questions for turners

[Ken S]

My turning has been very occasional over the years.  Also, I purchased my two modern (high speed steel) gouges from the instructor at a week long class.  He had already reshaped them.

I realize the Tormek's strong area is sharpening rather than reshaping turning tools.  My question is how much longer does reshaping take with a Tormek versus a high speed dry grinder for the average tool?  And, how many turning tools would an average home shop need which require reshaping?  Built into this equation is the assumption that the Tormek wheel has been maintained at full efficiency with both the grading stone and the dressing tool.

For a one time operation like reshaping, does the real world time saved justify the cost of a second grinder, including the adaptor kit and an extra fifty dollars for a good stone?

Thanks for your thoughts.

Ken

[robert4wd]

Hi Ken

I purchased a new Robert Sorby 1" Skew. After an hour and a half on the Tormek I still had not achieved the shape I wanted. I purchased the BGM-100 and a 8" slow grinder with an 80 grit white wheel. It took about 10 minutes to shape and about 7 minutes on the Tormek to sharpen to a razor edge. It takes about 2 minutes on the Tormek to maintain the edge after use.

I just shaped and sharpened a new 5/8" Bowl gouge, about 12 minutes on the grinder going slowly so as not to heat the tool excessively and about 5 minutes to sharpen.

I would not consider the Tormek for the major shaping its too slow. That said I would not use anything else for sharpening once I had the shape I wanted.

Get a grinder you will be glad you did

Regards
Robert

[Ken S]

Good post, Robert.  Just curious, but did you frequently dress the wheel with the diamond tool?

I happen to have a dry grinder.  It's a six inch (high speed) Sears I bought almost forty years ago.  Replacing one of the wheels with a Norton 3X 46 grit stone really improved performance.  With a light touch, the stone is very controllable.  With a little more pressure, it cuts very quickly. Of course, it isn't as cool cutting as the Tormek, but the coarse grit 3X stone is both faster and cooler than the standard stones.  I think it's well worth the cost.

Ken

[robert4wd]

Hi Ken

I dress my wheel whenever I see that its nolonger flat against a straight edge. I find if you keep the wheel reasonably flat you only need to take a light cut slowly with the diamond tool. On average I will take a light cut after 8 to 10 tools sharpened or 2 tools sharpened on the tormek after they have been rough shaped on the grinder. I also keep the water in which the stone runs clean, it helps to keep the stone in better condition. In between I use the grading stone to keep the surface in good condition. One thing I have found is that you need to take you time when you change surface roughness with the grading stone. Especially when you go to the fine finishing surface. Keep grading until it feels smooth. Similarly if going back to rough I keep grading until it feels uniformly rough. It can take a couple of minutes. Hope this helps.

Regards
Robert

[GIPPER]

Hi Robert & Ken.
Just for comparison, after "truing", I find there are multiple grooves, equally spaced across the face of the wheel.  It takes me no less than 10 minutes with the course grader to smooth the surface out.  When changing from course to fine grit, or visa versa, I takes me no less than 5 minutes to make the change.  I use what I would call "moderate" pressure on the grader  Do you guys have any secrets in shortening the time to regrade?. Gipper

[robert4wd]

Hi Gipper
I had this problem as well until I redesigned the tt-50 truing tool. The tool as provided relies on pressure from the stone to hold the diamond in position. So on a light cut as the pressure comes off the diamond can bounce within its carrier and hence you get the radial grooves that take so long to remove with the dressing stone. The other contributing factor is the design of the diamond tip itself which is not optimum for producing a smooth graded surface.
One solution is to move the carriage very slowly and hence give the vibrations time to settle. I found that not effective as any variation I speed gives different areas of the stone with different characteristics.
Recently I got sick of the time to produce a great surface on the stone and I modified the truing tool remaking the carriage so that it has a dovetail slide at the top opposite the diamond. I then made a dovetail piece that fits on the underside of the tool body. This is lightly lubricated with oil and the tip of the tool now moves across the length of the tool with 0.0015mm variation under reasonable variation in load. I next obtained a new diamond tip with a evenly distributed pattern of diamonds and made a housing to fit onto the dovetail carriage.
This solved the problem for me I now can work immediately off the dressed stone. I am considering getting a different diamond tip to produce a fine graded stone from the dressing process
I hope this helps
Regards
Robert

[GIPPER]

Thanks Robert.
Your information is very helpful.  Your modifications to the TT-50 is also interesting.  Can't figure out how it works but it got me to look more closely to how the "truing tool" really works.  It could be worth your time to contact Tormek about your modifications.  Who knows, they might be interested.  Gipper

[Ken S]

Thanks for the replies, guys.  Just out of curiosity, has anyone tried shaping turning tools with the SB grinding wheel?

Ken

[Ern]

To return to the OP, if reshaping HSS turning tools you should be prepared to use the grading/cleaning stone every couple of minutes.

T. lit. refers variously to the time needed but 10 mins sticks in the mind.  Use plenty of pressure.  Be prepared to use the top mount position for a faster cut but be very careful here with bevels over 45 degrees.  You risk the edge digging into the wheel.

Re diamond truing, the grooves should be left if you are doing reshaping; effectively they increase the pressure per sq. inch and so help, not hinder.  They'll be gone soon after a few wheel cleanings anyway.

HTH.

ps what's the SB wheel?  The black one?  It's just for touching up.  Reeeal slow.