G'day all from Queensland Australia, first time on this site and it's a ripper. I have been milling mostly hardwood with a husqvarna 395xp and a 36 inch bar with .404 two skip chain and a Alaskan mill for a few years now, recently I decided to put a 44 inch bar with 5 skip .404 chain on I added a external oiler to aid in lubrication, once I got cutting I hadn't gone 200 mm into the log when the chain tensioner screw snapped and the chain went slack, I changed over to my other 395xp with the same result, is there a upgraded screw tensioner one can purchase?or am I doing something wrong,I realize that a 44 inch bar is a bit large for the saw according manufactures specs however I don't do it all the time, any advice or suggestions would be greatly appreciated!!
Husqvarna 395xp chain tensioner screw
- Thread starter Cobron
- Start date
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kimosawboy
ArboristSite Operative
I found this with a bit of searching...google can be your friend
Good luck
G Vavra
Not sure what size bar bolts are on the 395XP, But Bar bolts
are typically 5/16 – 18 tpi, assuming SAE grade 5, the bolts should hold a
clamping force of 3300 plus Lbs, and a load force of 4400 plus lbs on the bolt
nuts when the bar nuts are tightened to about 17 ft-lbs or 204 in-lbs. However the tensioning screw is typically a #
10 – 24 tpi, and is being used in the load force position, Not clamping when
tensioning the bar chain. The torque value of a #10 carbon steel , grade 5 machine
screw is about 25 in-lbs, with a load force of 1000 plus lbs, and is being used much like a “screw
Jack” to tension the chain onto the bar. Never mind offset tensioning screws
that use a small pinion gear, which would require a few more calculations. Oh,
also metric grade bolts are fairly close to load sizes if comparing a comparible
size like a M6 metric to a #10 standard screw, since it’s the dimensions of the
screw and grade that are important.
So what does all this
mean, the tensioning screw should be used just to tension the chain onto the
bar, and Not to hold the load that is exerted onto the bar and chain by some
external force like a Granberg small log mill. (Also I’m not sure how much
force can be exerted onto the bar and chain but obviously If its bending or
breaking the tensioning screw its more than a 1000 lbs plus.)
So here is what I would suggest or try: Use the tensioning
screw to tension the chain onto the bar, Next use the Bar nuts to clamp the bar
in place using the correct torque values on the bar nuts.
I also suspect that the bar nuts maybe loosening up a bit to
allow the bar clamping to be reduced and slip, so I would try a few drops of “blue”
mild strength “Loctite” for threads or equivalent thread lock. Do Not use Extra
strength thread compounds because you do want to take the bar nuts off in the
future.
Finally, after everything is tight, I would then take a turn
or turn and a half off of the tensioning screw (CCW), because If the bar Nuts
are clamping properly you should not get any movement, and this will prevent
the force of the Granberg from being exerted onto the tensioning screw.
Good luck
G Vavra
Not sure what size bar bolts are on the 395XP, But Bar bolts
are typically 5/16 – 18 tpi, assuming SAE grade 5, the bolts should hold a
clamping force of 3300 plus Lbs, and a load force of 4400 plus lbs on the bolt
nuts when the bar nuts are tightened to about 17 ft-lbs or 204 in-lbs. However the tensioning screw is typically a #
10 – 24 tpi, and is being used in the load force position, Not clamping when
tensioning the bar chain. The torque value of a #10 carbon steel , grade 5 machine
screw is about 25 in-lbs, with a load force of 1000 plus lbs, and is being used much like a “screw
Jack” to tension the chain onto the bar. Never mind offset tensioning screws
that use a small pinion gear, which would require a few more calculations. Oh,
also metric grade bolts are fairly close to load sizes if comparing a comparible
size like a M6 metric to a #10 standard screw, since it’s the dimensions of the
screw and grade that are important.
So what does all this
mean, the tensioning screw should be used just to tension the chain onto the
bar, and Not to hold the load that is exerted onto the bar and chain by some
external force like a Granberg small log mill. (Also I’m not sure how much
force can be exerted onto the bar and chain but obviously If its bending or
breaking the tensioning screw its more than a 1000 lbs plus.)
So here is what I would suggest or try: Use the tensioning
screw to tension the chain onto the bar, Next use the Bar nuts to clamp the bar
in place using the correct torque values on the bar nuts.
I also suspect that the bar nuts maybe loosening up a bit to
allow the bar clamping to be reduced and slip, so I would try a few drops of “blue”
mild strength “Loctite” for threads or equivalent thread lock. Do Not use Extra
strength thread compounds because you do want to take the bar nuts off in the
future.
Finally, after everything is tight, I would then take a turn
or turn and a half off of the tensioning screw (CCW), because If the bar Nuts
are clamping properly you should not get any movement, and this will prevent
the force of the Granberg from being exerted onto the tensioning screw.
Excellent thank you and I'll let you know... I too have never had a problem with 36 inch bars... The only difference being this is happening on a 44 inch bar which is a GB bar however it is stock standard to fit huskies.
Finally it worked out... Thanks for all the advice, initially I tensioned the chain bolted everything down released the tension screw got cutting and... Bang the chain went slack... I stopped and took off the chain brake cover and had a closer look at the internal of the cover I noticed a bit of a raised surface on it I took my battery grinder with a sanding disc and gave it a light sand I did the same to the bar spacer which was also slightly protruding from the bar slot I reassembled everything tensioned the chain tightened the bolts and could see immediately that it had clamped the bar much better..... After 7 slabs all about 900mm wide never had another problem
Attachments
Good to hear you found the problem.
In your photo, I see you are milling with the mill rails direct onto the log and the mill is pushing a small pile of sawdust ahead of itself.
If you use the log rails every time you will have a lot less friction. My mill rails on my mills a lined with HDPE so they have even less friction
I also see you are milling with your arms wide apart.
I'd recommend setting up a remote throttle and adding a higher up handle.
As well as saving shoulders and arms it gets your head up away from the exhaust fumes and sawdust.
Sorry if I show this a zillion times but this is a far better position to be milling.
Arms just steer and activate throttle, forward pressure is done with my hip/thigh - note use of log rails to reduce friction.
In your photo, I see you are milling with the mill rails direct onto the log and the mill is pushing a small pile of sawdust ahead of itself.
If you use the log rails every time you will have a lot less friction. My mill rails on my mills a lined with HDPE so they have even less friction
I also see you are milling with your arms wide apart.
I'd recommend setting up a remote throttle and adding a higher up handle.
As well as saving shoulders and arms it gets your head up away from the exhaust fumes and sawdust.
Sorry if I show this a zillion times but this is a far better position to be milling.
Arms just steer and activate throttle, forward pressure is done with my hip/thigh - note use of log rails to reduce friction.
flashhole
Addicted to ArboristSite
Cobron - what kind of wood are you milling? The color of that sawdust doesn't look like it should be coming from that log. Glad you solved your problem.
Oh nice one... I'll give that a try... Yeah in all honestly she's a hard push through a big dry blue gum
Hi mate... It's bluegum...The sawdust is red in colour... The log itself has been sitting in the sun for possibly 5 years
flashhole
Addicted to ArboristSite
Very nice. I hope to do some milling in the next week or two on a large ash that the beetles killed. I did a few last year that slabbed out nicely. Hopefully this one will work out well too. My rig is a 394XP with a 32" Alaskan.
Oh thanks mate.....Yeah I love my 395xp's it went through that hardwood pretty good.... First time I've used a 44 inch bar on her too... Is Ash a softwood tree?
flashhole
Addicted to ArboristSite
Ash is considered a hardwood. It's main notoriety is they use it to make baseball bats. Ash is very plentiful here in NY and comprises most of my firewood pile. I rank it 3rd in burn qualities behind hard maple (my favorite) and shag bark hickory. Not a lot of Oak where I live so I didn't include it in the ranking. My 3/8" pitch 36" bar and milling chain is a good fit to my 32" Alaskan. I have also found the shallower 10 degree cutter angle makes a smoother cut. Another thing I learned is having the log on a slight down angle allowing gravity to help move the saw through the wood is way easier on the back.
flashhole
Addicted to ArboristSite
I set up like this to mill. Two cinder blocks in the back and one in the front for the downhill angle.
I made a fixture to trim the edges, it bolts to a 16" bar that I use with my Stihl 460.
I made a fixture to trim the edges, it bolts to a 16" bar that I use with my Stihl 460.
flashhole
Addicted to ArboristSite
This is the fixture I use to trim the edges. Easy to make but I burned up two drill bits drilling holes through the bar.
flashhole
Addicted to ArboristSite
This is the blow-down I milled. What a chore cutting it to the long lengths I wanted and getting them up out of the ravine.
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