Squaring up your mft for cross cuts

[woody]

Well this might be a little over kill for woodworking, but the more precise the better, plus I had nothing to do, so i decided to play around, anyways, this is how i square up my table.

Step 1-  I register and clamp a square on the fence, and put my indicator base against the square

Step 2-  Then i indicate inside of the saw kerf, I use a last word indicator cause I have a small contact point for it

Step 3-  Then I slide the whole base assembly along the square,  as you can see, after 24" its off by only .0008. Good enough for me!

Thanks for looking!
                                      Woody

 

[pci]

Hi,
nice photos.
Where do you find this indicator ? is there another name (more precise) ?

thanks,
Pierre.

 

[woody]

Well you can get one online from a precision measurment tool dealer, or if you have a machine shop nearby, or industrial park, then they will be able to tell you where (close by) there are dealers.  This type of measurment tool is called a dial indicator,  this particular style is called a "last word" indicator because you can read up to .0005 where as regular dial indicators read up to .001.  Its called as "last word" because of the accuracy of it.  If you barely touch the contact point with your finger, the needle jumps quite a bit, at least half way around.  If you search for dial indicator or last word indicator on the net, you'll find what your looking for.  You will also need a base to hold it, and that can be found in the same place as the indicators cause there almost useless without them.  The set up in the picture is of a mitutoyo last word indicator on a NOGA flex base (the best money can buy, as far as bases go) Ive seen prices from $89-$280 for just the base and about $100-$200 for the indicator, depending on the brand it could be cheaper.  Its a good investment cause I use these type of tools to set up my saw, drill press, bits, whatever you can think of.  The brands in the picture are top manufactuers, but if its just for woodworking then you can go china if you want.  Good luck with your search!

 

[pci]

Many thanks.
I'll go to china ;-)

 

[greg mann]

Last Word was/is a name used by Starret to designate their line of indicators made in this style. I might be able to scrounge up a 40 year old "Last Word" that would make you laugh. Not trying to demean your post Woody, just adding some trivia.

This is a very clever idea as long as your kerf is in good shape and you are only as accurate as your framing square, which around here comes under criticism quite regularly. I like this idea, and for those who question the accuracy of the square, just substitute the one you are sure is traceable to NIST. (National Institute of Standards and Technology)

 

[woody]

Its all good Greg! BTW I just replaced the sacrificial insert in the table and Just thought I would share what I do to square it up since I had a fresh kerf to work with.  As for the square, its a starrett so im not sweating the accuracy issue to much, although when I accutally perform this task for real I use a machinist square that is 24" but its getting fixed cause of some  corrosion, I should be getting it back tommorow, anyways I was just trying to give the general idea.  Thanks for your comment!
                            Woody 

 

[johnny t]

That is whats called a test indicator.  they are more precise, well actually more sensitive. than the more common dial indicator we are more accustom too.  it is also more flexible with positioning.    test indicators come in various configurations and graduations. from .001", .0005" and even .0001"!  most common/standard type reads .0005" and a split dial reading 0-15-0.

you don't have to spend $200 dollars on a starrett though....this is the festool forum .  there are cheap asian ones from CDCO, Shars, or ENCO for around $30.  those are alot healther to oneself to drop on the floor.  I use the cheapies for even my everyday metalwork, only pulling out the starretts or interapids for the critical stuff. 

woody, I like your idea for using the indicator for squaring and might try that with a good known square and the guide rail. 

 

[greg mann]

You know, one could do this by placing the square under the guiderail, mounting the indicator to the saw, and running it along the square. Kerf wear would be irrelevant. 

 

[Steve Jones]

Then again, if you don't have the time and money to spend on neat gadgets.....

You can flip the offcut and set the fence to dead on without any tools other than the MFT, a TS, and a scrap of plywood.

 

[Dave Ronyak]

Woody,

I like your idea of using a replaceable kerf line insert in your MFT top.  Currently I avoid cutting into my MFT top by clamping a sheet of 1/4" birch plywood (very inexpensive at HD) on my MFT before squaring up the fence/Guide Rail using an 18" precision right triangle from Woodpeckers.  I realign the kerf cut in this plywood sheet whenever I reinstall it and check it with my TS 55 saw on the Guide Rail.  But I am getting tired of messing with that sheet of plywood.

Such a precision right triangle / square could be used for your setup with or without the dial indicator by first setting one edge of the the precision right triangle exactly in line with the [near] side of the kerf cut, then adjusting the fence to exactly 90 degrees to the kerf cut, then installing and aligning the Guide Rail mechanism parallel with its edge aligned to the kerf cut.

How do you secure the replaceable wood kerf strip?  Is it a press fit or do you use an adhesive or fasteners, e.g. brass or nylon screws?

Dave R.