Husqvarna 3120 - milling

[Delphy]

Hi guys,

Happy holidays! I'm new to this site, and must say the amount of knowledge here seems vast, glad to here!

Anyways; got my hands on an older 3120. The saw is bought as the large companion to my existing 460, which I've had for 10 years, taking down primarily beech and oak of sizes 20"+. The "new" 3120 is expected to be saw for the felling of the odd 30"+ trees, as well as doing milling. And the latter is where my question arrives:

Upon purchase, it was equipped with a worn-out .404 28" bar and chain, without sprocket at the front of the bar. As I want to do milling, I don't want a larger cut than needed, and as had trouble finding a .404 bar with a front sprocket, I decided to convert the setup to 3/8" - and ended up with 36" 3/8 bar and chain, and obviously exchanged the rim sprocket with a 3/8 to match. Fitted a ripping chain (10 degrees cut) and good to go.

However, I've had some trouble with the chain coming off when milling - when using the normally (upright) there's no problems, it just rips through (3120 has A LOT of power!) however, it comes of when milling - and I'm expecting the "loose" rim sprocket on the clutch drum to be the problem - when tilting the saw, the gravity will have the floating rim sprocket drop to the "bottom", and with the weight of the saw in the alaskan-mill (style) also weighing downwards, this could cause the chain to be forced of the rim sprocket?

Have you guys any experience here?

Is the solution to keep the chain tighter (currently adjusted so that the chain with little force can be pulled free at the middle of the lower side of the bar)?

Or getting a fixed sprocket setup (i.e. fixed to the clutch drum)?

Or getting "non-sprocket" spacer to ensure the existing rim sprocket doesn't go al 5 mm to the bottom?

Or is the problem a completely different sort? (Not ruling out ignorance of the operator!)

Oh, and this little endeavour allready cost me 1 completely new ripping chain - when coming off, the lower part of the chainlinks (steered in the bar) was damaged fro the majority, causing it not to fit the bar

Cheers!

 

[Bwildered]

The chain is getting too loose while cutting, it should snap back to the bar, being blunt will cause heat, which will cause the chain to stretch, the burred chain drive tangs can be cleaned up with little grinding to be functional again.
Thanski

 

[Knobby57]

My milling is very limited . I don’t have that kind of time on my hands ..... but as said before you ham gring the bits off the chain links to work for you again . Make sure your chain is always tip top sharp !! Always . I would hit withe a file and touch up after every tank . 2 .. are you sure your getting enough oil to the chain . Maybe a aux Oiler may help but you should be more than capable to oil a 36” if all is working ok . 3 a hot chainnwill get loose . So if you ajust when hot make sure you slack it out before it cools back down or you will be putting a bit ton of pressure on your crank and bearing . 4 . Have you thought about a washer for a spacer between the clutch and the sprocket . Just not so much to throw the sprocket to far in . Good luck and make lots of slabs

 

[SeMoTony]

Hi guys,

Happy holidays! I'm new to this site, and must say the amount of knowledge here seems vast, glad to here!

Anyways; got my hands on an older 3120. The saw is bought as the large companion to my existing 460, which I've had for 10 years, taking down primarily beech and oak of sizes 20"+. The "new" 3120 is expected to be saw for the felling of the odd 30"+ trees, as well as doing milling. And the latter is where my question arrives:

Upon purchase, it was equipped with a worn-out .404 28" bar and chain, without sprocket at the front of the bar. As I want to do milling, I don't want a larger cut than needed, and as had trouble finding a .404 bar with a front sprocket, I decided to convert the setup to 3/8" - and ended up with 36" 3/8 bar and chain, and obviously exchanged the rim sprocket with a 3/8 to match. Fitted a ripping chain (10 degrees cut) and good to go.

However, I've had some trouble with the chain coming off when milling - when using the normally (upright) there's no problems, it just rips through (3120 has A LOT of power!) however, it comes of when milling - and I'm expecting the "loose" rim sprocket on the clutch drum to be the problem - when tilting the saw, the gravity will have the floating rim sprocket drop to the "bottom", and with the weight of the saw in the alaskan-mill (style) also weighing downwards, this could cause the chain to be forced of the rim sprocket?

Have you guys any experience here?

Is the solution to keep the chain tighter (currently adjusted so that the chain with little force can be pulled free at the middle of the lower side of the bar)?

Or getting a fixed sprocket setup (i.e. fixed to the clutch drum)?

Or getting "non-sprocket" spacer to ensure the existing rim sprocket doesn't go al 5 mm to the bottom?

Or is the problem a completely different sort? (Not ruling out ignorance of the operator!)

Oh, and this little endeavour allready cost me 1 completely new ripping chain - when coming off, the lower part of the chainlinks (steered in the bar) was damaged fro the majority, causing it not to fit the bar

Cheers!

Welcome Delphy: Read thru the CS milling 101 to get answers to questions you did not even know you needed to ask. My saws oil feed is maxed out and I use the "top" of the bar while milling since that is the oiled side. Persons using the "bottom" side of the bar add an auxiliary oil feed at the nose of the bar to lube & cool. My avatar shows off a 60" bar on my Alaskan w/skip chisel being driven by a ms-460 tuned to match the muffler mod and 40:1 mix. The chain droop under the bar occurred in the brand new Oregon chain from "stretch" which may happen from metal wear rather than elongation.
Learning to sharpen the cutters is not enough, setting the depth gauge relation to the cutter is equally important for milling to maximize the efficiency of the chain with the power available.
Stay safe & enjoy

 

[Delphy]

k, so got going again - decided on new chain, to ensure no problems encountered there. Running the 3120 with a 36" 3/8 bar/chain, and tightened the chain, so it can nearly/just be lifted free except 1mm by the middle of the lower side if the bar. Good to go! Starting the saw, and starting to cut - about 5 cm. into the cut, it seems the saw is not moving forward anymore - and therefore not cutting anything. Pushing a bit on the mill handles, causes the cut to go downwards, and upon inspection of the chain afterwards, it seems the teeth being on the "upper" side (I cut with the lower side of the bar) are somewhat more worn - especially on the outside (!). Pics attached of my setup, as well as the cuts gone wrong.

From SeMoTonys post above, I discovered the 101 CM milling guide - (thanks! - lots of valuable input!) and I noticed the hints related to chain wear and the actual build of the mill - however, since the chain was all new, based upon the hints, I can only see that the mill setup must be slightly off - i.e. with the "front" of the cut being slightly lower than the "back" of the cut. The mill is all new, newer used before - so if indeed this problem, it must be related to setup and rigging. The problem could also be caused by the chain dulling super quickly, causing it to skew, but is doesn't contact with anything inside the wood. The wood is a cherry, cut down app. 1,5 years ago - having rested outside until taken inside for the cut, I wouldn't suspect this to cause th wood to go "dead" that quickly.

What do you think - Am I hitting some spots here to explain the problem, or am I completely off track?

Thanks guys!
​

Pic 1 - Saw and setup.




Pic 2 - the skewed cuts.


Pic 3 - The skewed cuts from the other side....



Pic 4 - showing the chain tooth of the "upper" side when laying the saw into the cut - notice the wear on the "outside", as opposed to the new pic.


Pic 5 - The "lower" side of the chain when running, not nearly as worn.

 

[Delphy]

Guys, any opinion here? All input highly appreciated

 

[pioneerguy600]

I am transferring your thread over to the milling forum, there will be more members there to answer your questions.

 

[Grandedog]

Howdy,
Check to see if the bar rails are square.
Regards
Gregg

 

[pioneerguy600]

I don`t do a lot of chainsaw milling and am no expert by any means but that mill setup looks to be very unstable in the connection between the upright posts and the cross members between the rails. Would it not allow the saw to tip somewhat either up or down if pressure is applied to the mill frame?

 

[mdavlee]

Check the clutch cover or spike mounting bolts to make sure it's not what killed the cutters on that side. Forcing it without the whole bar in the cut can cause it to rock the mill and bind.

 

[Delphy]

I am transferring your thread over to the milling forum, there will be more members there to answer your questions.

Thanks !

 

[BobL]

My Oregon Manual says that "Oregon 73" is a 0.058" gauge chain.
If you have an 0.063" bar this will cause EXACTLY what you see happening with the chain drooping over in the groove.
Don't be too upset - I did this some 30 years ago on an old 50 cc Homelite, no AS back then - took me a week to work it out.

 

[Delphy]

View attachment 628262
My Oregon Manual says that "Oregon 73" is a 0.058" gauge chain.
If you have an 0.063" bar this will cause EXACTLY what you see happening with the chain drooping over in the groove.
Don't be too upset - I did this some 30 years ago on an old 50 cc Homelite, no AS back then - took me a week to work it out.

Yeah, that would have caused it, absolutely. But the width of the bar is 1,5 mm (equivalent of 0,058”) and youre right abot the chain being 0,058” / 1,5 mm, so all should be in good shape

 

[BobL]

Shoulda remembered the Husky stuff is usually 0.058".
OK - then look to your rails not being square - that will do the same thing.