Thread: So, where should the blade REALLY run on the top wheel?

Originally Posted by Jerry Thompson

I added roller bearing guides, new thrust bearings and a new thicker tension spring to my 14'' BS. These have helped immensly. The tension spring allows me to tension the blade to where it needs to be. I don't mean over tension but it is tensioned correctly when it is on the mark for that blade width.
Next I am going to add a riser block, a 2 hp motor and a smaller pully to pick up blade speed some which should give a better saw all around.
These are all recommendations from our BS guy of Iturra Designs here in Forida.

Jerry, I don't mean to be rude, but how does this apply to the subject?

I'll keep everyone posted when I get it done. I have to amass some more cash before I get it all done.

Perhaps you could start your own workshop build thread?

Originally Posted by wheelinround

I do like the table adjustment he makes wish mine was that easy.

And me. Mine has 4 bolts to play with.

Also, I've noticed that many bandsaw tables including mine have the blade slot parallel to the line of cut instead of at 90 degrees to it. Besides the higher potential for error and slight table misalignment along this plane, it also means that the rip fence extrusion has to be removed before the table can be taken off. A bloody nuisance when changing blades.

Hermit;
You are correct. This should have been a new thread. Soory.

When I got my new saw I could never understand why people complained of drift but mine did not have any and I put it down to having a brand new saw with no wear. I had made a mistake now I come to look back after seeing the Snodgrass video and reading over the last little while about drift. The mistake I made was not to read the manual, I just set the tracking so that the blade was perfectly centred on the wheel as that to me seemed logical.

Recently I had read about how tracking could be controlled by placement the blade in relation to the crown of the wheel and it all started to make sense as this dictates the angle of the blade in relation to the table and I reckon it might be possible to see that angle while the saw is running and adjust it with the tracking adjustment but I haven't actually got around to it yet but I will give it a go one day.

The next thing that occurred to me was something an engineer told me years ago when we were talking about the behaviour of beams when they fail. If beam gets overloaded and starts to bend it also rotates about its own centre. Thinking about that the blade being the beam if it gets overloaded and pushed very hard backwards into the rear thrust bearing I wonder if it is also forced into deflecting or twisting thus causing what we see as drift. It would be interesting to see some high speed photography of what is happening in this regard. If this were to be the case feed rate is again the culprit.

A lot of reading in this thread, but V good. Only recently have I installed my 1/2" blade to try some re-sawing. Went thru the usual setup routine and with my blade in the center - that I thought - set the fence to approx 7deg. Re-sawed a small 5"x5"x6 1/2" block of spalted maple, all looking good, nice thin cuts.. Been wanting to cut these forever..

Attachment 216018

Today I finished a log sled and needed to try it out. So after the reading here I reset the blade as discussed, and did 1 cut using the sled to take off some stringers on a piece of a poplar trunk, then removed the sled.

Attachment 216019

Installed the fence, set it back to 0 deg, and completed other cuts around the block. The next pic shows a freehand cut,

Attachment 216020

and finished off with the fence..square all around. Last pic a little to fast of a feed.

Attachment 216021
Attachment 216022

I'm happier that 'H' since I have a 8 - 10 more logs to do and a dozen or so fireplace size pieces, maple and poplar and a bit bigger - someday - and a couple of new birch at 42"L x 12"D,, Need my son in law to buck them shorter.

So with the small maple block cut and the poplar block above, I guess I have the material for a small box or 2.

Will do the same with the small blades as I use them.
I'm a convert, cheers

glenn

Glad it worked for you too Glenn.
It seems that everyone that tries this is pretty happy.
I'm still getting great performance compared to before and have yet to see any side-effects. The top tyre doesn't seem to be wearing excessively. (I do release the tension every night, though.)

Had to replace the blade on the Mens Shed BS the other day.
Did it as per Alex Snodgrass, even took the table off - not easy one bolt hard to get too. Adjustment was a cinch, had to juggle the table about to get it back into place with the blade in.
Re-sawed a piece Oregon 200mm x 20mm to 5mm thick slabs - no drift - didn't have to adjust the table. Then re-sawed some Tassi Oak to 150mm x 15mm again no problems.
This is the first time we have been able to re-saw with out problems since new!!
As a final test did free hand curved cuts and was able to get tighter curves than we could before and this with the standard 10mm blade that comes with a Carba-tec BS.

Maybe it’s because of the quality of the blade? What blade are you using? I also do re sawing a couple of times in a week. I use Haltbar Hard Back Carbon blades from sawblade.com. I haven’t experienced any re sawing problem since I used these blades.

Originally Posted by bosox

Maybe it’s because of the quality of the blade?
What blade are you using?

We got two extra blades from Carba-tec when the saw was bought. Several times blades have been snapped and needed repair, sharpened and replaced without altering the adjustments of the saw. It was one of these blades that I used the other day and setup as per Alex Snodgrass.

Originally Posted by bosox

I use Haltbar Hard Back Carbon blades from sawblade.com. I haven’t experienced any re sawing problem since I used these blades.

A member donated a high quality blade, don't know the details of it, but even that had problems because the tracking of the blade was not altered from the factory settings.

It must be remembered that the members of the Mens Shed are not necessarily qualified woodworkers and can be hard on machinery.
Unless someone with some woodworking/machinery knowledge makes a decision to replace blunt cutters/blades most members will continue to use the machinery and then complain that it isn't working properly.

We should consider every factor in using a band saw machine. The blade is just a part of it. Check on the guides, tires, blade tension and more.

As woodworkers, qualified or not, it would be nice to seek tips and advices from other people. Their experience might be the answer to our problems or vice versa.

This site could give some information about band saw machines, blades and more: BandSawBlog | News, reviews and articles about band saw blades and partsBandSawBlog.

Originally Posted by vk4

Hi All,

I tried setting up my small bandsaw as per the ALEX SNODGRASS, video,

Well the results are in after a few tests, I set the tooth gullet on the wheel crown, and the guides as suggested, just behind the gullet of the teeth, I then found the top wheel osolating slightly, this was traced back to the 3 small grub screws behind the top wheel.
When tightened the osolation stopped, .

Well to the point the cuts are now verticale, drift has nearly all disappeared, all this with a blade that is not really new , and has been resharpened twice.( by me).

A convert , I don't know as yet but it appears to do what he demonstrated and said. I also tried the test , cutting into a piece of timber , then moving it to the back of the blade and letting the blade run in the cut, my saw would never do this before ( due to all the misalingments), it will now .

You never stop learning , and I have learnt a lot from ths forum.

Jeff
vk4

Alex Snodgrass seems to be confident enough to be right don't you think?

Seriously the advice just seemed to be right to me and I am glad that someone tried it out and reported here. The reason why it's right seems to be widely misunderstood. For example when he game me my (recycled) bandsaw a couple of weeks ago my father said that it was so the offset on the teeth would not be flattened out. Since the bottom wheel tracks quite differently and is not adjusted, that would not appear to be the reason. I think it provides the best strategy for presenting a blade with a stable alignment. Note that I say stable not "correct" - I think that Snodgrass is correct when he states that it not absolutely critical to get the fence alignment precisely perpendicular to the blade, and hence his derision for the notion of "blade drift".

Snodgrass's method for checking tension is less satisfactory in my view. I am new to bandsaws but this seems to be a critical setting and "when tapped lightly the blade should deflect less that 1/8 inch" is hardly reproducible or repeatable. I tried my best at a tune up yesterday and when I turned on the saw there was so much blade vibration on the return side that it was touching the return blade guard.

Thank you for your post, Jeff - I am learning a lot from this forum too. especially from posts like yours

GarciaJ,

You should not have any blade vibration , I can remove my Guards and the blade does not vibrate, .

Have you checked the following,
1, Bearings (for wear /alignment)
2, wheel tires ( for wear, damage)
3, motor bearings and alignment to the drive)

These could all contribute to blade vibration,

Jeff
vk4

Originally Posted by vk4

GarciaJ,

You should not have any blade vibration , I can remove my Guards and the blade does not vibrate, .

Have you checked the following,
1, Bearings (for wear /alignment)
2, wheel tires ( for wear, damage)
3, motor bearings and alignment to the drive)

These could all contribute to blade vibration,

Jeff
vk4

Thank you for post Jeff. I only got the saw recently and had not tried to set it up until this weekend. Yesterday I stripped it down and gave it a good clean and had a first pass at setting it up.

I had another go at setting up the saw today. I used Snodgrass's 1/8" deflection rule of thumb for tension and quickly realised that that is a lot tighter than what I had the blade before. With the extra tension the blades no longer vibrate so much that they touch the return the blade guards.

Yesterday I ran the motor on its own and spun the wheels by hand. they seem to be OK.

You are right about the tires - they are cracked and have a flat spot which is making the blade rock from side to side very slightly. They had not been glued down (I did not know that they should be until now). I plan to replace the tires as soon as I can, and buy 3 assorted blades while I am at it...

The guides are OK for now. had to WD40 the back bearings though.

Any advice as to what my first three blades should be?

Jorge

Originally Posted by GarciaJ

Any advice as to what my first three blades should be?

Jorge

What do you want to do with it?

Paul