Dumb question re: Tape measures in the shop

[Durnik]

To all,

Ok, complete beginner, newbie, idiot, etc. here. Question I have is the proper use of a tape measure.

Example 1: Using the tape hooked over the end of a board to measure a set distance to mark and saw off.
Example 2: Using the tape hook pressed against a wall corner then measuring out "N" distance.

How do you take into account the hook length when you're doing these types of measurements? I realize in some cases it's relative (e.g. both measure and cut are done the same way, say hooked over the end of the so it doesn't matter since the relative lengths are the same). However, in the case when you're taking a measurement using outside and then the inside of the hook (or, you're transferring the measurement to something like a straight edge), how do you handle these differences?

Just wanted to know if there is some common practice used for this sort of issue (e.g. I can see tape with those curved tabs/hooks at the end skewing the measurement by more than enough to be seen in the final product).

Thanks in advance,

Bob H
<aka Durnik>

 

[allisnut]

Most tapes have a little play in the rivets where the hook is attached to the blade. The amount of play is equal to the tickness of the hook, so it cancels it self out.

 

[Skymaster]

always use the SAME tape.

 

[Gofor]

Both of the previous answers are correct.

If the tape end is damaged, corroded or plugged with debris, it may not slide the exact thickness of the tab.

I have compared different tape measures (as well as yardsticks, etc) and have seen up to 1/16th or more difference at one length and have them agree at a different length.

Bottom line, they are okay for rough measurements, and if the same tape (or yardstick, scale, ruler, etc) is used for comparing inside-to-inside or outside-to-outside measurements, you can get a good measurement.

The most accurate way to transfer measurements is with dividers, trammel points, or the like.

Go

 

[tarheelz]

No Tape Measures!!!!!

 

[Mark Gottesman]

Looseness in hook corrects for inside and outside measurements.

Only use one measuring instrument per project. Two or more will lead to measuring errors.

Starrett makes a line of really good tape measures.

 

[Berta]

always use the SAME tape.

+1

 

[JackLeg]

​I prefer my Lufkin rule.

 

[redknife]

Other point worth mentioning is to try to measure as little as possible for important cuts. For example, I use stops when possible for final length repetitive cuts. There are other techniques to avoid relying on a measurement.

 

[jcz]

The better question is...... Where are all my dang tape measurers. How do they all seem to disappear when I need one.





Sorry for the derail.

 

[Mike Davis]

A folding wood rule works great, a story stick is a good way to make repetitive cuts, A Starrett 24 inch steel rule works great, for small measurements use dividers or a sliding square. Most of the time I mark directly off the space the piece needs to fit.

Never buy cheap measuring tools, that includes tapes and rules.

 

[Jeff]

An accurate tape measure is indispensable when used correctly, but there are limitations to be aware of (see the attached).

1. They're fine for ball parking measurements; probably +/- 1/32" to 1/16".

2. For more accurate measurements at crunch time switch to a good quality metal ruler.

http://www.leevalley.com/US/wood/page.aspx?p=32587&cat=1,42936,42944

 

[StephenK]

The length of a chair leg isn't as important as making sure it's the same length as the other chair legs. :gar-La;

 

[NCJim]

i use a good quality folding ruler all the time for accurate measurements. I use to have a old school, apprentice trained carpenter, who worked for me. He would always used his folding rule for "close cuts".

 

[bguil]

Always using the same tape for a project is good advice. I also maintain my tapes by checking inside and outside measurements to be sure they are the same, and I check both right/left corners of the tape to be sure they measure the same. A little bending brings them into line if they have been altered by use.

 

[CDPeters]

All above good advice, I would only add that I use the tape measure for prep of material. Once I'm working on "finish" dimensions, I use an old Starrett 24" steel rule that was my grandfathers. If I have to make a long measurement, I will sometimes use the tape measure, but I index the start at the 1" line and add 1" to the measurement I need - this takes out any doubt about the proper "calibration" of the hook - but double check the measurement to be sure you accounted for the 1" difference!

+1 on Mike's story sticks - use those alot too!

HTH,
C.

 

[Durnik]

To all,

Thanks, all good advice and every little bit of knowledge helps. You all have helped me confirm my concerns and looks like it's time to go shopping for a good steel ruler

Bob H
<aka Durnik>

 

[JimD]

Another good measuring tool is an Incra ruler or t-ruler. I bought a 12 inch version of the latter mainly because of my track saw. I noticed some of my rips were off some due to my marking. I think the general rules are:

1) Don't measure unless you have to. Use the project, a stop, a story stick or other technique when you can to minimize errors.
2) If you have to measure, a good steel rule is preferred
3) If you are beyond the capacity of your steel rule, a tape measure is OK to use. Recognize that inside and outside measurements will probably not be identical. Using the same tape measure is highly recommended since even the basic markings can be a bit different.

I have tried more expensive tape measures but I did not find them to be better. As a consequence, I use cheap (often free) ones from HF. The belt clips fail after awhile but the measuring tape seems to be accurate (when checked versus a steel ruler).

 

[chris_goris]

I agree , use the same tape all the time if you can. Ive been woodworking for over 25 years now and any measuring device is only as good as the marking tool. For that, I use SHARP number 2 pencils. and that would only be for the "first piece" and then if I need more of the same, Ill typically setup stops where I can (if they arent too long) or sometimes you have to mark them all. But as one person mentioned, the length of a chairleg is nowhere near as important as the fact that they are all the same. I have never owned a 24" steel scale and I dont see the accuracy over a tape measure since a tape has a hook on it where now with a steel scale you have to align the "dumb end" and hold it there while marking the measured end. I do use my old starret sliding square ALOT for short measurements when I need repeatability. For extremely critical fits, I mark long and "sneak up" on my final dimension with repetitive cuts until the piece fits. But , alot of these techniques I learned along the way on my own, trial and error and youll discover what works for you and what doesnt.

 

[jerrye]

No Tape Measures!!!!!

View attachment 16629

Measure with a micrometer, mark with chalk, cut with an axe... :gar-La;