Bandsaw Tune-up

[keithkarl2007]

I bought a Jet Jwbs 16x second hand about 2 years ago. I have been mostly using it for rough shaping blanks for woodturning but would like to start using it for finer work for furniture making. While going over the machine I noticed that the top wheel doesn't run true. I took the wheel off and turned it around the other way. It ran a bit better but is still not exactly true. I'm guessing that this is a big problem. I originally thought it was the tyres but it may be a combination of both. Will these wheels need replacing?

 

[Steve Maskery]

Keith, what do you mean by not running true?
S

 

[keithkarl2007]

The outside of the steel wheel doesn't run true.

 

[Steve Maskery]

I'm none the wiser. Do you mean it is eccentric or do you mean that it wobbles to and fro? Or something else?
S

 

[keithkarl2007]

Yes I guess you could say it's eccentric. I placed a ruler against it and it hits and misses as I turn it by hand.

 

[Steve Maskery]

Ah, OK, so it is:
A The wheels are no longer round
B They are round but they are mounted off-centre
C The Wheels is round and runs true but the tyre is worn/compressed in such a way that it is thicker in some places than in others.

Is there any play in the bearing? If so then that is the first thing to put right. If the bearing is sound, see if you can do the test you have done on the tyre, on the metal of the wheel. That should tell you whether it is the wheel or the tyre.

If all those turn out right, I shall have to put on my thinking cap.
S

 

[keithkarl2007]

The bearings appear to be fine, no play in them. I didn't check the tyres because the wheel seems to be no longer round. I figured the tyres couldn't possibly run true if the wheel wasn't round.

 

[Steve Maskery]

Correct, but if the machine has stood for a very long time with the blade tensioned, I suppose it is possible that the wheel has been compressed at top and bottom, compared with the rest. If so, then get some new tyres.

 

[keithkarl2007]

Thanks for that Steve. I'm waiting for a local dealer to get the tyres in for me. I figured you'd be the first person to comment on my problem. I'm hoping to pick up your bandsaw dvd sometime next week. I'd like to get the bandsaw to cut accurately enough for resawing, cutting joints and veneers.

 

[Steve Maskery]

Well yes, I can see how dodgy wheels would make that a tad challenging...
S

 

[keithkarl2007]

The wheel itself I hope doesn't need replacing because I just seen the price of them.

 

[RobinBHM]

I have an old cast iron bandsaw which was not true when I got it. I trued up the rubber tyres with a parting tool!

It worked a treat, i did the top wheel by spinning it by hand.

 

[busy builder]

If it's the actual wheel thats buckled then it could be trued at a machining shop.
Spin the wheel by hand and place a rule say by the frame with the end of the rule just touching the side edge of the wheel, spin the wheel and see how much deflection there is as the wheel spins. if its out then it will need machining, assuming the bearing is okay.
If you mean the wheel is (say) egg shaped then to a degree this can be machined out as well.
Could it also be the axle that the wheel spins on ?

 

[Bluekingfisher]

If it's the actual wheel thats buckled then it could be trued at a machining shop.
Spin the wheel by hand and place a rule say by the frame with the end of the rule just touching the side edge of the wheel, spin the wheel and see how much deflection there is as the wheel spins. if its out then it will need machining, assuming the bearing is okay.
If you mean the wheel is (say) egg shaped then to a degree this can be machined out as well.
Could it also be the axle that the wheel spins on ?

If both wheels are of the same dimension with the same bearings you could remove the top wheel and place it on the arbour of the lower wheel (having removed the lower wheel of course) to establish if it is the arbour/axle causing the issue. In which case the wheel will run true.

If the wheel is running out of true it is more likely to be the wheel rather than the tyre. I have the JET 18" and if memory serves the tyre sits within the wheel rim, which would mean it wouldn't be the tyre as it doesn't protrude beyond the wheel rim.??

There was a thread on here a few weeks back regards leaving the machine under tension for long periods. I am still of the opinion that the blade should be slackened off after each period of use. I hope it hasn't been caused by over tension, which could, with prolonged downward pressure either 1. buckle the wheel 2. bend the arbour.

Although I am a big fan of JET machinery ( all mine are) they are not built to the same standards or have the heft of older British type machines of the past. therefore more likely to suffer from the huge amounts of force generated by a blade under tension .

Let us know how you get on or if you change the tyres. Best of luck

David