Does your sawdust talk to you?

welderskelter · February 21, 2019, 11:47:38 AM

No I am not real crazy. Just wondering if anybody looks at their sawdust to figure out what they might be able to change on their mill. I had a circle mill before and the sawdust on my band mill looks like flour. Is it supposed to be so fine?

moodnacreek · February 21, 2019, 12:36:13 PM

Fine sawdust means you can't feed fast enough.

kelLOGg · February 21, 2019, 12:44:27 PM

He's right. The only thing I would change on my mill is to put a bigger engine on it so the blade could take a bigger bite and not have to flex so much which shortens its life. Some day I just might do it and then I would get coarser sawdust, too. So, yes, it does talk to you.

Alyeska Pete · February 21, 2019, 12:59:34 PM

Should be like coffee grounds

GAB · February 21, 2019, 01:06:00 PM

When cutting trees sometimes the sawdust will tell you that the tree has rotting material i.e. not structurally sound internally.
Gerald

Southside · February 21, 2019, 02:55:50 PM

Flour is also a sign of a dull band.

Jim H · February 21, 2019, 03:03:15 PM

My dust is more like cornmeal. In something like a really dry cedar the dust will be finer.

welderskelter · February 21, 2019, 03:10:59 PM

Maybe that is why mine is so fine. It is all logs that have been down for a while. Years, Ash and oak. I was bidding on a bigger engine but lost it.

longtime lurker · February 21, 2019, 03:25:10 PM

Mine tells me don't leave... It needs me...that the boat is little better than a trollop.

Its Friday, she gets to feeling insecure.:D

Percy · February 21, 2019, 03:34:54 PM

The sawdust in my shorts says real nasty things. The pointy pieces talk the loudest 🤓

moodnacreek · February 21, 2019, 05:43:32 PM

Quote from: Percy on February 21, 2019, 03:34:54 PM
The sawdust in my shorts says real nasty things. The pointy pieces talk the loudest 🤓

Me to and my sawdust is coarse and sometimes splinters. Try to ignore it and keep working except one night it wasn't sawdust, it was a *DanG tick well attached.

moodnacreek · February 21, 2019, 05:58:03 PM

[*DanG tick]

Banjo picker · February 21, 2019, 09:35:08 PM

When I see the coffee grounds Pete was talking about hitting the ground about 20 feet from the mill, I know she's cutting pretty good. Banjo

YellowHammer · February 21, 2019, 09:46:25 PM

Here's what my sawdust says to me, it may say something else to others:
If the sawdust exits the cut directly in line with the band then its cutting straight. Crank up the speed until the sawdust trail twitches up or down and it means the band is now waving. Slow down until the sawdust trail settles down and realigns with the band again and keep the hammer down.

If the sawdust trail is extremely narrow, then the gullet is doing its job, properly mixing the sawdust with air, keeping it in suspension, and the sawdust is coming out clean and fast. This means sharp band, correct set, correct speed, keep on sawing, put another log on the mill.

If the sawdust trail is in line with the band but spreads out like the flame from a torch when it exits the log, it means the band is getting duller, and there is starting to be some gullet spillage. Set is dropping as the teeth corners dull down. This means keep sawing, but since its about lunchtime, get something to eat and come back and change bands.

If there is very little sawdust on the boards, its basically dry, and it falls off to the ground when the board is tilted, then life is good.

If there is a thick layer of cornmeal dust on the board, there is a problem but if the cut is straight, keep on sawing but jack the feed up and watch for waving.

If the sawdust is fine and packed like flour, the feed is way too slow, band set is too low, and the log may be too hard to increase speed. As long as the cut is flat, finish the job and then swap bands.

If the sawdust is fine and packed like flour, and gray or blue, then the body of the band is rubbing against the spilled, packed sawdust, and metal is rubbing off and causing the sawdust to blue, especially in oak. This means stop sawing and put on a sharp band.

Anyway, this is what sawdust says to me.

moodnacreek · February 22, 2019, 07:51:10 AM

Y.H., you been sawin for awhile.

Sixacresand · February 22, 2019, 08:20:18 AM

Y.H. That was educational.

mitchrm · February 22, 2019, 09:07:36 AM

Wouldnt a circular mill have a thicker kerf and a larger chip?

welderskelter · February 22, 2019, 09:26:48 AM

mitchrm. That is why it seems so different for me. And I am not having to haul out sawdust all the time. Ha

Weekend_Sawyer · February 22, 2019, 10:09:16 AM

Yellowhammer, I have watched the sawdust fly from my mill but I have never studied it. I will from now on.

It's a good day when you have sawdust in your pocket.

Jon

Woodpecker52 · February 22, 2019, 10:12:42 AM

My sawdust talks to me says "Shovel ME"

YellowHammer · February 22, 2019, 12:47:22 PM

The sawdust trail I'm talking about is just as the blade exits the log, and before it get disturbed by the idler wheel blade guide. That couple inches will tell much about what is happening in the cut.

moodnacreek · February 22, 2019, 01:09:03 PM

I sawed under powered for years. [circle mill] Slow feed is slow feed regardless of saw type. More and smaller [closer together] teeth needs faster feed. You need not only the power but the condition of the whole set up to feed to the choking point. Since I got decent power My teeth last 3 times longer. Slow feeds dull teeth fast and make fine dust. You can only saw as fast as your equipment will allow but always strive to go faster.

SawyerTed · February 22, 2019, 05:13:55 PM

Yellowhammer has explained what I've been thinking. The sights and sounds from the machine will tell how well the machine is running. Planers, jointers, saws all will tell how they are working. Sawdust and chips are just one indicator. So, yes, my sawdust talks to me....

longtime lurker · February 22, 2019, 05:53:02 PM

How many HP and how deep does she cut Doug?

Rule of thumb here is you want a minimum of 3 to 5 HP for inch of saw in the cut sawing eucalypt species. Thats part of the headsaw + resaw as standard in Australian hardwood mills: you can never get that much power to the headsaw so we gear our carriages slower and take less cuts there, then send big cants and flitches to the circle resaw where you can get enough power to be effective. I've struggled around the bottom of that rule for years.... my antique resaw runs 40HP 3 phase and cutting 6" deep shes good, at 8" deep shes okay... but after that shes struggling and the dust gets finer and finer. I get below that 3 HP/inch mark and shes dangerously underpowered and while I've never had her spit a cant back she's been close a couple of times.

Queensland Maple at 39 lbs/ft3 (air dry density) on the left. Spotted Gum at 68lbs/ft3 (A.D.D.) on the right. Cutting 10 x 2's in both so its a pretty good look at the effect of density on the power requirements of a circle saw. ¼" kerf FWIW.

I imagine you'd have a similar difference between summer and frozen?

My sawdust told me to buy bigger better faster toys... I shan't have this issue much longer