Thread: Milling Bloodwood

Originally Posted by newjon

...Also have an issue with the band riding up at the start of the Cut, It returns back to level after about 10 Inches and then remains flat for the rest of the cut. Anyone got any Ideas on what this might be?

Cheers,
Jon

If the cut is what we see in photo 1, the band is trying to follow the grain.

Was the band freshly sharpened?

You could try the initial feed rate a little slower at the start of the cut.

Any chance of a closeup of the slabs, be interested to see the grain as I have a couple of bloodwoods here and am wondering what to do with them.

Originally Posted by newjon

Had 1 spit open with the tension in Log as I was Cutting. Also have in issue with the band riding up at the start of the Cut, It returns back to level after about 10 Inches and then remains flat for the rest of the cut. Anyone got any Ideas on what this might be?

Cheers,
Jon

Jon

I think the split occured as you approached the heart, admittedly in a log that was always going to be prone to tension.

Was the band an old one? If so, put a straight edge along the back edge of the blade and see where the gap is. If at the ends the blade is good, but if the gap is in the middle the blade has lost it's tension. The cutting edge of the blade needs to be a fractionally smaller diameter than the back of the blade.

However, I don't know why it came good.

As KevM advised feed veryslowly until the fullwidth of the blade is in the timber as this does act as some support.

Nice looling timber.

Regards
Paul

Originally Posted by gonetroppo

Any chance of a closeup of the slabs, be interested to see the grain as I have a couple of bloodwoods here and am wondering what to do with them.

Gonetroppo, I am away from home for the week, will take some when I get home on the weekend, see Post "No Better Feeling". These are photos of a blanket box made from Bloodwood I cut some time ago.
Cheers,
Jon

Originally Posted by Bushmiller

Jon

I think the split occured as you approached the heart, admittedly in a log that was always going to be prone to tension.

Was the band an old one? If so, put a straight edge along the back edge of the blade and see where the gap is. If at the ends the blade is good, but if the gap is in the middle the blade has lost it's tension. The cutting edge of the blade needs to be a fractionally smaller diameter than the back of the blade.

However, I don't know why it came good.

As KevM advised feed veryslowly until the fullwidth of the blade is in the timber as this does act as some support.

Nice looling timber.

Regards
Paul

Paul, was not too worried about the split, I expect that on the outback hardwoods when you get close to the heartwood. The blade is an older blade but it has not done too much work, I freshly sharpened it before I cut this log. The strange thing is the initial cut was completely flat, this is the one in the photo, all following cuts had the hump at the start.

Cheers Jon

Might have hit a bit of grit just enough to take the edge off, then the blade will be more likely to follow the grain, maybe a bit more blade tension to help keep it straight


Pete

Band being the problem doesn't make sense with what is being reported...
I'm not bandit miller (and surprising we haven't had our milling expert 'someposs' tell us exactly whats goin on) but reasoning it through, Jon said band rose at the beginning of the cut, then finished fine through the rest of the log...
if it was in bad shape and following the grain to begin with, then I'd expect it would keep following it???...
if feed rate was the issue, then as Jon isn't a machine, his feed rate would alter throughout the log and give 'feed rate' results all over the place, not just in the first 10"...
I presume Jon would tell us and would have picked up if there was a ruddy great big branch stub at the beginning of the log causing a mass of tight grain the band didn't like...

My thought would be something I picked up from Bob's chainsaw slabbing threads, I seem to recall (and correct me if I'm recalled this badly) him mentioning he docks off the entry point of the log as he'd found the first few inches on most logs dries out a lot, and gives a chain a heap of grief, maybe this could be whats happening for you Jon???

Like I said, I've not operated a band mill so only spitballin.....

I had a similliar thing with some Huon Pine I had cut by the mill (bandsaw in Tas), the start of the cut was low then rose up dipped again then settled down to something half acceptable
Attachment 187923Attachment 187924Attachment 187926Attachment 187925
All the slabs followed the same curves and with close inspection of the grain the cut tends to follow the grain, no idea what was going on with the bandsaw but it wasn't right, at the end of the day it's only pine so should have cut it easy, these slabs had quite a bit of sawdust left on the slabs so maybe feed rate was too high for the width of slab, (~700mm) I also reckon blade was probably blunt and too loose but I'm only guessing

Al, I recall BobL does cut the end off a dry old log

Jon, How fast is your band speed? I had a look at your utube vid cutting a log, the band speed looks to be fast, if it is usually you don't get the same life out of the cutting edge as if the speed is slower, it's a compromise between how fast to remove mat'l (sawcut) (time) and the next sharpening cycle, How many times have you sharpened the blade? there's not much depth of hard tip to the woodmaster B blades, Are you getting any build up of resin/wood/crap on your teeth/blade, buildup can cause probs especially with surface finish.

Just a few other odd tips with the B blades....In the past I have had my B blades sharpened by the saw doc, came back sharp allright but there machine changed the shape of the gullet to a flatter bottom with a sharper radius at front and back of tooth and a coarse grind, I had a lot of blades break propogating from the gullet after being ground even had swarf hanging off the blade tip they don't sharpen my blades anymore!!! avoid changing the gullet shape if possible, also make sure the back of the blade comes away from the bearings, the blade can also break from the back if it overheats or is damaged, even a slight nick/scratch can propogate a crack so be careful when removing/replacing blades, I have recently put some rubber and brush scrapers onto the blade to help keep it clean, if the blade starts to jump forward stop and inspect for cracks


Pete

All close I reckon but noone gets the cigar

It is NOT feed rate. Log end being a bit dry can do it but not often. Being a seasoned bandit miller heres what i think but only in accordance to what my Woodmizer does. My blades will begin to lose their set before they become dull and on my machine for some reason the set on the up side of the blade comes off before the lower set, Thus when I enter the log the blade will rise into the cut and then come back to normal, Time to change blade.

If it were your feed rate the blade is more inclined to dive because your saw head is slightly forward of the blade, or moving faster than the blade can cut, thus trying to pull the blade down.Check your set and keep blades fresh, dont run them for too long.

Gullet depth and shape is the most important thing, watch your blade exit the log and watch sawdust coming out, it will tellyou the story

One more thing on feedrate. You are cutting at your optimum speed when the saw cuts left on the timber look to be running at a slight angle. As if the drive side is pulling the non drive side along a little bit. If the saw cut marks look square, not quite fast enough.

Time to change the blade I reckon. Don't know about that cut angle thing Nifty. Must be a woodmiser thing. Reckon I would pull the blade back on the wheel before I could achieve a cut angle.
I do get the rising up thing but only after the blade is pretty much blunt..
regards
Steve

I think the angle Nifty is talking about is the angle left on the face of the board after a cut relative to the band blade, about 5 to 10°, if the blade is moved back over the cut face (after a cut) the lines made by the teeth won't be parallel to the blade, a slow feed rate will have an angle of 1 to 2° and a fast feed rate will be somewhere about 10 or more


Pete

It`s called duck billing, the reasons for it are mostly temperature. More water at the start?

Originally Posted by Stopper

Time to change the blade I reckon. Don't know about that cut angle thing Nifty. Must be a woodmiser thing. Reckon I would pull the blade back on the wheel before I could achieve a cut angle.
I do get the rising up thing but only after the blade is pretty much blunt..
regards
Steve

Coming to the think of it Steve it could be a woodmizer thing as they are a cantilever head, not a 4 post head