Sawing Speed Experiment

YellowHammer · March 21, 2025, 11:42:12 PM

I don't know how many, if any watch my videos, but I thought some of you might like this one. It was an experimental progression of several cuts through a 15 inch cant, sawing very slow to wavy fast, and looking at cut quality and sawdust ejection after each cut. The only thing I changed was sawing speed, which I regulated via my Accuset speed governor, and the results were more than very dramatic. I thought it might answer some questions that always seem to pop up about washboard, band resonance, sawdust packing, spillage, etc. It's pretty long because I did several cuts and examined the boards after each and discussed the results in detail.

customsawyer · March 22, 2025, 06:51:37 AM

I'll have to watch it later but I appreciate you taking the time to make it.

Ron Wenrich · March 22, 2025, 08:46:12 AM

I'm a circle mill guy and I also found that there was a certain tone that you needed to have your optimum speed. The feed rate would vary from log to log, because the width of the board, species, wood temperature, moisture content, etc would vary. When you're bogging down your engine, you're cutting too fast.

Circle mills also have a problem with gullets filling up. It comes about from having poor gullets, or feeding to fast. Feeding too slow isn't much of a problem unless you have poor shanks. But, circle mills have a dust discharge at the bottom of the cut. I often wonder what difference it would make if band mills worked like that. Gravity is your friend.

Good presentation.

doc henderson · March 22, 2025, 08:51:11 AM

Cool video. I wish my mill would go that fast.

Machinebuilder · March 22, 2025, 10:05:01 AM

I watch most of your videos, Thank You for doing them, I have probably learned more from your videos than the other youtubers all together.

I have learned to push my mill until the engine bogs too far.
I found when I switched from the 4degree blades to the 7degree it seems to help with less sawdust left behind.
the saw dust is also coarser.

I had the opportunity to use a friends LT40WIDE with the 26.5hp engine. I found i could saw MUCH faster.
I sawed my first pine on that mill, compared to the red oak I have sawn it is so much easier except for the resin build up.

this video was very interesting to me, coming from a production metalcutting background there is a lot of emphasis on how much material each tooth is removing.
the variables are spindle speed, feedrate, tool geometry, and material. I see the same principles as you are talking about.

Larry · March 22, 2025, 10:50:17 AM

The faster the feed rate the slower the blade speed. Blade speed is the secret and there is an optimum range which YH found to be an "E" flat. I agree.

More than 16 years ago pineywoods found another way to find the optimum blade speed. He hooked up a cheap bicycle speedometer to the band wheel. I tried it and what I found is if the blade speed was to fast I got excessive sawdust and rough cuts, same as YH. Blade speed too slow and I got waves. Horsepower is a big help in maintaining the optimum blade speed in those wide cuts. When I hit the optimum speed I started to notice the blade singing. After a while I didn't need the speedometer as I had calibrated my ears.

Remember blade speed is dependent on feed rate, band sharpness, species, and width of cut.

Thanks for the video YH, you probably spent half a day making it to help out other folks.

taylorsmissbeehaven · March 22, 2025, 11:24:16 AM

Thank you sir for another great video. Im sure it was painful for you to spend so much time on one log! Very nice to see all of those variables in one spot. I would be interested to know how blade cleaner/lubricants affect those variable. I also wonder if a dust collectioin system has any bearing on amount of sawdust moved off of the log. Thanks again!

Resonator · March 22, 2025, 12:49:59 PM

Interesting to see the different sawing speed results.

You could probably go through the video with sound editing, and isolate the blade sound to find what note it's "singing". Could also try clipping a instrument tuner to the mill itself, but I think the droning of the engine would overwhelm the sound.

John S · March 22, 2025, 01:00:07 PM

Will watch later, I always think that I should be going faster, Currently working on removing the roll in on the debarker in and out motor pulley.

YellowHammer · March 22, 2025, 03:28:28 PM

The LT70 has a blade speed display, I should have had a camera on that, as I was sawing. It should have occurred to me. Thanks, I'll get it on video.

I have no musical talent but I should be able to do as Resonator describes and isolate the waveform into any handy spectrum analyzer and see what the primary and secondary frequencies are, I was hoping a few pitch perfect folks would just tell me. When the band is running right, I swear I can hear harmonics, best described as a "ringing" I guess. However, with my ears, it may be just the sound of the neighbor's cat in heat.

I wore my starter out on this log, turning the mill off, even turning the dust collector off sometimes so I could talk, then turning everything back on. It took forever to get this log done and ruined a few boards the process.

I think I may do one on band cleaners and even one on different band profiles.

Hilltop366 · March 22, 2025, 04:32:54 PM

Well I don't have perfect pitch in a sense that I can name the note it is playing out of my head but I keep a guitar next to the sofa and tried it again to compare it and it is still real close to e flat.

I wonder what effect a different pitch blade would have, would it give you a different note or would you have to adjust your feed rate and end up with the same note?

On the prefect pitch thing I was at a local orchestra concert sitting half way back in a church a few years ago that my sister was playing violin in and after the concert I asked her if the lady playing violin in front of her was a little bit flat....she said I was correct so I guess my ear ain't too bad.

doc henderson · March 22, 2025, 04:51:49 PM

I think a lot of factors may change the pitch but comes down to the vibration frequency.

I think A# blade would cut the best.

bu-dut-cheee!

beenthere · March 22, 2025, 04:54:03 PM

Doc, that is real close to B flat

But sharp is preferred.

barbender · March 22, 2025, 05:03:35 PM

One of the handy things that has come along for guitar tuners are models like a "Snark", which are a small tuner that clips onto the headstock of your guitar. It has a transducer, I think, that picks up the vibrations in the instrument. They're nice because you don't have to plug them in, or have a microphone "hear" the instrument.

I bet one of those would read the tune the band is playing if one attacked it to the mill head somehow.

beenthere · March 22, 2025, 05:24:35 PM

A phone app will give the note, I believe.

Resonator · March 22, 2025, 05:38:53 PM

QuoteOne of the handy things that has come along for guitar tuners are models like a "Snark", which are a small tuner that clips onto the headstock of your guitar. It has a transducer, I think, that picks up the vibrations in the instrument. They're nice because you don't have to plug them in, or have a microphone "hear" the instrument.

This is what Barbender is referring too. I tried to tune mine down from E to E flat, all I got is D sharp.

Like I said, I think the engine noise would interfere, but you could try it.

barbender · March 22, 2025, 06:57:40 PM

As a side "note", I hate the convention of using letters for notes. Trying to read Eb on sheet music must be torture.

Some of you guys are "for real" musicians (I'm not) but are you familiar with the Nashville Number System?

Resonator · March 22, 2025, 07:16:00 PM

I just hack out 3 chords on the guitar and hope for the best.

Yes, I've heard concept. Nashville recording studios streamlined the music system so a country song could be broken down into 1 to 7 chord parts based on their scale position. Session musicians can quickly learn and play a new song just knowing the part numbers, and putting them in what order the song is written. That way they can record an album quickly, as it's many thousands of dollars an hour to book a studio.

doc henderson · March 22, 2025, 08:37:42 PM

some are audible like we used in band for all the instruments.

Hilltop366 · March 22, 2025, 08:46:58 PM

Not a "real" musician here, mostly strumming chords and a bit of finger picking. I don't use the NNS but somewhat understand it.
My oldest brother who does not read music can transpose a song to another key in his head and it took me a while to figure out how he was doing that. Some cord progressions he just knows in several keys and muscle memory takes over others he thinks of the chords as barre chords and moves the pattern to another key to figure out the cords in the new key. It seems to take about 15 seconds to do.

Larry · March 22, 2025, 09:03:05 PM

Quote from: YellowHammer on March 22, 2025, 03:28:28 PMI think I may do one on band cleaners and even one on different band profiles.

Band profiles, 7 vs T7......something I've noticed but don't have a good handle on the cause. The standard 7 degree leaves more sawdust on the board and I believe the cause is the smaller gullet. The T7 cleans the board better and cuts faster but I can't get the extra smooth cut of the standard 7. Not really a problem for me but just curious.

barbender · March 22, 2025, 10:55:17 PM

You guys are picking up what I'm laying down😊

Ron Wenrich · March 23, 2025, 06:13:09 AM

The Nashville system uses numbers instead of letters. But, when you get to the music theory side, you will get into flatted numbers. For example, a major chord is 1-3-5, but a minor cord has a flatted 3.

Certain notes will always come up in a progression of a chord. Certain chords will fall into a key. The key of G will always have chords of G-Am-Bm-C-D-E-Fm-G. The key of A would bump them up to the next level. Or, you can just put a capo on the guitar and that bumps it up for you and you still play the same progression without transposing.

I play pedal steel guitar. I can use the same progression for nearly any song. But, when the key changes, I have to change everything with my hand, as my bar is my capo.

For the non-musically inclined, I'm sure that's as clear as mud.

doc henderson · March 23, 2025, 06:44:42 AM

I "play" dobro. after finding the base cord or the key the song is in, the other cords are 5 and 7 frets up. If the song had a "bridge" it is 2 frets up. a bridge is an interesting progression that for the moment sounds like a key change. sometimes I climb up a fret at a time, or decline using triplets as a classic dobro sound. I like that for blues. I would play any sound from you tube and never really know or care what actual key it is in, or care. If I play with a group, they can name the key, and that is my base cord. again, with a stevens slide across the fret resting on the strings, (not pressed to the fret).

doc henderson · March 23, 2025, 06:56:58 AM

Folsom Prison Blues

Now this is an example in the key of G (so open strum of the dobro is a G cord). No, this is not me playing. I am occasionally asked if I am a good dobro player, and I have also been told there is no such thing as a good dobro player.

to stick to the thread, it sounds a little like yellowhammers saw.