Feeding fast

moodnacreek · July 01, 2022, 10:01:35 PM

Now that I have a faster feed in my hand I can't help trying to use it. For years I sawed with a 3" feed, then 4" and this mill will go 5 1/2" [per saw revolution] I can't get past 5 in a nice soft pine log. It will suddenly cut rough and maybe start making thick and thin if I don't back off. It does not seem to matter which saw is being used. What did help is keeping the guides real close. I am pretty good with circle saw performance or so I thought :D.

Don P · July 01, 2022, 10:24:07 PM

Not enough teeth, as in can't get rid of that much dust with the gullets you have at that feed?

moodnacreek · July 02, 2022, 09:52:27 AM

Quote from: Don P on July 01, 2022, 10:24:07 PM
Not enough teeth, as in can't get rid of that much dust with the gullets you have at that feed?

I suppose but I am running 52 teeth with a 52" saw but then it is a 2 1/2 so the gullets are small. The 44 tooth B should carry more sawdust but I don't see a difference in feed speed. How would one know that the gullets are packed and the limit has been reached? The good thing here is that there is no problem, just hot rodding a bit.

longtime lurker · July 02, 2022, 10:28:11 AM

What's the sawdust look like, that'll tell you if you need more teeth. If she's overflowing the gullets you'll get more powdery where it's slipping out and into the next tooth and getting recut.

Maybe starving for power and starting to lose rim speed? Electric isn't she? Wire an ammeter in where you can see it, that'll answer that one.

What guage saw you running? I can't even imagine feeding that fast without breaking things here but deep fast cuts maybe you need to step up to 5ga. Steel has limits etc etc

moodnacreek · July 02, 2022, 02:01:41 PM

L.L., I did see some fine sawdust in with the 'chips' and unless I was easing through some tough stuff that should not be. Yes electric, 75 + 15 percent part time. Saws are all 8 rim ga. For other reasons I considered changing the drive pully to the feed to a smaller dia. and that would slow it down. So I wanted to see weather or not I could use all the feed that was there before I took it away. It is of course only the real easy logs I can tear through at 5" + feed. Slowing down this feed will also slow the gig. It is only recently I got the nerve to go fast with this new to me sawmill. Also got the boards falling on the take away hands off which has increased my appetite for speed.

Jeff · July 02, 2022, 07:46:22 PM

How do you know when the limit is reached? Instant hung saw, and hopefully the weakest point is the belts when the saw instantly stops.

I could get around 6" with a 56" 50 tooth f pattern on a hundred hp.

JRWoodchuck · July 03, 2022, 12:55:33 AM

So are you guys saying the saw is cutting through 5" of wood per revolution of the blade as the log advances through the saw? If so that sounds awesome and I would like to see it in action!

ladylake · July 03, 2022, 06:33:47 AM

I think at 500 rpm thats 208 fpm, sound good. Steve

Ron Wenrich · July 03, 2022, 10:52:20 AM

Just because you can go fast doesn't mean you should. I always found if I went too fast the quality of the lumber suffered. Not all logs saw the same, and hitting knots means that you're crosscutting wood and not ripping it. I always listened to my saw and tried to maintain the same sound. If the sound dies, your RPMs die, and your saw is more prone to movement, and that movement can be outside your saw guides. I matched the saw sound to the conditions.

I didn't saw much pine and I used a 46 tooth 54" B pattern saw. I could maintain the 4"/revolution on nice oak. Knotty stuff was slower. In theory, I could have sawn a lot faster, since I was running closer to 700 RPM and 125 hp electric. My carriage speed was the same forward and back, so I didn't feed with my joystick all the way.

Looking at the Lunstrum book on circle mills, a 2½ with a 12 inch cant face needs 72 hp cutting a group 1 hardness at a 5.5" feed. Seems like you should have enough hp to do that.

Walnut Beast · July 03, 2022, 11:25:00 AM

If you go fast your quality goes down more than if you didn't.........

moodnacreek · July 03, 2022, 11:31:43 PM

Thanks for the comments. No real problems here just trying to see what I could do on the easy logs. I doubt it is lack of power in nice soft logs but I can not saw straight and smooth at 5" +. Of course I don't need to but had to try it.

longtime lurker · July 04, 2022, 05:13:51 PM

Makes sense to me to try and push it to a limit. A circular saw is like a car tyre... they all go round and round quite well at 20mph... you don't figure out what's running true and what's unbalanced or not perfectly aligned until you hit 60.