Thread: Blade movement

Originally Posted by Tahlee

Hi all,
I am new to bandsawing and recently took delivery of a new bandsaw.

I am calibrating it and I don't know if the movement of the blade is normal.

I set the dial to zero at the weld, and rotated the wheel.

During the rotation the blade moved from -4minus 4.jpg to +10 thousandth .... plus 10.jpgmost readings were in the 0 to 5 range. the -4 happens once with each blade rotation and the +10 happened three times.

Is this normal?

The blade was a 1/4 6tpi on a Laguna 14/12

Thanks for any advice

Regards

Rob

Rob,

Measuring the "run out" (if that's what you'd call that measurement) on a bandsaw blade is not something that is normally done. When tuning a bandsaw, the focus is on; 1) correct tracking (alignment) of the blade on the top wheel (in the case of the Laguna, that means that the blade is adjusted to be on the centre of the wheel rim), 2) correct tensioning of the blade, 3) correct adjustment of the upper and lower blade guides, and 4) correct positioning of the upper blade guide to be as close to the top of the work piece as practical. If those parameters are correctly adjusted, then the "run out" on the blade that you're measuring takes care of itself.

That said, the point where the blade has been welded should be smooth to touch on the sides and on the back edge of the blade. If the weld on your blade is poorly done, you may feel a lip or ridge at the weld. If that's the case, I'd return the blade for replacement. Poor quality cheap blades often have a lip or ridge at the weld. Better quality blades from dedicated Saw Blade Suppliers & Sharpening Companies usually have a near undetectable weld. So, without seeing your blade in person, I'd suspect a poor weld, but that doesn't explain all of the lumps and bumps that you've measured.

I suspect that the most likely cause is a combination of lack of blade tension, and incorrectly adjusted blade guides. Maybe a bit more information would help. What problem prompted you to make that particular measurement ?

Regards,

Roy

Hi Roy,
I think you have covered all the bases for me. Thanks

What prompted me the measure run out? It is because there is small chirp and a vibration on start-up, that vibration almost entirely disappears when at full speed, but the vibration returns when slowing down, and fades out before the blade stops.

I was advised to take the blade out and leave it in the sun (on concrete) for a day ... it was very hot today in Melbourne ... seemed to made it a bit better for a while. I release the tension after use now ... but I had left it tensioned for a couple of weeks.

I tried the blade at various tensions and nothing much changed in the readings... used the 3/8th setting and it was worse, used the 1/8th setting and it was very similar.

I was going to measure the wheel for roundness ... but I couldn't find a place for my dial reader in the cabinet ... so I did the blade. The same readings appeared at the same spots on the blade ... so unless the wheels are unitary with the rotations of the blade ... then it is my blade and not the wheels that is moving (sorry Roy... this might not be very clear).

Any further advice, please?

Regards

Rob

I agree with Roy and will just add this.

Blade tension is something you will learn as you go & the tension gauge in most bandsaws is next to useless. check out a few You tubes.

Blade guides and bearings should be set with a slight gap, I use a piece of doubled over paper. Make sure you set your blade tension before your guide / bearing clearance.

Blade guides / Bearings should be set just shy of the gullet between the teeth

All Bandsaw blades have some runout. Best way I have found to set your fence is to:
Loosen the screws that hold your fence square and move your fence away from the blade, you wont be using it for this cut.
take a straight piece of timber about 600mm long
Rule a line parallel with the long straight edge
freehand cut as best you can along the line about 3/4 of the length
Stop the saw ENSURING NOT TO MOVE THE TIMBER, so the timber is still in the blade and still pointing exactly as you were last cutting
Now, HOLDING THE TIMBER SO IT CANT MOVE, slide your fence up against the timber and tighten up those screws again.

Your Fence is now set to the runout of THAT blade. Sometimes, you can get away with not having to do this when you change blades but it really depends what you use your Bandsaw for.

I dont generally make furniture cutting all the pieces on a Bandsaw, I use my Table saw for that. I do cut out Bowl Blanks and things like that on my Bandsaw and so I dont use my fence all that much anyway.

Steve

You could have a look at this video for some tips. It's fairly long but well worth it and easy to watch. It challenges a few preconceived ideas.

Originally Posted by Treecycle

You could have a look at this video for some tips. It's fairly long but well worth it and easy to watch. It challenges a few preconceived ideas.

Rob,

The Carter Bandsaw Tutorial video that Treecycle has linked to contains some really good information - in fact, an earlier version of this video is what I referred to when I got my first Carbatec 14" Bandsaw a few years ago, and initially had difficulty getting it to cut well.

However, there are a few differences between the bandsaws discussed in the content of the video, and Laguna's machines. As the bloke in the video says a few times, if in doubt refer to the manufacturer because they know their machines.

Obviously, the Laguna has the Ceramic Guides, and these are adjusted in a similar manner to that shown in the video, but Laguna advise more accuracy in adjustment (i.e. use feeler gauges of some sort). Also, don't be alarmed when you use the Laguna and initially see sparks coming off the top edge of the top rear blade guide - it's just the ceramic insert smoothing the back of the blade.

Also, Laguna profile the wheels on their bandsaws differently to many other manufacturers. Laguna specify in their Owner's Manuals, and in their online videos, that the blade must be centered on the top wheel - NOT the bottom of the blade gullet centered on the top wheel. In fact, on the LTS-18 it is impossible to adjust the top wheel to place the bottom of the gullet of wide blades on the centre of the wheel, and from memory of when I used a 12/14 at a Woodworking Club, the same applies to the 12/14. On narrower blades (i.e. 5/8" down to 1/4") centering the bottom of the gullets on the centre of the top wheel on the Laguna 18" causes the blade to track off the wheel. Centering the bottom of the gullets on the centre of the wheel certainly tamed my old Carbatec 14" bandsaw, but it does not work on the Laguna!

Have a good look at the Carter video - there is some great info in there. Also have a look at the Bandsaw related videos (especially the "David Marks On The Bandsaw" video) at the Laguna Tools website at http://www.lagunatools.com/company/videos.

Regards,

Roy

Thanks for the info Roy. Not being the proud owner of a Laguna, I didn't know there were such variations. I used the info in the video to set up my Carbatec and everything made sense and improved the saw.

Thanks Roy and Treecycle.

I will have a look at the video tonight.

BTW the chirp on start-up is the drive belt ... I tried to find out the recommended belt deflection data ... but I can't find it in the handbook ... I might just tension until the chirp goes and leave it at that.

I have the belt dead in the middle of the tyre .... and have set the gaps at 1/1000th ... and I was surprised that, even with the 14/1000 total run-out (now I know what it is called), there is no audible rubbing on the guides.

The top ones are easy ... the lower ones take some contortions to get at.

Thanks all for your help on this topic (great forum)

Regards

Rob

Very informative Youtube video .. but the laguna link lead me to a CAD machine.

I think that I will stick with the Laguna recommendation and run the centre of the blade in the centre of the tyre

Thanks

Rob

Hi Tahlee,

Have been looking into getting the 14/12 myself and while looking at a review on you tube, the guy mentioned a slight vibration which he wasn't happy with. His solution was to replace the tyres with some good quality polyurethane tyres which solved the problem. Let me know if you're interested and I'll see if I can find the link to the video.

Sounds like you're having way too much fun there

Peter

I had no end of strife with my Laguna 14-12 when it first arrived. You can see my comments here

I was unaware that the Laguna blade sits in the centre of the wheel - I was applying Snodgrass' advice from his video.

In the end I just adjusted the angle of inclination of the top wheel using the adjustment knob at the back of the bandsaw to get zero drift - lots of testing, as the adjustment is very, very sensitive.

I also removed that bloody excessively long guide bar that the Laguna fence is attached to, ( always banging in to it with my hip) and put in my own tall melamine fence which clamps to table. That fence is a lot more stable than the tall aluminium one that came with the saw ( I found it easy to deflect by pushing the top edge, not good for resawing) The face of that melamine fence is parallel to the mitre slot, but I have not had any need for that slot yet.

It is a good resawing bandsaw, if you take the time to set up the guides properly. I usually take the table off to adjust them, and that needs a bit of upper body strength. That table is heavy, and needs to be twisted at awkward angles. I am never sure if I have the guides set up correctly - the cheap and nasty plastic knobs on the adjusting screws make it difficult to do any fine adjustment.

Originally Posted by 3 toed sloth

Hi Tahlee,

Have been looking into getting the 14/12 myself and while looking at a review on you tube, the guy mentioned a slight vibration which he wasn't happy with. His solution was to replace the tyres with some good quality polyurethane tyres which solved the problem. Let me know if you're interested and I'll see if I can find the link to the video.

Sounds like you're having way too much fun there

Peter

Peter,
I'm no expert, but I Read, Saw or heard somewhere a while ago, that there is no performance benefit to replacing rubber tyres with Poly tyres. The benefit of Poly tyres is their long lasting property.

I reduced vibration on my Table Saw by replacing the belt with a Link Belt, but the belt on the 14-12 looks pretty short in the picture, so I'm not sure the benefit would out weigh the expense.

Steve

My 14" SUV makes that industrial start up sound too. VVVRRRrrrrrrrrrr and then settles down. I ignored it.

The Resaw King wasn't staying dead-on when doing tall resawing and was giving crappy finish. I sort of followed Snodgrass and have the tips of the RSK overhanging the front of the top tyre. It is now absolutely 100% perfect. Dead smooth.... and I mean DEAD smooth, zero track and spot on even with the tall resawing.

I use it for everything even remotely concerning to do on the TS.

Per thread, I cant saw I ever measured the deflection of the blade for I havent noticed it at all in my work.... and I do a LOT of work on my Laguna.

Reminds me... need some more 1/8" blades! Wrecked my last one in a moment of inattention.....

Set the guides and tension properly.