that will take care of anything you need less than 4" or so.

Story Sticks also work. (where you cut the first stick to size and use it to set machines for every major dimension in your project)

The "clamp-together sticks" trick is a good one too. What is that called? It has an official name. For that to be reliable, I don't know that one could rely on a spring clamp. A C-clamp or two would be better.

Tape measures - the trick with these is to make sure they match your ruler(s) and squares. I accomplish this by bringing the blade of my Starrett 12" combination square when I'm shopping for a tape measure. I'll go through the whole rack of tape measures in the store to find one that matches right down to the 1/32". My 6" rule is also a Starrett, which matches the combo square. Also with tape measures, remember that they change over time as the connection between the tip & tape is worn. For instance, if you let the tape snap shut, it will elongate the holes that the tip is attached with and every measurement on that tape becomes stretched out. So check your tape measures frequently and don't let them snap shut. I agree that tape measures are not the best way to go, but they are so convenient it is hard NOT to use them.

Marking knives' scribed lines are more accurate than pencils, but harder to see. But they have the added benefit of preventing tear-out on cross cuts. (instead of the spinters breaking loose further down, they always break where they're scribed)

One thing I'm going to do in the future is replace my beloved 6" Starrett rule with a hook rule; this will speed up measurements from and edge. (i.e. most of them)

I'm going to try the sticks more in the future.

[Jerome Hanby]

I buy all good stuff and the same brand tape measures. Helped 1000%.

That makes me wonder. I recently got the Incra TS-III joinery system and later found a deal on an 18" Incra T-Rule. Since they are all the same brand, think it's a safe bet that those (and other future Incra items) measurement scales are identical?

I guess if I ever get around to getting the things out of their boxes, I could check that myself:D

[mike holden]

[quote=Jerome Hanby;825671]That makes me wonder. I recently got the Incra TS-III joinery system and later found a deal on an 18" Incra T-Rule. Since they are all the same brand, think it's a safe bet that those (and other future Incra items) measurement scales are identical?

Nope! Bad Assumption! The only thing in common is their wholesaler.

The method of measurement is not even the same. The joinery systems rely on scales printed on mylar and the interlocking plastic ridges - the rules are either etched or stamped on and rely on registration to one end.
I *might* make the assumption that two rules of the same design would read identically, but *never* two rules of differing design (and a 6 inch and a twelve inch are differing designs)

All manufacturing processes have variances. When you get to higher accuracy measuring tools, the tools will come with both a form showing its relationship to a national standards of measurement and what the tools relative accuracy is - 4, 5, 6 decimal places. Oh, and the temperature at which the accuracy applies - usually 20 degrees celsius.

Going from one measuring device to another is always a bad idea.

Best is not to measure at all, but transfer the data directly by marking where the cut needs to be or using miter gage to transfer angles, etc.

Mike

[Jacob Reverb]

Excellent thread topic and some really good replies. I have only a couple tidbits to add.

1. Use measuring instruments that you trust, that you'll take care of, and that you'll consistently use. My Dad was a mech. engr. and got his employers to buy Starrett stuff that he then liberated, so that's what I use: A Starrett combo square and 6" rule. They're well made, and I trust them to be accurate, and that in turn makes me more careful to be accurate. It's like having a really accurate gun: If you're confident that it'll put the bullet exactly where you put the crosshairs, you're more careful to put the crosshairs exactly where they need to go.

2. When laying something out using a rule, tip the rule up on edge such that the engraved graduations touch the surface you want to mark. Then put the point of your sharp mechanical drafting pencil (or better yet, the scribe from your combo square) into the engraved graduation on the rule and transfer the mark to your work.

[Brad Shipton]

For accurate measuring tools, layout and straight edges you need to take a look at McMasters. They give you the specs for the tools so you know what you are getting. If you want a 24" digital caliper or a 10' straight edge milled to within .005", they got it.

Brad

[Cliff Rohrabacher]

My next big project is kitchen cabinets and I've realized I need to be in the sub 1/16ths of accuracy which is maybe the width of a pencil line or blade width.


And while I can now cut that with the rail system no problem, I'm still not 100% confident I getting that kind of accuracy in my initial measurements of markings.

If you are building rail and stile cabinet doors
You'll need to make jigs and fixtures for all the repetitive cuts involved.

[Rob Will]

Walgreen's Drug store carries some nice metal rulers in the school supply dept.

A dial indicator caliper is handy to have in the shop.

I use my Biesemeyer fence to measure a lot of things that are cut on the table saw.

I use a pattern jig on the router table to make EXACT copies of curved shapes.

My CMS station has four adjustable cut-off stops.

And last but not least. I use American made pencils becaue Chinese pencils only work with the metric system. (Walgreens and the office supply stores sell American made pencils).

Rob

[Jim Becker]

I only "measure" the primary components for something like a carcass...everything else is taken directly off the workpiece as I progress. I also use story sticks to help with consistency. I try to avoid a tape measure as much as possible and have several steel rules of differing length that are highly accurate. (Lee Valley) I have to say that the repeatablity with my slider has also helped increase the accuracy of my work...although if you make a mistake on the first piece...ALL of them have the same mistake! (DAMHIKT!)

[Stan Welborn]

I'm a big fan of "relative dimensioning". Use the work, not a rule. When I do measure though, I'm realizing I'm using metric measurements more and more. It's just plain easier after you get used to it.

[david kramer]

I'm also a big fan of all-metric. I used a table saw for a long time and never noticed that the tape measure was off. The first time that I used the metric side of the rule it was obvious that the ruler was off by about 1/2 mm relative to a steel rule. This is about 20/1000. It was immediately apparent with the naked eye.

I'm also kinda weak at dealing with fractions that are powers of 2, and I get really messed up when I go from 64ths to thousandths. It's just oh so much easier to talk in mm.

I searched high and low to find an all-metric tape measure in the US. You can find the half metric, half imperial ones on line. Eventually I bought one when I travelled out of the country. So if someone knows of where one can order a good quality, all-metric tape measure in the US, please speak up.

David

[Stan Welborn]

nevermind. Misread post


David, try the FastCap PMMR=True 32

http://www.fastcap.com/products.aspx?id=346

[Richard Spain]

I find it interesting that no one has mentioned using a folding wooden ruler. I used it while doing electrical work years ago and I still use it today while wood working. I find it helpful creating a story pole with the metal slider and marking the lumber with two flat surfaces. The metal slider works great for inside measurements as well. Of course the biggest drawback is the limit in length.

[Michael Wildt]

What can I say 'metric rules'. I grew up with the metric system, so I may be biased, he he.

Google is your friend. Here is a place for tape measures, no experience with this place though:

http://www.right-tool.com/starhigqualm.html (starret) You can also find them on the starrett web page but there is no prices.

Instead of a tape measure, "folding wood rules", are also used in the metric world.

http://catalog.starrett.com/catalog/catalog/groups.asp?GroupID=181
(not a metric example though).

The folding kind can loose the accuracy just like other measuring devices. Funny thing is that it in Danish is called a 'Tommestok' which can be translated as 'inch-stick'. Invented in 1883 no less.

http://www.hultafors.co.uk/default.asp?LanguageID=2
(goto to products->measure and mark->folding rules)


EU Class III
1 m
2 m
across joint
Wooden (javascript:changeCategory(14,%200);)folding rule
±1,0 mm
±1,4 mm
±0,5 mm
Fibreglass folding rule
±1,0 mm
±1,4 mm
±0,5 mm
Aluminium folding rule
±1,0 mm
±1,4 mm
±0,5 mm


Michael

[Greg Hines, MD]

For large measurements, I use a tape measure. Just one. Then you at least are off by the same amount for each measurement.

For smaller components, I use a 4" combination square, a 6" Incra T-rule, or a 12" combination square.

Doc

[Jay Basen]

I'm a big fan of Incra products including their table saw fence. The advantage that I find is that they offer repeatable results. While the accuracy of the cut with the fence is going to depend on how well you set it up, the cut will be exactly the same as the last time you set it to that measurement.

The one thing I have found with their fences is that the directions for zeroing the fence don't work that well. What I have found works better is to set the fence for, i.e. 2". Then run a piece of wood through the fence and check it with a micrometer. Make adjustments and cut another piece of wood. Once you have it dead on, zero out the micro adjustment and set the tape to exactly 2". Once I adopted this methodology, the accuracy of the cuts using this fence improved quite a bit.

I also use one of their rulers. The slots with a sharp pencil also give you very repeatable results.

Jay

[John Browne]

Great tips here. For me it's a .7mm mechanical pencil for marking...but mostly I mark on my Fast Cap flat-back story stick. Then I take that mark and move it to another piece. Also stop blocks on any cross cut. And when ripping, I set the fence then rip all the identical pieces before unlocking the table saw fence. The traditional rulers like tape measures I only use for figuring out how big stuff is.

[josh bjork]

If you need consistent cuts, you can just use a long, skinny stick with a short block nailed to it for a stop. Use that to space your fence from the edge and it will be a lot closer than "measuring" will. Of course, if you can just rough things out and run them through the planer, that would work fine also.

[glenn bradley]

Thank you very much for all the replies! Lot of good info, please keep it coming!

All good info here. I tried marking knives and do still use them for marking out stuff I do by hand. Pencils work better for me in general, your mileage may vary.

A wise move for me was to get a couple right-to-left tape measures for rough dimensioning (one by the bench and one by the TS/RT combo) and a set of rules for fine work. I picked up a matched set of 6", 12", 18" and 24" metal rules. The 24" was off a bit but it was exchanged, no problem and now they all match and they match the tapes (as long as I keep the hook tuned). Add a pair of Garrett Wade ruler stops and this covers most of my measuring.

I have other stuff around but here are the items I trust and use regularly in addition to the tapes and the rules:

Calipers
Veritas saddle squares
Machinist's square
Combination square
Setup blocks
Story sticks
Framer's squares (one tuned for inside edge, one for outside edge)

-- and not for woodworking directly but, for the tools --

Straight edge
Feeler gauges
Digital angle gauge
Digital planer depth gauge
Digital blade/bit depth gauge

To avoid problems, I have established some habits. I never assume a factory edge is straight. I never assume anything is 'still' straight or flat if I didn't just machine it; I double check. Measure twice, cut once; an oldie but a goodie. I mark my pieces (chalk, pencil, whatever) with numbers, orientation triangles and so forth. I jot notes as I move along to remind me of things I want to do and the order I want to do them (that way when I come back tomorrow, I remember to cut the tenons before putting the curve on the long edge).

Have fun.

[Matthew Hills]

I seem to remember Tolpin has a good book on this sort of thing.

Some of the lessons I'm learning:
- square stock
- be careful in using a consistent reference surface/edge
- don't use a numerical measurement if you can avoid it (many times, part-to-part matching is more important than hitting an exact value). Things like story-sticks are more useful here.
- use up your scrap to fine tune your equipment setups
- use jigs to help make the measurements for you (ie, the dado guides for a router w/ trim bit, etc.)

and...
- buy extra wood

Matt

[Chris Parks]

Incra rules, Wixey instruments, digital calipers, story sticks and top quality steel rules. Digital means repeatability every time and I wish we could move more towards it and the Wixey has opened my eyes, no more test cuts as long as you have measured it correctly. I can't emphasis enough the ability to cut to the same repeatable measurement is a real time saver.

[Rich Engelhardt]

Hello,
Cheap (~ $7.00 on sale) Harbor Freight digital caliper.
Best under $10. item I bought all last year.
Makes setup a breeze.
Combined with a story board, stop block or setup block, of known dimensions, it allows me to "dial in" the final inch or few inches with an amazing degree of accuracy.

[Greg Hines, MD]

One thing that I haven't seen on the list are the Veritas, Lee Valley, or Woodcraft set-up bars. I use my Woodcraft bars all the time for the router table, or the table saw, as well as setting up routers for hand held use. For $10 to $20, I find these to be very handy.

One thing, Woodcraft has a 4" set, for a few extra dollars. I find the longer set much handier than the shorter ones, though I have two sets of them.

Doc

[Vince Shriver]

David, your explanation of two sticks with a common line across the two of them is way simple. I've always marked a line somewhere in the middle of the rail and measured from the stile to the mark and added the two lenghts together. I come out close most of the time. You take the math out of the deal and come out dead accurate. I guess I'm just too smart to have come up with such a simple idea - thanks for sharing that. Excellent.

[Curt Harms]

Sort of along the lines of two sticks marked or clamped together
http://www.leevalley.com/wood/page.aspx?c=2&p=32585&cat=1,43513
pretty handy for checking diagonals.

[Mark Singer]

Sticks. Two of em' each a bit shorter than your "net" measurement. For example, say you need to cut a rail between two stiles. So you butt one stick against each stile and mark across the sticks. Then place the sticks together with the lines matched up and you have a "gauge" for setting whatever saw you are using. A small spring clamp will hold them together if you need. No numbers required. Just look down there on the floor next to your table saw to find the sticks. Many shops (mine included) lay out entire projects on sticks and then cut and fit without ever touching any other measuring device. This eliminates any variation that might exist between your tape, your ruler, your saw fence scale or whatever.

Disclaimer: This is not something I thought of myself!

DD

This is the same Japanese technique I use. Lee Valley bar gauge heads are a step up!