protocol for testing grinding belts
August 15, 2015 04:13PM
i am trying to come up with a basic protocol for testing grinding belts. so far i have:
belts would all from same Mfg. package(should be same mfg lot)
record belt speed, coolant used(or not), time, pressure applied. i have 20+ blade blanks cut from same piece of tool steel. blades mounted on same jig.
would time to grind a bevel ??millimeters wide at ??degrees angle to a depth of ??millimeters be fair? subjectively you would also be able to compare the finish of the bevel.

i am looking to test effect of belt speed, coolant used, and type of belt. A Norton Blaze belt is about twice the price of a Norton Norzon Zirconia belt will it grind twice as long? which coolant is the most effective(oil or water or forced air or special solution)? is there a sweet spot(combination of speed, coolant and pressure) where you get most economical grinding?

i also want a test that is repeatable that anyone could do.

am open to any and all ideas.
scott
Re: protocol for testing grinding belts
August 15, 2015 04:37PM
Belt speed, with and w/o coolant, is a major factor in belt life and grind result.
Re: protocol for testing grinding belts
August 15, 2015 04:56PM
Scott,

In most experiments it is useful to do some kind of tooling run where you look at your measurements and see what kind of consistency you can obtain. For example if it was me I would pick the most basic belt I could and ideally some scrap pieces of steel and grind a few kiridashi's. In many cases small issues come up in actually doing experiments and it may take a few attempts to iron out all the issues. How are you going to maintain some standard of force applied for example as the grinding speed will be essentially proportional to that load?

The other thing is that you might want to start simple, right now you have three independent variables (abrasive belt type, speed and coolant). Unless you want to use a multi-dimensional analysis you might want to scale this back a little and for example use the recommended belt speed for each abrasive as a baseline and see what kind of difference you get in lifetime without coolant. Then you can vary coolant and/or speed and look at that difference. It is possible to do all of the changes at the same time with a multi-dimensional analysis but only 20 points won't do it across three changing variables, it isn't enough data.
Re: protocol for testing grinding belts
August 15, 2015 05:05PM
Grinding pressure is also a huge factor, especially when using ceramic belt. Oh heck, I can stop a 2hp 2x72 at low speed with my kind of pressure. It's quite a useful when grinding hardened high wear resistant steels.
Re: protocol for testing grinding belts
August 16, 2015 11:06AM
cliff, i understand having only one variable per test. i guess i would like to define the "Standard Task" that is going to be performed. was thinking something like:
Grind a 10 degree bevel 0.5mm deep at apex 2" wide
this would be a "real world" task that should be fairly quick and easy.
i guess the most difficult variable to define will be blank pressure.
scott



Edited 1 time(s). Last edit at 08/16/2015 11:31AM by oldsailorsknives.
Re: protocol for testing grinding belts
August 22, 2015 11:41AM
inventoried my steel drawer and found that i have 40+ unground O1 blades. I am going to start grinding and recording results and see what the data shows. i should be able to do my standard task, "Grind a 10 degree bevel 1mm deep at apex" at least 200 times.



Edited 1 time(s). Last edit at 08/22/2015 11:45AM by oldsailorsknives.
Re: protocol for testing grinding belts
August 26, 2015 11:00PM
This should be interesting. I always love to see statistical results and see if what I 'feel' is indeed correct. My two favorite belts for regrinds (taking a knife from .040" thick at the shoudlers down to about .010"winking smiley on hardened steel are Pheonix Abrasives yellow belt and the 3m's Cubitron II (984f) as I can get about 3 regrinds each before having to move the belt to the "sharpening and roughing/reprofiling" only rack, where I will get more use out of it due to the pressure going up because of the smaller contact area.

Also keep in mind that different belts do better/worse w/ different speeds.
Re: protocol for testing grinding belts
January 20, 2016 02:51AM
If you are using a slower grinder, then most of the ceramics may be a waste. FWIW, I thought the Norton Blue Fire held up well at slower fpm on gummy stainless, seemed a nice compromise between cost and longevity.