Odd clamping jig/workholder

Don Foreman fired this volley in news: snipped-for-privacy@4ax.com:

Heh! Well... they never really bothered me much before now, although I admired them from afar.

LLoyd

It can be 4-500 BHN and still take a licking and eat up cutters.

I cut Abrasion resistant steel for a business. AR-400. It is easier to grind than the good blade.

I bought a set of blades that didn't have a hole but a cloverleaf to mount it. I'll have to grind it - but that won't be true to center.

So the steel will be used to harden surface needs.

You might have cheap blades that are not keeping an edge long.

I have a 54" triple blade mower myself.

Mart> "Martin H. Eastburn" fired this volley in

Just because your little doggie ruins your grass, is no reason to weed-whack it. ;-)

"Martin H. Eastburn" fired this volley in news:SsGLn.395016$ snipped-for-privacy@en-nntp-02.dc.easynews.com:

A) You've apparently not ever cut dry Bahaia. 6-10 acres per sharpening is about as good as it will ever get. The stuff's like cutting plastic-coated wire.

B) Nothing Scag makes is "cheap" either in quality or price.

LLoyd

I went looking for a picture of your mowers blades. Not a very nice item to clamp on.

If yours look like the one I saw there is a very small flat between the sharp end and the lift wings.

Which model so you have so I can look into this a bit more?

The one I looked at had a flat section under the edge that a tee shaped parallel and an angle vise could hold.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

Wes fired this volley in news:BwDMn.489922$ snipped-for-privacy@en-nntp-04.dc.easynews.com:

It is the Scag Turf Tiger 61".

But I have the jig made, and sharpened two sets of three blades today.

So far, I'm just using step-block and tee-nut hold-downs on the work, and it's fine -- no chatter or motion.

Since that worked, I'm going to drill the jig block for some permanent built-in clamps, so I don't have to fiddle with the silly step blocks every time I flip a blade.

The jig ended up being pretty simple. It's just a tapered "saddle" for the entire business end of the blade. It's got a rear edge stop milled in so that the work can be forcefully pushed down into the stop by the clamps.

The wing end didn't turn out to be as tricky as it looks. A narrow hold- down just fits in the valley of the bend, and is just barely out of the way enough so that the mill misses it as it goes by the tip.

Works good!

I did one set that had never been re-ground with excellent results, and almost no re-balancing to do afterwards. (same depth of cut on both ends, means the same amount of metal is left after).

Then I re-did a set that had been "licked with a file", "belt sanded", or "touched up with an angle grinder", as recommended previously here on the list.

Of course, following human nature, the person who had sharpened them only worked out the dull part - the part furthest out to the tip - leaving the blades slightly tapered along the bevels.

That took more passes to fix, and now there's a distinct "inset" of the cutting edge from the old leading edge. But they're straight, sharp, and again, they balanced almost perfectly on the first try.

LLoyd