Thread: Small Bandsaw Milling

Bob

I was warned back when I first had my bandsaw mill that some people have an adverse reaction to Silky Oak.

Regards
Paul

Yes I had a reaction to it about 10 years ago milling some green logs, same again last year milling green logs.

The Silky oak I cut above was for one of my brothers and as it was already so dry he has just finished turning it into a living room wall shelf.
He didn't need to but I love the way he decided to make a feature out of two of the cracked boards.

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Wrap araound display shelves! Nice conceptualisation, design and crafting by your brother, Bob. Is it suspended on French cleats?

Also like the dingo.

Originally Posted by GraemeCook

Wrap araound display shelves! Nice conceptualisation, design and crafting by your brother, Bob. Is it suspended on French cleats?

Also like the dingo.

Thanks.
RE: Design and french cleats. I dont know - I will find out.

RE: Dingo:
He's a very affectionate, even sooky, dog and he's called "Moorditj" which means "hard or tough"
They reckon he has some dingo in him which is not consistent with his "sookiness" so I do wonder.

Originally Posted by BobL

Thanks.
RE: Design and french cleats. I dont know - I will find out.

Design was by my Brother's other half.
No cleats, it's attached directly to the wall.

Originally Posted by BobL

Design was by my Brother's other half.
No cleats, it's attached directly to the wall.

Thanks, Bob; I like the minimalism approach a la Shaker/Scandinavian/Japanese schools and that is right in that ethos. So light visually. Couldn't have removed another line without it falling to pieces!

loved it.

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Been testing out our mill in it's new location.

First Photo is some 1/4 sawn London Plane. I hit 31x nails in the first leveling cut... We persevered and got a couple of usable slabs out of it. On the last slab I hit 10x nails. In the photo you can see where I circled a single nail with a marker. We do this to highlight defects before we go any further with it.

After a blade re-sharpening session, today a couple of members brought in the own Red IronBark for a session Photo 2 and 3. The grain looked fabulous. We got about 2 hours good productivity from the resharpened blade (there were no nails in the Ironbark) .

Crikey all those nails!
I usually give it away on a log after 2-3 nails.
Are you using bimetal blades?

"Are you using bimetal blades?"

I use Lenox woodmaster_B from Henry Bros. 148" x 1.25"x 1 TPI. They are Bi-metal and I get a good run out of them.

We have discovered 1 or 2 framing nails are survivable. 15 is way too many. What happens is the nails force the blade backward, & when the teeth start to climb onto the under surface of the idler wheel, the blade angles down.. That means the inner teeth actually cut into the nails, blunting the inners while the lower teeth stay sharper. This causes the lower teeth to cut better, which makes the blade tend to dive. The extra friction from the dive then causes the blade to heat up and it just goes blunt. When the blade starts to heat up, it starts to melt the tire rubber from the drive wheel, which sticks to the blade and just makes the whole friction thing much worse

Today I spent 4 hours cleaning blades, then sharpening with a fairly aggressive grind angle. I used Laundry booster with hot water and it seemed to work reasonably, with no toxic fumes (cheaper than white vinegar I previously used, but not quite as good. I dry with a tea towel & I then use a wire wheel in a cordless drill, keeping the direction of rotation in the direction of the teeth. I then WD40 them before sharpening.

On Tuesday I should be sawing more Plane, from higher in the tree (hopefully less nails), Silky Oak, Box Elder which I am hoping has flame pattern, Green Ash and Claret Ash.

I'll get pictures of interesting stuff hopefully

Thanks for the info.

We also use Lenox Bimetal bands but get them from a local supplier at a slightly lower price than Henry Bros, plus as we can just pick them up there's no shipping involved.

We use water cooling on our mills so there's no resin build up.

The large mill (2" wide band 1TPI) uses a fine water spray from a hose, result is there's a fair bit of water used and pooling around the mill - yes its messy but its outside so not that much of a problem.
We have to use water on this mill because the guide blocks are Wandoo (very hard timber) - if we dont use water, smoke comes out of the blocks.
Temperature of band is basically always that of the water.

The smaller mill (1.25" 1TPI) uses a water drip feed from a 10L tank with a squirt of detergent is added every time the tank is filled. About 10 logs can be milled on a tankful of water.
This mill is under cover on a concrete floor, the small amount of water used is easily absorbed by the sawdust so there's no water mess.
Temperature of band is dependent on sharpness of band and hardness of timber. In general the band is about 10ºC hotter on the outfeed than the indeed. Blunt band and harder wood can see that up to 25+ºC hotter than the water.
We can increase the water flow but then the tank would need refilling more often and it would start to make a mess.
It's just better to change bands.

On the subject of lubricant, we have a 10L tank.

I put a squirt of dish washing detergent (about a tablespoon) and a bit of chain oil into a 2L milk bottle, fill with water, give it a shake, empty into the tank, then fill the tank with water. Our flow rate is about 3 700mm diameter logs to 3/4 of a tank. Water is cheap, its outside & I've honestly never noticed the mess. The lubricant keeps the outside of the blade quite clean. Our "problem" is coming from the rubber on the tire, when the blade gets hot from hitting nails and deflecting. I may be getting some slippage but I am running the standard 25 ft/lb of tension. It may also have something to do with the WD40 which I use to get the last of the water off the blades before sharpening (& prevent rust), but it doesn't happen with our other bandsaws, and it has only started happening on the mill when we hit a lot of nails in this particular tree, and got that massive deflection.

I have not actually measured the blade temperatures, but they are hot enough that they will give you a burn.

I also have not disassembled the guides (yet) to inspect them. I have a backlog of material to saw as a result of weather & downtime while we poured the new block and moved the mill etc. When I get the chance I will pull the steel pillow blocks and get the boys in the forge to resurface them on the milling machine. I might also try some grey ironbark guides

The instructions that came with the small mill say not to use any lubricant on the blades as this will effect the tyres, which are loose pulley type belts.
So far there's been no band rusting but we haven't been through winter yet with this mill.

The big mill also uses pulley type belts as tyres and because this mill sits outside (covered in a tarp) I usually removed the band or I lube it with B&C oil and run the mill for about 30s. The guide blocks wipe most of the oil off the inside of the band and most of the oil on the outside gets flung off the outside so it's only covered in a very thin layer. That lasts for weeks but sometimes that mill goes for many months without use and eventually some rusting does start, usually before then I bring the band inside.

I usually spray the bands from both mills with WD40 or Inox before sharpening and setting as it helps get them through the sharpener/setter more smoothly but I do rough wipe it off afterwards.

Water on the blade of my saw is an absolute prerequisite, but the wheels are a different type in that there is no rubber tyre and the blade protrudes over the leading edge of the aluminium wheels. The heat generated on the tips of the teeth is high as they travel through the log and potentially a big problem. As the blade heats it expands and if it reaches the point where the front of the blade is longer than the back, the blade will inevitably wander in the cut. This issue is not so noticeable in smaller logs and it may be possible to run dry, but a larger log has more potential for this to occur. As the blade dulls (as it must) the teeth are subjected to more and more heat.

I too add detergent and borax powder to maintain blade cleanliness.I don't know the rate at which the water is used. I start with a 20l drum mounted high on the shuttle and refill it when it empties!

Regards
Paul