A few tips for Measuring and Marking

[Tom Bender]

Before I measure and mark to final dimensions, I sand. It's not the most efficient time to sand but it improves my accuracy.

After making a cut most times I knock off the burrs with a sander to prevent splinters.

As soon as a mark is no longer needed, I erase it so it can't mislead me.


Please add yours.

[David Ragan]

Hi Tom,

Maybe I'm a little short on coffee, but I can't follow what you'd like.....I enjoy reading your posts, so this surprised me.

Seems like in your introduction, where you sand, I would be milling/planning?

For myself, have just read, and re-read in the latest WW journal about precision marking/measuring......what a source of error.

For the way I work, the take home is.....use direct comparison marking when possible, without a scale (for the architects-purists)/ruler, etc; ie, don't even measure, just get a datum face on your project and work from there.....it's all intra-shop work, right?


For what you says up front, normally, my milling gets me close enough so that (barring any classic blunder) all my final cuts are pretty close (maybe 1/16-64") to final joint-ready surfaces...….(wouldn't it be great to practice enough to have joinery-ready surfaces right off the saw?)

Now, at that point: There is a school that finishes evertyhing before final assemble...…….I have never done that but am considering it for some tiny felt lined boxes that are in process now.


Howzzat?

[Lee Schierer]

Measure twice, cut once.

Always use the same device for all measurements on a single project.

I mark cut points with a .5 mm pencil.

[Michael Costa]

While I don't do it, I can see where marking a sanded piece of stock would allow for more accurate measurement.

[Rod Sheridan]

Hi, mostly I mill pieces to size without marking.

I use the measuring system on the saw or planer to produce the parts I need.

Now, if I'm cutting dovetails for example then I transfer markings and saw/pare to lines.

Most of my work involves no marking, for example mortise and tenons are cut by machine either with the mortiser or shaper so work is registered with stops/fences.

Now there is some marking depending upon the project, and for that I use a mechanical pencil or a knife.....Rod.

[Chris Parks]

A measuring trick when I am forced to use a tape is to lay the square over the tape and straight onto the dimension I am working to rather than mark with a pencil, remove the tape or rule and then lay the square on the mark.

[Derek Cohen]

I use a tape measure to mark long lengths, and then a steel rule for small dimensions. It is commonly advice to use the same tape measure through a project (assuming that one owns and may be able to choice from a few tape measures). It is important that the tape measure you choose is accurate. Not much point in using it if it is a half-mil or more out.

Here is the tip:

Yesterday, as I was gearing up to start my current build, I pulled out the three tape measures I use, and compared them by measuring a known length (which is a metre steek rule). My favourite tape was 1mm out. The other two were spot-on. The favourite needed to be adjusted back to accuracy. The part of the tape measure that is responsible is the hook at the end. What happens is that it can bend. Bending one way or the other will increase or decrease the length of the tape, per se. In my case, the hook had been bent a smidgeon inward. Straightening it up (which I had to do a couple of times to get the exact accuracy I wanted) restored the tape to an equal with the other tape measures.

Regards from Perth

Derek

[Edwin Santos]

My accuracy improved a lot when I increased my use of story sticks and transfer of measurements wherever possible. I make a story stick now for each project with all the critical measurements, usually with a hook tacked on the end. A while ago, there was a very informative post on the forum here about using dividers which is perhaps the ultimate method of transferring measurements. Until that post, I was not aware that you could set the dividers using the etched markings in a high quality steel rule.

On the subject of dividers, using them to divide is way better for me than trying to perform math involving complicated fractions.
Edwin

[Doug Garson]

Don't do a lot of projects requiring high precision, more often it's important the mating pieces are identical so stop blocks on the crosscut sled are the answer. Sometimes use painter's tape on woods that are hard to mark.

[Donn Ward]

Very interesting discussion; thanks to all who have contributed. Recently, I checked the two tape measures I use most often in my shop and found them to be off by a little of 1/16". When I checked the rule on the square (cheap, big box store variety) I often use, it was off by well over 1/16". As a consequence of these findings, I have started to take a more critical look at my measuring devices and methods. The use of a Story Stick is intriguing. I can see how a story stick could be useful, but it seems to me that it would also have its limitations. Some of my woodworking friends have even told me that that they "never" use a rule...which I take with a grain of salt, since I can't imagine building anything without taking a measurement of something! All things considered, I have come to the conclusion that investment in a quality combination square is important, as well as using the same measuring device(s) throughout a given project, and being patient!

[Derek Cohen]

Hi Donn

I work with story sticks all the time, except when making repetitive cuts - which may have been marked with a story stick. Nevertheless, marking starts somewhere, and often with a tape measure and/or steel rule. Accuracy is as much about repeatability, so get your measures aligned as well as accurate.

Regards from Perth

Derek

[Bill Dufour]

If you are making something to fit an existing space it may be better to use a metric tape. Any car made in the last 40 years is metric dimensions even if the fasteners are English.

[Andrew Seemann]

Understanding tolerance. Knowing how accurate something needs to be is essential to working at a economical pace. Some things need to be very accurate, some things need to accurate, and some things just need to be close enough. You can waste a lot of time (and money if you are getting paid) making things less accurate than they need to be, and you can waste just as much time (and money) making things more accurate than they need to be.