Thread: Judging blade height

Originally Posted by Arron

I use my ts for a lot of trenching cuts - with accuracy being very important. Currently, I set blade height by measuring near enough, then doing trial cuts and checking/adjusting after each cut till I'm satisfied. My current project is to eliminate this sort of stupid, old fashioned, time wasting behaviour from my shed. Is there a better way set up blade height ?

I have looked at these digital gauges Digital Height Gauge - Rockler Woodworking Tools but my hesitation in buying one is that the trenches are very shallow, so I dont get a very good view of the blade, and I dont think I would ever be confident that I had the tooth I"m measuring at the very apex of its rotation. Has anyone else used one ?

cheers
Arron

Hi Arron,

I had previously thought about a similar idea. My thought to overcome making sure you were measuring at the top of the apex, was to have the base plate of the measuring device cut to match the curve of the blade (and have it rest across say 3 teeth). These have only been ideas floating around in my head though (and may tell you more about my mental state than necessarily be helpful to your idea).

As I understand it, this will still only get you to nearly correct, as the blade when running may cut at a slightly different depth than when stationary (I am sure I read that somewhere), although I never did understand how it cut when stationary.

I would be interested to see what you eventually come up with, or what others have done.

Cheers,

Camo

Originally Posted by Arron

I use my ts for a lot of trenching cuts - with accuracy being very important. Currently, I set blade height by measuring near enough, then doing trial cuts and checking/adjusting after each cut till I'm satisfied. My current project is to eliminate this sort of stupid, old fashioned, time wasting behaviour from my shed. Is there a better way set up blade height ?

No. Making test cuts is still the best and most accurate way in my opinion. Why are you in such a hurry anyway?

Originally Posted by camoz

I had previously thought about a similar idea. My thought to overcome making sure you were measuring at the top of the apex, was to have the base plate of the measuring device cut to match the curve of the blade (and have it rest across say 3 teeth). These have only been ideas floating around in my head though (and may tell you more about my mental state than necessarily be helpful to your idea).

Thats a damn good idea. I could shape the base plate by lowering the blade, clamping some dense timber over the table, turning the saw on and raising the blade into the timber. That would give me the perfect profile because its actually made by the blade itself.

Originally Posted by camoz

As I understand it, this will still only get you to nearly correct, as the blade when running may cut at a slightly different depth than when stationary (I am sure I read that somewhere), although I never did understand how it cut when stationary.

Probably close enough. I guess if I had to specify the accuracy that I require its about 0.3mm. I'm sure the issue you mention (and any others due to eccentric blades etc) are significantly less than that.

cheers
Arron

The ONLY way to accurately measure blade projection is by making a test cut, unless you have a CNC panel saw (and even then I wouldn't trust it without a test).

Besides, how long does trial-and-error really take for something like this? 1 minute, maybe 2?