Motorized TT-50 Truing Tool

[RichColvin]

I've been thinking of motorizing my TT-50 truing tool.  The thinking is that it would allow it to run slower (I sometimes get impatient and run it too fast). It would make it run consistently, and I can enjoy a cup of coffee whilst it runs ("Look ma, no hands!").

Rich

[cbwx34]

I've been thinking of motorizing my TT-50 truing tool.  The thinking is that it would allow it to run slower (I sometimes get impatient and run it too fast). It would make it run consistently, and I can enjoy a cup of coffee whilst it runs ("Look ma, no hands!").

Rich

That sounds pretty cool!

(Bonus points if you can get it to run a sharpening jig back and forth)... 

[Kavik]

LOL!
I was JUST thinking about this while writing my response to the truing tool conversation in my thread. Submitted that, come back to the thread list, and here this was haha

My thinking was that it would also eliminate any tendency to put pressure on the tool while turning by hand

[justme]

This would be interesting to me as well.  The idea of a very consistent movement where pressure is constant along with speed across the stone.

[Elden]

   Here is an idea I picked up from Kurt Johansson.

I am in the process of making another gizmo he mentioned. He made a wooden cup to fit on the knob (friction contact) of the TT-50. It has a spindle like piece fastened to it so that it can be chucked in a cordless drill. The cup is  held in contact with the TT-50 feed advancement knob and is rotated with the drill on low speed. This gives a consistent and even feed rate.

For me that would be great as my left hand does not function well. I have to advance the TT-50 one handed. If it works well for me, I envision making the cup of rubber from an old forklift tire eventually. The cup possibly would be of metal with a rubber insert.

   I got the wooden cup made and did not get any further with it. The wooden cup did grip the knob of TT-50 and would turn it when it was placed in contact by hand. I just never followed through connecting it to a cordless drill.

[justme]

One would think that a high torque, low speed stepping motor with micro switches at either end and a selection switch would do a really nice job.  Two (2) passes at a given depth should ensure that the surface is absolutely smooth.  Selection switch would determine the speed across the stone - with four options: SB-250, SG-250 coarse, SG-250 fine and SJ-250.  Granted, truing tool "this way" would be more expensive, but at least you'd know that each stone was 'trued' to what Tormek suggests, as they know/expect a stone to be in a certain condition for optimal function - likely quite a bit of engineering time.  At a minimum, would suggest two passes to ensure that the both edges of the stone are addressed in both directions - three passes may be a bit much?

Perhaps one of the engineering folks at Tormek might chime in as to whether this might even be plausible (or not).

There was a post on youtube about an issue whereby someone only did one pass and experienced some anomalies.  I don't recall the post, but there were three parts (separate videos) about the issue.  Suspect that speed across the stone, combined with variations in pressure and potentially the number of passes - had an impact.  One could easily see where this could happen.

Thoughts?

[RickKrung]

One would think that a high torque, low speed stepping motor with micro switches at either end and a selection switch would do a really nice job.  Two (2) passes at a given depth should ensure that the surface is absolutely smooth.  Selection switch would determine the speed across the stone - with four options: SB-250, SG-250 coarse, SG-250 fine and SJ-250.  Granted, truing tool "this way" would be more expensive, but at least you'd know that each stone was 'trued' to what Tormek suggests, as they know/expect a stone to be in a certain condition for optimal function - likely quite a bit of engineering time.  At a minimum, would suggest two passes to ensure that the both edges of the stone are addressed in both directions - three passes may be a bit much?

Perhaps one of the engineering folks at Tormek might chime in as to whether this might even be plausible (or not).

There was a post on youtube about an issue whereby someone only did one pass and experienced some anomalies.  I don't recall the post, but there were three parts (separate videos) about the issue.  Suspect that speed across the stone, combined with variations in pressure and potentially the number of passes - had an impact.  One could easily see where this could happen.

Thoughts?

I don't think it needs to be that complicated. I have a model train speed controller that controls small DC motors, 14 VDC output.  I have a small gearmotor from Jameco with a 200:1 speed reduction.   At 12VDC it turns at 13 rpms, but with the train controller I measured it at 20 rpm. I have it for extracting bamboo fly rods from the varnish dip tube at rates from 1"/min. to 4"/min.  I had to gear it down further, thus the timing pulleys.  Oh, yeah, instantly reversible. 




Using my forefinger and thumb on the output pulley, I could not easily stop the gearmotor.  I know that is not as much pressure that I use when driving the truing tool across, so I am convinced even this small motor is up to the job.  I will need to find one that runs at a higher rate but that should be easy.  I've already looked.

The TT-50 takes 41 rotations of the knobs to traverse the full width of the feed screw but only about 36 to traverse the width of the stone.  If I get a motor that runs at about 60 rpms, that would yield the faster rate of approx. 30 sec.  The train controller will allow slowing it down greatly for slower traverses, easily up to the 90 sec. rate and probably more. 

Don't know when I'll have time to play with this further as things are hectic in my life these days. 

Rick

[justme]

I was thinking purely "automatic".  Turn on after setting speed and let it go to town without having to worry about it.

The motor sounds like an excellent start.  A variac certainly provides option(s) for speed.  I'll have to look into that Jameco motor - as I have a couple things where that would be useful. 

[RichColvin]

Rick,

I was thinking of something like an Rose Engine lathe overhead drive (here's a good article about one http://www.whidbeyworks.com/root/Ornamental_Obsessions_files/Overhead-Spring2008.pdf ).  Your motor would work with that.   And, adding micro switches to stop it at the end might make this a really cool option where you could start it and walk away (to grab a cup of coffee ...).

Rich

[justme]

Start and grab coffee.... Perfection!

[Ken S]

You could turn a threaded holder to fit in your metal lathe ( as long as the swing was greater than the diameter of your wheel);put the diamond dresser in the lathe's tool holder; and use the power feed to control the cross speed. 

In my very low tech world, I just use a thermal lidded coffee cup and use the truing tool the regular way. My coffee stays warm.

Ken

[justme]

Ken,

The original reason for 'my' commentary is the premise that an organic engine input (hands) likely would have an impact.  For example, learned that the SJ-250 needs an *extremely* slow movement.  (>90 seconds) otherwise, you'll end up with what appear to be "waves" on/in the stone.  Resulting in the need to make multiple passes to "fix the fix".  Seeing how something like that can occur, my preference would be to remove the organic component so that the results are consistent every time and correct the first time around.  I also noticed that as you grab/rotate/change between hands trying to keep a constant movement/pressure - that on the SG wheel, not an issue.  On the SJ wheel, it appears to be far more sensitive.  Which my suspicion is that this fact had bearing on why/how the "wave" happened - not just speed across the stone.  Something akin to a minor "torquing" of the tip on the stone.  - Granted, some conjecture is involved and would be most amicable to thoughts on that.

Granted, I'm far "newer" at using the Tormek than [likely] the majority of folks on this site.  However, learning a great deal and of course - learning through mistakes as well.  (Fewer being the optimal goal).  <sheepish grin>

Perhaps being "hopeful" that Tormek would produce an AC-based truing tool variant (as previously described) so that outside of setting height adjustment that there's far less potential for mistakes as part of one of the most critical maintenance tasks.

I use a coffee cup warmer - although it doesn't help with refills. 

[Elden]

   When you get this perfected, figure out how to use the wasted heat from the Tormek motor to brew your coffee while the grinding wheel is absorbing its load of water. Oh by the way, figure out automation of the stone grading while you are at it. DC backup would be nice as well, the battery could charged while the Tormek is under idle or low load usage through a small generator inside the Tormek frame. 

[RichColvin]

Ken,

The original reason for 'my' commentary is the premise that an organic engine input (hands) likely would have an impact.  For example, learned that the SJ-250 needs an *extremely* slow movement.  (>90 seconds) otherwise, you'll end up with what appear to be "waves" on/in the stone.  Resulting in the need to make multiple passes to "fix the fix".

I'm just lazy.

[Ken S]

Justme,

You make a very good point. Although I have owned an SJ-250 since 2010, I have not used it very much. This is not due to any fault in the stone. If you have read my posts over the years, you will know that I have spent most of my Tormek time testing and reviewing. My knives and woodworking tools have survived with just the traditional SG/leather three step.

I have trued my SJ. Among other things, I lent it to Rich Colvin for a test drive just before he purchased his. I had just trued it. As I recall, I thought the edge looked like new. Perhaps Rich will share his recollections. I am generally very cautious with truing, both with depth of cut and speed. Except for special situations, I traverse the stone in more than ninety seconds with no deeper than a half a number cut. I am on no production schedule, and I enjoy peeling the onion and watching the stone gradually become true.

I have thought the round plastic turning knobs are less than ideal for a continuous turning motion. I have wondered how a crank would work. Rich made a very nice looking crank for a jig he designed. I think a lighter duty crank similar to that would be useful for the truing tool.

I think I could be content with a single slow speed. Over the years I have accumulated a dozen wheels for my Tormek. (The non Tormek wheels were purchased for forum experiments.) The quick traverse method does make the wheel briefly. Switching to an 80 or 180 grit CBN wheel is a long lasting fix. They can be used wet or dry. (Add Hone Rite Gold when using them wet.) The quick traverse method is a useful trick and one I did know for many years. (I must have nodded off while reading that page of the handbook....) 

If a motor arrangement would lead toward more regular truing, I think that is a worthy objective. My wheel can be quite stealthy in becoming untrue.

Keep thinking!

Ken