Measurements and Measuring

[kelLOGg]

Wow! You guys do some precise work. Even with grossly larger tolerances I have encountered problems. I built 2 bookcases each 3 ft long to nestle under a window and between floor to ceiling built-in bookcases. I measured meticulously the distance between the built-in units (in the winter) and built the 2 add-ins to fit with a reasonable amount of tolerance, I thought. I tried to install them in the following spring and they wouldn't fit. The distance I measured so carefully was now 0.125" shorter, presumably due to humidity changes, even though it was in A/C and heated space. All I could do was take one of the new units home and saw/re-finish it.

 

[Graywolf]

I am curious, do you all work in inches? I do, but I grew up overseas with the metric system, the fractions kills me!!. I am always wondering if it is the fact that more than half my life I worked in millimeters and just can get used to the imperial system?

Like Phil, in my day to day work I use the imperial system and use inches for everything. In my personal shop I work to proportions and my tools are the guide, what mean here is a chisel width is the mortise width and what I set the gauge to and using only hand tools I work to gauge lines and knife lines. The measuring devices are dividers and story poles. Some projects much like Mike, its what I feel or imagine and it's an orchestration. Accuracy is in what you do and how consistent you are in the common tasks of laying out. Now that dose not rule out failure. I have several projects that started in one direction and took another direction, sometimes much to my surprise. Now you have to keep in mind I don't generally do that with reproduction pieces and I don't do that much of that.

 

[JimD]

I keep a 24 inch steel ruler on the rip fence of my SawStop and use it for measurements within it's capability. It is not a "fancy brand" but I subscribe to the theory that is not necessary, it is consistency we want. I find the rip fence gauge of the SawStop to be pretty good but how you look at the hairline can make me off a little so if the measurement is important I use the ruler.

I keep a fractional dial caliper in the top drawer under the extension wing of the SawStop. For thickness measurements. I have used electronic calipers but the battery always seems to be dead when I need it. I don't love moving from caliper .001 measurements to fractions of my other measurement tools - so the fractional dial caliper works best for me.

I got a Incra t ruler when I got my track saw. I cut to a pencil line more often with the track saw than with any other cutting tool. I found putting that mark on the wood was a significant source of inaccuracy. I have to make sure I have a 0.5mm pencil handy but that and the t ruler will let me put a line where I want it up to a foot from the edge. I made some track setting gauges I use now to avoid having to work as much to pencil marks.

I use free harbor freight tape measures and have at least half a dozen laying around. If I have to use it for a project, I try to keep using the same one. But whenever possible, I use the other work piece parts to adjust my stop or rip fence. I find that helps avoid errors. It also helps with accuracy. I assume that a measurement with a tape measure may be off at least 1/16. I sometimes use other brands of tape measures but I have not found one that matched my steel rulers much better than this.

 

[Rwe2156]

12" Starrett combo square . You'll never regret it. Great for machinery setup, too.

Tapes are OK just use the same one throughout project. I like the flat tapes made by Fast Cap.

Also, I keep a metric tape around handy in some instances like dividing up a space it makes the math easier.

I also use rulers often. I just get the cheap ones. 12, 24, 48 and 60". For certain applications its handy to clamp them down.

 

[ErnieM]

I have several metal rulers in the shop. I use them for drawing reasonably straight lines.:eusa_danc

 

[Charles Lent]

I went digital wherever possible. Digital table saw fence, digital height gauges, digital calipers, digital planer gauge, etc.

I also realized many, many, years ago that in most cases of woodworking, that the dimensions aren't all that important, if you realize that many woodworking chores require two of each, so making two at the same time and with the same machine setups makes two parts that actually are the same dimensions, but maybe aren't exactly to some desired plan dimension. For instance, when making a box = two short sides - a left and a right, two long sides - a front and a back, and two ends - a top and a bottom, although sometimes the top and bottom are different by plan, but then they don't have to be the same. You can carry this pairing to other projects - 2 rails and two stiles for a door, etc. The overall dimensions may vary slightly, but keeping your pairs of parts accurate to one another makes projects go together very well, even if their overall size may not be perfect to plan.

I have the greatest problem when I discover that after I have completed a project, that I have to make another one "just like it". I could have made two at the same time (4 of each part), but now I have to repeat the setups and get them the same as when I made the first. I can get close, but almost never,"exactly the same".

Charley

 

[nn4jw]

I had to make a picture frame for my wife's latest needlepoint project this weekend. It was an odd sized item so buying a pre-made frame just wasn't possible.

She mocked up the size frame she wanted using paper, including the width of the rabbet. The poplar stock I was using (1x2" nominal) was a little wider than she mocked up but I was able to use dividers and the depth pin on a caliper to set the dado on my table saw to the drawing. I also transfered the inner 45 degree miter positions to my miter saw setup.

Frame turned out great and I still couldn't tell you its actual measurements. Never had a ruler or tape anywhere near it.

I may make a story board from it as she has 3 more pieces she'll be making that should be the same size.

 

[Skymaster]

good tools are lifetime tool. there is consistency in ALL measurements. Starrett, brown and sharpe, mitutoya, all machinist quality, you ONLY BUY THEM ONCE.

 

[drw]

Metric vs. Imperial. Professionally, I had to work in the metric world, but I must confess that I made mental conversions of metric to imperial....I just seem to be able to better relate to the imperial measures.

Mention was made of the challenges associated with fractions...I can relate. I have and app on my phone that I use extensively. It cost two dollars, but I have saved a lot of good wood by not making crazy mathematical errors with fractions.

https://play.google.com/store/apps/details?id=com.digitalchemy.calculator.fraction&hl=en_US

 

[nn4jw]

I too have trouble relating to metric. I can work in it ok, just not really visualize the units very well compared to imperial.

What I much prefer is the best of both worlds, decimal inches. I prefer not to extend that to feet and yards though decimal miles work just fine for me. For example 38.37 inches but not 1.whatever yards. Or 2 feet 4.7 inches, not 2.whatever feet.

OTOH, too many decimal places in woodworking is a little too OCD given wood movement for me.

 

[Rwe2156]

I too have trouble relating to metric. I can work in it ok, just not really visualize the units very well compared to imperial.

What I much prefer is the best of both worlds, decimal inches. I prefer not to extend that to feet and yards though decimal miles work just fine for me. For example 38.37 inches but not 1.whatever yards. Or 2 feet 4.7 inches, not 2.whatever feet.

OTOH, too many decimal places in woodworking is a little too OCD given wood movement for me.

Can’t see how this will work unless you have a decimal ruler.

Matematically it’s the same as metric.

Tapeulator app or construction calculator indispensable solves all the issues for me.

 

[patlaw]

What I much prefer is the best of both worlds, decimal inches.

It's funny that this popped up. Just a couple of days ago, I picked up an old ruler to measure something, and I noticed that it was a decimal ruler. Phil previously told me that he uses metric for his small projects, and I always listen carefully to what Phil says. However, at my age, making the transition is not the easiest thing to do. Looking at the ruler, I decided to look for a tape measure with decimal inches. I forgot, but now I'm reminded. Has anyone seen such a thing? Using decimal inches would not be much of a transition at all for me. It would help avoid ripping some boards to 6-1/4" instead of 6-1/2" like I did when I misread the tape measure on my table saw fence.

 

[Mike Davis]

I have a decimal ruler, nice Starrett. Haven’t seen a tape but should be available. Makes working with calipers much easier when you also have ruler and tape to match.

I’ve said before and I’ll say again. They messed up the introduction to metric in a big way, it failed only because of the teaching method.

They tried to teach conversions, way too complicated. We don’t need to know that an inch is 25.4 mm. Just use a metric ruler for metric and a fractional ruler for imperial.

They could have bought 20,000 metric rulers for all the elementary schools in 1965 and we would all be using metric now. Instead the tried to teach all these complicated conversions and nobody thought it was easier, nobody wanted to learn it, and now very few use it.

 

[nn4jw]

I have a decimal ruler, nice Starrett. Haven’t seen a tape but should be available. Makes working with calipers much easier when you also have ruler and tape to match.

I’ve said before and I’ll say again. They messed up the introduction to metric in a big way, it failed only because of the teaching method.

They tried to teach conversions, way too complicated. We don’t need to know that an inch is 25.4 mm. Just use a metric ruler for metric and a fractional ruler for imperial.

They could have bought 20,000 metric rulers for all the elementary schools in 1965 and we would all be using metric now. Instead the tried to teach all these complicated conversions and nobody thought it was easier, nobody wanted to learn it, and now very few use it.

Too true.

 

[patlaw]

 

[nn4jw]

Can’t see how this will work unless you have a decimal ruler.

Matematically it’s the same as metric.

Tapeulator app or construction calculator indispensable solves all the issues for me.

I have no problems working in either system, as I said. What I meant by not being able to really visualize metric has more to do with "feeling" the units. For example, I can hold my fingers apart close to an inch or six or hold my hands a foot or two apart. Ask me to hold my fingers apart 1 cm and it just isn't going to happen since I don't "visualize" centimeters. A pound means more to me than a kilogram and paying for a gallon of gas "feels" more natural than a liter of gas. Tell me someone weighs 200 lbs and that tells me something useful I can relate to. Tell me someone weighs 90.7 kilos and it's just a number. 200 lbs = 90.718 for the mathematically challenged.

Converting the numbers between systems is a simple mathematical exercise, but visualizing metric in the real world would require (for me) doing away with the imperial system, converting to metric and never looking back. We'd all get used to it, some more quickly than others, but it doesn't look like that's going to happen during my lifetime.

For now for woodworking a good dual tape with well marked fractions and a metric scale works just fine. No converting necessary.

 

[Skymaster]

i have dual tapes and my calculator speaks both languages :rotflm:

 

[danmart77]

After reading all three pages of measuring styles and the different tools that folks are using I am almost embarrassed to say I put a full size plan for every thing I build more than one copy. I just take the plan and tick off a story stick and I never use a tape measure after putting the plan on paper.

Just a one simple stick to build the table. When done it hangs on the wall.

​

 

[patlaw]

Well, to be honest, a story stick is just another way to make a ruler or tape measure.

 

[Pop Golden]

They could have bought 20,000 metric rulers for all the elementary schools in 1965 and we would all be using metric now. Hang on Mike, Back when the idea of converting to metric came up, I thought how much money and time it would cost to convert. 1st. Convert all machines to metric $ $ $ $ 2nd. Retraining existing work force $ $ $ $ $ $. 3rd. Convincing Americans that something not American is a good thing. I don't think so. Good old human nature & American pride. This idea was a loosing proposal from the get go. SO! We're going to keep trudging along with our Imperial system and "D..m the torpedoes full steam ahead"

PS. I have a metric rule, just in case.

Pop :no: