Shearing combs and blades

[cabaer]

I own a Tormek T-3 which I mostly use for wood carving tools. I also shear alpacas and it dawned on me that I could possibly sharpen the combs and blades with my tormek. Anyone have experience with that? What jig should I use/get?

PS this is what they look like: Www.lightlivestockequipment.com/combs&cutters.php

[grepper]

Looks like a pretty specialized hollow grind for shearing cutters.  I suspect it would be pretty easy to trash the blades and maybe the shear if they were sharpened incorrectly.  The grinders cost about $1,500.00 new, and a set of disks is about $600.00. 

http://www.shearingworld.com/Training/grinding/grinding.htm

http://heiniger.com/en/home-international/products/grinders/

http://www.youtube.com/watch?v=UMa4j_t6luE

This shows the convex disks:
http://www.youtube.com/watch?v=A0UA_Z5uZqI

[Ken S]

Welcome to the forum, Cabear.  Speaking just for myself, I'm not ignoring you; I just have no background with shears.

Good luck.

Ken

[cabaer]

So in other words I cannot use the tormek grinder for this?   

[Rhino]

I am not a shearer.  But you sparked an interest and I did some web research.  I think a shear is a big cutting blade, with multiple fingers and a complex form, that has to be ground flat to interface with another blade.  The second blade also has to be ground flat. 

In other words, you need to grind a 2.5 inch by 2.5 blade completely flat to it can interface with another 2.5 inch by 2.5 inch flat item. Since the comb is in industrial work, it can get quite dull, and a lot of grinding is necessary.

From the machines I see on the web, it appears they are all really heavy duty for making thousands of grinds fast and accurate.  The shaft for the grinding wheel looks like it is one inch in diameter and the nut is 2 inches in diameter.  Therefore, I expect the machines to be really really rigid.  Also, since they are using sandpaper, dressing the machine is not an issue.

Based on the above, I don't think Tormek is suitable for this.  This is only my opinion.  The grinding stone on the Tormek does not have a flat surface except on the side and there is no way to dress the side if it goes out of flat.  You can make anything work, but the time and energy required (at least for me) would make me just hire a pro with a dedicated machine to do this.

[RobinW]

I fully agree with Rhino.

I know there are comments about flattening the backs of chisels on the side of the Tormek wheel, which I have done, but always resort to waterstone as not accurate enough for me.

I was at the Royal Highland Show in Edinburgh in June, and watched the sheep shearing competition there. Those guys were shearing a sheep in just over a minute! They come on to the platform with one tool and several sets of blades - they don't last long.

I also had a look at the Lister grinding machine, and spoke with their representative and he was on about the accuracy and flatness required. I think he said that the blades needed re-grinding in less than 10 minutes. The Lister machine was a very similar set up to the machines referenced in an earlier post, and you will note the swinging arm jig on the Youtube video.

[Herman Trivilino]

I have never had much luck sharpening those shearing blades.  With or without a Tormek.

[cabaer]

Rhino and everybody else, thanks! You have some really good points! I'll send the blades to a professional. Oh well! I'll go sharpen my wood working chisels... 

[Herman Trivilino]

Make sure that the professional has the proper tools to do the job.  I've had mine done a couple times by people who didn't do them properly.

[grepper]

Cabaer,

The site that you referenced in your original post sells a sharpener:

http://lightlivestockequipment.com/sharpening.php

Note these blades are not flat ground, and the sharpening plates are convex, "the wheels have the proper bevel to create the hollow grind that is so important for shearing".

If you do a lot of shearing it might be worth it.  They have a payback calculation on that page. 

Probably a fun machine to use too!