Horizontal band saw adjustment

[JeffF]

All,

I had a good weekend with the new tools and am really starting to get the "feel" for both the lathe and the milling machine. I am now able to get very consistent finishes and sizes on turned and milled pieces and am actually finding these processes easier than I thought they would be. That said, I'm SURE there are MANY challenges ahead. You guys have been great though in guiding me through some of my early concerns and helping me gain confidence that I am going in the right direction. I am now sure that I have both the lathe and mill setups right.

One of my problems this weekend related to my new horizontal band saw. It took me forever to get it adjusted correctly so it would cut straight and not throw the blade off the spindles. I finally got there, but it wasn't an easy trip! One question I have is how you adjust the cutting pressure. I can't tell if I should have more or less pressure when cutting. Is there some guideline for this? If not, about how long should it take to cut through a 1 inch thick piece of aluminum at medium speed? Maybe having some idea of how long it should take would give me some idea how to adjust it.

Jeff

 

[Philjoe5]

Jeff,
If you own the ubiquitous 4x6 import bandsaw this info may help.

A good guide for folks using a metal cutting bandsaw is available from Little Machine Shop's website:

http://www.littlemachineshop.com/info/bandsaw.php

Just went into the shop. For a 1.25" (sorry, no 1") aluminum round @ 120 FPM with a well used blade, takes 70 seconds. I run it at this intermediate speed for everything. I use Starrett bimetal blades and the only time I've had it cut off the line is when I had a dull blade.

Once a blade has been used for a few cuts, I adjust the cutting pressure as much as I can without stalling the blade.

Make sure the blade is in contact with all the guides and adjust blade tracking with the blade tightened on the wheels. I adjusted tracking on my saw maybe 4 years ago and haven't touched it since. And I should mention my bandsaw gets used several times in any week.

Hope this helps

Phil

 

[JeffF]

If you own the ubiquitous 4x6 import bandsaw this info may help.

Phil,

Very helpful, thank you!

Jeff

 

[surfside]

The link is very helpful. Thanks for sharing .
Jeff, do you always consult your speed and feed chart ?

 

[JeffF]

The link is very helpful. Thanks for sharing .
Jeff, do you always consult your speed and feed chart ?

>
I'm leaving the saw on the middle speed even though it says you can go to the higher speed for aluminum. I'm in no real hurry. I have not seen anything which states how to adjust the feed. It just says that going too light on it will dull the blade, going too heavy can break the blade. Not much help there.

Jeff

 

[starnovice]

My 4x6 has a long silver handle with a spring on it. I twist the handle to tighten the spring to increase the feed. The amount of feed I get away with changes with the pitch of the teeth I am currently using. Although I can cut pretty square to the vise I always figure I am going to clean up the cut anyway so I don't worry too much about appearance.

 

[JeffF]

My 4x6 has a long silver handle with a spring on it. I twist the handle to tighten the spring to increase the feed. The amount of feed I get away with changes with the pitch of the teeth I am currently using. Although I can cut pretty square to the vise I always figure I am going to clean up the cut anyway so I don't worry too much about appearance.

>
Doesn't it work the other way around? The manual says turn the handle clockwise to decrease pressure, which is tightening the spring. Tightening the spring helps hold up the end of the saw arm, which lightens the feed weight, right?

Jeff

 

[surfside]

Feed rate calculations are important because it is directly related to productivity, surface finish ,tool life and so on.....
It is really necessary to know the recommended speeds and feeds to use for the material you will be cutting.
different materials require different cutting rates

 

[rodw]

>
I'm leaving the saw on the middle speed even though it says you can go to the higher speed for aluminum. I'm in no real hurry. I have not seen anything which states how to adjust the feed. It just says that going too light on it will dull the blade, going too heavy can break the blade. Not much help there.

Jeff

I have found that aluminium does not cut well with a fine tooth blade that you use on steel. Make sure you grab a coarse tooth blade (6-8tpi) if you need to take thick cuts of aluminium. I cut a lot of plastic with mine and I find the coarse tooth blade is necessary for that as well. Makes the difference between a 2 minute or 20 second cut!

 

[JeffF]

I have found that aluminium does not cut well with a fine tooth blade that you use on steel. Make sure you grab a coarse tooth blade (6-8tpi) if you need to take thick cuts of aluminium. I cut a lot of plastic with mine and I find the coarse tooth blade is necessary for that as well. Makes the difference between a 2 minute or 20 second cut!

>
Very good thought! I probably am using a far too fine of a blade. It cuts perfectly straight and eventually makes it through, but it takes forever!

Thanks!

Jeff

 

[starnovice]

>
Doesn't it work the other way around? The manual says turn the handle clockwise to decrease pressure, which is tightening the spring. Tightening the spring helps hold up the end of the saw arm, which lightens the feed weight, right?

Jeff

sorry Jeff you are right.

Pat

 

[surfside]

What's the brand of the blade you are currently using?

 

[bb218]

I would like to mention when adjusting the blade tracking that the blade should be close to the ledge on the band saw wheels but not rubbing them. You can take a piece of paper and with the saw running let the paper go between the wheel and the blade if it cuts the paper like a pair of scissor's then the blade is rubbing the wheel ledge and you need to tweak the tracking to where is does not cut the paper. The wheel ledge will eventually wear off if left to run the blade. Mike

 

[SmithDoor]

I have found with band saw some time the blade is bad on one only. Before adjusting the saw try a new blade from a new box of blades.

Dave

 

[rodw]

>
Very good thought! I probably am using a far too fine of a blade. It cuts perfectly straight and eventually makes it through, but it takes forever!

Thanks!

Jeff

Hmm, I wish mine cut perfectly straight. I pulled down a document off the yahoo bandsaw group about setting it up and spent a few hours reworking the setup in including spacing the sliders that hold the top wheel in by putting washers behind the 4 screws and finally got the up and down alignment the best I have ever had it but when cutting, it was still not square top to bottom. The cut pulls to the outside of the machine. The instructions I had said moving the roller guides further apart will cause the cut to drift left and closing the gap will make it drift right. Does that mean I should open up the gap between the rollers? Is drafting right the same as drifting to the outside of the Machine? I ran out of time to play with this.

 

[surfside]

rodw, try checking videos in youtube.

 

[JeffF]

I had so much trouble getting the saw adjusted I suspect I dulled the blade that came with it and that is part of my problem. I have ordered a new blade using the guide one of the members posted for me earlier.

Now, finally maybe a chance for me to contribute something!...

When I was adjusting the blade, I laid the saw head down and adjusted the blade guides in that position. I put a square on the bed and make sure the blade was square to the bed. Then, I also set the square so I could make sure the blade was cutting straight down into the stock. My original setup had the blade going in at an angle rather than a direct cut, so it was not cutting well (essentially cutting on one side of the blade teeth) and that probably dulled the blade.

Once I got the blade square in both directions and made sure the blade tracked through the blade guides right (pinched between the two wheels and laying against the back guide wheels) things got a lot better.

Jeff

 

[rodw]

rodw, try checking videos in youtube.

Thanks, after enduring a particularly boring 35 minute episode, I finally found out one pearl of information. It is pretty simple really.

1. Remove the blade, and put a 12" steel rule in its place. tighten the guides to hold the ruler in place.

2. Square the blade vertically with a set square at both ends. You might need to do this a couple of times as adjusting one end tends to throw out the other end.

3. Adjust the back stop so it is square to the ruler if necessary. Mine did not move.

4. Place the blade in the guides but don't fit it to the drive wheels. Adjust the clearance so that you can turn one guide wheel by hand (One side can get locked by the curve of the blade).

5. Fit the blade and you are done! Perfect square cut. Probably the first time ever!

My learnings about getting the drive wheels aligned from yesterday were:

1. Unbolt the guide roller assemblies and remove them so the blade is not being twisted.
2. Make sure the plates that the top wheel slides up and down between when adjusting blade tension are tight so there is no play in the adjuster block.
3. Checking alignment with a straight edge between the wheels but it is better if you cut it to length so you can do this with the blade fitted as tension changes the top wheel mounting geometry.
4. If you need to move the top wheel to get it aligned with the bottom one there are two methods:
4.a) To move out along the shaft. Remove the bolt on the shaft and use a puller. You will need to add a couple of washers on the end of the shaft so you don't push the wheel back on when you tighten up the bolt on the end of the shaft. The washers obviously can't be any bigger in the diameter than the shaft.

4.b) To move the pulley in. The easiest way to do this is to pack up the slider plates described in step 2 out. I placed 3 washers under each bolt securing the plates. This moves the whole top wheel mounting assembly back. I will replace the washers with a spacer plate.

5. Fiddle for an hour or so until the blade tracks nicely and does not push really hard against the back flanges on the wheels as mentioned above by bb218. Test with his scissor trick (which I did not do).

6. So when you have this all done, refit the guide roller assemblies and then follow the procedures with the ruler to square the blade.

So there you have it, a two step process to get a perfect cut! It is so much easier to square the ruler than the thin blade due to its width.

 

[surfside]

Happy to help!