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In the Shop => General Tormek Questions => Topic started by: DoggyForager on February 05, 2025, 11:01:15 AM

Title: Flatten side of SG 250 with grading stone?
Post by: DoggyForager on February 05, 2025, 11:01:15 AM
Hi, I use the flat side of the SG 250 quite a lot and am thinking it will get dished at some point.

What do we think of using the grading stone to 'true' the side of the stone back to flat?
Title: Re: Flatten side of SG 250 with grading stone?
Post by: Ken S on February 05, 2025, 02:33:45 PM
I don't like the idea of using the side of a non diamond wheel to flatten a tool and trying to true the stone with the stone grader.

Before Tormek introduced diamond wheels, the dreaded hollow grind was not considered a problem with large diameter grinding wheels. If one felt a need to correct for a hollow grind, the easiest way was just to set the Anglemaster to 28° instead of 25°. Flattening could be minimized in several ways: 1) Purchase premium chisels which require considerably less flattening. 2) Only purchase the chisel sizes you actually use. Years ago, I purchased a complete set of Marples Blue Chip chisels from 1/8" to 2". I labored at flattening the backs. When I eventually gave the set to my nephew, some of the larger widths had never been used, and the backs were never flattened. Half a dozen chisels are more than enough. 3) Chisels with a "belly", where the middle of the back, ideally should be returned to the dealer. "Concave" chisels, where the middle of the backs dips, only need the edge area to be coplaner. For plane irons, do an online search for "David Charlesworth Ruler Trick" which will eliminate most of the flattening time.

In the past, I used oilstones, waterstones, and wet and dry sandpaper on glass for flattening. Recently I have switched to diamond stones. For my low volume needs, these are sufficient.

Ken
Title: Re: Flatten side of SG 250 with grading stone?
Post by: Thread Killer on February 06, 2025, 01:47:02 AM
I'd worry about changing the width SG-250 wheel. If you are using the flat side enuff to dish it, I would invest in a diamond wheel.
Title: Re: Flatten side of SG 250 with grading stone?
Post by: tgbto on February 06, 2025, 02:48:58 PM
I haven't tried yet, but maybe it's possible to setup the MFB in such a way that you could somehow use the truing tool on the side, at least between the outer edge and a minimum radius ?
Title: Re: Flatten side of SG 250 with grading stone?
Post by: Ken S on February 07, 2025, 07:53:32 AM
Quote from: Thread Killer on February 06, 2025, 01:47:02 AMI'd worry about changing the width SG-250 wheel. If you are using the flat side enuff to dish it, I would invest in a diamond wheel.

The taboo about grinding on the side of the wheel is an old safety issue with thinner wheels exploding on high speed dry grinders. it really isn't an issue with 50 mm thick slow speed Tormek wheels.

Ken
Title: Re: Flatten side of SG 250 with grading stone?
Post by: Herman Trivilino on March 01, 2025, 03:30:54 AM
I doubt very much you could true the side of the grindstone with the grading stone. Perhaps a diamond plate?

Another option might be to use spray-on contact cement to glue a full sheet of sandpaper to a flat table top, remove the grindstone, and rub it on the sandpaper. A flat surface can be created with a scrap of 3/4-inch MDF. Cut it a bit larger than the sheet of sand paper and fasten it to your benchtop with a few drywall screws, countersunk, of course.
Title: Re: Flatten side of SG 250 with grading stone?
Post by: RickKrung on March 01, 2025, 06:06:05 PM
Quote from: Herman Trivilino on March 01, 2025, 03:30:54 AMI doubt very much you could true the side of the grindstone with the grading stone. Perhaps a diamond plate?

Another option might be to use spray-on contact cement to glue a full sheet of sandpaper to a flat table top, remove the grindstone, and rub it on the sandpaper. A flat surface can be created with a scrap of 3/4-inch MDF. Cut it a bit larger than the sheet of sand paper and fasten it to your benchtop with a few drywall screws, countersunk, of course.


This is probably a reasonable path for flattening the side of the SG wheel.  If not careful, sanding one portion more than another could cause it to not be perpendicular to the arbor hole/outer surface (which is trued by the Truing Tool).  Such non-perpendicularity would cause the side of the wheel to have a wobble, which might not work well for some sharpening operations.
Title: Re: Flatten side of SG 250 with grading stone?
Post by: jimon on March 13, 2025, 04:40:18 PM
Quote from: tgbto on February 06, 2025, 02:48:58 PMI haven't tried yet, but maybe it's possible to setup the MFB in such a way that you could somehow use the truing tool on the side, at least between the outer edge and a minimum radius ?

here is showed as possible to use truing tool on flat side

https://forum.tormek.com/index.php/topic,4682.msg33533.html#msg33533

https://forum.tormek.com/index.php/topic,4651.msg33300.html#msg33300