Drift Problems with Resaw King

[David Weaver]

Yes, the blade is centered on the upper wheel.

[Robert Reece]

I doubt your Jet can properly tension a resaw king. Then you are asking your guides to do a lot of work and relying on perfect bandsaw alignment and a super sharp blade. Also your feed rate will determine how much the blade wants to deflect.

[Van Huskey]

Which saw? If it is a steel framed Jet (someone mentioned Jet) is it a triangle or square spine. What width RK? What do you have the saws tension gauge set to. Is it also barrelling in the cut?

[Lance Peck]

A dull ResawKing blade will like to wander back and forth through the cut.
The RK teeth may feel sharp even when they are not. But if your ResawKing blade is still sharp then there are a few things that you should check.

Do your guides support the width of the blade? The ResawKing blades are thin and need support from the guides at the back of the blade as well as the front.
I have found that a slight mis alignment of the upper guides will cause the RK blades to not cut straight. When you have the blade under tension the guide surface must be exactly
parallel to the side of the blade. Don't assume that the guides are properly alligned just because you have tightened the adjustment. Most likely the guides actually move from side to side (twist) as you adjust the cutting height. Once you have your height set check that the guide surface is parallel to the side of the blade. It needs to be exact to keep the thin blade from twisting. Unfortunately you need to check and adjust this everytime you change the guide height. This may be easier with Laguna ceranic guides than roller bearing guides. Once I found this alignment problem my ResawKing blades cut perfectly straight until they start to loose their sharpness edge. They won't stay sharp forever but while they are sharp they should make a perfect cut.

[ian maybury]

On the other hand even a small misalignment in the blade weld (in my limited experience - the back edge of what was a very highly recommended blade wasn't quite straight - but I've no experience with a Resaw King or even a carbide blade) can throw the tracking off badly too...

ian

[David Weaver]

I doubt your Jet can properly tension a resaw king.

I think it can probably tension it fine. This is the thin kerf resaw king, 1", not a bigger thicker blade. This is not the older jet that had a lot of flex in the frame, it's a stiffer version.

Which saw? If it is a steel framed Jet (someone mentioned Jet) is it a triangle or square spine.

Steel framed jet, square, but not the version of the saw that wasn't rigid. This one is comparable to any other new steel framed BS. It is tensioned to the 1" indicator. What is barreling? The cut wants to drift and ultimately if you don't move it from the fence and face it back into the blade, it will come out of the side of the veneer you're cutting. I usually tension a 3/4" blade to about the 3/8" indicator on the saw and have no issue.


Is it possible that it's my feeding? I usually only feed nasty stuff through it (cocobolo, etc) and not a whole lot of it, but since my TS is gone, it's (or whatever replaces it) going to have to do full duty. It cuts thin stock almost as smooth as a TS. In fact, I always hand plane edges off the TS, so I don't think it takes any more effort.
It's funny that the weld was mentioned, it did tick past the guides when it was new. I sanded the weld down flush with the band to eliminate that (I did not sand any of the band).

[Leigh Betsch]

I've got a coulpe of Resaw Kings and a couple of Kerf Kings. The RKs are 1" the KK's are 1 1/2. I tension the RK to 1 1/2 setting on my MM20 and the KKs I overshoot the 1 1/2 mark by a bit. I read someplace that a carbide blade should be tensioned one mark above the blade width. They cut very straight even when they are getting dull. They seem to dull rapidly and one of the KK's developed cracks and "exploded". But I don't have any problems getting them to track straight. I run them with the teeth hanging off the front of the wheel, per MM instructions, the MM has flat tires not crowned. Finish wise the RKs when new are about as good as my jointer, not as good as my TS and WWII blade. When they get dull the finish goes down rapidly but they still track straight, although the cut will get bowed in the center when very dull.
I'm not expert but I would suspect that they are under tensioned or just a bad blade for a Jet saw.

[David Weaver]

I think you guys are right about tension. I had them tensioned at the 1" mark. I corrected for drift, and the cut was better, but still not straight enough to be confident for veneers so I took the blade off and put on a 3/4" timberwolf again to make sure I'm not high or something (figure of speech, i'm not a substance abuser), and sure enough, it had about the same amount of drift (using the cutting to the line method), about the max my crappy saw fence tolerates. But, I cut a 3/4 inch thickness planed board into 5 clean veneers intentionally leaving the guides about 4 inches above the cut height. No problem, and that was tensioned at the 1/2" mark.

I think I'd rather plane the edges of my boards a second stroke than crank the tension handle all the way to 1 1/2", but next time I put the resaw king on, i'll tension it to the 1 1/2 inch mark on my saw, which is full tension, and see how it does. I am generally a hand tool woodworker, there is only so much screwing around with power tools that I can tolerate.

[Van Huskey]

You are on thr right track, tension it to at least 1.25" then try 1.5" since it prefers 25,000 psi compared to 15,000 for carbon blades. Barrelling is when the cut is curved IN the kerf which would be another indication your tension is low. Finally the RK is designed not to overfeed, but enough pressure could push it offline.

[David Weaver]

van, I was getting the barrelling you describe with it once it got off track. Or maybe it goes off track because of the barreling. I ran several boards through at the 1" indicator, a couple of them went OK, and then one board had a knot in it and got off at the knot.

It'd be nice if it's (the RK) not a a $175 boat anchor, but I went through all of my hardwood scrap last night trying different things, so I'll have to wait until I have more scrap to ramp up the tension with it.

[Van Huskey]

I am betting it is the tension, if not it may be time to give Laguna a call.

[ian maybury]

Inability to deliver enough tension was the issue that led to sale of my Scheppach 5 series saw (to a guy doing rough cutting only) when trying to get it to re-saw straight. I'd bought an often highly praised US made blade which had the weld misalignment referred to above - no doubt not typical. Having run out of saw based stuff to try I eventually found a slight wobble front to back in the blade. (it wasn't obvious since it was in the line of sight) Some (also highly recommended) UK sourced blades of the same nominal spec (TPI, width etc) ran true and solved the problem 100% - the saw was suddenly cutting straight as a die.

But only up to about 5in thickness. With exactly the same blade and with the guides correctly set no matter what I did beyond that thickness it persisted (despite 12in of vertical capacity) in drifting badly.

My personal conclusion was that the saw (as it seems is typical of many hobby/lighter duty saws) couldn't apply enough tension to the blade, this despite it being narrower than the listed max width, and being cranked to the max the tensioning spring would allow. The blade was wandering badly in the upper part of the cut.

The best theory I could come up with for what was going on was this: Once the cutting force approaches the blade tension (since the blade is pulled down through the cut from the bottom the load increases as more and more teeth engage) the run of blade above the workpiece may at worst have zero tension - or even some slack/belly. It'll certainly have much reduced tension in the upper run of the blade. Which explained why it wanted to wander from the top of the cut - the lower part of the blade transmitting the cutting force from the lower wheel is still tight.

The bad news on this is that the more aggressive the blade and the tougher the wood (the bigger the bite taken by each tooth), the more likely this is to happen on a given saw. Put it another way - to tension and run a blade properly a saw has to be able to apply enough tension to overcome not just the cutting force (which for a given blade will increase roughly in proportion to the depth of the cut - which is why deep re-sawing requires lots of frame strength/controlled deflection as well as enough vertical capacity) but also to properly tension the upper run of the blade. If not the upper run is left free to wander and deflect.

Remember that tension by holding a blade straight greatly increases its buckling/beam strength too.

Another issue in frame design has got to be that of how well it maintains the band wheels in alignment/in the same plane (also the guide post and guides) under this load. Frames by definition deflect under load (with the amount reducing as the stiffness increases), but if one or other wheel or guide tilts out of line as the load increases/varies as the cut engages and disengages then drifting is presumably inevitable then too.

Tipped blades have I guess the ability to not only be much more aggressive than the conventional types (longer pitch, wider tooth), the wider/thicker band also needs more tension than stock blades to hold it straight.

This leads into the other little problem common to all saw blades. That being the reality that once drift/misalignment of the cut starts, then the natural guiding effect of the flat blade back will be to tend to keep it going in that direction. So if your tension (effectively frame stiffness) is insufficient to prevent the blade twisting under cutting forces, or to pull it back in line before any significant divergence gets started then it's gone.

This is presumably why wider blades are not always the most straight cutting, and why the saw must be able to tension them. i.e. once the deflection gets past something fairly minimal the system of forces in play is almost certainly unstable, or divergent. Meaning that as the blade deflection increases it will feed forces back into the system that (once a certain point is reached) will equal and then quickly overwhelm whatever blade tension is available - and this will happen more quickly in a given system with a wider blade.

A final thought on blades. I suspect that the inherently more accurate and consistent setting of teeth that you presumably get when grinding a carbide blade is perhaps one reason why they tend to cut straight. But to the above point. Lots of blade tension (the more the merrier?) will presumably enable straight cutting even if there is a little side to side imbalance in a blade - by preventing the blade from deflecting. i.e. within the limits of the kerf crabbing/cutting from very slightly off to one side (as in the case of a table saw blade) probably becomes possible.

Maybe band saws will in future eventually end up with wire-like blades running enormously high levels of tension. :-) Or at least very narrow high strength blades relying almost entirely on massive tensioning applied by incredibly rigid frames to prevent deflection.

Anyway. Next episode follows when my Agazzani gets up and running...

Ian

[Mike Heidrick]

Dave, could you slowly increase the tension above 1" and see how it fares? Sam Blasco I believe is the one that told me not to trust the tension gauge values of my MM20 but rather use it as marker of where each blade needs to be. I slowly increased the tension on my RK to where I got great results. I am no bandsaw expert thoough and many here may have better advice. My method works for me.

Also is 1.5" the max of tension you can apply or just the last number printed on the gauge?

[David Weaver]

This is a bring-back of an old topic, but just a confirmation that through all phases of setup, the resaw king blade I have wanders no matter what. I don't have a TS, so accurate cuts from the bandsaw are necessary, and right now I'm making kitchen cabinets, so cutting all of the sticking accurately would be a wonderful thing.

So far in 7 years, this remains the only blade that doesn't cut right on my saw, a $175 complete...and I mean complete waste of money. I've gone through everything on this thread, and I can only conclude that either the blade design is poor for general use on some saws (meaning it needs something very specific from a saw, like tires with no crown at all, etc), and I can't believe that I'm the only person to have issues (and know I'm not after reading reviews at amazon).

I had set this blade aside for 2 1/2 years (back when I made this thread, I think I still had a TS and I just wanted to resaw), but with all of the sticking I'm cutting, it would be nice now to be able to use it since it does leave a smooth cut. Went through everything last night, used featherboards to make sure feed was consistent, etc, set and reset guides, tried on different positions on the tires, and even with a super slow feed, just ripping 4/4 material had 2-3 hundredths of drift. with moderate feed, no matter the drift setting on the fence, the blade went left or right quickly and became bound.

Yeah, I know, 2 to 3 hundredths is no big deal. But when it occurs over a couple of inches on a piece of sticking that you're trying to get accurately cut so you can M&T and end and have a square face frame, it's a big problem.

Not a rant, more just exasperation.

[Jamie Buxton]

..So far in 7 years, this remains the only blade that doesn't cut right on my saw,.. Not a rant, more just exasperation.

Blades that don't cut right are generally dull. Spend the $40 or so to get Laguna to sharpen the blade. Or throw it away. 7 years is too long to be exasperated.