Just had a Duh moment

Self Made Knives

Self Made Knives

Well-Known Member
I feel kind of stupid I didn't notice this earlier. I'm working on #8 today and I've been struggling with my grind lines matching, just like all newbies. But, problem wasn't alignment, I'm keeping them even. The top little turnout line never matches side to side. One side has a nice little radius, other is squared off.

Finally noticed why today, insert big DUH, it's my platen! I built my own grinder and used a piece of 4x4 angle iron for the platen. The factory corner has a radius, the other side I milled down to a 2" width. Of course it has a nice sharp edge, never thought about it because I'd never ground any blades. Moral: if you make your own platen, make both sides have the exact same edge radius.
 

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Good thing is you figured it out! Now you will find something else to correct. I'm told you never really make a perfect knife. Even with "factory manufactured stuff" there will a few got'yas.

Congrats on finding why.
 
Another thing that can effect side to side is the belt edges left and right.
They wear differently, you can flip your belt.
 
Good tip. That was one of the things I was looking at yesterday while trying to figure out what was going on. I was using a 50 grit to start my finish grind after heat treat and I thought it was that belt at first. But, went to 120 grit and had the same thing. Then I thought it was the way I holding the knife, you know, the old strong side vs weak side grind. I've had this problem on every knife so far and I've been correcting by hand sanding (which I'm sick of!) so relieved I found it. A minute with a big file and now both sides have relatively the same radius.
 
I Had that same "Duh" moment on my home made platen! Learning as we go, so keep going and we'll shake that Newbie thing soon enough! By the way, been seeing you all over the forum and I have to say, I like your style! Keep it up buddy.
 
Thanks for the heads up on what to look out for on the build your own stuff. Atleast it wasnt a huge problem that destroyed blades.
 
Another "Thing" that can happen to your platen on a self made or store bought machine is that they can dish out where you make most of your contact.

Every so often I Flatten my Platen on a 6 x 48" sander and roll those two corners, so that they match.
 
This might be helpful....

[video=youtube_share;wKYIDxt8nvc]http://youtu.be/wKYIDxt8nvc[/video]
 
If one goes to far, get a grinding magnet and use your platen as a "surface grinder" to bring the line back down a tad.
 
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