4.1 hours, 3.25 gallons, and 20 slabs

[mtngun]

Another personal CSM record smashed today, logging 4.1 hours run time on the CSM -- though it would be more impressive if I could cut the same amount of wood in fewer hours.

The CS62 felled this 23" dead standing doug fir. The tree had been killed by a slash fire.

It was 108 years old.

Rate my stump.

Four 12' logs.

Look, Ma, it's self feeding. Using a fresh GB'd chain, throttle zip tied.

Another view showing the slope, so BobL can calculate the angle with photoshop.

It didn't self feed all that fast, but it was making some serious chips, as you can see.

Last slab of the day -- no, I didn't have time to finish this log.

The Granberg mill balances better when the guide is placed on the left edge of the log, rather than the center.

 

[mtngun]

20 slabs (my personal record is 21 pieces in one day, but those 21 were not as big as these 20). The Oly earned it's keep today.

Photos rarely do justice to the steepness of the terrain, but you can get a good idea from this view.

All of the chains that I used today performed satisfactorily when they were fresh, and all of them were useless after one hour run time. Speed test results and conclusions after I unload the truck tomorrow.

 

[Stihlman441]

Nice work,are those rails made from uni strut (dont know how to spell it) ?.

 

[mtngun]

Yep, unistrut, sometimes called superstrut.

 

[Timberframed]

Mtngun, Again good work! Do you bother with the with bar oil in the saw or do you just rely on the aux oiler like I do?

 

[mtngun]

I do put oil in the saw because I worry that it might hurt the oil pump to run dry.

Plus, the flow on the Granberg aux oiler is not consistent. Sometimes the needle valve seems to get plugged up, and you have to open it all the way or even blow into the tank opening to unplug it.

Or when you remove the aux to flip the mill over to swap or file a chain, sometimes the oil drains out of the line and then it'll take a good minute to fill the line when you resume milling.

One of these years I'll relocate the aux needle valve to just above the drip point, so the line will always be full of oil at least to that point.

 

[Timberframed]

I was just curious. On my 60"saw there is no oiling provision. I had used a Coleman camp stove fuel tank (pressure) hooked to the water intake for oil at the drive with the last 7 or 8 gallons of fuel but found it unnecessary. I'm not suggesting removing the oil pump to gain what...1/100th hp? In my case there was no choice. I did like the fact that under pressure, it delivered -not relying on gravity. Along with all the machines in the shop I have three old Harleys plus I'm a married man and so I have to make sure everything is lubricated properly. Oil and oil pressure is on my maintenance schedule daily. Food for thought.

 

[BobL]

Another personal CSM record smashed today, logging 4.1 hours run time on the CSM -- though it would be more impressive if I could cut the same amount of wood in fewer hours.

Good work - I'm dead jealous you got that much time on a mill.

Rate my stump.

9/10

Look, Ma, it's self feeding. Using a fresh GB'd chain, throttle zip tied.

It didn't self feed all that fast, but it was making some serious chips, as you can see

.
You need more weight - why dontcha dump a big cookie on the mill ala Will Malloff and see what it does?

The Granberg mill balances better when the guide is placed on the left edge of the log, rather than the center.

Yep that's what I find as well, I tend to open up the rails so that the LHS rail is hard over to the left and the RHS rail is about 2/3rd of the way across.

 

[BobL]

I was just curious. On my 60"saw there is no oiling provision. I had used a Coleman camp stove fuel tank (pressure) . . . . .

Sounds like the "ducks nuts" . . . . have you got a picture. Sounds like just the thing for my next mill.

 

[Cowboy Billy]

Looks great Mtngun

How do you edge/size your boards?

Billy

 

[Timberframed]

Here you go BobL. You can see a fine stream of oil coming out. It can be regulated to a very slow drip. Full of oil and pumped up it can feed the bar for 3 hrs or so.

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[mtngun]

How do you edge/size your boards?

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.

 

[mtngun]

speed tests

Four different chains were used, and this is what we'll call them.

chain #1 -- 33RP with 6 degree raker angle
chain #2 -- 33RP with 7.5 degree raker angle
GB'd -- 33RP modified to GB style, 5 - 6 degree on regular cutters, more on scoring cutters.
virgin 33RP -- I will measure and post the virgin geometry later.

The hours referred to in the results is the run time on that particular chain at the time of the speed test.

chain #1, 0.7 hours, 15", 0.30 inch/sec
chain #2, 0.1 hours, 15.5", 0.32 inch/sec
GB'd, 0.1 hours, 16.5", 0.33 inch/sec, 9500 rpm
GB'd, 0.5 hours, 16", 0.233 inch/sec, getting dull after only 1/2 hour.
GB'd, filed, 17", 0.185 inch/sec, my filing in the field sucks.
virgin 33RP, 0.1 hour, 17.5", 0.375 inch/sec
virgin 33RP, 0.6 hour, 19.5" 0.286 inch/sec.

I think there's one more test hiding somewhere, maybe it'll turn up when I edge the boards.

Chains #1 and #2 liked to spin at 9000 - 9400 rpm.

GB'd liked to spin at 9500 - 10,000 rpm.

Virgin 33RP liked to spin at 8800 - 9200 rpm.

Virgin 33RP was by far the easiest chain to bog, and it spun the slowest. It was obviously taking bigger bites than the other chains. It wasn't excessively boggy, I'd say it was "just right" for this powerhead. The other chains could stand to be slightly more aggressive.

GB'd dulled the fastest. On a previous day in the woods, I noted that GB'd had dulled the slowest, so I'm not drawing any firm conclusions based on a single experience. The tree fell in some bare dirt, and some dirt got embedded in the bark -- dirty bark will dull a chain instantly.

Chain #1 was swapped after 1.4 hours.

Chain #2 was swapped after 0.8 hours

GB'd was filed after 0.7 hours, and swapped after 1 hour.

The virgin 33RP had logged 0.9 hours when I called it a day. It had perhaps one more decent pass left in it.

The winner of this shootout was clearly virgin 33RP. Even though it was not particularly sharp -- you can often see glint on the cutters of new WP chain -- it took big bites and cut fast.

I don't understand why virgin 33RP, with its lame raker angle and glinty cutters, was actually more aggressive than my experimental chains. There must be something different about the geometry of virgin chain, something besides the raker angle. I will study the virgin chain very carefully and try to figure it out.

 

[BobL]

Here you go BobL. You can see a fine stream of oil coming out. It can be regulated to a very slow drip. Full of oil and pumped up it can feed the bar for 3 hrs or so.

Thanks TF.

 

[gemniii]

OOOHHH!!

Good numbers!

/edit - so it looks like your cranking out 20 to 30 square feet a minute while your in the cut.
Oh - and any figures on total bar oil consumption?

 

[huskyhank]

Good work!
Bet you were tired.
Thanks for the report.

 

[BobL]

Thanks for posting such detailed data mtngun - especially the width of the logs cut.

I took the data for Chains 1 and 2, the first reported GB measurement, and the 2 new chain data and calculated the cutting speed in terms of "Area cut per unit time" (Sq"/s) and plotted these against the width of the cut and this is what I got

The 2 new chain data points have been combined into one point to get an average of both the "area cut per unit time" and "average cut width" (These can't be just simple averages but have to be time adjusted)

The way the chains 1, 2 and the GB plot on an approx line tells me the are cutting speed is simply proportional to cut width, ie wider logs are cut at a greater area/s. This means that if chains 1 and 2 and the GB were all placed in the same width log they would all cut at the same speed, ie about 0.3x "/s (divide sq"/s by cut width).

Now the new chain (and there is hint of this from the GB chain) is not cutting faster but slightly slower than the others ie <0.3 "/s (remember it's the sq"/s divided by cut width).

This could be due to a number of factors.
Less aggressive cutter, went blunter quicker etc

But the way the graph is bending over towards horizontal could also mean that at about a 17" cut width your entire setup approaches its "area cut per unit time" limit for that type of wood, ie no matter what you do, the combo of saw/chain etc simply won't cut any faster than about 6 sq"/s of wood. It would be interesting to include some lo pro in this kind of analysis.

 

[deeker]

Good work guys!!!

Good reading and I am learning.

A new package from Baileys.....a 3 footer for the 088....and only one ( for now ) ripping chain....

How many chains should I usually have?? Not counting the bandsaw....sometimes I have to slab with the CSM. Too big for the mill.

Thanks...

Kevin

 

[mtngun]

How many chains should I usually have??

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:

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.

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.

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.

 

[jimdad07]

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.