Tormek Community Forum

In the Shop => Knife Sharpening => Topic started by: osterdahl on August 22, 2018, 09:54:50 PM

Title: Grinding question
Post by: osterdahl on August 22, 2018, 09:54:50 PM
Hello.

I am looking for a tip which technique I should use when grinding this knife?
I have tried to attach the jig in different angels in relation to the edge.
I have also tried to lift, pivot and a combination of both techniques. Nothing works...
The edge-angel gets too steep towards the tip.
Hope You understand despite my english...

I have also contacted Tormek support, but is awaiting their answer.

//Leif


Title: Re: Grinding question
Post by: Ken S on August 23, 2018, 04:21:02 AM
Leif,

Welcome to the forum. I am not a knife expert. I just want you to know that support is fluent in Swedish and Norwegian if either of those languages are more comfortable for you than English.

Ken
Title: Re: Grinding question
Post by: RickKrung on August 23, 2018, 07:15:25 AM
That looks to be a good candidate for free-handing on a platform.  Or a Pin Pivot Collar, which is not a Tormek jig, but a different collar for a knife jig that allows pivoting at a single axis point. 

For your knife, I see the potential for finding a "center of the circle" for the tip curvature.  Placing a single point pivoting collar at that center should allow you to pivot the knife through the radius somewhat matching the curvature of your knife.  When done pivoting through that curve, glide the whole knife/jig assembly along the USB, for the more straight section of the blade. 

I think Jan would be a great one to show us graphically. 

Free-handing on a platform would allow you to rotate the blade through whatever curvature it has and maintain the bevel angle throughout.  I know Herman Travilino posted about making a platform, but I haven't found his original post.  Others have made similar ones.  For mine, I used the Scissor Jig (SVX-150) platform and added a length of aluminum plate.  I believe others have used the Tool Rest platform (SVD-110). 

Rick
Title: Re: Grinding question
Post by: osterdahl on August 23, 2018, 08:08:17 AM
Thank You for the answer!
I did not think of the SVS-110...
But, I have sharpened a pizza slicer with that!
I will test this.
Title: Re: Grinding question
Post by: osterdahl on August 23, 2018, 08:09:02 AM
"SVD-110"
Title: Re: Grinding question
Post by: RichColvin on August 23, 2018, 10:07:19 AM
The platform to which Rick is speaking is attached to the SVD-110.  I've a picture of Jan's approach on my site in the Jigs section. 

Kind regards,
Rich
Title: Re: Grinding question
Post by: osterdahl on August 23, 2018, 10:39:26 AM
Thank You Rich for pointing me to Your site! Bookmarked!
Title: Re: Grinding question
Post by: Dutchman on August 23, 2018, 10:47:31 AM
Herman's thread: http://forum.tormek.com/index.php?topic=1592.0 (http://forum.tormek.com/index.php?topic=1592.0)
Title: Re: Grinding question
Post by: osterdahl on August 23, 2018, 04:34:11 PM
Hello again.
A good nights sleep and some trying solved the problem!
A weird angle for the jig provided enough space for me to be able to go straight on the first bit of the blade. Then I combined lifting an pivoting on the radius. Worked real well!
Title: Re: Grinding question
Post by: WolfY on August 23, 2018, 07:36:49 PM
Rick's explanation couldn't be more accurate. He nailed it perfectly and you got it right. Nice job.
As for sharpening pizza slicer? Did you get it perfectly round with the platform?
Title: Re: Grinding question
Post by: osterdahl on August 23, 2018, 08:21:10 PM
I canĀ“t say "perfectly round", if I should look in a microscope maybe it would look terrible...  :)
But to me it was ok. And my daughter said it was SHARP!  8)

Title: Re: Grinding question
Post by: Herman Trivilino on September 01, 2018, 03:35:14 AM
Quote from: RickKrung on August 23, 2018, 07:15:25 AM
I used the Scissor Jig (SVX-150) platform and added a length of aluminum plate.  I believe others have used the Tool Rest platform (SVD-110). 

The tool rest won't work because the platform is too far from the rotation axis. You need something like the base of the scissors jig.

The tool rest works well for blunt edge angles. Knives are sharpened at much smaller angles.
Title: Re: Grinding question
Post by: Ken S on September 01, 2018, 10:47:46 AM
I am one of the "others" who used the SVD-110 platform to make two small platforms (one for the T4; one for the T7). They work, however, the scissors jig platform used by Herman works much better.

Both the SVD-110 and the scissors jig platform require some minor user modification to work as small platforms. The scissors jig platform sits closer to the support bar. Herman is correct; that's the one to use.

Ken