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Asian 4x6 Band Saw V belt sizing

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superc:
Yep that's the model.  Uses 10mm belts.

Gentlemen.
My statement was, "use of a 1/2 inch wide replacement belt produces wildly high excessive blade speeds."

There exists a reason I chose those specific words.  I measured the speed that resulted with a 1/2 inch belt and the pulleys configured for a blade speed of 80 feet per minute.  Precisely, with a Jaquets Indicator.  Then I double checked pulley setting and also the Jaquets against a known standard (a tractor PTO) and yeah it works just fine.  Then I took a reading of the blade's speed again, and again. 



I stand by my use of the words wildly excessive.

Average feet per minute speed of the blade with a 1/2 inch belt was about 1,100 fpm.

In the 6 seconds allotted the  small wheel spins and passes the 300 inch mark not less than 7 times.

DaveH:
I have a similar 4x6 band saw and my belt is metric 13 x 560 A590 A22.

My saw is set on fastest 200 ft/min - which means by your reckoning my blade speed would be about 2750 ft/min. I can say without measuring it it doesn't run any where near that speed.

I find it hard to believe that the speed can go from 80ft/min to 1100ft/min with just a small increase in belt size. Something just isn't quite right.
 :beer:
DaveH

 

Manxmodder:
superc,I agree with David,there has to be some error here somewhere because those readings are massively over what would be seen by fitting a 1/2" belt to a 3/8" pulley.....OZ.

superc:
Is 'massively over' the same as 'wildly excessive'?  I think so.

Philf is on the correct path, but his numbers are too small.

The big pulley's (bottom) central shaft (which a 10mm belt rests against) is 43mm in diameter.  However, because it is too wide to properly enter the pulley, a 1/2" belt sits around the pulley at 59mm.  The other pulley has a shaft of 48mm diameter which a 10mm belt reaches, but the 1/2" belt never gets closer than 60mm to the shaft.



philf:

--- Quote from: superc on April 09, 2014, 12:06:22 AM ---
  Precisely, with a Jaquets Indicator.  Then I double checked pulley setting and also the Jaquets against a known standard (a tractor PTO) and yeah it works just fine.  Then I took a reading of the blade's speed again, and again. 

In the 6 seconds allotted the  small wheel spins and passes the 300 inch mark not less than 7 times.

--- End quote ---

Hi Superc,

I agree with Dave H and Manxmodder.

I haven't any experience of the Jacquet instrument.

You can usually see the welded area of the blade so why not just time how long it takes the blade to a full pass.

The 4x6 bandsaws use a 64.5" blade. At 80 feet per minute the blade would take about 4 seconds to do a complete lap.

For 1100 feet per minute the blade would be doing a full lap in 0.3 sec!

Something just doesn't add up.

Cheers,

Phil.

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