Author Topic: Lessons learned and forgotten/learned  (Read 2062 times)

Offline Ken S

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Lessons learned and forgotten/learned
« on: August 10, 2018, 10:38:34 pm »
Lessons  learned and forgotten/relearned

I don't feel I have discovered new additions to Tormek technique. I do feel that I have learned some things previously unknown to me and remembered some things that I have forgotten. Here are some lessons from my recent skew reshaping/sharpening project. I hope they might benefit the forum:

Both reshaping and sharpening work better as separate functions. When I switched to reshaping with the tool held at ninety degrees to the wheel, my efficiency improved.

Not all grinding requires jigs. When I reshaped, I supported the skew chisel with the support bar placed very close to the grinding wheel. Working carefully, this gave me very good control.

The revolving base does not have to be used in only one of two orientations 180º apart. By rotating my Tormek 45°, I was able to work in much better light. This was easier than trying to reposition my magnetic base LED light.

For grinding the radius part of the bevels, I needed easy access to pivoting to both the left and right.

My water spillage was very minute. I had more water (and ACC ) loss from evaporation over the several days involved. At the start of every grinding session it is important to check that water is flowing over the grinding wheel. Once or twice, I noticed that my grinding wheel was dry. I am learning. As the diamond wheels work wet or dry, no damage was done.

I switched from using the Multi Jig traditionally used to the platform. My skew actually fit in the closed seat of the Multi Jig. The jig just didn't work in my situation. Was this the jig or the user? I will leave the jury out on that. The platform works.

I found that the platform worked better in reversed orientation in my case. (The locking knob needed to be located to the left of the grinding wheel for clearance.) I placed two thicknesses of plastic gift cards on the platform going down to the surface of the grinding wheel. This let me easily use the Anglemaster with one edge against the grinding wheel. I needed to convert Alan Lacer's "bevel length one and one half the thickness of the tool" to "Anglemasterese". The answer was very close to 20º for each bevel.

The reversed platform orientation also allowed me to place my thumb beneath the rear facing part of the platform to counterbalance the four fingers placed on top of the platform and skew. These are placed very close to the edge. The light grinding touch needed for diamond wheels makes this very steady.

Grinding the new bevels did not go quickly. However, the DC-250 gave a satisfying grinding sound and feel during the entire operation. Progress was not fast. It was also not frustrating. It was a pleasant change from my experience with the SB-250.

Once the platform was properly set for the settings did not change when the coarse completed and the wheel switched to the fine (and extra fine) grinding wheels. I removed the support bar with the platform still in place during the wheel changes. No readjustment was necessary when the support bar was replaced. No readjustment is necessary for future touch ups of the skew chisel. With spares available, the combination can be dedicated and left ready to go, a trick I learned from Jeff Farris' video sharpening the turning scraper.

Incidentally, Alan Lacer sharpens his skews to 80 grit and uses a 600 grit hone for honing. This method, while initially slow, may be as fast and as sharp as Alan Lacer's own method, or at least very close. The DF-250 is 600 grit.

That was as much new technique as my brain cells can absorb in one new project. I hope it also proves useful for you. As always, I welcome suggestions.

Ken

Offline Ken S

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Re: Lessons learned and forgotten/learned
« Reply #1 on: August 11, 2018, 09:01:04 pm »
I finally had the chance to actually turn today. (hurrah!) I love the expression the old British woodworking writers used to use, “the veriest tyro”. (a complete beginner). That is an accurate description of my turning skill.

One of the things Alan Lacer emphasizes the importance of safety. All skews have a reputation for being difficult tools and prone to catches. There is some basis for this, although it can be minimized. The best way to tame any skew is to switch the traditional four prong drive center to a safe center. In the event of a catch, or in my case multiple catches, the wood will slip and stop turning. What can be scary and potentially dangerous become no big deal. I had numerous catches in my maiden voyage. They did not bother me. I consider a safe drive center a must. Mine is by Oneway and cost $30. I also purchased a Oneway live center for the tailstock. It spins with bearings instead of being a dead center and just rubbing. the safe center should be the first priority.

Be sure to watch Alan Lacer's you tube of his Dallas presentation. It will benefit using any skew.

Ken

Offline cbwx34

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Re: Lessons learned and forgotten/learned
« Reply #2 on: August 13, 2018, 03:28:33 pm »
...
Both reshaping and sharpening work better as separate functions. When I switched to reshaping with the tool held at ninety degrees to the wheel, my efficiency improved.

Not all grinding requires jigs. When I reshaped, I supported the skew chisel with the support bar placed very close to the grinding wheel. Working carefully, this gave me very good control.
...

I have found the same thing with knives... it's usually better to repair/reshape, then sharpen... and often do it freehand... 90° (or at least at a much higher angle if a jig is used) to the wheel as you indicated.
Knife Sharpening Angle Calculators:
Calcapp Calculator-works on any platform
or, a couple of iOS Calculators

Offline Ken S

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Re: Lessons learned and forgotten/learned
« Reply #3 on: August 13, 2018, 03:41:17 pm »
Good thought, CB.

I certainly did not invent the technique. It just seemed worthwhile to borrow it.  :)

Ken

Offline Rob

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Re: Lessons learned and forgotten/learned
« Reply #4 on: August 14, 2018, 06:34:01 pm »
There's a variation on that theme when grinding gouges that I wont go into now as I'm short of time.  It's known in our club as "the horseshoe" technique and its extremely useful when aiming to get a symmetrical grind on the swept back wings of a bowl or spindle gouge.  it's a virtually fool proof method of avoiding the common gotcha of grinding the wings unevenly and winding up with a tool that looks and feels unbalanced.

I'm pretty sure Jeff used to talk about some years ago too if I recall correctly.

When I get chance I'll ferret out a training class I gave on it and send you the document Ken.
Best.    Rob.

Offline Ken S

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Re: Lessons learned and forgotten/learned
« Reply #5 on: August 14, 2018, 07:39:22 pm »
Thanks, Rob. I will look forward to it.

Ken