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What is causing my band saw to bog down even on the simplest cuts?

9K views 37 replies 15 participants last post by  contact_5037 
#1 · (Edited by Moderator)
Good Day All !
I have a 14" Band saw that I recently bought used, I installed a 3 tpi blade (new) & set it up according to the U tube videos I watched. It has a 3/4 h.p. motor. The saw is 26 years old.

Automotive tire Tire Font Gas Automotive wheel system


My problem is when I cut it bogs down really bad! It also sounds sick while it gets up to speed before I start cutting, then it sounds all right. Would this be belt tension? or something else?

Any input would be most appreciative!
 

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#3 · (Edited by Moderator)
It also sounds sick …. - sawdustmaker1961
Define sick?
Growl, screech, whine, clunk, etc….
Specifically where does noise originate from?

Band saw is pretty simple.

With blade removed, spin the upper wheel.
If tight, growls, grinds, makes any loud noises, or takes long time to coast to a stop; time for new bearings.

Turn on saw. Motor should not make any sick noises without blade either.

- Are belts loose or dirty? Are they slipping?
Could be belt tension issue, or need new belts.

Disconnect power. Remove the drive belt(s) between motor and lower wheel.
Reconnect power and turn on motor.
If it makes a soft click in 1-2 seconds, and then a subtle purr/whine, all is good.
If the there is no click, or it takes longer than 3-4 seconds to come to speed; might be issue with centrifugal switch or start capacitor.
If it growls, or screeches at all; is time for new motor bearings.

With belts removed, spin lower wheel.
Should be almost silent, spinning smoothly, just like upper wheel.

If nothing makes any noise with blade off, try a different blade. :)

My SWAG with 26 year old band saw is 1st belts, 2nd the bearings.

Best Luck!
 
#4 ·
You did not say what you were cutting. It should chew through an inch of Oak, but don't expect a 3/4 HP to re-saw 8 inches of hardwood at more than a snails pace. Mine will go right through, but it is a 3 HP.

WhyMe had good advice. Actually hard to test. Might consider replacing.

On the belt, if it squeals, it's too lose. If too tight, it will wear out the bearings. Usually an older belt will have set and a new belt will lower vibration. If a V belt, then an AX series Gates. Most use a multi-rib though.
 
#8 · (Edited by Moderator)
Way too little info - way too many possibilities. I would start with what Ken said - make sure it's wired correctly and you are providing the proper voltage. Symptoms do sound a lot like trying to run a machine wired for 240v on a 120v circuit. Then we can move on to figuring out the "Sounds sick" problem.

Cheers,
Brad
 
#14 · (Edited by Moderator)
New information:
It takes a really bad bearings to starve cutting power from 3/4" plywood cut.

Which bearings need replaced, and how bad are they?
Noisy bearings alone may not be the source of cut power loss, and only be making it worse.

Suspect a possible capacitor or centrifugal switch issue due issues with wimpy 3/4" cut.

How many capacitors are mounted on motor? 1, or 2?
A bad run capacitor will suck power from a motor.
A start capacitor is only used for first 1-2 seconds of start up, assuming centrifugal switch is working properly. Switch would have to be stuck on, for it to effect motor power. Would also over heat start capacitor, and/or trip breaker.

Make sure to inspect the motor carefully.

Best Luck.
 
#19 · (Edited by Moderator)
You are posting stuff faster than I can read it. LOL

Expect you will find a start capacitor inside the junction box on side of motor.
3/4HP often does not need large capacitor with a separate housing on side of motor.

IME - Lower wheel bearings are more likely to fail when too much tension is put on belt(s).

If lower wheel bearing is bad with 26 year old band saw of unknown repair status, and it were my 'new' saw;
would replace bearings in both wheels, lower shaft, and the motor.
If don't do it all now, history has taught me that I will be back inside the saw in 3-6 months replacing another bearing.

The shaft bearings in housing can be tricky to remove. The shaft and one bearing will come out the side with snap ring. Tap on end shaft with block of wood and hammer to press it out. Remove the shaft key first.
There is often a ridge in middle that prevents pushing both bearings out one side. The opposite side will have to pushed out from open side with screw driver/punch. If middle divider is short enough, and screw driver is not working; can use slide hammer to pull bearing out from center.

Cheers!
 
#21 · (Edited by Moderator)
Was there a key in the motor side shaft and pulley? Looks like it may have run for awhile w/o one.

Make a setup to pull from the threaded end of the shaft, snap ring off. A couple blocks of hard maple or maybe a couple of long reach sockets on the cast iron bearing boss of the housing up close to the O.D. of the bearing and a metal strap across the supports with a hole . Use a long bolt or piece of all thread an washer and nut. It would be better to pull with the nut on the thread than turning a bolt using the internal thread of the shaft. Put tension on it and if necessary tap on the opposite end of the shaft. There may be a internal sleeve between the bearings and it will come out as an assembly. Replacement, you are on your own.

That could be a split phase motor w/o a capacitor, or a capacitor could be under the wiring cover. if you checked the wiring you would have noticed it. Occasionally the capacitor can be mounted remotely such as in air-conditioning equipment. I would bet on a split phase motor. My 40 year old bandsaw with aluminum wheels originally had one. They don't have as much starting torque so with a light inertial load they are smoother starting.

I see you found the capacitor while I was typing. Are you sure you verified that wiring configuration is not for 220-240 volts, maybe you need some help in that area.
 
#24 ·
OK. Don't shoot me for saying this but I spent over a year trying to put lipstick on a 14" pig. I ending up buying a new saw. IMHO bandsaws are unique in that they have sooooo many moving and adjustable parts that make it hard to tune them, especially when it's an older saw with older parts. The combination of multiple older and worn parts just compounds any existing problems.
 
#25 ·
OK. Don t shoot me for saying this but I spent over a year trying to put lipstick on a 14" pig. I ending up buying a new saw. IMHO bandsaws are unique in that they have sooooo many moving and adjustable parts that make it hard to tune them, especially when it s an older saw with older parts. The combination of multiple older and worn parts just compounds any existing problems.

- Andybb
Odd, I find them a very simple machine. But then again, I used to repair Siemens cold fusion laser printers, Line printers and 9-track tapes. What I gather from following these threads, is cheap machines built very poorly, the ubiquitous broken upper mount on "Delta" and clones, or just plain abuse.
 
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