Grinding problem(s) (pic attached)

[bullet101]

I started this blade this very evening and had some problems during grinding, I had them before but know they rellay start to piss me off, so I thought I should ask you guys about a solution .

Problem No 1 :

When I ground the false edge on my platen I had the problem that I always ground on both edges of the platen, so it wasn't really possible to control the grinding.
In the end I ground the false edge on on platen edge only, but I'm not that pleased with the result. Anyone of you got some hint's on this topis (grinding recurves is actually quite the same thing isn't it)?

Second and more important problem :

As you can see in the pic, the grind worked out quite ok so far, but it get's more and more difficult to achieve a clean and straight grindline, the flater the angle of the grind gets (the higher and closer the grind gets to the back).

When I grind the blade on my grinder (this one, but heavily modified and the grinding arm mounted 90 degrees to the ground so the belt is running down)

the whole grinding arm of the the grinder starts to "shake" and the belt (3M quality stuff) starts to "whobble" my blade. So it's pure luck to achieve a good finish grind and I often end up messing my blades so close to the finish line .
The closer I get to the tip (so the less surface of the blade is in touch with the belt) the worse it get's. Because of the whobbling I also loose the felling if the surface of the blade is still properly in touch with the belt.

Is it because the grinder is not stable enough mounted or is it because of my technique? I grind on lower breast height (I know that's pretty high but that's just what's dictated by the workbench height, but if necessary I could change it), and move the blade with my free arms across the belt.

I read several times that the grinder should be mounted lower, the arms should be tucked into the sides and then you should move your whole body instead of just the arms.
Could it be that I'm not having enough power and stability with my free arms to get proper results?

I'm looking forward to your answers.

Regards Marcus

 

[Mike Hull]

As I can't see the false edge, I'll just say something about the grind height.

You can have the grind go towards the back of the blade, or toward the edge, by merely torquing the handle whichever way you want it to go.

Lets say you're grinding with the edge up, and the belt running into the edge, if you want the grind to go more to the edge of the blade, twist the handle slightly(twisting the edge into the belt) as you have the blade pressed against the belt.
You do the opposite for higher grind lines.

Practice this a few times, and you will see what I mean.

And, speaking of practice, that will be the main way for your grinding to improve.

The blade jumping on the belt usually means a dull belt.
Another way to stop that somewhat is to put a "pyroceram" platen liner on the platen, and of course, using sharp belts.

 

[Matt Shade]

Any chance you put the belt on backwards and the seam is catching when you put pressure on it grinding? That would make it jump.

 

[Don Hanson III]

First, a good veriable speed grinder would solve most of your problems. Slower speeds help more than you know and you have a lot more control.
When grinding a recurve you have to use the edges of the belt because the edge of the blade wont lay flat on the platen. A 1'' belt works much better for recurves but you need a 1'' platen also. Hey, you're doing a fine job with what you have though, keep up the good work.

Don Hanson lll

 

[Gib Guignard]

Don is right, then grind the swedge/faults edge on the wheel with the blade vertical. Gib