Palax Combi 600 mk1 blade wobble

[Billhook]

I have owned this machine since 1996 and had no trouble in all these years.  I have changed the 700mm blade several times for sharpening and have three spare blades all multi teeth carbide tipped.

A blade that was due for a sharpening suddenly started to vibrate and looking down the line of the blade a 1/8 inch wobble could be seen on start up but it ran true when cutting or when slowing down after I turned the  3 phase electric motor off.  I assumed that the blade hade warped and become heated at some time so I changed it for a brand new blade today which did exactly the same thing.

I grease the bearings regularly and I can detected no play at all in the blade and when I put my finger on top of the bearing shaft on the grease nipple I cannot feel any vibration when running there but it is quite apparent that the whole machine is shaking slightly.  Apart from having two unbalanced blades by sheer chance, can anyone think of anything else to check.  

[openspaceman]

1 hour ago, Billhook said:

I have owned this machine since 1996 and had no trouble in all these years.  I have changed the 700mm blade several times for sharpening and have three spare blades all multi teeth carbide tipped.

A blade that was due for a sharpening suddenly started to vibrate and looking down the line of the blade a 1/8 inch wobble could be seen on start up but it ran true when cutting or when slowing down after I turned the  3 phase electric motor off.  I assumed that the blade hade warped and become heated at some time so I changed it for a brand new blade today which did exactly the same thing.

I grease the bearings regularly and I can detected no play at all in the blade and when I put my finger on top of the bearing shaft on the grease nipple I cannot feel any vibration when running there but it is quite apparent that the whole machine is shaking slightly.  Apart from having two unbalanced blades by sheer chance, can anyone think of anything else to check.  

I didn't have TCT blades on my log saw but the practise is probably the same; when the sawblade is made the saw doctor "tensions" the steel near the teeth by  stretching the steel slightly. This has the effect of stopping the steel plate from wobbling. Over time and use the effect wears out and you get the wobble you see.

 

I would hand sharpen mine a few times and then send it back to be gulleted, tensioned and sharpened

[Stere]

Quote

tensioned

 

 

Does anyone  still do this in UK?

[Billhook]

I know where I can have it done , just could not believe it would happen with a brand new out of the box blade but I will change it back to one of my spares to check 

[Billhook]

2 hours ago, Stere said:

 

 

Does anyone  still do this in UK?

Very useful video thank you

[Billhook]

Took the new blade off and tried two more which worked fine without wobble and demonstrated that the new blade was faulty so it has been sent away to a saw doctor together with the first blade.

[Alycidon]

I had an occasional blade wobble on my Japa 700,  bearings on the drive shaft were shot. 

 

A

[Billhook]

22 hours ago, Alycidon said:

I had an occasional blade wobble on my Japa 700,  bearings on the drive shaft were shot. 

 

A

The bearing shaft seems to be as tight as (I cannot think of the proverbial!) and there ia no play but it runs freely.

It must have been something to do with what the guy in the video is trying to correct by judicial hammering.

I wire brushed the blades and the castings before fitting to make sure that nothing might cause distortion on tightening, and I did not tighten very hard as the  motion of the saw is self tightening

[difflock]

 .  .  .tick's arse!

[Billhook]

On 09/12/2021 at 21:42, difflock said:

 .  .  .tick's arse!

just found this on the web

Tighter than a .... in The AnswerBank: Phrases & Sayings

WWW.THEANSWERBANK.CO.UK

"Nun's Chuff" made me chuckle