bowl gouge question

[Ken S]

This came in from a new member and somehow,the message got confused in the pixels.
Advice from you turners wouls be appreciated.
Thanks, Ken




link=msg=40834 date=1719079141]
Sorry if this has been asked, many times, before! I have a bowl gouge with a 30 degree bevel (it's def a BG!) I will re-grind most probably very soon but for now, how do I set the jig on my T8 to sharpen this, please? Does not appear to be a setting for this. I presume I cannot treat it as a spindle gouge?
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[RichColvin]

There are three factors in play here, and as this is a non-standard grind angle, you will need to figure out the recipe for yourself.

I recommend you incorporate these thoughts:

• The USB's height above the grindstone: I recommend you use the TTS-100 to set this and start with hole A.  Using this approach locks down this variable and makes for a repeatable approach.
• The JS on the SVD-185 or SVD-186: this determines the amount of sweep in the bowl gouge's wings (higher numbers = greater sweep). The chart in the Tormek manual shows this (page 82 in edition 10.5).  Again, locking down this variable makes for a repeatable approach.
• The projection of the tool from the SVD-185/186 is the last variable.  It will probably need to be greater than 75mm, but you will need to experiment with this factor.

These notes are all based on grinding the tool's edge on the grindstone in a traditional manner.  You might want to also consider using the multi-base (MB-100 or MB-102) as this will allow for sharpening at these angles with shorter projections.  This will become more important if you don't have enough tool shaft to achieve the needed projection. This approach is a little less repeatable though, and I'm sure that you already know that turning tools need to be resharpened often, so repeatability is key.

Good luck, and do keep us up-to-date on what you find.

[Rob]

Rich's response is a comprehensive one and will save you hours of time finding the right pages of the manual.

I will add one thing further that should help once you're grinding. Once you've got a trial and error match for the angle as per Rich, you need to be really careful at the nose of the tool, lest you grind away a smooth curve. As you swing the tool through the arc controlled by the jigs, there is a tendency to spend too much time at the nose. Instead, focus the grind on wing 1, then wing 2 and only when they've reached nirvana, join the sides at the nose so you have a rational, continuous curve.

Once done, when turning, keep the jigs dialled in and when you want to get that gorgeous finishing cut, just re mount the gouge and give it a tickle, avoiding the tedium of a full jig resetting.

If you have the silicon black stone it helps too if you're removing a lot of material and tool is high speed steel (it likely will be)

Hope this helps
Rob