Is my bandsaw losing power?

[Edwin Santos]

Hi,
I asked a question a while back about thrust bearing activity when cutting on a bandsaw. This question has nothing to do with set up of the bearings.
Here's what's happening, when I start a more demanding cut (like a 4" or more resaw), the cut starts fine for an inch or two with the thrust bearing touching now and then. Then things change and I need to use more feed pressure, the rate of cut slows down dramatically and the thrust bearing starts spinning like a banshee, and this will continue until the cut ends. The motor never stalls and I have never tripped the breaker.
I think something is wrong. The saw is a Laguna 16SEC made by Meber with a 2.5hp motor. It's plugged into a 20a 240v outlet with a twist lock plug which says L6-30P on it.

I tested the receptacle with a multi meter and it tests at 240v.

I have had this saw for about 20 years, and remember it cutting with much more ease. Changing to a brand new blade makes no difference. Could this be a problem with the motor? Or the electrical service?

Thanks for helping me diagnose it
Edwin

[andy bessette]

What b lade? Could it be too fine a tooth pitch?

[Bill Dufour]

I think you are in Brazil? is this single or three phase? I wonder if you have lost one phase into the motor.
Bill D.

[glenn bradley]

My first check would be tooth count. Once spoil cannot be ejected rapidly enough, the impact on feed rate and cut is very apparent.

[Edwin Santos]

Hi,
Thanks for the replies. I'm in the southwest US, not Brazil. It's a single phase motor. The blade I am using is a 1/2" 3tpi Lenox tri-master, but when I tried a brand new blade, I switched to a never before used carbon steel 1/2" 3tpi.
Maybe my memory is playing with me, but I recall being able to saw with much greater ease and no particular stress on the thrust bearing like I'm experiencing now.
Oh, and I recently replaced the belt thinking an old worn belt might be a contributor, but the new belt hasn't made a difference.
Edwin,

[John TenEyck]

A 1/2"x 3 tpi blade won't cut all that fast in 4" wood in any case but it sounds like yours is loading up with sawdust, as Glenn suggested. I'd try a wider blade if your saw can handle it with a low tooth count. Also, do you have dust collection to handle the sawdust?

John

[Ken Fitzgerald]

I agree with Glenn and John. If your bandsaw was losing power, it would do it from the beginning of the cut through to the end of the cut of 4" tall material. The fact that it starts easy and then requires more pressure after you are into the wood indicates the blade isn't clearing the sawdust and it's loading up the cut causing more friction requiring more pressure to feed it.

[Edwin Santos]

A 1/2"x 3 tpi blade won't cut all that fast in 4" wood in any case but it sounds like yours is loading up with sawdust, as Glenn suggested. I'd try a wider blade if your saw can handle it with a low tooth count. Also, do you have dust collection to handle the sawdust?

John
Hi John,
The lowest tooth count blade I have is a 3/4" variable 2/3 tpi. I just tried it and the cut behavior is the same. I don't feel this particular saw is suited for a blade wider than 3/4". I do have a centralized Oneida dust collector and the 4" hose is connected to the port just under the table. I'm tensioning pretty much along the saw's scale indicator. Maybe I will try cranking it higher.
Edwin

[David Kumm]

Crank the tension 1/2 turn and experiment with the Trimaster. You won't overtension that blade, just be sure the spring is not bottomed out. If not, go another 1/2 turn. Indicators on the saw mean nothing other than reference from day to day and a 1/2" blade can deflect pretty easily under lower tension. It is possible that the spring has weakened and that is why the saw used to cut better. If that doesn't help, back to square one. Dave

[Lee Schierer]

I had an very similar problem with my 14" Delta Band Saw a few years ago and a while after I had it set up and running. It would bog down when making a resaw cut. I thought I needed more horsepower, a better blade, etc. What I ended up finding was that the belt was loose. I tightened the belt just slightly and it was walking right through boards that previously had stalled the cut. Before you go nuts checking things, check the belt tension.

[Jebediah Eckert]

I had a similar problem recently and it was a head scratcher. My issue was belt tension. I originally went with that thought and put a new belt on. Worked great then the problem returned. Belt needed to be tightened again, either the setting moved or the new belt stretched. My saw did the exact same thing, fine the first inch or two then it bogged down. Makes sense now the belt was slipping. Maybe double check the belt tension?

Edit:

I guess Lee and I were typing at the same time.......

I also have a Laguna.

[Charles Lent]

Tighten your motor V Belt and all should be OK. You have already eliminated almost everything else. Usually, it just takes loosening the motor mount bolts, moving the motor a little until the belt is tighter, and re-tighten the motor mounting bolts.

Charley

[Edwin Santos]

Thank you gentlemen, this was good advice on the belt being the source of my trouble. I had a new link belt lying around that I've been meaning to try out. So I installed it and did my best to adjust the motor so the belt was good and tight. It seems like the saw has a lot more power. It's not straining through the cut anymore, you can feel less stress on the saw. I'll keep an eye on it because I've heard that link belts need another tightening after break in.

As a bonus, the link belt reduced vibration and noise quite a bit.
Edwin

[David Kumm]

Keep in mind a link belt is a fractional HP belt so your application isn't ideal for the long term. Glad you got it sorted out and it ended up being a cheap and easy fix. Dave

[Edwin Santos]

Keep in mind a link belt is a fractional HP belt so your application isn't ideal for the long term. Glad you got it sorted out and it ended up being a cheap and easy fix. Dave
Dave,
Thank you for educating me on this. I had no idea. Now that I've I.D'd the problem, I'll have to go out and get a conventional V-belt when I get a moment. Do you have an opinion about cogged vs. conventional type v-belts for this application? Why are link belts so heavily promoted in woodworking circles?
Edwin

[David Kumm]

Probabaly a VX belt but it depends on how different the pulley diameters are and the distance between them. I have a motor shop that sells Optibelts and they give me advice. Dave

[Lee Schierer]

Keep in mind a link belt is a fractional HP belt so your application isn't ideal for the long term. Glad you got it sorted out and it ended up being a cheap and easy fix. Dave

Not necessarily. I have a link belt on my 1-1/2Hp saw and it has been working just fine for 20+ years. Link belts are commonly used to replace any similar sized v-belt in industrial settings.

[lee cox]

I had a problem on my Minimax 4500mm 18 inch where the motor belt was rubbing the large bottom wheel just slightly. It was enough to cause the motor to run hot. I added washers to the motor to push out the motor so it would not rub. What a difference now. My motor runs much cooler and the saw cuts better.

[David Kumm]

Anyone feel free to correct me as I'm wrong a lot, but my understanding with link belts is that in order to transmit higher torque applications, they need higher belt tension than V type belts. That puts more load on the bearings. Not a big deal on the slow moving wheel side but more so on the motor bearings. Machines now run fairly small lighter load bearings so that may or may not be an issue. They do mute vibration or alignment issues and are often easier to install but I've never heard of them as a superior choice for my type of machines ( although I do sometimes use them ). Dave

[Edwin Santos]

Not necessarily. I have a link belt on my 1-1/2Hp saw and it has been working just fine for 20+ years. Link belts are commonly used to replace any similar sized v-belt in industrial settings.

Lee,
After you first installed your link belt, did you have to come back and tighten it due to break in stretching?

[Lee Schierer]

Lee,
After you first installed your link belt, did you have to come back and tighten it due to break in stretching?

My link belt is on my table saw and the motor weight provides the tension. Link belts do relax a little after they have run for a bit, so it is a good idea to re-tension them after a few hours of running.

[Edwin Santos]

My link belt is on my table saw and the motor weight provides the tension. Link belts do relax a little after they have run for a bit, so it is a good idea to re-tension them after a few hours of running.

Lee, indeed after a couple of day, it seemed to me that the link belt relaxed some so I moved the motor and re-tightened it. The saw seems to have regained all it's lost power so my experience is similar to yours. Time will tell how the link belt does for durability.

Edwin

[glenn bradley]

Dave,
Thank you for educating me on this. I had no idea. Now that I've I.D'd the problem, I'll have to go out and get a conventional V-belt when I get a moment. Do you have an opinion about cogged vs. conventional type v-belts for this application? Why are link belts so heavily promoted in woodworking circles?
Edwin

I run link belts on my bandsaw and other tools since day one. Many of them of been in service for over a decade with no problems. I’m not sure where the bad rap on these belts comes from. They are used in industrial settings under very harsh conditions. However, we all have our opinions based on our experiences and these very :-).

[Edwin Santos]

I run link belts on my bandsaw and other tools since day one. Many of them of been in service for over a decade with no problems. I’m not sure where the bad rap on these belts comes from. They are used in industrial settings under very harsh conditions. However, we all have our opinions based on our experiences and these very :-).

Glenn, I've been impressed with the link belt I installed a few days ago. Contrary to my other message, I'm going to leave well enough alone, and see what happens over time. All I can say is my power is back and the vibration is reduced, so I don't seem to have a problem to solve. It's helpful to hear others' experiences, thanks

[Curt Harms]

Probabaly a VX belt but it depends on how different the pulley diameters are and the distance between them. I have a motor shop that sells Optibelts and they give me advice. Dave

My understanding is that VX (notched) belts don't take a set like the link belts at a lower cost and may run quieter if that matters. One place the link belts shine is they're easy to adjust the length.

[Lee Schierer]

My understanding is that VX (notched) belts don't take a set like the link belts at a lower cost and may run quieter if that matters. One place the link belts shine is they're easy to adjust the length.

Link belts reduce vibration because they don't take a set like conventional v-blets. The VX belts are also a good choice.