24" Minimax bandsaw bogging down....

[dirk martin]

I'm running a new carbon steel blade on my MM24 Minimax. 2TPI Hook, and 1".
Resawing 6" cherry, bogs the 5hp motor, if I feed it too fast.
If I keep bogging the motor for 4 or 5 boards, the internal breaker on the saw's switch trips, and I need to let it sit for 15 or so minutes, before it'll turn back on.
The saw's about 7 years old.
Does that seem right?

My sister resaws wider boards than that, on her 24" Grizzly saw, and she says it never even thinks of bogging down.
She's resawing with a 1/2" blade, at 3TPI.

[Jamie Buxton]

No, that's not right. With a five hp motor and a sharp blade, 6" cherry should not slow down the saw.

Are you seeing burning on the cherry? If you're seeing a lot of burning, that suggests the blade is dull.

Can you put a voltmeter on the 230 volts? It should not drop more than a few volts when the saw is running.

Does the plug feel real hot? If it gets hot, it isn't making good contact to the outlet.

Can you spin the wheels by hand? (Pull the plug before you reach inside the saw.) Maybe the blade guides are set too tight.

[Matthew Hills]

Is your blade facing the right direction? (seems like a silly question, but when I was buying a used planer from one guy, I asked how his laguna bandsaw performed as the blade looked a little funny facing up; and I've done this with a circular saw before)

Matt

[J.R. Rutter]

I have an old 20" saw with a 1-1/2 HP motor, which is pretty marginal by today's standards. I struggled to resaw using 3/4" + blades regardless of tooth count and style. I found that a thinner blade worked much better for resawing. While the beam strength is lower, if the saw and guides are tuned up, a more flexible blade works just as well. These days, I just keep a 1/2" carbide tipped blade on for everything except tight radius cutting.

[Rick Fisher]

Dirk.

I have a 24" SCM Bandsaw with a Baldor 5hp motor and it won't bog down at all. Period. Its spooky. I run a 1.3 tpi Carbide blade and had run a Lennox Tri Master 3 tpi.

I have resawn 2x10 Sapelli, 2x12 Wenge, and 2x10 Zebrano.. Loads of 2x10 Maple. Never even makes a funny sound.. I am convinced that the blade would fail first..

I have always felt I should have put a 3hp motor on my saw when I restored it as 5hp is so crazy over powered..

[Stephen Cherry]

Maybe check the amps and volts at the motor.

It seems like that would be the first place to start troubleshooting.

Is the belt slipping?

[Jim Andrew]

What happens if you just open the door and rotate the bandwheels by hand? Is there a lot of resistance?

[Ken Fitzgerald]

I have a MM-16 and I have sawn 13" apricot that was hard as rock with a 3/4" blade sent with the saw. In short, your saw should easily cut that.

I'd check the incoming power, the brushes on the motor and bearings on the two wheels. Something is causing the motor to draw too much current and trip the circuit breaker. It's not too unusual to have to wait for the breaker to cool down before it will reset properly.

[Erik Loza]

...check the amps and volts at the motor...

This ^^^

If motor internal protection is tripping, the motor is drawing too many amps under load. I would get out the voltmeter and see what you are actually getting at the switch. If the voltage is low, that would explain it.

Good luck,

Erik Loza
Minimax USA

[dirk martin]

No, that's not right. With a five hp motor and a sharp blade, 6" cherry should not slow down the saw.

Are you seeing burning on the cherry? If you're seeing a lot of burning, that suggests the blade is dull.

Can you put a voltmeter on the 230 volts? It should not drop more than a few volts when the saw is running.

Does the plug feel real hot? If it gets hot, it isn't making good contact to the outlet.

Can you spin the wheels by hand? (Pull the plug before you reach inside the saw.) Maybe the blade guides are set too tight.

First, a little more info.
I thought the blade was new, but just found out about 100 linear feet of 6" ash had been resawn with this blade.

There is no burning on the cherry at all.
The plug stays perfectly cool.
The wheels spin freely, the guides are not to tight.

[dirk martin]

Is your blade facing the right direction?

Matt

Yes it is.

[dirk martin]

Maybe check the amps and volts at the motor.

It seems like that would be the first place to start troubleshooting.

Is the belt slipping?

I have a VOM. How do I check the amps and volts at the motor?
The belt is not slipping.

[dirk martin]

This ^^^

.... I would get out the voltmeter and see what you are actually getting at the switch.....


Erik Loza
Minimax USA

Can someone be more specific as to how I do this?

[HANK METZ]

Assuming it's been working well for you the last 7 years, I'd kinda suspect either the start capacitor has gone bad or the centrifugal switch circuit is malfunctioning- I assume single- phase supply use. With the start windings remaining in- circuit, it'll go into thermal cutout in about 5 minutes or so. unbelt it and let it free run and see if the motor case gets hot, if it's a winding problem she'll cook and trip- simple, easy, no meter needed first diagnostic step, if no problem then get more technical with the troubleshooting.

[Stephen Cherry]

Assuming it's been working well for you the last 7 years, I'd kinda suspect either the start capacitor has gone bad or the centrifugal switch circuit is malfunctioning- I assume single- phase supply use. With the start windings remaining in- circuit, it'll go into thermal cutout in about 5 minutes or so. unbelt it and let it free run and see if the motor case gets hot, if it's a winding problem she'll cook and trip- simple, easy, no meter needed first diagnostic step, if no problem then get more technical with the troubleshooting.

This sounds like a plausible explanation. And a great first step.

My troubleshooting strategy is to eliminate as much as possible, to measure voltage I would take off the motor connection cover, and measure it right at the motor. For amps you need a current clamp. I have one of these:

http://en-us.fluke.com/products/elec...id=-O5XMxcNF2k

But you can also use an accesory current clamp with a vom, you just clamp onto one of the legs, set up the current meter to match the ratio, and read the amps. Usually, one milliamp on the meter equals one amp through the clamp. Also, if you are not comfortable with electrical, it's no shame in asking for help.