Universal Support Extended - How Long of Blade Will It Sharpen?

[Thy Will Be Done]

I have knives and even swords that are in the ballpark of 10-18" and wonder if this extended support will cover all of that.  If not, where is the upper limit of what it will work with?  How well does this work with blades that have significant curvature in the belly near the tip?  I get some machete type patterns that are almost a 1/4" circle sort of heavy radius to them.  I find the standard support has difficulties with the heavy curvature and allowing you to keep the consistent angle all the way to tip.  What it wants to do is actually raise up the angle higher by having the part of knife contacting wheel be higher up on the wheel.

[Ken S]

From the Sharpening Supplies website:

Sharpen Longer and Wider Tools
The Extended Universal Support is for sharpening long or wide tools such as long knives, cleavers and machetes. At 212 mm (8 3/8") tall, the US-430 allows for an additional 57mm (2 1/4") in height adjustment. And at 436 mm (17 1/8") long is grants an additional 130mm (5 1/8") side-to-side travel.

Features the Micro Adjust with scale for setting a precise edge angle and cutting depth.

Fits Tormek T-8/T-7/T-4/T-3 and older Tormek models.

Ken

[3D Anvil]

I have a machete with 16.5" of sharpened blade and the extended USB is long enough to accommodate it.  But, as you mentioned, there is the issue of the big belly towards the tip.  If I was going to sharpen the machete on my Tormek I would do the long, straight section and then reclamp and sharpen the belly separately -- almost like sharpening a huge tanto blade.

[RickKrung]

What about using two (or more) knife jigs?  As one approaches the end of the support bar, the next one comes into contact.  Seems like this could be done using the standard support bar, negating the need for the extended support bar.  Never tried it, just thought of it.  I sharpened a machete once, but used a platform jig on a belt grinder. 

Lifting and/or pivoting, in the same way done for curved tips is how I dealt with keeping the bevel width and angle the same over the tip area.  A jig at the tip would be very handy for this operation. 

Rick

[cbwx34]

I have knives and even swords that are in the ballpark of 10-18" and wonder if this extended support will cover all of that.  If not, where is the upper limit of what it will work with?  How well does this work with blades that have significant curvature in the belly near the tip?  I get some machete type patterns that are almost a 1/4" circle sort of heavy radius to them.  I find the standard support has difficulties with the heavy curvature and allowing you to keep the consistent angle all the way to tip.  What it wants to do is actually raise up the angle higher by having the part of knife contacting wheel be higher up on the wheel.

Platform Jig?

[RickKrung]

I have knives and even swords that are in the ballpark of 10-18" and wonder if this extended support will cover all of that.  If not, where is the upper limit of what it will work with?  How well does this work with blades that have significant curvature in the belly near the tip?  I get some machete type patterns that are almost a 1/4" circle sort of heavy radius to them.  I find the standard support has difficulties with the heavy curvature and allowing you to keep the consistent angle all the way to tip.  What it wants to do is actually raise up the angle higher by having the part of knife contacting wheel be higher up on the wheel.

Platform Jig?

Just a tool rest "platform" device.  Not really a jig.  Like the base platform of the scissors jig.  Like this one Tormek SVD-110 Tool Rest

[cbwx34]

Just a tool rest "platform" device.  Not really a jig.  Like the base platform of the scissors jig.  Like this one Tormek SVD-110 Tool Rest

Seriously?          

Well OK then...

Definition of jig (Entry 1 of 2)
1a: any of several lively springy dances in triple rhythm
b: music to which a jig may be danced
2: TRICK, GAME —used chiefly in the phrase the jig is up
3a: any of several fishing devices that are jerked up and down or drawn through the water
b: a device used to maintain mechanically the correct positional relationship between a piece of work and the tool or between parts of work during assembly
c: a device in which crushed ore is concentrated or coal is cleaned by agitating in water

Kinda sounds like one to me....   

Or maybe the jig is up.          

p.s.....

... I sharpened a machete once, but used a platform jig on a belt grinder. 
...
Rick

[Pietje]

I have a machete with 16.5" of sharpened blade and the extended USB is long enough to accommodate it.  But, as you mentioned, there is the issue of the big belly towards the tip.  If I was going to sharpen the machete on my Tormek I would do the long, straight section and then reclamp and sharpen the belly separately -- almost like sharpening a huge tanto blade.

Hey there!
There is a toolbar with 65cm lengh availeble at https://schleifjunkies.de. There is also a doublejig. International shipping is possible. I have this long toolbar. It works fine. But using the full lengh needs attention to the Tormek jig. The black screwhead hits the two vertikal bars.

Pietje

[cbwx34]

...
The black screwhead hits the two vertikal bars.

Pietje

You can replace the screws, or maybe pry off the black part of the knob for more clearance...

[Ken S]

There is no need to pry the black plastic lock screws apart. They have a standard 6mm thread. Just replace them with 1mm long 6mm thread socket set screws, also known as grub screws. You will need three of them, one for the jig and one each for the two horizontal sleeves. Total cost is around $5 USD at any good hardware store. You will need a metric Allen wrench. You should already have a set of them.

You will need to grind down a small area of the back of the knife jig. This will take around five minutes and be obvious when you run the jig across the support.

The knife jigs were designed sharpening using the vertical sleeves. The Tormek honing technique is hand held. With these minor modifications, jig held honing is possible.

Ken