Thread: Problems with resawing red gum

Interesting how the beginning and end of the cuts are very neat

May be just too fast.

I can see jumping and burning , how old was the blade??, and how sharp??.

with the variation in thickness the blade was wandering slightly, were you cutting free hand or with a Fence, if with a fence , I would look at the blade guide set-up, and tension , if a new blade was used.

jeff
vk4

hi vk4, thanks for answering. The blade is an old one, but hasn't been used much, but was a bit rusty. It did feel sharp to the touch.

I used a full height and strong fence and kept the workpiece against it.

Reading about it today, I realised that I had not aligned the fence to the natural offset of the blade - would is have also caused that cut pattern?

The problem seem to lie on the quality of the blade. Change blades and run it in a range from 2000-3000 sfpm. A 3 TPI blade will do the job, but it is recommended best when resawing larger blocks, lesser tooth in the count have larger gullet area allowing sawdust from leaving the blade.

Originally Posted by Dengue

Does the appearance of the final result as shown in the pics give anyone an idea of what I might be doing incorrectly?

Link: https://www.woodworkforums.com/f27/ta...ml#post1502407

This is just one point in quite a saga that Hermit had with his new bandsaw.
He had pictures of the results before (I think) and after (I'm sure) my post where I tried a cut on my middle-of-three bandsaw.
His initial results were perhaps a bit worse than yours, but similar.He managed to get through it in the end and now pumping out intricate toys and models
If you have a week, it might be worth reading through ...... it's only 15 pages ...
Or just PM him to ask if he has any advice.
Actually I did a short video at some stage there (linked in the thread) just to show the rate of cut, compare technique/setup, etc.
Cheers,
Paul

OK - video here: https://www.woodworkforums.com/f27/table-bowed-new-h-f-bp-305-among-other-things-152827/index12.html#post1503413
Hermit's pics (there may be more): https://www.woodworkforums.com/f27/ta...ml#post1504235

Woooo ... this was a test ... first time I've ever seen an inline Vimeo video in wwf.

Have yopu looked at the video by ALEX SNODGRASS, on how to set up a band saw,???.

It is worth the effort and Time.

The basics of the video , are ,
1 be safe , disconnect the power.
2 open the covers,
3 back off all guides .
4 adjust the blade , so the GULLET of the teeth is running on the wheel crown
5 set both of the thrust bearings (top & bottom) at the back of the blade , so that it is just clear of the back edge,0.5mm , and do not touch the blade when you spin the wheels BY HAND.
6. set the side guides , so they sit just to the rear of the tooth gullet, and just clear the blade , but do not quiet touch.
7 close the covers , connect power and test , this should cut dead straight, with almost no drift.

Watch the video , first in case i missed something out though,

I have adjusted my little chinese bench top Band saw , and I cut 75mm hardwood , with no trouble.

Jeff
vk4
6

Many thanks for this info, Jeff, I shall look at this video and spend the weekend tuning and testing the bandsaw after fitting a new bimetal blade. Will let you know how it goes.

The manual for my Metabo BAS-500 bandsaw says not to use the side guide bearings for 1/2 inch blades and bigger, because the heat generated damages the bearings

regards,

Dengy

Had a go at putting the gullet at the centre of the wheel using the adjustment knob at the rear of the upper wheel, but after a couple of turns of the wheel, the blade returns to the front of the wheel. The rubber tyres were replaced 6 months ago and haven't been used much at all. Can anyone please suggest where I might be going wrong? I didn't use the rear adjusting knob, as Snodgrass quite strongly said not to touch anything that affects the manufacturer's coplanar settings.

Also, the original rubber tyres were not glued, as recommended by Snodgrass, so I didn't glue the replacement tyres

Dengy,

The knob at the back is used to adjust the tracking of the blade, I believe that the coplaner is in respect to the vertical alignment of the wheels.

If the original rubber wheels were not glued , and the new one's are a very tight fit, then don't glue the new ones..

Adjust the blade to track with the gullet on the crown , as per the video and try the system, it has worked for many here on the forum , and if it doesn't work for you , all that's lost is some time.

Jeff
vk4

Dengy,

If you are going to be doing more re-sawing consider a Lennox Woodmaster CT 1" blade. I have put thousands of feet of timber through these blades and they would have to be the best re-saw blade on the market. The finish is very smooth and the kerf only 1.2mm. Have a chat to Henry Brothers Saws in Sydney.

regards,

AD

Well, I re-read all the comments, read Lonnie Bird's Bandsaw Book, and studied Michael Fortunes article in Fine Woodworking #173 p66 " 5 tips for better bandsawing". Jeff a.k.a vk4 gave me the confidence to use the rear wheel to position the 3 tpi 1/2" blade. Stayed with the old blade, and the original speed, which is too fast for hardwood according to the manual, but I cannot work out how to select the 2nd fastest speed as recommended - the schematic drawing in the gear housing door is just about impossible to understand.

1. The rim of the upper wheel is 30mm wide, so I positioned the bottom of the gullet 15mm from the front edge, and then resawed a block of radiata pine, but the finish was quite rough; very disappointing.

2. Rotated the blade by hand ( with power disconnected), and found that the rear of the blade was quite wobbly where it came out of the upper guide bearings, and that the rear thrust bearing was rotating. Moved the thrust bearing back a smidgeon until it was not rotating, and the blade wobble stopped.
Resawed another test piece, it was better but still a fine corrugated finish, but almost a hairline kerf, and square the whole length of the test piece, and no curve in the vertical cut line. The corrugations were quite vertical, and there were no burn marks, big improvement on my first effort posted.

3. Still not happy with it, so cut a length freehand following a marked line and found the blade drift line was significantly slanted to the right.....mmmm. Put the fence in parallel with this line and the resaw result was a big improvement. But according to Snodgrass and also Fortune, if you align the blade correctly on the wheel, then you don't have to touch the fence. Fortune had an excellent drawing showing the cause of the fence slanting right, and which way to turn the upper wheel. End result, after much testing, was that with the gullet 13mm from the front of the 30mm wide rim, the blade drift was zero, and the manufacturer's fence could be positioned anywhere at the designed 90deg. to the left hand table edge

4. The finish is still slightly rough with fine corrugations, but I don't know what quality of finish is expected with a 3tpi 1/2inch HSS blade. Should there be corrugations, or should it be a very smooth cut surface?

5. Thanks to everyone above, am slowly getting there. Are there any suggestions for improvement in the quality of the resawcut, or should I just accept the result?