Thread: An alternative approach to resharpening Bandsaw Blades.

Stewie can you give us a run down as to how the machine works while sharpening circular saws? I saw it on Ebay and wondered how they are

This morning I used my Circular Saw Blade Sharpener to re-sharpen the front rake angle on a bandsaw blade. Less than a minute to set up, and 2-3 minutes to complete every tooth

If we split the difference to 2.5 minutes per tooth, on a 3.5m long 3TPI blade that works out to ~17 hours!

Maybe you mean 2-3 seconds?

Originally Posted by BobL

If we split the difference to 2.5 minutes per tooth, on a 3.5m long 3TPI blade that works out to ~17 hours!

Maybe you mean 2-3 seconds?

Bob; 2-3 minutes to complete every tooth.

Originally Posted by chambezio

Stewie can you give us a run down as to how the machine works while sharpening circular saws? I saw it on Ebay and wondered how they are

chambezio; the following video should help. https://www.youtube.com/watch?time_c...&v=Tznkw3Viw88

Stewie;

Originally Posted by planemaker

Bob; 2-3 minutes to complete every tooth.

OK it would have been clearer to add ".... every tooth on the band"

But now this sound like too short a time unless maybe you have a short blade with a very low TPI count?

3.5m long blade @ 3 TPI = 413 teeth If you do the whole blade in 2.5 minutes thats 150 seconds, or about 3 teeth per second?
I'd like to see a video of that.

Are you sweeping out the gullets as well, or just the front of teeth?

Originally Posted by BobL

OK it would have been clearer to add ".... every tooth on the band"

But now this sound like too short a time unless maybe you have a short blade with a very low TPI count?

3.5m long blade @ 3 TPI = 413 teeth If you do the whole blade in 2.5 minutes thats 150 seconds, or about 3 teeth per second?
I'd like to see a video of that.

Are you sweeping out the gullets as well, or just the front of teeth?

Bob; just the front of the teeth. (the rake angle)

I haven't trialed this machine to work the gullets.

Stewie;

Thank you for suggesting this method, Stewie.

I would be interested to know the differences in sharpening a bandsaw blade via the front of the teeth (Sherwood) versus back of the teeth (Dremel).

I have a machine similar to the Sherwood, not yet used (purchased for the table saw, but I have since purchased a new table saw and new blades), and wonder whether it would do a better job than my current method of sharpening bandsaw blades, which is to use a Dremel and diamond disk on the back of the blade. The Dremel method is very effective. I have posted pictures of this here on previous occasions.



Both methods would likely reduce the size of the tooth, but the back of the tooth (Dremel) method would also reduce the size of the gullet and the amount of set more. Point to Sherwood.

The back of tooth method is so easy, does not require a special machine and may be done freehand, and is quick (may be quicker than the machine, which requires more movements). Point to Dremel.

Sharpening the face requires keeping the blade at a specific angle or the rake will change. That will affect the cut. Sharpening the back of the blade does not alter the rake angle. Point to Dremel.

It takes me 15-20 minutes to sharpen a blade for my Hammer N4400 (17 1/2" wheels). This is freehand. I cannot imagine that the Sherwood could be done in 2-3 minutes.

I usually resharpen bandsaw blades (I use bimetal from Henry Bros) at least 3 times, sometimes 4. What is the experience of others with the Dremel method? Has anyone used the Sherwood method, and if so, able to comment?

Regards from Perth

Derek

zip.

Moving onto using this machine to grind the back of each bandsaw tooth. To achieve clearance away from the motor housing there is a requirement to reverse the direction of the bandsaw teeth. This is done by simply twisting the blade inside out. Each gullet line is then ground at a slightly increased angle to gain some additional depth. The time taken to complete the back of every tooth was 4-5 min. On completion the bandsaw blade was then twisted back to its original form. Quite a handy machine to have in your workshop.

Stewie;

It should be pointed out that the forward mounted slide table is not required when sharpening bandsaw blades. Its use is restricted to sharpening Circular Saw Blades.

Stewie;

Originally Posted by derekcohen

I would be interested to know the differences in sharpening a bandsaw blade via the front of the teeth (Sherwood) versus back of the teeth (Dremel).

Derek

Provided you are light handed or using a jig there will be little difference between sharpening the face or back of the tooth over 2-3 sharpenings. Any more than that you are going to start to change the tooth geometry using either approach, in which case the gullets will also need to be reground.

The additional reason for regrinding the gullets of a blade that has been resharpened that number of times is that micro-cracks will have started to form in the bottom of the gullets and these need to be ground out before they cause blade failure.

Without going into detail, if you are not using a jig, jointing of the tip heights will also become an issue after a number of resharpenings. All teether may be sharp but only some will be doing the work.

I would think that adding a pawl to the Sherwood (or any similar unit) to set the depth and position of grind would greatly increase its usefulness (accuracy, repeatability and speed) for this task. Maybe it already has that feature but I couldn't see that in their video.

If I had a Sherwood I would definitely have a go at adapting it for this use.


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Hi Neil

Thanks. That is my understanding as well.

The amount I estimate that I remove from the back of a tooth using the Dremel and diamond disk is probably in the region of 0.1m (my method is to gently stroke the steel) - that is unlikely to affect either the size of the gullet or the set. After 3 or so sharpenings, about 0.5mm would have been removed. Still not a significant amount. I am guessing at my numbers. I wonder what others believe them to be?

The above is completed with the blade on the bandsaw. This facilitates an easy sharpening movement. Prior to doing it this way, I used the edge of a wheel on a high speed bench grinder (having watched demonstrations on Youtube). Looping the blade around and over, keeping it flat and orientated ... all this was hard work and quite cumbersome and time consuming. Since this has a similarity to the Sherwood, grinding the face on the Sherwood would be a valuable method if it can be demonstrated to create a better edge (overall) and at a efficient speed. We need someone to do both. Any volunteers?

Regards from Perth

Derek

Not sure why someone would need to replace the bandsaw blade after a loss of only 0.5mm of steel from each tooth.