an improved substitute target

[Ken S]

My idea of a substitute target is for a piece of flat metal to be placed in a Tormek knife jig instead of a knife. It can be used with a user chosen Protrusion of the knife in the jig, however, I recommend a protrusion of 139mm for consistency. Substituting the flar metal substitute target for the knife gives a large, flat measuring surface for the Anglemaster. This can be very useful when grinding bevels other than one's standard. It can be used with an individual knife or as part of making a kenjig. Used this way, it eliminates the need for math for users not math comfortable.

My original metal substitute target seemed to work well. Fortunately, Jan informed me that it was too thick, and that the extra thickness wouls effect the accuracy. After  some brief thinking, I realized that Jan was correct. I looked into correcting the target. I found that two plastic gift cards were close to the ideal 1.25mm or .050".

I wanted something more durable. I found aluminum 1 1/2" x 1/16" x 4 feet at my local big box store.
Hillman ALUM - FLAT
                      6245
1/16"x1-1/2"x4-ft
H# 11323

I will start with a piece 1 1/2" x 2".  the 1/16" thick metal is actually about .010 too thick, but should be plenty accurate enough for our work. I plan to grind at least a partial bevel <15°. on the substitute target. This should make using the A nglemaster more concenient for thos e who prefer it.

Since I have four feet of the material, I am not concerned if the first attempt doesn't work.

Any thoughts?

Ken

I

[SharpenADullWitt]

Any thoughts?

Yes, pictures please.
With my work schedule and life being nuts again, I am not always following as my mind is going 100mph.
And I can't get that .vbs script out of my head, as I need to figure out how to tranfer it to a bash script.

[Ken S]

SADW,

Yes, pictures would help. Actually, I posted two photos of the earlier , thicker steel model. The concept is the same.

If you play two give cards or similar in the knife jig, you can see the concept in action. In fact, I was thinking of using gift cards. Two are not far from the ideal thickness.

I will work on pictures.

Ken

[RickKrung]

Yes, pictures please.

Yes, pictures would help.

I started this back a while and had the angle crudely ground using a high speed grinder.  What I really wanted to do was mill it and then grind it on the Tormek.  I finally got my mill set up after moving a year and a half ago, so I could now do it. 

First set it all up in the mill.  My brother turned me on to this cool angle measuring device.  He used for setting angles on his CNC mill, doing professional machining.  I figure if it was good enough for that, it should be good enough for me. 

Setting the base angle at zero.


Setting the angle vise angle at 15 deg.


Milled surrogate knife plate.


Ground surrogate knife plate.


When setting up the Tormek for 15 deg., I used Wootz's applet and so I thought it would work out great.  But no, the angle I set on the Tormek was way too steep.  I had to keep lowering the USB until the marker was removed from the center of the taper.  It took a while, but finally got it done, but did not bother going so far as to take off the secondary bevel along the leading edge caused by the earlier wrong angle settings.  I have not gone back to try to sort out what the problem was. 

While setting up to take this picture, I realized that if I want to sharpen at shallower angles than 15 deg., this surrogate reallyu won't work because it will get tilted up and not represent the right angle.  I'll have to take it down as far as I can go with the jig.  Not sure how important it is, though as I plan to use Wootz's applet for most work. 


Rick

[RickKrung]

While setting up to take this picture, I realized that if I want to sharpen at shallower angles than 15 deg., this surrogate reallyu won't work because it will get tilted up and not represent the right angle.  I'll have to take it down as far as I can go with the jig.  Not sure how important it is, though as I plan to use Wootz's applet for most work. 


Rick

I put the plate back in the mill and set the angle at 10 deg.  Much better angle, better clearance.  The milled surface is much better and I was able to take it down far enough to remove the errors from the previous grinding.  I'm leaving it this way, no need to grind anything.




Rick

[cbwx34]

...
When setting up the Tormek for 15 deg., I used Wootz's applet and so I thought it would work out great.  But no, the angle I set on the Tormek was way too steep.  I had to keep lowering the USB until the marker was removed from the center of the taper.  It took a while, but finally got it done, but did not bother going so far as to take off the secondary bevel along the leading edge caused by the earlier wrong angle settings.  I have not gone back to try to sort out what the problem was. 
...

I must admit... I'm stuck on this part of what went wrong? 

Otherwise, good stuff... you definitely have an attention to detail. 

[Ken S]

I think the problem is that the surrogate is too thick. I made my substitute target approximately 1.25mm or .050 thick to match the milled portion of the knife jig. I did this using a belt grinder. At least, I think I did. The target I found was 2.8 mm thick. I thought I made a thinner target, based on the ideal centering for the knife jigs.

I measured the bevel angle I used. It measured 7°. If anyone finds my original post with the photo, please quote it. I will requote it and post it under my second username, which is ken s2. I set this up solely to quickly locate frequently needed posts.

Ken

[cbwx34]

I think the problem is that the surrogate is too thick. I made my substitute target approximately 1.25mm or .050 thick to match the milled portion of the knife jig. I did this using a belt grinder. At least, I think I did. The target I found was 2.8 mm thick. I thought I made a thinner target, based on the ideal centering for the knife jigs.

I measured the bevel angle I used. It measured 7°. If anyone finds my original post with the photo, please quote it. I will requote it and post it under my second username, which is ken s2. I set this up solely to quickly locate frequently needed posts.

Ken

Maybe?

An aid to help setting bevel angles

or

A new angle setting tool

[Ken S]

Thanks, CB. Both of the topics you found explain the substitute. The first has Jan's excellent drawing and thickness thoughts. The second is my original topic with the photo.

Great sleuthing, CB

Ken

[jeffs55]

Is it safe to grind aluminum on a stone wheel? Or, if not unsafe is it a good idea? The aluminum is soft and may clog the wheel. I know you can use the diamond tip to clean it up but why dirty it up? I bet they sell iron at that same big box.

[Daniel]

Jeff,

I wouldn't use the TT-50 truing tool to clean the stone, that is mostly meant to make the stone paralell and true to the universal support and solving other issues that may develop as your stone gets used. It is also a relatively slow process that will dwarf your stone by a few milimeters.

The SP-650 stone grader is meant for that precise task, cleaning the wheel so you can keep sharpening, plus it will also allow you to rectify the surface of the stone between 220 and 1000 grades so you can reshape (220) or sharpen (1000) a bevel.

I do not have experience sharpening aluminium on the Tormek, but if it is anything like what happens with files then it will clog very fast. No issue, though: just as you would quickly use a brush on your file to get rid of the aluminium particles clogging it, same story with the stone grader.

Still, it would be wise to wait for an answer from someone more experienced than me

[Ken S]

Excellent point, Jeff. The problem is my memory. I made the substitute target a while ago. I just checked it. It felt heavy for aluminum, and it is magnetic; it is steel. I would not intentionally grind aluminum with the Tormek or any grindstone. I would use my belt grinder for aluminum.

I chose to make the substitute target using the belt grinder. The Tormek would have done the job; the belt grinder was just expedient.

As I generally use a kenjig, I rarely use the substitute target. Recently, I have found that two thickness of plastic gift card material work very well. Just keep the Projection the same. This is easily done with the adjustable stop. I stagger the two cards slightly to simulate a bevel. Any small amount of flex is negligable.

Daniel, like you, I do not use the truing tool to clean the grinding wheel. I probably do true lightly more than most users.

Ken