Thread: Hammer bandsaw - getting a blade to stay on?

Well done!

How much was it out when you started?

Dovetail,
the wheel was only out by about 5-6mm when I started. This doesn't seem like much but, given the almost flat camber on the bandsaw tire, it meant that the blade would not stay on the wheel.
Paul

Someone asked for this and it seems to have fallen off the posting above so here it is now.Bandsaw Lower Wheel Rear Axle Housing.png

Originally Posted by paul.cleary

Here is a description of the adjustment I made to the vertical tilt of the lower bandsaw wheel. I have added two photographs
to help with understanding my description:
LowerWheelVerticalTiltMeasurementSml.jpg - to measure the distance from the face of the bandsaw machine frame to the lower
wheel rims, I put a straight edge across the front of the bandsaw frame. I then measured from the front of the straight edge
to the top & bottom rims of the lower bandsaw wheel to check the amount of vertical tilt.
LowerWheelRearAxleHousing.jpg - shows where I did the adjustment and what are the parts I refer to in my description

Preparation Steps:
I loosened the tension on the drive belt from the motor to the lower wheel
I loosened the Allen head "axle retaining bolt" which clamps the end of the lower wheel axle to the lower
axle housing on the rear of machine frame.

Vertical adjustment steps:
There are 4 "adjustment bolts" on the axle housing positioned at 12 o'clock, 3 o'clock, 6 o'clock and 9 o'clock respectively.
1. loosened "lock nuts" on the 6 and 12 o'clock bolts
2. lossened 12 o'clock bolt by 1/8th of a turn, tightened 6 o'clock bolt by 1/8th turn to take up
the slack created by loosening the 12 o'clock bolt
3. measured tilt by checking distances from face of machine frame to the top rim and to the bottom rim of lower bandsaw wheel
4. repeated steps 2 and 3 until the distance from frame face to top rim = distance from frame face to bottom rim
5. tightened lock nuts and axle retaining bolt clamping lower wheel axle to to rear axle housing
6. rechecked that distance from frame face to top rim = distance from frame face to bottom rim.
This indicates that the face of the lower wheel is parallel to the machine frame in the vertical plane.
7. checked by putting a bandsaw blade on the upper and lower wheels and adjusted tracking using tilt adjuster on upper wheel
while turning the wheels by hand. The blade stayed in the centre of the wheel tires.

I also checked that the horizontal adjustment bolts (the 3 and 9 o'clock bolts) were still making firm contact with the axle
after all the above adjustments.

This is a few years removed, but I'm curious to know if you still have your first picture or if you could verify that you were making measurements from the FRONT of the frame to the bandsaw wheel, instead of the BACK of the frame to the bandsaw wheel?

The reason I ask is because I have the Felder version of this saw (the FB510) which also had some tracking and tire problems. A Felder service/alignment manual for field techs. showed a process of measuring from the BACK of the frame (on the flats, obviously) to the front edge of the wheel, and adjusting using the back assembly (identical to your re-posted picture). My wheel was angled, with the top of the wheel about 3-4mm closer to the frame than the bottom of the wheel, as measured from the back of the saw frame.

However, when I adjusted it dead on, the tracking was awful - I had to crank the upper wheel way over to one end of the scale to get it to track, and then it became pretty erratic.

Also, I'm curious how/why you adjusted the drive belt tension to the wheel? Is that something Felder/Hammer recommended?

Thanks for having posted this, it's been super helpful!

-t

(Ted)

Is this what Paul was on about? If so, I tried that without success.
Thought it made sense at the time
Not something to try with a new belt unless you like changing motor bearings the next day DAMHIK
SAM_4167.jpgSAM_4155.jpg

A beam with a block attached is the only way I've seen to be sure of anything, as there is no adjustment to the motor,
that's easily checked with a straight edge.


Could make it easy for yourself by using some inset rare earth magnets if you had some, as the blade needs to do its thing when the lower wheel is adjusted east/west
Top wheel parallel check.jpgWheel alignment.jpg

And you cannot do that if the beam is clamped like so
Calmping is useless for adjustment.jpg


Alignment check 2.jpg

Just a warning should you take a chance and hedging your bets on the frame being a referable surface,
it might result in taking the motor apart.
SAM_4611.jpg
Peter Sefton has one of those, seems he wasn't over the moon with his,
wonder if it's running as sweet as he'd like now that he made a through video series.
Didn't likely get to see all the tricks he used in the youtube preview.

Tom

Ive taken to using a self levelling laser level as used by tilers to get the wheels parallel ( or coplanar or whatever you like) Like this one Robotoolz Rt-7715-2 | 000600329361 | Cash Converters

pretty simple matter to get the line the same distance off the centre bearing of the wheels first, by measuring the offset and making it the exact same. Then measure at the top and bottom of the wheels and adjust them accordingly. I’ve found this to be very close when the band is put on and tensioned, usually only requiring a slight adjustment of the top wheel to have perfect tracking.

Interesting to hear someone actually using the laser box, as I have heard the same thing
said to me by a bandsaw technician before, but including a lot of other tall tales of assembly procedure also.
So not seen or heard of it in action before in reality.

It seems like it would be easy to do, and I was thinking even a cheap pointer laser might work
with a magnetic block, after the machine is levelled that is.
I made these blocks for doing that, so would have been the next step if the beam didn't work.
Should one not have a fancy laser, and want to get wheel protrusion the same, if those tires are crisp edged...
the blocks are necessary for getting a plumb line onto both of the wheel bolts, so that obviously needs to be set up first.
I spent a week trying to level up my machine on the adjustable base with no success until I made these wee beauties,
as my saw wouldn't sit level without being tippy, tried swapping my base around to see if it would cancel any twist without success.
I think I could see some hint of deflection of the column whilst changing from fully supported on 4 corners but tippy, and levelled but not exactly supported on all corners but more stable.

Its a bit strange that there is machines that are going out the door which aren't set up bang on...
especially if that laser seemingly works so well.
Maybe the way they're mounting the laser isn't on the machine itself?

As I've a feeling there could be some jig at fault, or some systematic welding procedure being ignored..
And seemingly from looking at some saws, all this could be to do with the guide post being misaligned, would be one reason
why they wouldn't use a laser on the wheels itself.
The 20" saw I had previously, the jacking screws were hanging off and the company was trying to get off the hook by
suggesting I shouldn't have gone near any jacking adjustment, why if such a problem?

Twisting seems a problem for little saws too, I've seen a little 10" saw with an inch of twist on one corner.

I ponder if this seemingly troublesome machine might be a bit tippy also?
On the far eastern machine I had, I couldn't tell due to the floor.

All the best
TomAttachment 502469SAM_4738.jpg

Tom, the laser simply sits on the floor at roughly 90 degree square to the blade, and I set it up to be about 2” out from the wheels, then, it’s simply a matter of locking the swinging pendulum of the laser, and adjusting the body of the laser unit, it’s on a swivelling ball type of mount, to be equidistant from the centre of each wheel. Once you have this, then just adjust each wheel to be the same distance off the laser line at the top and bottom of the wheels. It’s quite simple and quick. And on my three saws, each one only needed a little tweak on the top wheel once a band was on and under tension.

Hi:

The laser is a great idea! I already went at it again yesterday, and this time I leveled the machine as best I could, pulled the cast iron top off and jointed a straightedge out of wood. Then I cut a pair of notches out of the 'straightish' edge for the bandsaw frame and used that directly against the wheels. It was slow, because I'd basically hold it up against the wheels, mentally note gaps to the top or bottom the lower wheel, make an adjustment, then recheck. It took about 3 rounds to get it pretty close. The laser level trick probably would have let me just measure the offsets and get it in one shot. I'm lucky in that it doesn't look like there's any problem with wheel alignment in the "3 o'clock to 9 o'clock" orientation.

As it goes, the 1/4" or ~6mm blade now seems to track really nice. I hate the 'flutter test' for blade tension, but given that I needed to power everything up with the guides off and the blade loaded I was in prime position to do so. Not too surprising, the scale on the saw was set about one notch too light - the 6mm blade ran true when set tensioned to the 10 - 15mm setting.

I'll be swapping out blades over the next few, as the real proof that things are set right is when you can changeover blades in a few minutes without a bunch of fussing around. Thanks for all the help, building up a bank of ideas makes me a lot more confident that I can work this out.

-t

Hi,
I'm the OP who posted the detailed instructions. Nice to see they were of benefit to someone 11 years later.

The reason for my title of "missing step" is that before I did the steps in the detailed instructions I first checked that the metal box frame was not skewed or distorted in any way so it could be used as a reference. My frame was straight and square so when I used it as a reference for the alignment of the wheels I did the measurements from a straight level across the FRONT of the frame to the wheels.

My approach for checking the metal box frame was as follows:

I took the table off the bandsaw to give clean access to all points on the frame.

My bandsaw is in my under-the-house garage which has some large I-cross section (or is it H-cross section?) steel beams runnig across the ceiling from front to back. I choose one of these to be the starting reference point as the edges were straight and parallel.

I positioned the back of the bandsaw frame to be parallel to the edge of the I-beam by eye to begin with.

I dropped a plumbob on a string down from the I-beam edge to the floor to give me a reference vertical line and moved/tipped the bandsaw frame so the back vertical edge/corner of the frame was parallel to the plumbob string from top to bottom

I repeated this for the other back vertical edge/corner of the frame and moved/tipped the bandsaw frame so both the left and the right vertical edges of the back of the frame were the same distance from, and 100% parallel to, the plumbob string. This told me that the back of the frame was not twisted in any way.

I then used a large framing square to check the horizontal parts of the back of the frame were 90 degrees to the vertical edges.

This showed the back of the bandsaw frame was true and square so it was easy using a smaller square to check the front of the bandsaw frame was parallel to the back of the bandsaw frame and was therefore a good reference.

This old-fashioned method is trustworthy as the plumbob is using the earth's gravitational field as a reference.

Final comment: IMO Felder don't make their own bandsaw frame and I believe they contract this out to one of the major Italian bandsaw manufacturers, so it could be possible that a frame is twisted and Felder don't pick up on this. Addendum: It could also be possible that the frame comes with the top and bottom wheels installed, and the bottom wheel gets jolted out of position during transportation.

Paul

When I got my first bandsaw I fell into the "coplanar" trap. I struggled for quite a while trying to find a way to make it work.

As soon as I abandoned the thought that the wheels needed to be coplanar and instead removed all the spacers etc, set it back to how it left the factory and just tracked the blade to run where I wanted it to and adjusted the guides to suit that it has been much better and heaps easier.

My cuts are now much smoother, there is no such thing in my shed as bandsaw drift. I can cut veneers less than 1mm in thickness. Setup is quick and easy, blade changes take minimal adjustment to make them work. It's quicker, easier and most importantly gives a far better result with far less stress.

Is there a law somewhere that says that bandsaw wheels must be coplanar? Where did the idea come from in the first place?

Not sure if I ever heard of anyone suggesting a bandsaw works best with a coplanar setup, although I've seen plenty of folks
mention it's a technique for setup, maybe it's a law for extremely large resaw machines?

If not, I'm guessing it's a bit of Chinese whispers from some author or something, who led folks to believe that coplanar all is what's needed to be checked or adjusted to.
I can agree with you Doug, I chased my tail for a long while on the last machine, and this one too thinking it was an adequate
method of setup.

The beam is certainly a valuable tool for someone who's got a lemon, but a big hunk of timber is not the tool for the job.
I did try and do this again, better, as in surfaced both faces and edge to use a square in attempt to get figures for the east/west without success, but have no piccy of that.
Might have worked with a bigger square if I had one at the time, and something else could have been done to allow the wheels to move so the blade can track since it can have much influence in jacking adjustment, especially if doing so the way the market leaders suggest, doing so with the heaviest blade suitable.

Checking for coplanar .jpg

I think the plumb bob lines and blocksare hard to beat, if you've got a lemon.
You might chase your tail if you didn't have two lasers if you had a tippy machine.
As I was saying I think the biggest contributor to machines going out the door not setup correctly
is to do with the frame not being done right, possibly pointing to issues with the top wheel or even guidepost in extreme cases.

SAM_4240.jpg
Seems whoever "serviced" my machine coulda done with a beam, unless it was just a case of them being a chancer
This might explain the above

SAM_4491.jpg

SAM_4728.jpgSAM_4745.jpg

Saying that, I wouldn't say no to a mountable laser to assist the setup, as it might prove a whole lot better than lines and bubbles for checking the guidepost once the machine is plumed.

If you don't have the blocks, and using the plumb lines, you could spend a week faffing about.
Just make some up and tape them on, and leave them there..should the machine move or settle.

Its very difficult to sight a guidepost being out without the blocks, as those strings will move about for longer than going in for a cuppa after adjustment will take,
but the blocks settle the string in a minute, a real must.
As you can see the post is off as it's not in line with the column, machine is likely not even levelled correctly in the first place
and the string got knocked.
Just saying it's easy to check in this orientation by eye, but not so easy in the other axis.


SAM_4180.jpg

All the best
Tom











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