Replies

1. 
   JohnWW | Jan 13, 2004 12:20am | #1

   Kevin,

   Save your money, a 12 inch long blade from a combination square stood on edge across the joint between the table and the extension will work just fine for lining up and leveling the wings. 

   Since there is no way to correct for a warped main table on a tablesaw, there is little point in checking its flatness with an expensive straight edge.  Most main tables aren't especially flat anyway but they work fine for all but the most critical cabinetmaking demands.

   If you are adding larger shop made extension tables to the saw, an ordinary builder's level will be straight enough for lining up the saw to the extensions.  I don't think it would make a difference in my answer, but who makes a GI 185 saw?

   John W.

1. 
   UncleDunc | Jan 13, 2004 01:49am | #4

   >> Since there is no way to correct for a warped main table on a tablesaw ...

   Actually there is. If it's cast iron, it can be scraped flat with a hand scraper and a good straight edge. The book that tells how is Reconditioning Machine Tools.

1. 
   JohnWW | Jan 13, 2004 03:01am | #5

   Uncle Dunc,

   Well yeah, I've actually done it, though not on a table saw, but it isn't the type of thing most woodworker's are going to do on a Saturday morning in the shop.  Plus if you take down the top around the table insert opening you're also going to have to work down the lip that supports the insert and quite possibly have to deepen the miter slot. 

   To be practical for scraping a tool needs to be designed from the start with that in mind, the thin tops of the average tablesaw with a cut out in the middle aren't really meant to be scraped down though I suppose it could be done.  The book you recommended cost over a hundred dollars the last time I looked.

   John W.

   Edited 1/12/2004 7:04:37 PM ET by JohnW

1. 
   Mackwood | Jan 14, 2004 03:48am | #9

   Not that it applies to the guy with the new GI 185, but you can have the table ground as well.  I had the adjoining edges of the wings and main table milled back to 90 deg., assembled and ground flat as a unit.  Cost was under $130.00 with tax.  As mentioned, that left the miter slot shallow.  I had the requisite material milled off the miter gage bar.  Everything is dead flat and you can easily miss the joint lines if you're not looking for them.  The saw I restored was made the same month and year I was born 53 years ago so I felt the cost was worth while; (old Unisaw).

   Call the machine shops with total dimensions of table with wings mounted.  Not all shops have a grinder big enough to handle a piece that large.

   Mack

1. 
   wrudiger | Jan 14, 2004 08:13am | #10

   Did the same for my used Rockwell Unisaw - had a .008 valley right in front of the blade.  Not a lot of guys with the big Blanchard grinders, but they are out there and somewhere around $130 was what I paid as well - great investment to get to dead flat!

   Regarding alternatives to expensive straight edges - check out the Taunton book "Care and Repair of Shop Machines" by John White.  All kinds of great advice for tuning all of your big equipment, with lots of low/no cost jigs including one that will get you to just as accurate as a high end straight edge.

   Wayne

2. 
   Mackwood | Jan 14, 2004 08:34am | #11

   Wayne,

   Thanks!  I was beginning to think I was half crazy having my table ground.  My table would have been barely acceptable (just under .005 out same place as yours) but my wings were "drooped" at the outer edges (almost .020).  I suspect young hooligans jumping around at the high school shop where the old saw used to reside.  It's a much happier saw now!

   Enjoy!

   Mack

3. 
   davearnone | Jan 14, 2004 08:29pm | #12

   Where are you $130 guys getting this work done?  Here in northen CA I could not imagine getting any grinding work done for under a $1k!

   (I'm more ranting and expressing amazement than looking for a real answer)  :)

4. 
   wrudiger | Jan 15, 2004 07:09am | #13

   Dave,

   General Grinding, 801 51st Street, Oakland, CA 800-806-6037.

   It's pretty much all they do. Mostly big production stuff but they are always open to the little side jobs. Fast, friendly, quality work.

   Wayne

5. 
   Mackwood | Jan 15, 2004 07:57am | #14

   Dave,

   Allied Technical Services Corp.  6239 Airport Way S. Seattle, WA  206-763-3316

   Mack

   Edit: Kind of a long drive from N. Cal.

   Edited 1/14/2004 11:59:12 PM ET by Mack

2. 
   kevink | Jan 13, 2004 04:06am | #6

   John,

   I have a 12" starret combo-square I think i will use that.

   General International makes the 185.

   Kevin.

1. 
   RANGERP75R | Jan 13, 2004 06:21pm | #7

   K k

      Agree with all. If you go adding MDF or other extentions for extra support, the same holds true. The extra extentions don't need to be higher than your saw-top, but if they are a tad lower it won't hurt a bit.

   Regards...

   sarge..jtProud member of the :  "I Rocked With ToolDoc Club" .... :>) 

2. 
   forestgirl | Jan 13, 2004 12:31am | #2

   Kevin, I sometimes use a new planer blade to check flatness.  I figure they are going to be pretty darned straight, and I know from experience my big carpenter's squares aren't -- they may be 90* for the most part, but not always straight from one end to the other.

   forestgirl Another proud member of the  "I Rocked With ToolDoc Club" .... :>)  you can take the girl out of the forest, but you can't take the forest out of the girl ;-)

3. 
   BG | Jan 13, 2004 01:12am | #3

   KevinK,

   I agree with the others, don't spend your money that way.  For the most part just trust your hand to attach the wing(s).  BTW a 6" Starrets is real handy....

   Congratulations on the new General .....
4. 
   sprocket | Jan 13, 2004 06:45pm | #8

   YES. If you think you could benefit from a $60 Starrett 24" straight edge to measure for flatness, I don't think you can go wrong there. You'll be able to diagnose a lot more imprecision in your saw table and extension wings this way. The longer length will help you get a much clearer idea of overall flatness. I use a Starrett 24" on loan from a machine rebuilder friend and it is invaluable. You might prepare yourself for disappointment as the straightedge is going to reveal a lot. I learned that my cast iron extension wings were much flatter than the main table top which I learned has a .015" hollow in the center. I bought the saw over 10 years ago and wished I had done the flatness test when it was new and under warranty. There isn't much that an average woodworker can do for a situation that I described that I'm aware of. Tool and Die makers learn their craft over a lifetime and become trained in specialized arts like inking and scraping in order to flatten high spots on cast iron...not something for a weekend warrier like myself.