Accurate Scales for Balancing Cutters
What level of accuracy is required when weighing knives for balance during sharpening — and how do you achieve it?August 12, 2014
Question (WOODWEB Member) :
I understand from other posts that the Ohaus mechanical balance is ok for the purpose of balancing cutters. Apart from the magnetization advice can anyone suggest which Ohaus digital balance would be reliable enough? I don’t understand how you can pay either $300 or $1100 dollars for different models of digital scales designed to measure to 0.1gm and yet they have different degrees of accuracy. Do they measure to 0.1gm or not? I’ve been looking at the Ohaus scales and wondering how much must be spent for digital scales or whether the mechanical balance is the more reliable option.
Forum Responses
(Architectural Woodworking Forum)
From contributor T:
We use a mechanical balance scale and have for 25 years when balancing moulder tooling. I couldn't tell you the accuracy, but it is capable of showing very small amounts of discrepancy between knives. Oddly enough my scale of choice was bought from a specialty weights and measures business and it came from the food industry, cool old stainless thing. I do own an Ohaus mechanical balance scale that has never been out of the box, and from what I remember it was in that $300-400 dollar range.
From Contributor D:
I have used the mechanical models with no problems. What matters is the weight is pretty much the same, but exactly how much they weigh will not matter so much. When you need to adjust or remove some steel regardless of the scale used the process is the same when you are working by hand. You can use any digital scale or a set of balance scales with no measurement of weight.
From the original questioner:
The reason I’m asking is because I’ve heard that the same mass can measure differently each time its measured and also depending on where its placed on the scale pan with digital scales. Just wondering how true this is. So is the current Ohaus mechanical scale still good enough? I’m inclined to think that the mechanical balance would be better for check weighing.
From contributor U:
I have never had any of those issues you mention, no matter where I place the moulding knives with my Ohaus scale, but I do tend to place the moulding knives in the middle of the scale.
From contributor L:
We use an Ohaus balance scale here. No one cares what the knives weigh, just so they are the same. Just balance it before you put the knives on. It is very sensitive. The target is .1 grams or less!
