Portable band saw problems

H

Happychicken

Joined
Nov 14, 2018
Messages
176
hi all I have a jump or a knock in the bandsaw that speeds up as saw speeds up. It happens with all the blades I have tried and is especially noticeable with the Morse blade I am using now. Any ideas out there before I take it to repair center.
 
I have had this happen with some blades and there was nothing wrong with the saw. Before taking the saw to the repair center, I would inspect the blade and look at the weld. The bumpy blades I've seen always had an issue at the weld. Some had a kink, some did not have the weld ground, some were even welded together with an offset. I have had varying success fixing bumpy saw blades by hammering them to straighten out a kink. I've fixed one blade by grinding the weld flat with a dremel.
 
a bump can also be caused by one or two missing teeth. that is why i stopped using 14 teeth per inch, and now i use 18 teeth per inch. the less teeth per inch, the more likely you will break one off.
 
What kind of saw do you have?

Does it bump only while you're cutting, or all the time? Does it bump without any blade on the saw? Does the top wheel turn smoothly without a blade on it? Could be a bad bearing/bushing, or it could just be some debris in/behind the wheels. You can also try wiggling the blade wheels side to side. If there's a lot of wiggle or play in them, then you likely have a worn bushing or bearing (and/or shaft) which may be causing a knock.

A vid might help, but I'd try cleaning everything out really well, including taking the wheels off and cleaning/inspecting under them. Clean the shafts really well and re-grease.

Here's a video that might help (Not mine, just found it with a quick search):
 
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Well it was not the bushings but the springs That I believe are for the blade tension seemed very loose I tightened up the t 30 bolts on the bracket that tightenes the springs and put the top wheel back on. Less slop left and right for the wheel but it was harder to pull the lever when putting the blade back in. Can these be over tightened? Will the blade explode?
Thanks!!!!!!!
 
Happychicken said:
Well it was not the bushings but the springs That I believe are for the blade tension seemed very loose I tightened up the t 30 bolts on the bracket that tightenes the springs and put the top wheel back on. Less slop left and right for the wheel but it was harder to pull the lever when putting the blade back in. Can these be over tightened? Will the blade explode?
Thanks!!!!!!!
Click to expand...

The blade won't explode, though you might wear your bushings out a little faster if it's super tight. I imagine it'd take much more force than you'd think even to break the weld on the blade.
 
Thanks for the fast response!
The last two blades I have had on the saw have broke. Either I am pushing to hard or something isn’t set right with the saw
 
Happychicken said:
Thanks for the fast response!
The last two blades I have had on the saw have broke. Either I am pushing to hard or something isn’t set right with the saw
Click to expand...
What kind of blades are you buying? I can't remember ever breaking a porta-band blade. I've tweaked some pretty hard, or busted some teeth off, but never pulled a blade apart. Are they breaking at the weld?

Make sure you're buying quality blades, and let the blade do the work. Buy a tooth count (TPI) that leaves at least 2 to 3 teeth in the stock at all times. Also, I like to "break in" my blades. This is usually talked about for horizontal or larger vertical saws, but you can do it with porta-bands too. Set the blade to the slowest speed and get a piece of scrap to slowly push into the blade. Don't force it. You just want to let the saw lightly cut, in order to round the very points of the teeth off. Make a foot or two worth of cuts, and you should be fine. A little cutting lube can help too. I try to keep it on the outside of the blade so it doesn't get on the wheels/tires.

If you keep breaking blades, you may want to think about decreasing your tension a little bit.
 
Thanks I have the blades break usually after I have used them after a while.
The last one the blade started wobbling a bit the broke.
Thanks for all your help!
 
Hmmmm. Almost every one of my blades has broken on me. I thought that's how you know it was time to change it! I've tried Lennox, Milwaukee, Starret, and never "saw" any meaningful difference in life span so I just use the cheapo harbor freight blades and change them often.
When I start felling the bump I examine the blade and usally have some teeth knocked out or a break in the blade (never at the weld) and try to catch it before it pops on me.
Maybe I need to look into adjusting my tension as well.
 
I should probably add that I don't tend to "use them until they break", but swap them out as soon as I start popping teeth off or feel like they starting to dull. Once they get past a certain point, the overheat the steel and make it 10x harder to cut.
Usually, when I swap a blade, it'll still "cut", but it takes way more effort than I'd like.
 
How many knife blanks do you think before swapping them out?
Do you feel a vertical/horizontal saw would be and upgrade? I see one at harbor freight for like 250 but I have never had much luck with anything I bought there. But looking at most vertical/horizontal saws they all look suspiciously similar...
 
Happychicken said:
How many knife blanks do you think before swapping them out?
Do you feel a vertical/horizontal saw would be and upgrade? I see one at harbor freight for like 250 but I have never had much luck with anything I bought there. But looking at most vertical/horizontal saws they all look suspiciously similar...
Click to expand...

It depends on what I'm cutting. Stainless is much harder on them, but if I'm just cutting some 1095, if I get a good break in on the blade it'll last me for a good while. At least a couple dozen blanks. Granted, I'm also cutting pin stock, micarta and g10, and whatever else comes up in the mean time. If I'm cutting thicker, larger blanks, it's a little less too. Honestly, I don't keep track too terribly well, and now that I think about it, I need to order another pack of blades. :)

A vertical/horizontal is nice, as the blades do last a bit longer (though they're also more expensive), and you get a little more room to play around. I've heard good things about the HF V/H saw. The table it comes with is apparently junk, but they're easy enough to make. Craigslist may also be your friend, as I see them on there from time to time for half price, or if you're lucky, you'll find a better used industrial grade saw for about the same price as a new HF saw.
 
Hmm... everything I am cutting is mostly stainless nitro v or aeb-l. I was cutting some high carbon stuff before and it cuts much faster.
I Might just be using the blades too long expecting too much...
 
Drew Riley said:
I should probably add that I don't tend to "use them until they break", but swap them out as soon as I start popping teeth off or feel like they starting to dull. Once they get past a certain point, the overheat the steel and make it 10x harder to cut.
Usually, when I swap a blade, it'll still "cut", but it takes way more effort than I'd like.
Click to expand...

Pretty much what we do.

Happychicken said:
How many knife blanks do you think before swapping them out?
Do you feel a vertical/horizontal saw would be and upgrade? I see one at harbor freight for like 250 but I have never had much luck with anything I bought there. But looking at most vertical/horizontal saws they all look suspiciously similar...
Click to expand...

I guess you could say we use these little guys on an industrial scale. The wife cut out 85 AEB-L blades (two hours on Thursday and three hours yesterday). Two blades and the second one is still on. I've found that the blades vary even with in the same brand. some will last a long long time and others just a few blades ya just never know. When cutting blades I always have extra saw blades handy. I could afford a larger saw and have the room. don't have the need. Lil portaband does everything. Gave away my 14 inch bandsaw wasn't using it anymore.
 
Horsewright said:
Pretty much what we do.

What kind of portaband do you have? That sounds different from the experience I have been having- what blades do you use?
Can you write a book on how I can get my wife to cut my blanks out?


I guess you could say we use these little guys on an industrial scale. The wife cut out 85 AEB-L blades (two hours on Thursday and three hours yesterday). Two blades and the second one is still on. I've found that the blades vary even with in the same brand. some will last a long long time and others just a few blades ya just never know. When cutting blades I always have extra saw blades handy. I could afford a larger saw and have the room. don't have the need. Lil portaband does everything. Gave away my 14 inch bandsaw wasn't using it anymore.
Click to expand...
 
Dewalt portaband I prefer Lennox but use Milwaukee most of the time as there is a Home Depot across from the ranch and those are the blades they carry.
 

Yesterday. On your own on the training! I've written a book but not on wives!

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