Edge Inquisitor 3000 edge tester

Who in the real world makes hundreds of cuts on 3/8" sisal as part of a normal action, by hand or in a widget? I don't think either of us is doing "real world" by hammering on rope for hundreds of cuts, we're trying to get a predictive model of what might happen in the real world.

DM, I'm not claiming your results are no good, or Jim's or anyone else. I'm saying my own results are not falling into a range that gives me confidence. In the past doing rope cutting I had a hard time determining cut pressure and draw, and so had no confidence in determining a "fail" with any accuracy. So I effectively eliminated those variables.

I absolutely did hear and feel the difference of those two cuts compared to well over a thousand that all felt more or less the same. It was unmistakable.

I also did two other knives with my first roll of sisal - a kitchen knife that went just over 200 cuts before failure, a Bark River with Sandvik steel that made it just over 400. And the 52100 custom that felt like it was loosing steam at about 380 and seemed like it might go another 100 or 150 - it was staring to miss cuts. I changed rolls and it took off like a shot, making over 1000 additional cuts with very few misses and but for the damage it incurred would have eaten an entire roll and 1/3. Same rope, same label, same store. Clearly the 52100 has very good to excellent HT no matter the change in rolls, but the results might not be directly comparable to the other knives due to the change in rolls.

Before I put much stock in this method I need to get some control parameters for the rope, or switch to a different rope/media.
 
Twindog said:
You might try calling the engineering departments of some of the better rope manufacturers to see what they might recommend for the most abrasive and consistently made ropes.

This link will have a starting list: http://www.thomasnet.com/products/sisal-rope-69241008-1.html
Click to expand...

Thanks for the link!
I'm pretty sure the factory does not ever check for the qualities I'm looking for - I'll bet they are 100% for load limit though.

I'm going to try some Manilla instead of sisal. I also think I might make it SOP to make a series of cuts from one end of the roll, switch to the other end and cut, switch rolls, repeat, repeat etc - Never running the entire test off the same roll or working from the same end. Would be even better to run it with three rolls or more - probably overkill but maybe not.

Will do a few consistency tests this way and see how the numbers come back (will also keep track of what roll/end is on deck for final failures, just to see...). I cannot really afford any other materials, and not many will have the same qualities of being a good test media for draw and pressure cuts.
 
Quick update - have switched to 3/8 " manila rope for this tester, seems to be more consistent than sisal based on what's available at HD locally (Everbilt, both types). Have begun to retest some of the knives I used previously, the numbers are a bit lower, edge seems to degrade more consistently. Swapping ends and coils should tamp down any remaining variation in the numbers introduced by the test media.

And a picture of the current sled arrangement. Feed tube JB welded to the sled, clip on opposite side pins the rope against a pair of recessed saw blades so it doesn't want to pull back into the gap. I'm able to make cuts at a rate two or three times faster than before.

EI3k_sled_zps4mruef8h.jpg
 
You must log in or register to reply here.
Back
Top