Although sawguides are one of my favourite subjects, I occasionally develop writer’s block when asked to write another blog post about them. I have heard this happens to many professional writers. Since I’m not a professional, I guess the reasons behind my writer’s block are merely excuses. “Come on, think of something,” I told myself, looking around for inspiration, but there was none to be found. Just as I was about to give up on writing for this week, in walked the local delivery driver who works for one of the national courier services we use at Modern. He delivered a package to me at my desk and upon opening it, a new article was born.
Inside this inspiring package was a sawguide from a new customer. The first step of our process is for new customers to send us a sample of their existing sawguide, so we can discover what their issues are and manufacture a new one that solves their problems. As I pulled the sample out of the box, I became grumpy. The more I looked at it, the more unhappy and upset I became. This despair resulted from the many years I have been counselling, speaking and writing about sawguides. Looking at this particular sawguide, it felt like I have wasted my time all these years.
Let me start by saying that the purpose of this blog is to educate, not to criticize. This is not always easy for me to portray because of my passion for the product, and because I realize how important sawguides are to sawmills. I try to be tough on the issues and soft on the people. Sawmills are a critical employer in many regions and towns and my goal is to ensure they remain running, and running profitably. With this said, let’s get onto discussing the sawguide I received.
The first thing I noticed was its colour. It was black. Oh my goodness, another sawguide with cosmetic anodizing! Cosmetic anodizing on a sawguide is about as useful as dyeing a cat’s fur. No matter what colour it is, it’s still a cat.
The anodizing was worn in many places, like a scratched up mobile phone. We all know from experience how easy it is to scratch your phone, and that’s why a whole manufacturing sector that makes products to protect them exists.
Black cosmetic anodizing is inferior to engineering hardcoat anodizing (which is grey to dark grey in colour) and yet, it’s still used widely. It’s used because it’s cheaper to apply (many manufacturers even boast about this). It’s also very easy to control the thickness, so the manufacturer can claim that their sawguide is somewhat accurate. The very thin coating of cosmetic anodizing is much easier to control, which results in some accuracy. Whereas the thicker coating of engineering hardcoat is more difficult to control, as it must be processed after it’s applied. However, engineering hardcoat always results in higher accuracy.
Accuracy is one of the most critical aspects of a sawguide. It’s the whole reason sawguides exist, in fact! So if you are getting cosmetic anodized (coloured) sawguides, then you are not using accurate sawguides. Try building something in your house with a poor tape measure and see what your finished product looks like. Same thing with inaccurate sawguides – your finished product, lumber, will suffer.
So the colour was the first thing I noticed about this sawguide that arrived at my desk that morning. After that, I noticed that the babbitt pocket was very shallow. It was around 0.020”. When a babbitt pocket is too shallow, the coolant is not able to build up in the pocket which results in improper cooling. The coolant ends up just being smeared away and does not properly cool the saw. The company this sample was from definitely had problems with saws heating up. I could tell that just by looking at this sawguide they sent me.
Overheated saws tend to fold over and cause downtime. Whoever sold this babbitt mould or sawguide to this customer did not take into consideration a proper babbitt pocket depth. I have seen babbitt pockets that are too deep, which causes the same problem as it being too shallow, the babbitt pocket cannot fill up adequately and therefore saws cannot be cooled properly.
I then noticed something else, something that really bothered me. Someone had been cleaning the accurate surface of the sawguide with something very abrasive, like a course file. I want to ask you all if it would be proper to clean a precision bearing with a grinder, or a file, and expect it to function properly afterwards. I mean, really?! I realize that sometimes for whatever reason you may need to do this, but it should be the absolute exception and not a normal operating procedure. This area is a precision surface and should be cleaned with utmost care to ensure accuracy.
There are are few other things that were wrong with this sawguide, but I don’t want to write forever since I am already getting a cramp in my fingers. (How do professional writers do this?!) To say the least, this sawguide was really bad.
The sawguide varied by 0.006” on the accurate surface. To be fair, we measured in areas which had not been touched by the abrasive cleaning. This type of accuracy is unacceptable since the standard clearance of the saw blade to the babbitt pad, which guides the saw blade, is 0.0015”. How was the customer getting any sort of decent product out of their sawmill using this sawguide? As I said previously, accuracy in sawguides is everything. This sample sawguide I received was manufactured to some pretty low standards.
As many sawmills come under pressure to make good quality lumber at the highest efficiency, it is critical that the components you are using are manufactured to the absolute highest standard. If the components you use are not high quality, it will affect the quality of the lumber you produce and lower your efficiency.
Poor quality lumber and low efficiency affects the long-term viability of your sawmill. You wouldn’t make your breakfast with spoiled eggs and expect it to taste good. Likewise, you can’t expect your sawmill to turn out the highest grade lumber using subpar components. It is critical that you take this into consideration, as your business, and your town, depends on it.
Author: Udo Jahn
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