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Discussion Starter #1
I was cutting 2x2x1/8" angle iron and it was taking 3 minutes per cut. I had it in the saw like this ^. I'm using a 14tpi blade running at 200 fpm. It's a pretty new blade too.

I don't know what to base this cut time on, but it seems real slow to me. What should I be expecting?
 

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I was cutting 2x2x1/8" angle iron and it was taking 3 minutes per cut. I had it in the saw like this ^. I'm using a 14tpi blade running at 200 fpm. It's a pretty new blade too.

I don't know what to base this cut time on, but it seems real slow to me. What should I be expecting?
That seems excessive. Who makes the blade and what saw?
 

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The speed has more to do with the machine than anything else,,
If you are using a Porta-Band, the 3 minutes is fine,,

This saw, with a 5-8 variable pitch blade, will cut it a mite faster!! :laugh:



The jet saw will cut the 2X2x1/8 angle with the speed controlled only by the hydraulic drop rate cylinder

The saw will cut it in under 30 seconds.

I have an old 4X6 saw, it will cut it in maybe 1.5 to 2 minutes,,, it looks like this,,,

 

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I was cutting 2x2x1/8" angle iron and it was taking 3 minutes per cut. I had it in the saw like this ^. I'm using a 14tpi blade running at 200 fpm. It's a pretty new blade too.

I don't know what to base this cut time on, but it seems real slow to me. What should I be expecting?

'Sounds like you may have cut too fast and dulled the blade. That 1/8" thickness shouldn't be such a huge challenge. Was your very first cut any quicker than the last? I would try something closer to100 fpm if speed is adjustable. A bit of oil lube wouldn't hurt.
 

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I can not remember the #'s off the top of my head,,, but,,,
the weight of the blade at the cut is critical,,

I had to buy a scale to measure the weight.

If the weight is too light, the teeth are just rounded over,, they MUST cut.

You might need to do some "saw tuning",,,,
 

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Discussion Starter #7
'Sounds like you may have cut too fast and dulled the blade. That 1/8" thickness shouldn't be such a huge challenge. Was your very first cut any quicker than the last? I would try something closer to100 fpm if speed is adjustable. A bit of oil lube wouldn't hurt.
They were all the same speed, it didn't slow down. I used WD-40 cause that's what I had. I've been meaning to grab a couple of blades, I don't have any spares. I'll put a new blade on it, slow it down and try it again.
 

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Discussion Starter #8
I can not remember the #'s off the top of my head,,, but,,,
the weight of the blade at the cut is critical,,

I had to buy a scale to measure the weight.

If the weight is too light, the teeth are just rounded over,, they MUST cut.

You might need to do some "saw tuning",,,,
Thanks for the tip. I'm looking up youtube videos on this saw.
 

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Bandsaw surface feet is nearly identical to other non carbide speeds such as milling cutters. A general rule of thumb is 100 surface feet for low carbon steels.

I have tried to utilize online calculators for production sawing estimations and the surface footage is easy but references to the feed rate can vary several hundred percent from slow to fast and they are disclaimed with notations of "for longest blade life, for average blade life and for reduced blade life".

Step 1 is set surface footage.
Step 2 is if using a new blade you must break it in by running reduced feed for at least several minutes.
Step 3 is visual observation of the chips being produced to adjust optimum feed rate. (There are close ups on line of properly shaped saw chips)
Step 4 is maintaining the correct feed rate when sawing through profiles that change contact length of the blade such as your angle iron. It is important not to race through the thin contact zones as you will cut a far heavier chip.

Be aware that when cutting hot rolled products such as angle iron the surface of the material may be substantially harder (scale) than the rest of the chemistry and this kills the life of tools.

I would estimate that on a rigid band saw using coolant or oil your cut should not take longer than 30 seconds and could be as fast as 20 without damaging the blade.
 

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To make sure I'm not making a simple mistake, when you say surface feet, that is referring to feet per minute?
Yes sir.
 

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I used WD-40 cause that's what I had.
After replacing the blade, ditch the WD-40(just as soon use Budwiser):mocking: and get some Sawzit cutting fluid. :good2:
 

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Think I should step up to 18 tooth?
The other direction,,, you need like 8 or 10 TPI blade,,
The blade is touching about 3/8" of steel. If you have a 18 TPI blade, then almost 7 teeth are touching.

If there are too many teeth per inch, the gullets of the teeth will fill, then just drag along on the part.
If the teeth are dragging rather than cutting, they will get dull.
 

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For tooth pitch when doing general cutting it is always a compromise. Finer pitch (more teeth per inch) is smoother and easier to control but when length of engagement gets long then you have a much smaller gullet for the chips to escape in.

You will have to make a guess about the type of cross sections you expect to encounter in the cut for your projects to select "one blade".

We use a seven pitch blade on our production saw at work. It is a 1-1/4 tall blade and the machine has hydraulic feed and can digest a 13 inch round.
We keep some fine pitch blades for use when cutting small diameter rounds, thin cross section shapes and tube products below .250 wall thickness.

Two blade plan is a good one.
 

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Discussion Starter #18
I would say the majority of what I will cut will be >=.125 wall angle, flat, channel, square and round tube. 3" or less in the long direction. .25 wall would not be out of the question. At the small quantities that I will be buying in, I'll just have the supplier cut anything real heavy duty.
 

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FlyWeight

After replacing the blade, ditch the WD-40(just as soon use Budwiser):mocking: and get some Sawzit cutting fluid. :good2:
Thanks for Sawzit information. That is a very interesting site and I read the 11 page info paper they had about their cutting products and I would reccomend it to anyone needing to cut metal!
Leo
 
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