Learning Opportunity #4: What is the thickness of a human hair?

  • Advertise with us
Blog entry by Don posted 06-28-2007 03:38 AM 3943 reads 0 times favorited 13 comments Add to Favorites Watch
« Part 3: Forget the Easy Option Part 4 of Learning Opportunity series no next part

Yesterday, I took my new TS Aligner Jr. and DowelMax over to a friends home. (I purchased both of these tools during my recent visit to Canada.)

I was meeting with him and another Mate for a BBQ lunch and a chat about our mutual interest in woodworking. All three of us served on the executive committee of our woodworking club, so we have formed a close bond. I showed them the results of having calibrated my table saw with the TS Aligner by taking a sample of a perfectly fitted DowelMax joint. I was feeling pretty smug about the results, even though it had taken me a few hours to align my table saw perfectly.

So, naturally, my friend asked me to help him align his TS, to which I agreed. I set up the Aligner in his miter slot and began to measure his current set up.

The blade was a way out.

When I zeroed the gauge on the front of the blade, then moved the Aligner to the rear of the blade rotating the blade so that the same spot I’d measured at the front was then at the rear, the variance was a whopping .016. Wow! How could he do any fine joinery on this saw?

So, we then started to loosen the bolts that held the tabletop to the cabinet. (On this saw, one moves the cast iron tabletop to align the miter slot to the blade.)

Wait a minute!”, my friend protested. Just how much out is my saw?

That’s when the penny dropped. The gauge on my TS Aligner measures in point zero, zero ones of a millimeter. To visualize this, a human hair is .0254mm in diameter. We had measured a variance much smaller than the diameter of a human hair.

So then we all took a reality check. We were, after all, only talking woodworking, not micro-surgery. The human eye cannot even detect a variance of .016mm.

So sheepishly, I tightened up the two bolts I’d loosened muttering something about being glad I hadn’t moved the top out of alignment and chalked the experience up to another lesson well learned.

-- CanuckDon "I just love small wooden boxes!"

13 comments so far

View Bob Babcock's profile

Bob Babcock

1823 posts in 5305 days

#1 posted 06-28-2007 04:05 AM

What kind of saw does he have that hasn’t been aligned and yet is that accurate. I want one! I think you’ld have been much happier aligning mine Don. Too bad we don’t have the Cyber buddie share so I could get you to straighten it out.

-- Bob

View scottb's profile


3648 posts in 5545 days

#2 posted 06-28-2007 04:29 AM

You’d probably have found a variance equal to several hundred of my hairs on my saw. (that is, of course, after I’m freshly shaven)...

I second Bob’s comment – that is some accurate saw!

-- I am always doing what I cannot do yet, in order to learn how to do it. - Van Gogh -- --

View Obi's profile


2214 posts in 5455 days

#3 posted 06-28-2007 05:40 AM

It took me over a year to figure out why my sticks were getting burnt. I adjusted my table saw with a hammer last month and it’s much better now. My remedy is a simple one. Use this saw for dado’s and buy me a new saw. How’s that sound fellas?

View woodspar's profile


710 posts in 5318 days

#4 posted 06-28-2007 05:48 AM

You already have a cast iron top table saw Obi, no fair. They get me my 3hp 220v cast iron table saw first.

-- John

View Don's profile


2603 posts in 5395 days

#5 posted 06-28-2007 05:48 AM

I alluded to the time it took me to calibrate my saw – but I wasn’t happy with a variance of .016mm, I got mine to .008mm. I wouldn’t have sweat it so much if I’d only stopped to think about how ridiculous this kind of tolerance actually is.

Bob, my friend and I both own the same type of saw. It’s a twelve inch, 3hp Taiwanese generic, sold under the brand Leda in Australia.

-- CanuckDon "I just love small wooden boxes!"

View WayneC's profile


14359 posts in 5316 days

#6 posted 06-28-2007 05:50 AM

Keep you eye out on Craigslist Obi. Seen at least 2 cabinet saws for under $500 in Modesto in the last month or so….

Don, have you tried the TS aligner for any other operations?

-- We must guard our enthusiasm as we would our life - James Krenov

View Don's profile


2603 posts in 5395 days

#7 posted 06-28-2007 06:44 AM

Yes, I also calibrated my TS Fence as well as my Router Table Fence. In essence, these three operations are quite similar and use the TS Aligner in the same way, ie mounted in the miter slot.

The only slightly different setup I’ve tried so far is to calibrate my TS blade at a 45 degree angle. Whilst the TS Aligner Jr. is still mounted in the miter slot, the difference is the use of the ‘Angle Attachment Gage.

Once it was accurately reading 45 degrees, I adjusted my trunnion stop ever so slightly to assure an accurate angle. At this point I can’t ever see myself using the aligner for determining other blade angle settings, but who knows?

I plan to use it on my jointer and drill press at some point, but I want to get my head around the use of the TS Aligner Jr. before I do so.

-- CanuckDon "I just love small wooden boxes!"

View MsDebbieP's profile


18619 posts in 5379 days

#8 posted 06-28-2007 10:43 AM

that reminds me of the time when we got a “die press” machine at our resource centre for teachers … they could cut out shapes of cats, houses, moons, and a zillion other shapes with the press of a lever…
When asked if we had a “square”, (no), some were really disappointed because they didn’t know what to do—they were so used to the die press for all of their cutting that they forgot that they could simply fold a paper and cut.

-- ~ Debbie, Canada (, Young Living Wellness )

View Sawdust2's profile


1466 posts in 5306 days

#9 posted 06-28-2007 01:48 PM

Back when I was taking a course from Ian Kirby he often talked about precision and, he being British, measuring in millimeters instead of inches.

A classmate then commented that machinists commonly measured to ten thousandths.

Kirby’s response was that scientists worked with microns.

It’s all perspective, not to split hairs ;>)

-- No piece is cut too short. It was meant for a smaller project.

View oscorner's profile


4563 posts in 5529 days

#10 posted 06-28-2007 02:06 PM

Personally, I don’t see a problem with setting up your saw to be as accurate as can be. Of course, I understand what you are saying about the naked eye not being able to pick it up, but it is almost like that project you made for someone that has a not so perfect something or the other. The person you made it for will never know it, but it still bothers you because you know it could have been better. Great story, Don.

-- Jesus is Lord!

View woodspar's profile


710 posts in 5318 days

#11 posted 06-28-2007 05:50 PM

I think that it is great that Don is bringing this to our attention for many reasons, but I will limit myself to one: If enough of us care about accuracy, and the more we woodworkers demand of our equipment, the more the manufacturers will respond.

-- John

View David's profile


1969 posts in 5357 days

#12 posted 06-29-2007 07:44 AM

Don -

Looks like I need to invite you over for a visit!


View Don's profile


2603 posts in 5395 days

#13 posted 06-29-2007 07:55 AM

I’ll be there if you pay the way! LOL

-- CanuckDon "I just love small wooden boxes!"

Have your say...

You must be signed in to post the comments.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics