Author Topic: a question for Rob  (Read 1388 times)

Offline Ken S

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a question for Rob
« on: February 03, 2016, 12:05:57 pm »
Rob,

Regarding the larger capacity of the new 186 gouge jig:

I have read that the Ellsworth grind is really designed for a 5/8 inch bowl gouge. Does a gouge of that size fit in the older 185?

Do you use gouges which are larger than the capacity of the older jig?

Thanks.

Ken

Offline Rob

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Re: a question for Rob
« Reply #1 on: February 03, 2016, 09:45:45 pm »
Hi Ken

My largest bowl gouge is 1/2" and that fits well with plenty of room for growth so I would hazard an educated guess that the 185 will easily handle a 5/8" gouge.

I've not read the Ellsworth is primarily used on 5/8" but that makes sense since the long wings of that famous grind are very much for hogging off lots of material in the early shaping stages of a bowl.  To do that safely and with control you would want a substantial amount of metal and a robust handle to dampen the vibration.  I personally find 1/2" to be a pretty substantial tool and actually find myself using the 3/8" as my go to gouge so I can attest to the idea that a 5/8" would be a behemoth of an instrument.

So I don't use gouges larger than the capacity of the jig except for roughing gouges which ironically don't need an elliptical grind since they're typically ground straight ended at 45 degrees.  The Tormek recommend the SVS-50 multi jig for this purpose. 

So for me the benefit of the 186 over the 185 would be its ability to clamp down tightly on very narrow gouges such as 1/4" detail spindle gouges which get used for fine detail work on finials and small beads etc.  The existing clamp in the 185 is a brass disc with a sort of oblong of hard rubber attached to it with a screw.  The hard rubber usually slots in the flute of the gouge while the disc pushes down on the sides of the flute.  With the smaller gouges that procedure gets tricky and frequently fails.  I think you can unscrew the rubber piece and just use the disc but then it fails for larger gouges so it becomes an annoying faff to switch from plastic bit to not and of course with time...you stop using it for both.

If the upgrade solves that then I'd be a very happy man because the one job I really like the Tormek for still is gouge grinding for three reasons:

1) it gives a very sharp edge because of the water and the fine-ness of the grit in the stone on smooth setting
2) it has huge flexibility over the three variables in setting up the profile of the grind i.e. distance tool sticks out of the jig (p), distance from axis of rotation from the grinding medium (USB) and angle the bevel is presented at (knuckle setting).  Which means it will do 30 degree bevels easily and that's typically what spindle turners want for fine finial work (with their 1/4" gouges)
3) it takes a miniscule amount of metal off your expensive deep fluted gouges so they last much longer than any other form of grinding in my experience.

So if I can get a jig that meets all of my little challenges it will make my Tormek pretty much dedicated to that function.  That will leave my BGM 100 with the Torlok toolrest used for scrapers (on a cheapo dry grinder I have) and other machines for parting tools and skews which are less well served by the jigs on the Tormek.

I really hope it will handle narrow gouges :-)
Best.    Rob.