4.1 hours, 3.25 gallons, and 20 slabs

[mrbentontoyou]

Very good work, as usual. I still have not seen the photoshop from Bob of the slope incline, I am a little let down. The data you collect would make a good publication on chain saw milling. If you and Bob put your heads together, you could write one heck of a good milling guide, from the mill up.

hear hear!!!
thanks men!

 

[mtngun]

If you and Bob put your heads together, you could write one heck of a good milling guide, from the mill up.

Maybe one of these days we will, but I feel like I've still got a lot to learn, and that's half the fun.

 

[BobL]

Depends on whether you like to file the chain on the CSM, like BobL, or swap chains and sharpen them later on a grinder, like me.

I average one chain per hour of run time, and in a typical day I will use 3 chains. 99% of the time, 3 chains is enough for me. A fourth is nice in case I hit dirt or have an exceptionally productive day.
BobL, your graph does not take into account the "freshness" of the chain. To do an apples-to-apples, test, I would have to do all the speed tests with freshly sharpened chain.

I do that on my pine cant tests at home, but it isn't feasible in the field. For example, chain #1 was used to make the initial slabbing cut on all 4 logs, so by the time I was able to do a speed test with #1, it was already half-way dull.

Whenever possible, I do a speed test right after installing a fresh chain. Those are the tests at 0 hours or at 0.1 hours. Let's compare those numbers and ignore the rest.
chain #2, 0.1 hours, 15.5", 0.32 inch/sec
GB'd, 0.1 hours, 16.5", 0.33 inch/sec, 9500 rpm
virgin 33RP, 0.1 hour, 17.5", 0.375 inch/sec
Clearly, the virgin 33RP cut faster than the other two chains, AND it did it on a wider cut. That is impressive, my friend. :rockn:

Not really - freshly sharpened chain cutting speeds are rather meaningless quantities.

Fast cutting for 6 minutes is fun but it's average cutting speed that generates long term productivity. You can't ignore the fact that the virgin 33RP chain only managed 0.286"/s after 6 minutes of cutting. This is slower than all other cutting except for the GB chain. This suggests that the virgin 33RP chain had maybe more hook so it cut quickly for 6 minutes and then lost its edge.

It's not too hard to set up a chain that can cut like a speed demon for a few minutes - my semi skip square ground does this as a matter of course. If I use this with a higher than usual hook in dry aussie hard wood it will cut real fast for a couple of minutes and then it slowly dies and sometimes I cannot even complete a cut without resharpening.

As for speed being inversely proportional to width, I certainly agree that cutting speed decreases as width increases, but I don't have enough quality data to prove a linear relationship.

I don't think it can ever be proven but increasing amounts of evidence can be stacked up.

By doing speed tests on random widths and at various points in the chain's life, I only hope to illustrate typical "real world" cutting speeds. That's worth knowing. My pine cant speed tests are more scientific and repeatable, but they are not necessarily "real world." Both kinds of test are useful.

I don't think linear speed spot tests are worth all that much, it's area cutting per unit time over the effective cutting time a chain operates before it needs to be sharpened that counts in the end.

When I first started hanging out on this forum, there were guys claiming matter-of-factly their CSM cut about 2 inch/sec , and I would wonder why my CSM didn't cut nearly that fast.

I agree, even at 12" wide at 2"/s is 24 sq"/s - that dreaming for a CS!

If I can cut a 32 sqft at 4 sq"/s in my wood I'm happy enough.

In terms of what you do, one chain for 60 minutes at about 5 sq"/s is about 125 sqft of cutting area per chain - this seems like a lot of area?
I touch up after every 32 sq ft in the hard stuff and after about 64 sqft in the softer stuff.
I guess it's always a trade off between swapping/sharpening and cutting.

 

[mtngun]

the virgin 33RP chain only managed 0.286"/s after 6 minutes of cutting.

virgin 33RP, 0.6 hour, 19.5" 0.286 inch/sec.

That's hours, not minutes. The hour meter displays hours in tenths, so that's how I record it. 0.6 hours = 36 minutes. And the 19.5" width was the widest speed test of the day.

At the end of the day, the virgin 33RP had logged 0.9 hours (54 minutes). By then it had slowed noticeably, but it was still making chips, not dust. They usually start making dust around the 1 hour mark, so I'd say its longevity was no better or worse than my other chains.

This suggests that the virgin 33RP chain had maybe more hook

"Hook" is a term you hear filer's say. Grinders don't talk about "hook" because grinding machines don't have a "hook" adjustment.

The claimed specs for 33RP are 60 degree top plate cutting angle, 10 degree top plate filing angle, 80 degree side plate angle, and 0.028" raker depth. BTW, that's their terminology, not mine. Different companies like to confuse us by using different terminology.

Gullet width, as best I can measure with calipers, runs 0.250" - 0.260". If you believe the 0.028" raker depth spec, then the raker angle would be 6.3 degrees.

Thus far, I have been grinding to the 33RP factory specs, varying only the raker angle.

Your so-called "hook" theory is interesting, and when time allows, I'll try to take some close up pics of nearly virgin 33RP and compare it to my well worn 33RP, and try to determine what is different. With my aging eyes, I can't see much detail even with magnification, so I pretty much have to take a good photo and blow it up in order to see what is going on.

 

[RPM]

rate my stump.

Looks fine .. Make sure to trim the stump pull as soon as the tree is on the ground. Leaving that is asking to trip & fall on to it ....and anyone else that ever ventures near.

Nice board count!

 

[Cowboy Billy]

Snap a chalk line and cut it freehand with a worm drive Skil saw and 18 tooth ripping blade. The cut is not perfectly straight but good enough for framing purposes.

A aluminum straight edge to guide the Skil saw would be handy, but Santa hasn't brought one yet.

The board often bows as it is cut, anyway, due to internal stresses. I'll often edge an inch oversize, knowing that the board will immediately warp, then snap another chalk line and edge it again to final size. Twice the work, but that's what you gotta do to get straight boards. Maybe I'll post some edging pics later.

Ripping is hard on Skil saws (who would have thunk ?) so you need a good one. The worm drive saws have some gear reduction and they are generally a little heavier duty than the direct drive saws.

Thanks MTNgun

Most of the wood I cut to the size I needed. But naturally I got some odd ball size stuff that needs to be edged and was thinking of cutting on a table saw so I didn't have to set the mill back up to cut a few boards.

Billy

 

[gemniii]

<snip>
The claimed specs for 33RP are 60 degree top plate cutting angle, 10 degree top plate filing angle, 80 degree side plate angle, and 0.028" raker depth. BTW, that's their terminology, not mine. .

mtngun -
just to be picky, and make sure I'm not reading typo's -
First -
Are you discussing WoodlandPRO 33RP?
The BOX of 33RP I've got has specs of:
tpca - 60°
tpfa - 10°
spa - 80°
raker depth 0.022"

While at Bailey's

The top plate of the semi-chisel cutter is ground at a 10 degree angle, while the side plate is ground at a 75 degree angle.

and they say 0.025" for depth.

Main reason I'm wondering is because when I started with the 30RP I set the depth to 0.022" and it didn't cut very well, I went deeper, it cut better.
I've 3@ 92 link chains to grind and I ground the first one at 60°/10°/75°, based on Bailey's.
I realize the 5° spa difference may not be much, but I might as well try to get the other two correct to start.

thanks

 

[BobL]

virgin 33RP, 0.6 hour, 19.5" 0.286 inch/sec.

That's hours, not minutes. The hour meter displays hours in tenths, so that's how I record it. 0.6 hours = 36 minutes. And the 19.5" width was the widest speed test of the day.

At the end of the day, the virgin 33RP had logged 0.9 hours (54 minutes). By then it had slowed noticeably, but it was still making chips, not dust. They usually start making dust around the 1 hour mark, so I'd say its longevity was no better or worse than my other chains.
.[/QUOTE]

Yep I know its in tenths of hours but I'm now thinking I still maybe haven't things right.

When you state a cutting speed such as

chain #2, 0.1 hours, 15.5", 0.32 inch/sec

w hat it the actual length of time and distance you measure?

I have been interpreting "0.1 hours, 0.32 inch/sec" as having been calculated by measuring the distance over which it takes to cut for 0.1 hours or 6 minutes?

But from your recent posts I'm now wondering that you might be making a spot test using another stop watch and measuring the time taken to cover a short distance? In this case "0.1 hours, 0.32 inch/sec" is the cutting speed at the 0.1 hour use time of the chain?

Likewise for

virgin 33RP, 0.1 hour, 17.5", 0.375 inch/sec
virgin 33RP, 0.6 hour, 19.5" 0.286 inch/sec.

I assumed it means for 6 minutes the average cutting speed is 0.375 "/s while for 36 minutes its average speed is 0.286 "/s
But now I'm thinking you are doing spot tests and it is 0.375 "/s after 6 minutes and 0.286 "/s after 36 minutes?

Depending on what you mean it makes a big difference in calculating a reasonable average cutting speed over the full 36 minutes.

 

[mtngun]

what it the actual length of time and distance you measure?

Here's how I do and report the tests.

I've settled on a 24" long (by however wide) speed test. It's long enough to be meaningful, but short enough to do without pausing to install wedges, reposition my body, etc..

Before starting the pass, I select the test section on the log, trying to find a section that is constant width -- easier said than done. If there is a slight taper, then I use the average width, but I prefer to find a place that has constant width.

I use a carpenter's pencil to draw a starting line and a finish line. I record -- on the log -- the chain ID, and the hours of usage on the chain at the time of the test.

So I'm CSM'ing along, and as the chain crosses the starting line, I activate the stop watch.

When the chain crosses the finish line, I record the ET (elapsed time) -- just write it down on the slab with the carpenter's pencil. If I remember to do so, I also note the average RPM in the cut. But I've been known to forget.

As I unload the slabs at home, I transfer the data to paper, divide 24" by the ET to get "/s, then post the data like this:

chain ID --- hours of run time on that particular chain at time of speed test --- width of cut --- speed

I have been interpreting "0.1 hours, 0.32 inch/sec" as having been calculated by measuring the distance over which it takes to cut for 0.1 hours or 6 minutes?

No wonder we haven't been on the same page.

"0.1 hours, 0.32 inch/sec" means, in my shorthand, that the chain had been run 0.1 hours since last sharpening, and the speed result was 0.32 "/s.

you might be making a spot test using another stop watch and measuring the time taken to cover a short distance? In this case "0.1 hours, 0.32 inch/sec" is the cutting speed at the 0.1 hour use time of the chain?

You got it, Bob.

Sorry for the confusing shorthand, but I'm trying to cram a lot of data into a post without making it so long that people's eyes glaze over.

 

[BIG JAKE]

By doing speed tests on random widths and at various points in the chain's life, I only hope to illustrate typical "real world" cutting speeds. That's worth knowing. My pine cant speed tests are more scientific and repeatable, but they are not necessarily "real world." Both kinds of test are useful.

I agree-the goal is the best setup for speed/production. Eventually you'll bottom out on what is best and stay with that. Nice work. Appreciate your time to quantify and post the data for us.

 

[headleyj]

MTNGUN - got any closeup pics of your rollers on the mill?

 

[mtngun]

My wheels have evolved, and will likely be replaced by a skid this winter. Wheels don't work well unless they are huge.

Since this photo was taken, the wheel on the left side of the pic was melted by the engine exhaust.

 

[mtngun]

Following up on chain geometry:

I remeasured the raker angles using the DAF. This time around, I DAF'd 10 consectutive rakers, then took the average. The results are a little different than what I posted before, just in case you weren't already sufficiently confused by this thread.

Virgin 33RP. 3.6, 3.8, 4.2, 3.9, 4.1, 3.8, 3.9, 3.8, 4.1, 3.8, average 3.9 degrees.

Here's a closeup of the virgin 33RP so BobL can photoshop the hook.

Chain #2, resharpened 33RP, 6.8, 7.1, 7.0, 6.9, 7.3, 6.8, 7.2, 6.6, 7.5, 6.3, average 7.0 degrees.

Chain #1, resharpened 33RP, 5.3, 5.7, 4.9, 6.8, 5.7, 6.5, 5.7, 6.7, 5.2, 6.4, average 5.3 degrees.

I'm still puzzled, because I don't see any big difference in the geometry of these three chains, other than raker angle.

The virgin 33RP had the lamest raker angle, yet it took bigger bites, spun the slowest, and bogged the easiest.

Speaking of woodcutting, I had to run to town today to pick up the roofing tin for the woodshed, and as usual, passed a few logging trucks on the one lane so-called road.

This used to give me a good scare, but now it's all in a day's work.

 

[deeker]

Depends on whether you like to file the chain on the CSM, like BobL, or swap chains and sharpen them later on a grinder, like me.

I average one chain per hour of run time, and in a typical day I will use 3 chains. 99% of the time, 3 chains is enough for me. A fourth is nice in case I hit dirt or have an exceptionally productive day.

I file my own. I still think one or two extra blades that are sharp would save time. Or if one needs to be shortend or breaks.

Thanks guys!!!

 

[jimdad07]

This used to give me a good scare, but now it's all in a day's work.

[/QUOTE]
Is that why the toilet paper is in easy reach?
BTW, some good information on the raker angles.

 

[deeker]

This used to give me a good scare, but now it's all in a day's work.

Is that why the toilet paper is in easy reach?
BTW, some good information on the raker angles.[/QUOTE]

I think the TP is for close encounters with logging trucks on wet and winding roads....

 

[Winn R]

Thank you sir for excellent data and reporting.

I can feel a new addiction coming on.

 

[mtngun]

Is that why the toilet paper is in easy reach?

Well, it's a long drive with no restrooms along the way, so one has to be prepared. Never leave home without it.

 

[Metals406]

Following up on chain geometry:

I remeasured the raker angles using the DAF. This time around, I DAF'd 10 consectutive rakers, then took the average. The results are a little different than what I posted before, just in case you weren't already sufficiently confused by this thread.

Virgin 33RP. 3.6, 3.8, 4.2, 3.9, 4.1, 3.8, 3.9, 3.8, 4.1, 3.8, average 3.9 degrees.

Here's a closeup of the virgin 33RP so BobL can photoshop the hook.

Chain #2, resharpened 33RP, 6.8, 7.1, 7.0, 6.9, 7.3, 6.8, 7.2, 6.6, 7.5, 6.3, average 7.0 degrees.

Chain #1, resharpened 33RP, 5.3, 5.7, 4.9, 6.8, 5.7, 6.5, 5.7, 6.7, 5.2, 6.4, average 5.3 degrees.

I'm still puzzled, because I don't see any big difference in the geometry of these three chains, other than raker angle.

The virgin 33RP had the lamest raker angle, yet it took bigger bites, spun the slowest, and bogged the easiest.

Speaking of woodcutting, I had to run to town today to pick up the roofing tin for the woodshed, and as usual, passed a few logging trucks on the one lane so-called road.

This used to give me a good scare, but now it's all in a day's work.

Put a good CB in the truck. . . You can find out if there are any trucks coming, and where they are -- usually called out by mile marker. Takes the whole butt pucker factor out'a driving on a narrow haul roads.

 

[BobL]

I can see some differences in hook and front gullet profile between the virgin and the two chains but whether they are enough to make the differences you measure is another matter.

My guess is you are resizing the photos before you post them so it makes it hard to see the detail. How about taking the originals and cropping out and posting just one cutter for the three chains