Jeff B

Tuning a sawmill blade

Recommended Posts

I will try to tell the process of tuning A saw blade. I will start with the tools needed.post-2980-0-77073500-1314238288_thumb.jp
First you need a good saw anvil and Hammering bench. On this bench the saw lays on a sled witch slides in a track, the top of the saw lays on the anvil and the anvil is free to rock back and forth.post-2980-0-95550600-1314238567_thumb.jppost-2980-0-40314600-1314238584_thumb.jp
You will need some hammers to take out twist and ridges in the saw plate.post-2980-0-23375200-1314238713_thumb.jp
You will need some hammers to take out lumps and set the tension of the saw.post-2980-0-74180600-1314238873_thumb.jp
You will need straigth-edges to find the lumps twist's and ridges.
There will be more to fallow.

post-2980-0-27249600-1314239038_thumb.jp

Share this post


Link to post
Share on other sites

Thanks JeffB I will be looking forward to your post. I have heard about this for years but never saw how it is done. I have always heard it takes talent to know where to hit . The only thing I have straightened is what I am forging. I am still trying to improve my skills on a round bar to cut down on time. I could not imagine tackling a sawmill blade (skill saw blade as far as that goes)

Share this post


Link to post
Share on other sites

You will need some way to check the tension of the saw and set the RPM it ia to run at.
post-2980-0-35406600-1314285627_thumb.jp
This straight-egde is long to check 48" &52" saws.
post-2980-0-89986900-1314285450_thumb.jp
This is for smaller blades.
post-2980-0-96095200-1314285502_thumb.jppost-2980-0-97680800-1314285685_thumb.jp
This is an ajustable tension gauge, there is a wedge to drop the middle of the gauge to set dish of saw plate.
The pro's do not use this type of gauge, it would be to time consuming to rest for every saw. I have this gauge set for 500 RPM on a 8 gauge saw.
The man I got the gauge from told me you set it with a Micrometer. He told me he could not remamber but it was so may thousandth per RPM. YA right!
The compnay that made the gauge Is still in business so I called them to find out.
" no big secret hammer you saw till it runs on your mill and set the gauge to the blade and it will be set for the naxt time you hammer your blade."

Share this post


Link to post
Share on other sites

To start with use a straight edge that will reach from the canter of the saw to the rim marking all the high spots. then hammer on your marks, as you work use a shorter straight edge and so on till the plate is free from lumps twists and high spots. this maybe all you need to do if the saw is to run on the same mill it has before.
post-2980-0-30159000-1314410535_thumb.jppost-2980-0-16344500-1314410588_thumb.jppost-2980-0-40416200-1314410613_thumb.jppost-2980-0-52750700-1314410674_thumb.jppost-2980-0-51173600-1314410692_thumb.jppost-2980-0-51196800-1314410710_thumb.jp
I have had the best luck checking with the saw upright and then laying down.

Share this post


Link to post
Share on other sites

this pitcher shows the slab side of the blade, most work will be done on the cant or log side
post-2980-0-08455600-1314411024_thumb.jp

Share this post


Link to post
Share on other sites

If these pictures are clear, The lumps are marked with an X and the twists and ridges are marked with a line in the direction they are running.
post-2980-0-41117700-1314487054_thumb.jp
post-2980-0-27250700-1314487090_thumb.jp
post-2980-0-96484300-1314487115_thumb.jp

Share this post


Link to post
Share on other sites

In the first picture I am taking out the lumps with a dog face hammer.
post-2980-0-00372200-1314487574_thumb.jp
In this picture I am taking out the twist with a combo cross and straight pen hammer.
post-2980-0-64394100-1314487617_thumb.jp
and taking out the ridges with the hammer flipped
post-2980-0-95908700-1314487640_thumb.jp

Share this post


Link to post
Share on other sites

By this point the saw should be free from High spots and be straight. Now we need to check tension to see if more work is needed. The first picture is using the adjustable gauge, with the saw laying on the slab side the fall away or dish should match the gauge pretty well.
post-2980-0-60173100-1314487968_thumb.jp
The next way Is most used by the pros and take a lot of practice. With the saw standing on the floor, pinching the rim of the saw between two fingers bump the center of the saw with your knee and feel the vibrations and watch the rim and center, they should stay fairy still while the inner area moves.
post-2980-0-10916300-1314487991_thumb.jp
The last way is to hold the long straight edge along the saw and lean it over to watch the center fall away, the diameter that falls away will indicate the RPM.
post-2980-0-43937800-1314488018_thumb.jppost-2980-0-73499000-1314488039_thumb.jp

Share this post


Link to post
Share on other sites

"the diameter that falls away will indicate the RPM"

What do you mean by this? Wouldn't the diameter that falls away be the same as the saw diameter? Do you mean the depth of the arc? If so, then how does this relate to RPMs? What should it be for a typical saw and a particular size blade? I can guess that it would be a deeper arc for a faster saw, but how much (roughly).

Share this post


Link to post
Share on other sites

If more tension is needed Great care should be taken because it is easy to put to much tension in a saw but difficult to take out.
You will need to first draw a line half way between the rimm and center of the saw and at least two more one on either side of the first about 2 to 2.5 " apart.
post-2980-0-20224100-1314563668_thumb.jp
Start with the center line, placing every blow next to the other and with equal force. You should never have to hit a saw so hard as to leave a hammer mark!
post-2980-0-17616000-1314563701_thumb.jp
Checking tension after every round. then move to the Inner line.
post-2980-0-01337500-1314563729_thumb.jp
Then the outer line. I tend to hit a little on the lite side (beginner) I just let the hammer fall, if this is to lite I mover to a bigger hammer.
If a saw has to much tension or needs to have the dish moved to the other side ( for a different handed mill). You will need to pull the tansion out, you will take the dog face hammer and work around the rim of the saw About a inch from the shanks. But removing just the right amount is very touchy.

post-2980-0-48507600-1314563746_thumb.jp

Share this post


Link to post
Share on other sites

This is it in a nut shell, One should not take this and try to work over a $1500.00 blade. A saw can be recked easly.
Diameter = RPM I should have said the center will touch the straight edge not fall away. 1"=100 RPM. remamber the saw is under tension so all of it will not fall away or come in cantact with the straight edge.
the pictures are just to give an Idea of how it works and may not be acurate

Share this post


Link to post
Share on other sites
On 8/25/2011 at 11:43 AM, Jeff B said:

You will need some way to check the tension of the saw and set the RPM it ia to run at.
post-2980-0-35406600-1314285627_thumb.jp
This straight-egde is long to check 48" &52" saws.
post-2980-0-89986900-1314285450_thumb.jp
This is for smaller blades.
post-2980-0-96095200-1314285502_thumb.jppost-2980-0-97680800-1314285685_thumb.jp
This is an ajustable tension gauge, there is a wedge to drop the middle of the gauge to set dish of saw plate.
The pro's do not use this type of gauge, it would be to time consuming to rest for every saw. I have this gauge set for 500 RPM on a 8 gauge saw.
The man I got the gauge from told me you set it with a Micrometer. He told me he could not remamber but it was so may thousandth per RPM. YA right!
The compnay that made the gauge Is still in business so I called them to find out.
" no big secret hammer you saw till it runs on your mill and set the gauge to the blade and it will be set for the naxt time you hammer your blade."

Hope this information is still out there.  I cannot see any of the pictures on this post but would be happy if you could post the name of the people who make the tension gage. thanks.  email address removed

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now