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View Full Version : Bandsaw - More of my stupidity



derekg
03-17-2012, 07:08 PM
My bandsaw wasn't cutting too well after I put it back together. After many passes of 3/16" steel plate, I noticed all the teeth were facing upwards. Very strange, but since I never really looked while putting on the blade before, figured maybe there were different rotational directions or something when you order the blades. Yesterday I took it to my buddy's house for him to use and pointed out the upside down teeth. He looked at me, told me I was an idiot, and explained the blade was "inside out", like a shirt. After flipping the "innards" of the blade to the outside and reassembling, the teeth now point in the correct direction and it cuts much better :)

I love home shop machining. You learn something new every day!

Derek G

Doozer
03-17-2012, 07:11 PM
"Dough!"
--Homer Simpson

SteveF
03-17-2012, 07:19 PM
You had the teeth facing upwards and it still was able to cut 3/16" steel plate???


Steve

darryl
03-17-2012, 07:27 PM
Hm, actually that's a special blade with soft teeth. With the action of cutting the 3/16 plate, which was probably OSU99 (outer space unknowingnum) the teeth turned upwards. When you reversed the blade after that, you end up with sharp teeth again. Right? :)

Ridgerunner
03-17-2012, 07:31 PM
In the late 60's a friend gave me a piece of steel from a building they were working on. It was COR-TEN. I just bought a Craftsman drill press and was anxious to give it a try. I burned up about 5 drill bits and figured this new type steel must be made from diamonds. Then when shutting off the drill press I realized I had wired the motor wrong and the bits were spinning backwards.

Dr Stan
03-17-2012, 07:53 PM
I noticed all the teeth were facing upwards.

Derek,

Don't feel too bad, I've seen experienced "professional" machinists make the same mistake only with 1" wide expensive blades for a horizontal cut off saw. :eek:

BTW, I was running a Lucas boring mill using a 24" dia carbide insert face mill and had just indexed all the inserts. Oops, turned the spindle on the wrong direction. :(

sasquatch
03-17-2012, 08:31 PM
Back years ago i had a guy working for me that had a drinking problem.

After not showing up for two days he finally came in one morning and knowing i was pi##ed off at him for his absence again, he got right to work quickly using a jig saw cutting some parts i needed.

I noticed him pushing on the saw but he wasn,t making any headway, then he noticed he had the blade in backwards.

He looked up at me and i looked at him and we both busted out laughing!!

The rest of the week he was a good worker. Couldn,t help but like the guy.:D

R_Audano
03-17-2012, 09:15 PM
I had a very conservative machinist friend whom I spent Saturdays with during my Younger days. He was an amazing Machinist that almost always offered sound advise based from experience....

Long story short; He was so conservative that he would cut bad sections from his saw blades and cut a new strip from the coil. it was nothing to have 3-4 weld joints on one blade and I always harassed him for it. One Saturday he was cutting some 1" 1045 bars and complaining the saw was just taking entirely too long and he supposed he just needed to make an entire new blade! I was crouched down by the machine and noticed the teeth were facing the wrong way! He was completely embarassed and stated that in 30 years of teaching the trade and his entire active life in the shop had never had that happen!!!

Guess it happens to the best of us.

Kernbigo
03-18-2012, 08:00 PM
If you want to cut sheetmetal run the blade backwards they cut great

Doozer
03-18-2012, 08:12 PM
Cor-ten also known as A588 is just A36 with copper added to the steel alloy to make it a weathering steel. It is not any harder to drill than any hot rolled.
You can run the blade forward or backward when friction sawing. That is if your saw has the speed and power to run it. I have a DoAll set up to friction saw, and it will cut hard files in half like candy.
--Doozer

T.Hoffman
03-18-2012, 08:31 PM
The blade welder on our saw is finicky and tempermental to work with.

It is always a small victory when you produce a nice , durable weld.

I was so proud of a dandy first attempt weld and then when I was installing it I realized I made the blade going the wrong way.....

Toolguy
03-18-2012, 09:52 PM
All you have to do is twist it around and it's going the right way. No need to cut and reweld.

T.Hoffman
03-18-2012, 11:01 PM
At the time I was so mad that THAT never occurred to me.
Lessons learned...

ak95xj
03-19-2012, 01:18 AM
i worked in a factory that made semi trailer chassis a few years ago...took a big piece of 3/8" plate out of the dumpster.dont know anything about the steel ( I was only there 3 months) except that we mig welded it with 80-s wire..i cut some pieces in my 4x6 bandsaw this weekend, noticed it seemed longer usual to cut..put a piece of 1" in it right after that and it cut down on a nice 45 degree angle and stalled halfway through.whatever that 3/8" stuff is it smoked my blade..

Black_Moons
03-19-2012, 02:54 AM
At the time I was so mad that THAT never occurred to me.
Lessons learned...

Haha, you think that sucks? I recall someone braging about how they got paid good money to snap thier bandsaw blades... And reweld them... Going through holes in work!

Yes, they had to snap and weld the blade (or maybe he just brazed/unbrazed it?) for every thing he cut (From the inside anyway)

Boostinjdm
03-19-2012, 03:58 AM
i worked in a factory that made semi trailer chassis a few years ago...took a big piece of 3/8" plate out of the dumpster.dont know anything about the steel ( I was only there 3 months) except that we mig welded it with 80-s wire..i cut some pieces in my 4x6 bandsaw this weekend, noticed it seemed longer usual to cut..put a piece of 1" in it right after that and it cut down on a nice 45 degree angle and stalled halfway through.whatever that 3/8" stuff is it smoked my blade..

On a semi trailer, it could have been Domex or AR. I haven't tried to saw any, but both are hard to bend shear or grind.

Steve Seebold
03-19-2012, 04:20 AM
OOPS! OOPS!

malbenbut
03-19-2012, 04:50 AM
Thats nothing!
I put the batteries in my clock the wrong way round and it ran backwards. When I got out of bed it was yesterday.
MBB

gwilson
03-19-2012, 08:49 AM
My HLVH lathe starts up so fast I have twice turned it on in reverse and tried to cut when not paying enough attention. When it's running fast,you can't tell which way it's running.

I turn the lathe on in reverse to help screw in the collets,and have forgotten to put it in forward .

Haven't put a blade on upside down,though.

I recall a story about a customer at Sears who returned a blade with backwards teeth. The clerk searched the other blades till he found one with the teeth going the right way for the customer!!

sasquatch
03-19-2012, 09:14 AM
At SEARS yup, i,m not surprised, or at a number of stores with clerks who have no clue!!:o

David Powell
03-19-2012, 09:36 AM
Then we can learn from them and carry on. Its when we get upset and angry about them that perhaps we should consider whether we are well enough to carry on in our workshops. I have only known a handful of home machinists who have deteriorated so much that they could not continue to work in their shops. If you know one , well give him a hand to do what is now difficult for him.You may have a lot of fun and learn a lot helping ' one of the old boys' finish his last project. regards David Powell.

Martin0001
03-19-2012, 09:39 AM
My bandsaw wasn't cutting too well after I put it back together. After many passes of 3/16" steel plate, I noticed all the teeth were facing upwards. Very strange, but since I never really looked while putting on the blade before, figured maybe there were different rotational directions or something when you order the blades. Yesterday I took it to my buddy's house for him to use and pointed out the upside down teeth. He looked at me, told me I was an idiot, and explained the blade was "inside out", like a shirt. After flipping the "innards" of the blade to the outside and reassembling, the teeth now point in the correct direction and it cuts much better :)

I love home shop machining. You learn something new every day!

Derek G
Seller should take it to back room, invert it, bring it back, explain that the one with tooth pointing the way you want is much more expensive and charge you a difference.:)