B-20 Chain Log Turner

[chickenchaser]

I'm having issues.  :D

Loaded a red oak yesterday. 28"x17'...fairly uniform. Took a little assist from the customer's compact (toy) Kubota as it was front heavy.

Tried to turn knotty side (burls??) up for first cut. This was too much for the turner. After using all available manpower+toy Kubota again, turned and opened worst face.

When I had the same results turning (or NOT turning) for the 2nd cut, I decided maybe it was a fluid/filter issue, even though other hyd. functions were fine. Turner raised log but would not rotate it. So I changed the fluid filter and added fluid. Still no luck.

I am almost positive, weight-wise, I have sawed similar logs without a problem while getting OJT with previous owner. I am wondering if the weight distribution (front heavy) could be the problem, or the turner's hydraulic motor? Valve? I don't think it would be a pump issue. I blew the line to the front toeboard roller on the final attempt to turn it. The hose had made contact with the pavement at some point, so it was weak at the point of the rupture.

After repairing the line, I will check out the control valve. I assume I can swap the connections and see if there is a difference.
Edit: per the manual - this might be the wrong thing to do. May need to make a call first...

Any suggestions would be appreciated.

CC

[redbeard]

The heavy logs you have to play with the balance it won't rotate big logs when pinched against stops you have to walk log out a bit and raise and rotate at same time to get log to flip. Always raise loader arms so you can catch the log.

[chickenchaser]

...you have to walk log out a bit and raise and rotate at same time to get log to flip. Always raise loader arms so you can catch the log.

Redbeard, thanks for the reply. Tried different combinations. I can't say for sure, but I think it struggled to MOVE the log back toward the loader. When I lowered the arm, the log would rock/roll away from the stops. Line blew before I could try your method. Thanks for the reminder about the loader arms. Prev. owner stressed this.

Customer asked if we needed to cut in half before we loaded it. I said "No problem...sawed some like this before."  :

Thanks again.

CC

[Tom the Sawyer]

My B-20's chain turner needs some help once in awhile when turning very large logs.  The log you described figures out to 6400 pounds.  The load limit for the B-20 is 5000 lbs. and I'm pretty sure that the chain turner won't roll a log much over 4000 lbs without some help.  The arm can lift considerably more than the chain can turn. 
That components fail at 28% over their load limit isn't surprising.

But now that it is on the mill, what do you do?  I have found that (making sure the loading arms are up all the way) sometimes you can raise the turning arm just high enough to make contact with the log and then use the chain to 'nudge' the log outwards, away from the log stops.  Then raise the arm and the log should roll towards the stops - perhaps with help from a cant hook while activating the chain.  You might have to try a couple of times.  If you don't already have spares you should probably pick up a few repair links for the size chain that came with your mill.

[ladylake]

 
On the B20 the chain turner will run out of power on the big snarly logs sometimes.  I put a 1 tooth smaller sprocket on the drive motor which helped quite a bit, way better than it was.  Also put on a 60h chain which is way stronger than the regular 60 chain it came with

[redbeard]

Another helpful trick is slide some ABS or PVC plastic pipes over log stops. learned that trick from the forestry forum,  whoever was original sawyer that posted that Idea thanks!

[ladylake]

 Good tip on that pipe over the stops.  I'd put that 1 tooth smaller sprocket on the turner drive motor as that helped quite a bit and when you get those big ones lube the chain and gears up good.  Steve

[chickenchaser]

Well...it's a stack of 2x6s now!  8)

Tom - I looked through the manual again and when I saw the load limit, I remembered the faded sticker on the control panel stating 5000lb. max load. I knew then I was prob above that - easy. 6400! WOW!

Do you have a formula for figuring such things?

I like the smaller sprocket and pipes idea, too.

Many thanks, guys.

CC

[beenthere]

The FF toolbox (bottom left column) gives estimated weights for logs.
The diameter mid length of your 17' red oak might be around 32" so comes in just a bit over 6000#

[Ga Mtn Man]

Look to the left and scroll down to the FF Tool Box.  It's just below the sponsor links.

[chickenchaser]

Ahhh...yes, there it is.

Thanks!

CC

[snakeknuckles]

Not to interrupt your train of thought... I don't come up with that kind of weight even using 32" dia: weight= 32^2/4*pi/144*17(ft)*46(lb/cuft=4367lb.  a 6400lb log of this size would have to have a density of 67lb/cuft???

[John S]

I also came up with just under 4400 lbs.

[bama20a]

4652 lb. say_what

[beenthere]

Remember the tool box log weight is diameter at MID length, not small end. I missed that when I first used the formula.  ;)

Plus this is an estimated weight, as there are variables in density from different growth rates. Slow growth in red oak will have higher density (and weight) than fast growth, due to the ring porous characteristic.

But seems the key point is that the log may be over the weight designed into the turner.

snakeknuckles
Welcome to the Forestry Forum    8)

[Tom the Sawyer]

The app I have on my Android phone, SawLogCalc Pro, calculates the large end diameter if you provide the small end and the length.  A 28" small end, using their 'standard' taper formula, calculates the large end at 36.93".  The average diameter, times the length is used to figure the cubic footage.  The green weight per cubic foot of southern red oak that they use is 65 lbs. per cubic foot (I have seen tables with it listed as 63 or 64 lbs/cu.ft elsewhere so it is pretty close).  They figured 98 cuft = 6400 lbs.  They round up in 100 pound increments for safety.