Flat grinders Bubble Jig is in production.

[Fred.Rowe]

It has taken me a while, but I have finally gotten it in production.

I designed this jig to help grinders establish identical bevels on both sides of the blade being ground, while still maintaining full freehand control.

The bubble is 180 degrees adjustable and will work on anyone's vertical belt machine, no matter what the pitch of the platen.

This jig can be used with a grinding guide or placed directly on flat stock, via a strong magnet recessed in its base.


It allows the person grinding, to produce the same angle of approach on both sides of the blade, by simple moving the jig from one side of the blade to the other as the bevels are being ground.
Everyone that flat grinds blades grinds at the same angle of approach; a maximum of 5 degrees for edge development down to as little as 2.5 degrees angle of approach for wide blades, such as fighters and Bowies.

This jig gives you full freehand control; it just allows you to approach the belt at the same angle ever time.

It does not restrict the varied grinding that takes place along the tip.

It is great for grinding swedges at precise angles or cleaning up the swedge after heat treat.
I set it at twelve degrees to sharpen my knives on the belt grinder.

There was a lot of interest in my original post on grinding with a bubble jig; so for those of you who have been anticipating this, it is finally in production.

I have applied for a patent on this jig and believe it will be a real benefit to those people just learning to grind and also to seasoned veterans. I find it has multiple uses in the knife shop.

I will have this jig for sale in September. It comes with a set of plastic wedges at varying degrees that will cover most any grinding situation.

This jig will be available at my table at the show in Cambridge, Ohio that is being held the last of October.

I will be happy to answer any questions you might have.

Happy grinding, Fred



This is the jig sitting on a 5 degree wedge, the bubble has been centered and you are ready to grind the edge of the blade.

If you are grinding flat stock without a bevel guide, attach the jig to the flatstock, grind the bevel on one side, switch the bubble to the other side and grind the other bevel.


If you are using a bevel guide on your blade, like the one pictured, attach the jig to the guide.


Heres the reverse.


You can attach the jig to the blade and use it to grind machined looking
false edges.


Finished!

[Kostoglotov]

Looks interesting.

Price?

Any chance of a video if it in operation?

[DaveRuhlig]

Originally Posted by Kostoglotov

Looks interesting.

Price?

Any chance of a video if it in operation?

I agree. I'd love to see a video or more pictures of it in use. It's hard for me to imagine how it works. Is it attached magnetically? How do you assure the same placement each time you take it off and put it back on - or oes that not matter?
-Dave

[Fred.Rowe]

Originally Posted by Kostoglotov

Looks interesting.

Price?

Any chance of a video if it in operation?

We are working on getting the video completed. Looks like the first of Sept.

The Bubble Jig along with the degree wedges to used to set the desired angle is priced at 35.00.

[Fred.Rowe]

Originally Posted by DaveRuhlig

I agree. I'd love to see a video or more pictures of it in use. It's hard for me to imagine how it works. Is it attached magnetically? How do you assure the same placement each time you take it off and put it back on - or oes that not matter?
-Dave

Dave,

Good questions. It is attached magnetically. You only have to place it on the same surface on both sides of the blade surface, to get an accurate grind. When you center the bubble and contact the moving belt you will automatically reproduce the same angle on both sides of the blade blank.

The way I start grinding a blade is I set a 5 degree angled wedge on my platen, set the Bubble Jig on top of it, center the bubble in the vile, then place the jig on the profiled blade.
I am then grinding at an approach angle of 5 degrees to the moving belt. I develop the future edge of the blade at this angle. After the edge is thinned to 40 thousands, I change the angle, set in the jig [ make it flatter] and move the grind up the blade.
If you do stock removal there is no need to scribe a line along the edge; the use of this jig does not require it. The bevels will be even, I assure you.

I stop using the jig as soon as the flats are established, about 50percent of the grind. The surfaces you end up with are identical on both bevels. And they are flat, not convex.

The nice thing about this set up is you still have full freehand control and it adds no appreciable weight to whats in your hand.
I will pm you when the video goes up.

Fred

[DaveRuhlig]

Fred-
Thanks for posting the additional pics - it makes a lot more sense to me now. I really like the idea and can definately see how it could be useful. Nicely done!
-Dave

[Fred.Rowe]

Originally Posted by DaveRuhlig

Fred-
Thanks for posting the additional pics - it makes a lot more sense to me now. I really like the idea and can definately see how it could be useful. Nicely done!
-Dave

It is a handy tool. With just a little practice most anyone, can do beautiful flat grinds.

Thanks for commenting, Fred

[moon]

I have used this tool in Fred's shop, once you get the feel for it, and that does not take long, it works like a charm. Moon