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What to do when coarsest bandsaw teeth are too fine? (12" dia solid round)

JasonPAtkins

Hot Rolled
Joined
Sep 30, 2010
Location
Guinea-Bissau, West Africa
I'm trying to saw slugs off of a 1' piece of 12" dia solid round. I routinely saw blanks off of 6-8" solid rounds, but this is the biggest I've ever attempted on my workhorse Wells 8m (which I realize can't take a 12" bite, I'll have to saw most of the way from one side, flip, and connect.)

The cut is chattering like crazy now that I'm down into the widest part of the profile. I'm using a 4tpi Lenox Classic bimetal blade. The chips are coming out trapezoidal like the Lenox instructions show indicate gullets getting filled up and skating through the last part of the cut. The normal remedy is to use bigger teeth for more gullet capacity. Problem is, they don't make any coarser in 3/4" blades.

Several brazed blades have broken at the braze, I'm sure because of the excessive vibration (this was after the first blade stripped a tooth, which then stripped all of the rest of the teeth on the blade before my assistant shut it off - I've since moved to start a different cut, not wanting a new blade to find any of those old teeth.)

Any advice?
 
If you've got the time, have you tried a finer pitch blade? I've cut a fair bit with a small sized cheaper saw of 1-2" plate with length of cuts up to 12". They cut great, just took forever to cut, left the oil on and away it went. The saw didn't have the power or rigidity to run the big tooth blades, but it'd run forever.
 
If you've got the time, have you tried a finer pitch blade? I've cut a fair bit with a small sized cheaper saw of 1-2" plate with length of cuts up to 12". They cut great, just took forever to cut, left the oil on and away it went. The saw didn't have the power or rigidity to run the big tooth blades, but it'd run forever.

Well, I'm too cheap to buy the optimal blade for every section I cut so I err on the finer side. It may take forever, but an 8/12 will cut through 6" round bar. :skep:
 
I think a slower surface speed might help or maybe it's at the lowest now? If that isn't an option then turn the part 90 degrees 3 times as suggested to reduce the thickness of the cut.
This is the times when one of those Marvel saws are appreciated.
Dan
 
Thanks all, I had planned to turn 180 degrees to get around the bridge height limit of the saw, but it never occured to me to do it several times to reduce the LOC. That sounds like the ticket. Not to go rebraze the three blades that broke because of the vibration and get back at it. :)

This is a better solution to get around the saw height limit anyway, but because it'll be easier to pick up the same cut by rotating only a bit, it would've been a lucky guess if I'd picked it up after flipping the stock all the way 180 degrees.

Thanks again!
 
Rotate the stock more than once, like 4 or 5 times, but only 45* at a time and as soon as the blade is working across 6-8" of material.. It's a PITA, but keeps the effective LOC well below 12".

Regards.

Mike

^^^ THIS ^^^.

8-sided first go-round, split the angle, 4-sided, second go-round. On to the next. All done soon enough.

Also reduce the feed rate.

Volume to fill a gullet is a product of length of run AND depth over that length. Shallower cut takes a longer stroke to fill the gullet.

And up the coolant flow.. of course.
 
Rotate the stock more than once, like 4 or 5 times, but only 45* at a time and as soon as the blade is working across 6-8" of material.. It's a PITA, but keeps the effective LOC well below 12".

Regards.

Mike
Maybe I am getting to old. I don't remember LEARNING TO TURN THE STOCK. This is something that I ALLWAYS HAVE KNOWN.Just like sawing a six by six wood beam with a handsaw,nobody has to tell you to rock the sawblade. Edwin Dirnbeck
 
Maybe I am getting to old. I don't remember LEARNING TO TURN THE STOCK. This is something that I ALLWAYS HAVE KNOWN.Just like sawing a six by six wood beam with a handsaw,nobody has to tell you to rock the sawblade. Edwin Dirnbeck

Yeah. Far too old.

Expect someone to say "WTF is a "hand" saw?, you mean a portable, right? Battery or corded?"

Not I. "Diston RULES!"

:)
 
Yeah. Far too old.

Expect someone to say "WTF is a "hand" saw?, you mean a portable, right? Battery or corded?"

Not I. "Diston RULES!"

:)

Good for you. If I have to cut a 6x6 timber beam I'm reaching for my Stihl chainsaw. Life's too short for hand tools on a job like that.

PDW
 
Good for you. If I have to cut a 6x6 timber beam I'm reaching for my Stihl chainsaw. Life's too short for hand tools on a job like that.

PDW

Small stuff like that? If not the larger framing saw, then the Milwaukee recip. Corded. The BIG one. Chainsaws are for my tree work, still living, wet, green, and sappy wood.

But y'know.. I DO still own good US or Japanese-made handsaws, pull-saws, razor saws, bow saws, trim saws.. Many of them.

Just in case.
 
To answer a few questions...

The old Wells saws use an adjustable weight on the bow, and I had that set to as light as possible, exactly to try to keep from loading up the gullet. They were still overloaded.

The idea of reducing the LOC by rotating is the winner, I think. Once I get my blades rebrazed today, I'll give it a try (as I'm already half through on the top side). My blades broke at the braze, probably because of some combination of weak braze because of inexperience (I used to use a butt welder but it died recently, there was some porosity in the braze joints on these) and the cutting vibration. I don't think a resistance weld would've stood up to that either.

I am using coolant, although I HATE it on bandsaws. I always used to, had to have a catch bucket at the end of the stack of tubes to catch all that was filling them up, etc. I haven't used coolant in a long time. Much nicer. But for this cut, I did fill the tank back up and have it running, again to attempt to keep the chips flushed out.

My neighboring shops here in West Africa (which are mostly a guy, a generator/welder, and a hacksaw or angle grinder under a mango tree) do most of their sawing by hand with a hacksaw. I don't get romantic about the old, manual way. Mechanized is faster, cleaner, cheaper, and more accurate. I once cut a 2" solid round in two with a manual hacksaw when I was at an auction in MI and didn't want to leave it behind (part of a lot, didn't know it was included). That hour and a half was enough for my lifetime.

I don't have oxy/acetylene here, so I'll head over to my friendly gas welder to have them brazed. These guys are hardcore, they have tanks with removable tops for the aceylene - they put calcium carbide rocks into a basket inside the tank with water underneath, seal it, then "regulate" their acetylene flow by having an assistant periodically shake the can to get water onto the rocks or lower the basket into the water with a handle every once in a while. Amazing that more of them don't get killed in explosions...
 
Can you try a variable pitch blade?

We make a part that involves sawing a 1100mm long piece of 325 dia 4145H right up the middle along it's length. I do it with a 2/3 TPI variable pitch blade (Starret Intenss Pro), but have done it with a 3/4 TPI variable as well, just takes longer.
 
soooo,

you intend to cut a 12" bar of steel with a 1/2 hp , entry -level , no sump
8" rated bandsaw....with a 2/3 pitch band?

good luck on that . you'd be lucky to run an 8tpi without completely ruining
the gearbox . why use such a coarse pitch blade? saws that cut metal with that type
of band pitch are AMADA and MARVEL and DOALL . with 10x + the power and serious rigidity.

i cut big stuff with my similar Kalamazoo 1hp 816 , but i stick with the 8-10 tpi
band because it works. i have rotary chip brushes and a double nozzle coolant
flow. i made my brushes with blocks of pvc, 2" rotary wire brushes, and some
springs- about $5 worth of shop scrap.

you could have 1-tpi , but it won't help your situation .

good luck..

40" mud tires on a Toyota 4 cylinder truck ...........
 
soooo,

you intend to cut a 12" bar of steel with a 1/2 hp , entry -level , no sump
8" rated bandsaw....with a 2/3 pitch band?

good luck on that . you'd be lucky to run an 8tpi without completely ruining
the gearbox . why use such a WOOD cutting blade? saws that cut metal with that type
of band pitch are AMADA and MARVEL and DOALL . with 10x + the power and rigidity.

i cut big stuff with my similar Kalamazoo 1hp 816 , but i stick with the 8-10 tpi
band because it works. i have rotary chip brushes and a double nozzle coolant
flow. i made my brushes with blocks of pvc, 2" rotary wire brushes, and some
springs- about $5 worth of shop scrap.

you could have 1-tpi , but it won't help your situation .

good luck..

Yer not wrong, but .. D'y not ken his location and economic circumstances?

Where Jason has to operate, "good luck" isn't even in reliable supply with the blessing, now and then, of divine intervention.

I'm sure he'd be DELIGHTED if someone would ship even a severely clapped-out "real" saw - band or "hack" - to Guinea-Bissau, West Africa for his students to tackle as a rebuild project.

:)
 
Yer not wrong, but .. D'y not ken his location and economic circumstances?

Where Jason has to operate, "good luck" isn't even in reliable supply with the blessing, now and then, of divine intervention.

I'm sure he'd be DELIGHTED if someone would ship even a severely clapped-out "real" saw - band or "hack" - to Guinea-Bissau, West Africa for his students to tackle as a rebuild project.

:)

even more reason not to fuck-up what he has :) . i'd consider sending him some 1" x 10p band stock if he'll pay the shipping.
 
soooo, you intend to cut a 12" bar of steel with a 1/2 hp , entry -level , no sump 8" rated bandsaw....with a 2/3 pitch band? ...good luck on that . you'd be lucky to run an 8tpi without completely ruining the gearbox . why use such a WOOD pitch blade? saws that cut metal with that type of band pitch are AMADA and MARVEL and DOALL . with 10x + the power and serious rigidity.

It's easy for us to tell him the solution is a heavier machine but he's trying to get by with what he's got. Been there, done that.
 








 
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