Bandsaw TPI - machine struggling with coarse blades.

[pren]

Hi.

I've had an Axminster AWSBS2 bandsaw for a few years. I recently bought a 3 TPI, 12mm premium blade from Tuff Saws for deep (3") ripping. Well, that's deep for me, anyway! :lol: Really fantastic service and super sharp blades.

I've noticed since fitting it, the saw struggles with cuts it used to be able to make with no problems. It slows tight down and stops if I put anything more than the gentlest feed pressure.

I think I used to have a 6TPI blade for those cuts. Is it likely that the saw isn't powerful enough to cut with a 3 TPI blade? I don't have any 6tpi's left to check.

 

[Steve Maskery]

Hi Pren
Are you sure it is tensioned correctly? 3TPI should be better, not worse!
S

 

[iajon69]

Hi Bryn

As Steve said, the 3tpi should be a lot better - what thickness are you trying to cut?

I remember someone having a similar problem on an Axminster bandsaw and it was down the belt on the machine slipping.
Does the bandsaw have two speeds? If so, make sure that it's on the fastest speed and it could be worth checking the tension on the blade and the tension on the belt for the motor and if you still have no joy, let me know and we can try and find out what else it might be.

Ian

 

[9fingers]

With modern machines having safety interlocks it is difficult to watch what is actually happening.

In your position, I would take the blade off. bypass the interlocks on the lower door (s) and run the motor. use a piece of scrap wood to apply friction to the driven band wheel and see if either the drive belt is slipping (wheel slows but motor runs ok) or if the motor itself slows down in which case I would suspect the run capacitor is failing. If it is the latter, come back to me and I'll try and help further.

Bob

 

[pren]

Hi, thanks for the replys!

Ive had this bandsaw for a couple of years now, but never really took much time to get to know it. I was wondering about the speed setting for the belt. It's running with the belt on the smaller drive pulley and the larger ... blade wheel pulley. If my understanding is correct, should that not give me a slower blade speed but higher torque? I would have thought that was what I would want for thicker cutting. Moving the belt back gives me close to a 1:1 ratio. Hmm.... think I've confused myself here.

Belt slipping is a good point. I gave the guide bearings a squirt with some silicone lube a few weeks back. It's possible some could have made its way down and onto the belt/pulleys, causing the belt to slip. I'm pretty sure the belt is tensioned correctly. I've got it so it can only just be twisted through 90*, which is what I've read somewhere on belt setup.

Many thanks!

 

[CHJ]

...... I gave the guide bearings a squirt with some silicone lube a few weeks back. . ...

On an aside to your main problem, silicone lubricants are not recommended around wood subjects that are intended for glueing or surface finishing.
Silicones are notorious for preventing bonding.

 

[pren]

Hi. Just an update: I bypassed the interlocks on the bandsaw and ran some oak through, pushing hard to get the machine to stall. I saw that the drive pulley was spinning inside the belt. I've now moved the belt on to the rear set of pulleys and now the belt does not slip at all! Not sure if they've got more grip as the drive pulley effectively has a greater surface area, but the blade spins a lot faster and cuts thick wood very easily.

Many thanks!!

 

[Steve Maskery]

OK, that's a belt tension issue then.
The slower speed would normally be for metals and plastics, where heat build-up is an issue. If the drive-pulley is smaller, the belt will be slacker and the motor will need to be moved to accommodate that slack.
Changing to the faster speed has taken up that slack, as the drive wheel is bigger.
Glad you're sorted.
S

 

[pren]

I seem to remember I changed it to the slower speed when I first got the saw. I think I thought it would give me a higher torque for cutting thicker timber. I'm thinking now the faster spinning wheels would give have a greater momentum behind them and giver greater cutting force?

Either way, it's all sorted now.