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View Full Version : Improved accuracy and readability of ripping fence gauge















mikm
24th November 2008, 04:59 PM
Hi all.
I purchased a TSC 10HB table saw from Carbatec last week and got around to setting it up on the weekend. The saw in general seems to perform well so far, but as someone (sorry, I forget who) has previously mentioned, the stick on tape measure that comes with the "Align A Rip" fence is pretty ordinary.

Firstly, the units are centimeters and inches - we are not dressmakers, nor is this the 16th century. :) Secondly, a tape or rule usually has longer marks every 5 mm to aid reading, but this one does not. Neither issue is a serious deal-breaker, but I didnt like it. Further to this, the red index line and associated magnifier attached to the rip fence are high enough off the tape to introduce significant opportunity for parallax error to appear.

My solution fixed both the readability and accuracy issues at once:
I grabbed a 1 m steel rule, cut it down to 800 mm to fit the rip fence front guide rail and stuck it on with some liquid nails. Problem(s) solved! The scale on the rule is very easy to read and the reflection in the polished stainless surface entirely removes the parallax error, guaranteeing repeatable accuracy. If you have ever used an old analogue multimeter or something similar with a moving coil meter, you will know what I mean. Move your head laterally to like up the mark on the guide with the reflection of it in the rule and your measurement of choice. The attached photo shows the fence adjusted to 20 cm (ignore what I said above about dressmakers, that ruler was all I had on a sunday afternoon) at an off-angle to show all three lines.

In gory detail:
1) Fix the fence or ripping guide somewhere on the table. Suit your self where
2) Ensure the index marker (the clear plastic bit with red line in the middle in the photo) on the fence is in the centre of its lateral adjustment. You will need to fine tune it later.
3) Note the measurement from your blade to the fence.
4) Run a small bead of liquid nails (or other fast acting adhesive) along the length of the rule using a scraper to spread it thinly across the surface.
5) Stick the rule to the guide rail so that it reads the measurement taken earlier.
6) Get some scrap and take a test cut.
7) Adjust the index maker as necessary to suit the measurement of an actual cut.

Hope that makes enough sense to be understood. I cant see why this cant be adapted to other saw fences as well...
Enjoy.
Mick

Big Shed
24th November 2008, 05:03 PM
Neat solution, however there still appears to be parallax error (at least in the photo) and you are still a dressmaker, it is still in centimeters:rolleyes:

Now, if you were to install a Wixey Digital Fence, both your problems would be solved AND you would still have inches.

mikm
24th November 2008, 11:00 PM
Neat solution, however there still appears to be parallax error (at least in the photo)
Sorry mate, it's a bit hard to explain. The photo was taken at an angle to exaggerate how the reflection appears in the ruler. When your eye is perpendicular to ruler over the red mark on the clear index marker, the reflection is no longer visible. You can only see the reflection when you move your eye to either side. The point on the ruler directly below the red line then appears half way between the index mark and its reflection. In the photo, the fence is set at exactly 200 mm. Parallax eliminated. You'll have to trust me - it works a treat. :2tsup:


and you are still a dressmaker, it is still in centimeters:rolleyes:Don't forget I did say "(ignore what I said above about dressmakers, that ruler was all I had on a sunday afternoon)" What I am is impatient. :) I should have waited for a weekday to buy a better ruler maked in mm. Ah well. Next time.


Now, if you were to install a Wixey Digital Fence, both your problems would be solvedDefinitely, a DRO of some description would be great. This is a bit cheaper though, I suspect.


AND you would still have inches.Naahhh, imperial is old school. :p

Hope I was a bit clearer this time.
Cheers,
Mick

mikm
24th December 2008, 09:51 PM
The rails/guides for the rip fence are intended to be fixed to the saw with the LH end close the the LH edge of the router table extension wing. If you have the saw, you'll know what I mean. Conveniently, the rails are also pre-drilled to suit attachment to the saw and RH wing only, allowing another 250 mm or so rip capacity by moving them to the right. In addition to wanting more rip anyway, the LH wing was coming off for a sliding table modification so I removed the shortened steel rule described above and put a full length one on as I can now rip to about 950 mm (up from 695 mm).

The bit of use the saw had before the change brought several things to my attention, the most important being:
-I had the width of the rule evenly under the magnifier. Not being terribly flash optically, the lens magnified fine in the middle (where the rule has no markings) but poorly at the edges (where the information is). This turned out to be a bit of a pain, so the next rule was moved off centre a bit, providing a much clearer view.

-Also, the new rule has darker markings and better contrast, making it clearer again to read.