Washboarding?

[woodbloke]

Just a general query here really. I cut some deep veneers on my Startrite b/s and experienced the 'washboard' effect on the cut surface. In a recent article in F&C Alan Holtam mentions this effect and says that it's usually caused by the throat insert being too low and thus causing lack of support. I checked mine and it's dead level with the table. I'm using a new Tuffsaws M42 3tpi blade, 20mm wide that I've tensioned correctly according to the dial indicator on the saw and saw guides were also correct...but I suspect that the blade needs a lot more welly than I wound on. Support was adequate during the cuts and feed rate was nice and slow...so what was causing he 'washboarding'? - Rob

 

[Richard T]

I think it has to be down to tensioning and good alignment - I'm always surprised to see people's band mills cut so smoothly and accurately with both sets of bearings half a yard away.

IME (which is not very broad) the tensioning indicator on the machine is of very little use. Especially when a blade of 3tpi or less may have been joined one side of a tooth or the other - makes a big difference in circumference when it comes to reading the "tensionometer".

 

[paulm]

Agreed re the tensioning. The M42 blades are great Rob but they need considerably more tensioning than a normal carbon steel blade. Ian at tuffsaws advised me to drop down a size (width) to compensate for this and ensure the blade could be fully tensioned so went from 3/4" down to 1/2" and there was a noticable improvement in performance and finish in deep cuts.

Cheers, Paul

 

[woodbloke]

Agreed re the tensioning. The M42 blades are great Rob but they need considerably more tensioning than a normal carbon steel blade. Ian at tuffsaws advised me to drop down a size (width) to compensate for this and ensure the blade could be fully tensioned so went from 3/4" down to 1/2" and there was a noticable improvement in performance and finish in deep cuts.

Cheers, Paul

Thanks Paul. I had the same advice from Ian and went from a 25mm blade to a 20mm one, but I only set the tension for a 20mm blade according to the gauge on the machine. Next time I use it I'll give it the full welly at set it to maximum...should make a difference - Rob

 

[RogerM]

Agreed re the tensioning. The M42 blades are great Rob but they need considerably more tensioning than a normal carbon steel blade. Ian at tuffsaws advised me to drop down a size (width) to compensate for this and ensure the blade could be fully tensioned so went from 3/4" down to 1/2" and there was a noticable improvement in performance and finish in deep cuts.

Cheers, Paul

Thanks Paul. I had the same advice from Ian and went from a 25mm blade to a 20mm one, but I only set the tension for a 20mm blade according to the gauge on the machine. Next time I use it I'll give it the full welly at set it to maximum...should make a difference - Rob

Rob - I've got a 20mm M42 on order from Tuffsaws so would be interested to know what result you're getting and how you went about tensioning the blade.

 

[woodbloke]

Agreed re the tensioning. The M42 blades are great Rob but they need considerably more tensioning than a normal carbon steel blade. Ian at tuffsaws advised me to drop down a size (width) to compensate for this and ensure the blade could be fully tensioned so went from 3/4" down to 1/2" and there was a noticable improvement in performance and finish in deep cuts.

Cheers, Paul

Thanks Paul. I had the same advice from Ian and went from a 25mm blade to a 20mm one, but I only set the tension for a 20mm blade according to the gauge on the machine. Next time I use it I'll give it the full welly at set it to maximum...should make a difference - Rob

Rob - I've got a 20mm M42 on order from Tuffsaws so would be interested to know what result you're getting and how you went about tensioning the blade.

Rog, as the blade in question is 20mm or 3/4" roughly, that's the setting I used on the tensioning gauge on our machine...clearly it t'weren't enough and the 'washboarding' effect was quite bad. The next time I use it for anything I'll set the blade on max tension and see how it goes. Fingers crossed, it ought to be OK as the tensioning spring on the Startrite is massive - Rob

 

[Steve Maskery]

+1
IIUIC the M42 blades are thicker than standard and any mid-range BS is going to be at its limit tensioning such a blade. It should certainly be possible to get clean cuts with blade only 1/2" wide, let alone 3/4, if it is set up and tensioned properly. It's the ability to tension the blade properly that is the limiting factor, rather than the wheel depth, on most saws, including my own.

S

 

[woodbloke]

+1
IIUIC the M42 blades are thicker than standard and any mid-range BS is going to be at its limit tensioning such a blade. It should certainly be possible to get clean cuts with blade only 1/2" wide, let alone 3/4, if it is set up and tensioned properly. It's the ability to tension the blade properly that is the limiting factor, rather than the wheel depth, on most saws, including my own.

S

Both Rog and I bought our band saws at Yandles and when I bought mine, the bloke on the stand was at pains to point out the huge tensioning spring on the Startrite, which he then asked me to compare to an equivalent Record machine on the same stand...the Startrite was far larger than the Record so I'm confident that the machine will be able to tension a 20mm M42 blade. However, as it's sooooo cold I'm not even going to poke me nose in the 'shop to have a play... - Rob

 

[RogerM]

Both Rog and I bought our band saws at Yandles and when I bought mine, the bloke on the stand was at pains to point out the huge tensioning spring on the Startrite, which he then asked me to compare to an equivalent Record machine on the same stand...the Startrite was far larger than the Record so I'm confident that the machine will be able to tension a 20mm M42 blade. However, as it's sooooo cold I'm not even going to poke me nose in the 'shop to have a play... - Rob

Do we allow wimps on this forum? Just got in from spending the day in the garage machining 40 pieces of iroko to size for windows! Thermometer says -2 deg. Come on Rob - get a grip! :lol: :lol: :lol:

 

[woodbloke]

Both Rog and I bought our band saws at Yandles and when I bought mine, the bloke on the stand was at pains to point out the huge tensioning spring on the Startrite, which he then asked me to compare to an equivalent Record machine on the same stand...the Startrite was far larger than the Record so I'm confident that the machine will be able to tension a 20mm M42 blade. However, as it's sooooo cold I'm not even going to poke me nose in the 'shop to have a play... - Rob

Do we allow wimps on this forum? Just got in from spending the day in the garage machining 40 pieces of iroko to size for windows! Thermometer says -2 deg. Come on Rob - get a grip! :lol: :lol: :lol:

Moi...wimp! How very dare you Rog. Have you banned your Mrs from munching on choccy bars yet, eh? :lol: :lol: - Rob

 

[newt]

Rob have you checked the blade for drift. I can remember on my little machine I had the washboard effect, max tension did not help, so I checked the drift, reset the fence, huge improvement. Before I reset the fence I could watch the blade wriggle from side to side. However I suspect you have already checked this, it was just a thought.

 

[woodbloke]

Pete, as far as I can tell, there's no drift on this bandsaw, but it may well be something to have a look at as well. I haven't had to adjust the fence to get it to run true - Rob

 

[woodbloke]

The tension, too little, it was...

The lower piece of elm shows the 'washboarding' which was quite deep, but when I turned up the volume on the saw blade tensioner to max and tried a cut on a bit of scabby elm from the offcuts box, the upper piece was the result...almost a planed finish straight off the bandsaw blade...now a happy, if wimpishly cold bunny (-2 in the 'shop) - Rob

 

[RogerM]

That looks really good Rob. So that was the 20mm M42 cranked up to max tension? As a matter of interest which fastcut blade do you use, and how much tension do you apply to that?

Have you banned your Mrs from munching on choccy bars yet, eh? :lol: :lol: - Rob

Haven't had to. She's just joined a gym as it's somewhere to go whilst i'm building doors/windows/kitchen and she's "on the wagon" so far as chocolate is concerned. She does a routine called "get a bum like Pippa's" :lol: :lol: :lol: Very apt seeing as our surname is Middleton!

 

[woodbloke]

That looks really good Rob. So that was the 20mm M42 cranked up to max tension? As a matter of interest which fastcut blade do you use, and how much tension do you apply to that?

Have you banned your Mrs from munching on choccy bars yet, eh? :lol: :lol: - Rob

Haven't had to. She's just joined a gym as it's somewhere to go whilst i'm building doors/windows/kitchen and she's "on the wagon" so far as chocolate is concerned. She does a routine called "get a bum like Pippa's" :lol: :lol: :lol: Very apt seeing as our surname is Middleton!

Rog, yep, a 3tpi, 20mm, M42 Tuffsaws blade cranked up to max volume on the dial...don't forget to release the tension though when you're done cutting (but you knew that :mrgreen: )
SWIMBO here has also joined a gym and goes twice a week as well as running at the weekends...mine isn't quite on the wagon though as she admitted the other day that she still has a craving for giant chocolate buttons. Me, I just stick to me 90% Lindt as it's supposed to be good for BP...my excuse anyway :lol: - Rob