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2:46 am
June 10, 2010
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I have a rather small shop so I only have a small 5x6 band saw using 64 1/4 blades. I use the saw a lot and after wearing out 3 of the Chinese models I bought a King Canada brand. They are made in Taiwan and a much better quality machine closer but not quite a Jet. Although the saw is miles ahead of the others I'm breaking blades like crazy and can't figure out what I'm doing wrong. I have the guide roller bearing quite close so there is really no slop and close enough that if a chip falls in when lifting the saw too high that it will lock it up, but this doesn't seem to be happening when it is in the horizontal and running the saw of course is off when I lift it vertically to put in a new piece steel, so only locks up when I turn it on. I broke my last blade yesterday so had to run to Princess Auto to buy one of their 14 tpi bi-metal blade as the industrial suppliers are closed on Saturday, the blade appears to be a Morse, I usually get Lenox 10-12 TPI?. This what I cut on the last blade 30 pieces of 1 1/2" square 20 pieces of 5 1/2" x 3/16" and the blade broke. The blade always seems to break opposite the cutting area, The blade is still sharp and I use that wax cutting lube. I like to keep a good tension on the blade but it is no different than with the old saws and on them I would often wear out the blade before a blade would break.
I would appreciate your thoughts I'm not sure what to add as to what I'm doing but figure it has to be something I'm doing wrong. Your thoughts are appreciated
6:08 am
September 26, 2010
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I used to use Lennox blades, quit a few years ago. I buy ones made in Europe now. The ones I used to get would wear out real quick or break. They last a few months now. Breaking all the time though is kind of weird. Depends on what they do welding it? Do they break on the welds? The drive and idler wheel might be to small if not welded right and the weld might be brittle, and when it comes around and through the guides might be to much for it. Just some things I would look at.
6:32 am
June 10, 2010
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Thanks Stretch, the problem is not the welds although I have had them break on the weld, it is usually somewhere else that they break.
7:03 am
September 7, 2010
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Daryl,
Have you checked the rollers? Not the ones that guide the blade from side to side but rather the ones that sit on top of the blade that 'push down' often these "snag" and then the additional load creates vertical fractures in the blade.
Those two rollers are often not even thought of because they are hidden.
Good luck with solving your problem!
Ian
3:19 pm
NWBA Member
April 22, 2010
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thats weird.
I usually use either the Lennox DieMaster II blades, or the Starretts. I use bi-metal blades, I like the 10-14 variable pitch too. And I cut mainly stainless, and a blade will last months.
I think its your saw, but I am not sure what.
How tight is the spring that controls feed rate? If you have it too loose, and the saw blade is just sitting on the metal, that might be the problem- I would try tightening it up to slow down the feed.
Bandsaw blades on the little saws need to be as tight as you can get em. That could be it, too, but I kinda doubt it.
Make sure everything is tight, too- if some bolt or nut is loose, and it bumps once in a while, that could do it.
5:30 pm
June 10, 2010
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Ries;15332 wrote: thats weird.
I usually use either the Lennox DieMaster II blades, or the Starretts. I use bi-metal blades, I like the 10-14 variable pitch too. And I cut mainly stainless, and a blade will last months.
I think its your saw, but I am not sure what.
How tight is the spring that controls feed rate? If you have it too loose, and the saw blade is just sitting on the metal, that might be the problem- I would try tightening it up to slow down the feed.
Bandsaw blades on the little saws need to be as tight as you can get em. That could be it, too, but I kinda doubt it.
Make sure everything is tight, too- if some bolt or nut is loose, and it bumps once in a while, that could do it.
I'm using the Lenox DieMaster II blades as well except for this one I bought Saturday, I took a couple blades up to the supplier this morning, we went through the possible problems with the Lenox trouble shooting guide and didn't really come up with any answers. If anything I'm siding with Ian and Ries that it is either too fast a feed rate or that the back guides are too far forward. I'm still on factory setting. I doubt that I will have an eureka moment with this problem as everything looks right. I'm going to run this in the upright position with the cover off, and see if everything looks okay if it does I will drop the feed pressure, and see what happens over time. What really upsets me is this little saw cuts like a charm when it isn't breaking blades, of course it always has a sharp blade as I break them so often.
I think I have everything else covered so we will see how long the next blade lasts.
Thanks for the input guys, this is one off those things that nothing is there that looks obvious.
7:39 pm
May 13, 2010
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I would see how long the Morse blade lasts. I used to buy the Morse blades both from my industrial supplier and Princess Auto and always had good luck with them when I had the little saw. The fine pitch may be part of your problem because of the diameter you are cutting. I know I used to get the coarsest blades I could get in the 1/2" blades, I think I was able to get an 8 pitch blade. I know I had the same problem occasionally and I think it was when I was cutting a lot of heavier stock with a blade that had too fine a pitch. (those little saws don't like 3" 4340 or 5 1 1/8" dia drill rod pieces tacked together)
8:08 pm
June 10, 2010
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John the Morse blade lasted a day. I'm cutting mild steel, my normal all round blade is 10-14 variable pitch the Morse was 14 tpi. We could find nothing wrong with the blade except the break, pretty much everything as it was supose to be.
I'm just finishing off my taxes, I can procrastinate even on bad years. 🙂
1:13 am
June 10, 2010
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I maybe found the problem. It appears that the top wheel is not in the same plane as the drive wheel not easy to measure but setting flats across the wheels the top apears to be out by 3/32". There is a bit of wear on the top wheel where the back flange is I thought it was machining be I can feel a bit of a bumb with my finger nail. I wonder if this might be the problem? I will run this new blade lower feed rate and see how long it lasts.
1:57 am
NWBA Member
August 7, 2010
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Good Morning, Daryl
How to make a holder for rewelding bandsaw blades.
Take a 6" (+/-) piece of angle iron (at least 1", but whatever you have), weld a piece of 3/8x1" flat bar on edge to make a u-shape. Drill and tap the 3/8 flat bar, 4 holes, 2- 1" from center & 2 - 2" from center, each side of center. Make 4 bolts with finger twist handles. Cut a 1" wide section out of the center of the angle flange that would be opposite the 3/8" flat bar (to give you access for silver soldering). Grind a bevel, about 1/8"long on both ends of the broken band saw blade. One on the inside, one on the outside of the blade. Hold both ends of the bandsaw blade so they slightly overlap in the center of the cut out section, hold the blade in place with the twist handle bolts. Keep the blade straight, check with a straight-edge of a ruler. Silver solder the blade back together. Carefully grind surplus from the outside of the blade, to original width.
Not a huge job, but a lifesaver when the last blade breaks at 3am and you are almost done!!
Neil
As long as we are above our shoes, We know where we are.:happy:
2:52 am
September 21, 2010
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the diemaster blades are for contour cutting.. so those might not be the best for this app..
http://www.lenoxtools.com/page.....y=bi-metal
i've got the busybee chicom saw.. and the top and bottom wheels don't line up.. they're out .. it rides with half the blade on the top bottom wheel... the QC on these saws is not so good
got a small portaband dewalt.. built a small vertical stand for it and a platen..... and buy the lenox wolfband blades at lowes for 20 bucks for 3x .... very nice for a benchtop saw... and you'd be surprised what it'll cut
good luck with the saw.... it does sound like its binding abit in the cut... hard to tell
i was told to have 3 teeth in the cut when you determine the tpi
often I use 14/18tpi
4:40 am
NWBA Member
April 22, 2010
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I have probably used fifty of the Diemaster 2 blades over the years, on 4x6 bandsaws, cutting literally tons of material, and they work fine.
In fact, since the wheels are so small on one of these saws, and the resulting amount the blade must curve is so much, you need a thinner, more flexible blade to work at all on one of them- which means pretty much any blade that will work at all is, by definition, a "contour" blade.
It usually works best to use a .025 thick blade for this, as opposed to the thicker .035 size which is also made in most of these bi-metal blades.
On a bigger saw, say one running a 1" wide or wider blade, the "contour" designation starts to have more meaning- it means a thinner, more flexible blade that will cut curves more easily. But on these tiny little guys, they are ALL contour- and thats why you cant expect the best results in terms of straight cutting on big stuff, like 4" round. A 1/2" blade will flex a fair bit- its just physics.
In fact, many of the non-contour blades arent even made in sizes that will fit these saws- the "basic" bimetal from Lenox starts at 3/4" wide, and goes up from there.
But that doesnt have anything to do with the blades breaking.
You should be able to adjust the top wheel by either grinding, or adding washers to shim it out, to get it in plane with the lower wheel. The Jet saws are more adjustable, and easier to get aligned- but, of course, they cost more, too.
5:15 am
June 10, 2010
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Well I have been running the saw solid all night, the only adjustment is the feed rate. I'm wishing I had another days worth of cutting to do but I don't. The alignment may be the problem. I sure wish Jet was available in Canada but not at the moment so King is the best I can do. I'm good friends with the supply house and I'm sure they will try to make things right.
I'm trying to figure out how to shim that top wheel, they are a press fit on to the shaft and the only real place to work would be on the guide, and you can't put a shim there and it needs to move when you tighten the blade....
I'll leave the head banging till tomorrow.
Thanks everyone for your ideas believe it or not, it is helping.
Neil I will be visiting your fair city in a few weeks. I should get you to give me lesson on silver soldering blades, I made the jig like you mentioned and really had poor luck, they usually broke soon after in the heat effected zone.
12:11 pm
September 21, 2010
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ah good to know about the contour blades.... i alway thought they were a special purpose blade ... thanks for info
same here.. my top wheel is adjustable, but you can't actually move the shaft outward... have to lathe up a new shaft... and in order to do that... have to get the lathe fixed ..... isn't that how it goes, sometimes !
well, i shouldn't complain too much.. so far its cut a tonn of 1.5inch 1050 shaft with the occasional popping off of the blade .... its abit maddening, with just a little bit more quality control... they could have a very solid product
and on that saw i use the bimetal morse blades...
2:56 pm
NWBA Member
August 7, 2010
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Good Morning,
I was at Renato's one time and he was showing me "Friction Cutting". He gets old wood bandsaw blades from a neighbour (who doesn't use them because they are dull), mounts them in his saw "BACKWARDS", teeth pointed the wrong way. He adjusts the blade speed for the fastest it will go and cuts sheet metal like it was a hot knife in butter. He is using an older 'verticle' wood style bandsaw.
Daryl, I won't warn the Vancouver Island Customs Authorities, that you are wishing to 'Jump Ship'. lol:bounce:. I will have a car here for you when you get here. Looking forward to the 'Get Together'.
All and any NWBA members are welcome to come to Victoria, May 26-27, for a Workshop at Vancouver Island Blacksmith Association Shop at Luxton Fairgrounds. The same place we held CanIRON VI. Daryl Richardson is the guest demonstrator.
Neil
As long as we are above our shoes, We know where we are.:happy:
3:15 pm
NWBA Member
April 22, 2010
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Friction cutting is great, but it requires huge horsepower and very high speeds to work very well. Maybe on very thin sheet metal, but a commercial friction cutting bandsaw, the kind that will reliably cut 1/4" plate, runs at 7500 to 15,000 feet per second- thats screaming fast. The really old ones, from the 40's, had 7 1/2 horsepower motors, but the newer ones are all 10hp and 15hp and up. And they weigh 2000-3000 pounds, as the vibration at those speeds is pretty scary on a lightweight saw.
But a proper friction saw (with the teeth pointing the right way) will cut titanium or tool steel or just about anything else- it was kind of like non-electronic plasma.
As far as adjustment- if you need to shim in, just run a couple short beads or even just a few dots of weld on the back side of the vertical adjustment guide block- the part that screws up and down when you adjust the upper tension knob. Then sand em off til they are the right thickness.
I use tig welding and silicon bronze rod for stuff like this- it sticks really well to cast iron parts with no pre or post heat, and no warping. And the bronze makes a great bearing surface, too. Easy to add a thousandths of an inch this way, or an 1/8", if need be.
If you need to shim out, just sand that adjustment guide block a bit thinner- mine is about 3/4" thick, and maybe 3" x 3"- and its easy enough to grind or sand a bit off it, so it sits closer to the main casting, and therefore the upper wheel sits a bit prouder.
11:06 pm
June 10, 2010
Offline
Neil Gustafson;15349 wrote: Good Morning,
I was at Renato's one time and he was showing me "Friction Cutting". He gets old wood bandsaw blades from a neighbour (who doesn't use them because they are dull), mounts them in his saw "BACKWARDS", teeth pointed the wrong way. He adjusts the blade speed for the fastest it will go and cuts sheet metal like it was a hot knife in butter. He is using an older 'verticle' wood style bandsaw.
Neil
Neil I remember buying some bandsaw blades from Island Saw and I noticed the teeth were backwards, I was about to take them back when the light bulb came on, DUH!
Thanks for the offer of the car, I'm not sure how much I will really need it, I'll be staying a stones throw from Downtown Esquimalt. I'm sure that I will have to make a trip out to Buchart Gardens, as I'm taking my wife with me. I do look forward to spending some time with you guys. I'm pretty sure I will learn a lot.
11:10 pm
June 10, 2010
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Ries;15350 wrote:
As far as adjustment- if you need to shim in, just run a couple short beads or even just a few dots of weld on the back side of the vertical adjustment guide block- the part that screws up and down when you adjust the upper tension knob. Then sand em off til they are the right thickness.
I use tig welding and silicon bronze rod for stuff like this- it sticks really well to cast iron parts with no pre or post heat, and no warping. And the bronze makes a great bearing surface, too. Easy to add a thousandths of an inch this way, or an 1/8", if need be.If you need to shim out, just sand that adjustment guide block a bit thinner- mine is about 3/4" thick, and maybe 3" x 3"- and its easy enough to grind or sand a bit off it, so it sits closer to the main casting, and therefore the upper wheel sits a bit prouder.
That is the ticket, I never even thought of that. I don't have a TIG Welder but have been wanting one. I was even thinking of a scratch start, but figured it would be better to buy a proper machine.
4:02 am
NWBA Member
April 22, 2010
Offline
If you saw blades with the teeth backwards, the blade was just turned inside out.
Friction saw blades have regular teeth, facing the right way, although they have extra big gullets, usually.
You can get nickel rod for stick welding, its pricey, but it sticks really well to cast iron.
Or, you could just gas braze, with a brass rod and flux.
4:20 am
June 10, 2010
Offline
Ries;15355 wrote: If you saw blades with the teeth backwards, the blade was just turned inside out.
Friction saw blades have regular teeth, facing the right way, although they have extra big gullets, usually.You can get nickel rod for stick welding, its pricey, but it sticks really well to cast iron.
Or, you could just gas braze, with a brass rod and flux.
I did figure the blade thing out, I was young and it was my first bandsaw, I felt a little foolish afterwards but can laugh about it now. Funny thing is that when I tell that story there are a least a few people that are nodding in agreement.
I got a couple nickel rods given to me, so I'm going to have to plan a repair day. I just got in from cutting some 3" sq 4140 still on yesterdays blade, it is cutting nice true, I will continue and see how long the blade lasts. the only change is the feed rate, or at least more tension on the spring, there is not a noticeable change in how fast it cuts.
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