Roller guides

[JoshNZ]

No I don't really have a way to do it easily. I bought a short length of 4140 off a friend in town for $50 ~30usd and I can make another 3 pairs with it. At less than $10 a pair I doubt I need to. I think the hardening process would knock them out of round slightly anyway? They'd need to be ground afterward which is getting tricky for me

[BtoVin83]

I built a set out of 1018  a year and half ago and they are still running. One got stuck against a log and got a couple of flat spots but through it up in the lathe and trued it up. My first thoughts was to use a setup like vertical band saws when I discovered the Cook's style?. I didn't know using these type of guide wheels was so touchy, I just made them, installed them and ran them without any issues. As far as I'm concerned the Cook's style work really well.
Josh, what "correct angle" setting are you talking about? 

[JoshNZ]

Just as mentioned above you want the back of the blade contacting the guides shoulder on the leaving side of the roller, not the approaching. So that any force pulls the band up into the roller, rather than trying to lift it away. So in the photo if the blue line marks the back of the band, the red line is the vertical plane of the guides shoulder/flange. Hopefully I've got that right.

I did it backwards late one evening and I can attest to the fact that it works like crap!



 

[Banjo picker]

I take that picture is just to make a point .  Cause that blade is way to forward.  Tim

[BtoVin83]

That absolutely makes no sense to me but I can't come up with an argument against it. If it works for you good onya

[JoshNZ]

Yeah banjo I banged them on there last night and had to head out for dinner haven't had a chance to setup yet. I'll bring the band back to 1/8 off the shoulder and set correct downward pressure.

Are you just running yours square bto?

[YellowHammer]

As good as a machinist as you are, I'd recommend putting a bump guide, similar to just the bottom half of a WM HP blade guide system, to never physically allow the band to climb the shoulder, or for that matter, wander off the blade guide roller more than just a fraction of an inch. 

[BtoVin83]

I run mine square 1/4" down pressure parallel to the bunk to keep the blade in line with the bunk, not hardened. Never had a blade climb over the flange or anything weird. I don't even bother to check the setup when changing blades even if the saw has set for a while, if the blade isn't tracking I know something is off and start checking. 

[JoshNZ]

You might be thinking of the angle of the line between the guides bto? The blade is still parallel to the bunks in both planes, but each roller guide on its own points ever so slightly in the direction the blade is coming from. So that on the incoming side where the shoulder would be lifting the band away from the roller, no contact is made. If you're setup works then no trouble, anyway!

I put it through a 1.1m wide redwood today and got a nice flat cut. I know that's no comparison to walnut but if I was getting waves on a 200mm walnut cant and a 1100 wide slab is flat I'm sure I've done some good.

It's the biggest log I've had on the mill yet. No interest in doing it again really haha.



 

 

 

 

[ladylake]

  
 If you run the flange that close to the back of the blade you'll be braking blades too fast.. The blade shouldn't hit the flange until it's dull, then time to put a sharp one on.   Steve 

[JoshNZ]

I'm pushing it there to show the hair of daylight on one side and contact on the other. It's running 1/8" off the shoulder.

[ladylake]

 If your running lower hook angles and push your saw 1/4" back will give way better blade life.  That 1/8" back came from the old days with a 10hp mill running 10° blades which wouldn't push back much.   Steve

[JoshNZ]

I'm running 10 degree blades at the moment because I can't get anything else. What you're saying makes me think I better get hold of a tension gauge

[RAYAR]

Great idea. I've been meaning to do that but my backstops are set quite far in from my outter blade guide. Do you not find them interfering with nobs/limbs and bends on some logs? That's why I moved my backstops out further in the first place...

I think you were asking me about my blade guides and blade guard position. I just deal with it when needed, such as sticking a piece of slab between the log and back stop. It's not often I have to do that.

[mike_belben]

Josh, does the surface of that slab have a sweep to it or is that just an illusion?  

Nice machine work

[JoshNZ]

I didn't put a straight edge on that one but I couldn't see any imperfections standing next to it.

I got working on some meter wide oak later, they were coming out dead flat once I got a new blade on it.

I'm sure those guides are happier being bigger and having a taller shoulder but I bet it's that angle that made all the difference. The small guides used to be the loudest thing you could hear when it was running. Just spinning too fast