Optimising an 090 for milling

[harrygrey382]

I'll be using my 090 for milling soon and have a question or two. I want to make the most of the high torque and low speed. I'll run 404 chain because that's what my bar is. I'm thinking of an 8 pin regular or 9 maybe even 10pin racing sprocket. But does anyone know from experience how these stand up to milling?

Assuming I go with the 8 pin, what should I set the rakers at? Bearing in mind it'll be milling only aussie hardwoods - mostly yellow box (sometimes dead) but also stringy and sometimes forest red gum. It's only a 34" bar so 32" max cut if that at the moment. But I don't want to compromise surface finish for speed and have heard lower rakers does this...

 

[mtngun]

Will Malloff milled with an 090 and wrote a book about it. Chainsaw Lumber Making

I've never run an 090, but do mill with a woods-ported 084, and have found a 7-pin 3/8 works best with it.

Generally you want the saw to maintain revs without working too hard. If you lug it, it makes the engine run hotter.

I presume your 404 bar could easily be converted to 3/8 just by swapping the nose sprocket ?

 

[flashhole]

opcorn:

Post some pics of the progress. I'm curious what all you will do to the saw.

 

[820wards]

I'll be using my 090 for milling soon and have a question or two. I want to make the most of the high torque and low speed. I'll run 404 chain because that's what my bar is. I'm thinking of an 8 pin regular or 9 maybe even 10pin racing sprocket. But does anyone know from experience how these stand up to milling?

Assuming I go with the 8 pin, what should I set the rakers at? Bearing in mind it'll be milling only aussie hardwoods - mostly yellow box (sometimes dead) but also stringy and sometimes forest red gum. It's only a 34" bar so 32" max cut if that at the moment. But I don't want to compromise surface finish for speed and have heard lower rakers does this...

Harry,

I'm running a .404x8 sprocket on my 134cc PowerBee motor. It increased the chain speed by about 14% over the 7pin I started with. By using an 8pin sprocket you will be reducing the overall engine speed and since you are running an 090 saw you have the torque needed to use that 8 0r 9 pin sprocket. I have a 50" bar on my mill and only when I'm milling hardwoods over 40" using the 8pin sprocket do I need to use more throttle. I would suggest if you haven't already done so, use a nose oiler. Increasing chain speed also increases friction/heat which decreases bar/chain life. I would suggest leave your rakers set as they are now and give it a try, if you find that the saw is not laboring or bogging down you could lower them an additional .005". I have mine set at .042" since my motor has a lot of torque. Hope this helps.
jerry-

 

[Uncle Rico]

Will Malloff milled with an 090 and wrote a book about it. Chainsaw Lumber Making

I've never run an 090, but do mill with a woods-ported 084, and have found a 7-pin 3/8 works best with it.

Generally you want the saw to maintain revs without working too hard. If you lug it, it makes the engine run hotter.

I presume your 404 bar could easily be converted to 3/8 just by swapping the nose sprocket ?

Does anyone have a pdf of this book that they'd be willing to share?

 

[flashhole]

I couldn't download it either. If someone has a .pdf I'll be second in line.

 

[harrygrey382]

Will Malloff milled with an 090 and wrote a book about it. Chainsaw Lumber Making

I've never run an 090, but do mill with a woods-ported 084, and have found a 7-pin 3/8 works best with it.

Generally you want the saw to maintain revs without working too hard. If you lug it, it makes the engine run hotter.

I presume your 404 bar could easily be converted to 3/8 just by swapping the nose sprocket ?

I've been reading that, and it's pretty good. He doesn't talk about sprocket sizes, and just says he sets his rakers at .045 and makes no mention about surface quality. The 090 has a lot of talk and I know will have no problems holding revs with an 8 pin 404 in 32" of cut. But I was wondering if others have found this is enough chain speed or they could get more, and the effect of raker height on surface finish.

Harry,

I'm running a .404x8 sprocket on my 134cc PowerBee motor. It increased the chain speed by about 14% over the 7pin I started with. By using an 8pin sprocket you will be reducing the overall engine speed and since you are running an 090 saw you have the torque needed to use that 8 0r 9 pin sprocket. I have a 50" bar on my mill and only when I'm milling hardwoods over 40" using the 8pin sprocket do I need to use more throttle. I would suggest if you haven't already done so, use a nose oiler. Increasing chain speed also increases friction/heat which decreases bar/chain life. I would suggest leave your rakers set as they are now and give it a try, if you find that the saw is not laboring or bogging down you could lower them an additional .005". I have mine set at .042" since my motor has a lot of torque. Hope this helps.
jerry-

Thanks Gerry that's great. So I'll start out with an 8 pin sprocket, then drop the rakers incrementally keeping an eye on the finish. Do you know how many revs in the cut your motor is making? Do you know how a racing sprocket will hold up to milling? This is my second mill - the first one I made on your plans and was great, but didn't survive the move from UK to Australia. My new one is also using your plans. I've got a nose oiler for it but haven't used it yet - been using the 070 on it and the bar just wasn't getting hot. Might hook it up for the 090 though.

I'll try and upload this Malloff book to a file sharing sight - my satellite internet is real slow so emailing isn't an option. Will PM with a link

 

[Greenland South]

Does anyone have a pdf of this book that they'd be willing to share?

I can probably help you out with this. Not sure how to go about it though. I guess if you pm me I could send it to you?

 

[Greenland South]

Does anyone have a pdf of this book that they'd be willing to share?

This is where I found mine. Scribd
Hope this is allowed:msp_wub:

 

[kimosawboy]

I just uploaded a copy for anyone, great book!!!
Cheers
G Vavra

Pogoplug: Chainsaw Lumbering

 

[Big Beech]

I'll be using my 090 for milling soon and have a question or two. I want to make the most of the high torque and low speed. I'll run 404 chain because that's what my bar is. I'm thinking of an 8 pin regular or 9 maybe even 10pin racing sprocket.

that's a little contradictory, I would of thought, given that a larger sprocket tooth set will increase chain speed, but decrease torque.
also I believe, the 090 standard is a seven tooth, well it is here in the UK at least, given you a very slow cut speed but masses of torque for the longer bar.
I am going to be using this setup soon with my mill on a 40" English Oak, so will post how I get on.

But, in my view forget the big sprockets otherwise you will end up with a wash board effect on your planks, and if the cutters and or rakers are not correct then vibration will cause havoc along the engine and crank.

good luck

simon

 

[BobL]

that's a little contradictory, I would of thought, given that a larger sprocket tooth set will increase chain speed, but decrease torque.

I don't think that is what he said. He just said that an 090 has lots of torque so it could handle a larger sprocket which would improve his chain speed, which is correct.

But, in my view forget the big sprockets otherwise you will end up with a wash board effect on your planks, and if the cutters and or rakers are not correct then vibration will cause havoc along the engine and crank.

I think sprocket size is only one input to the causes of washboarding. I reckon is related to a synchronization between the chain speed, width of cut, raker depth and cutting speed. The only time I see it in Aussie hardwoods with the 880 is in narrow (<18") cuts. If anything, going to bigger sprockets will require rakers to be set higher which will make smaller chips so the chances of washboard are even less.

The main problem I see with very large sprockets is whether the chain will still ride back onto the bar correctly after passing around the sprocket. The bars the racing boys use these sprockets with are usually modified to help them do this. A chain jumping the bar ay WOT at the start of the bar aint a pretty sight. I have a couple of 9/10/11 tooth sprockets I should drag out and mock up to see what they look like.

 

[flashhole]

Matching the bar length to the diameter of the log helps a lot too.

 

[harrygrey382]

I don't think that is what he said. He just said that an 090 has lots of torque so it could handle a larger sprocket which would improve his chain speed, which is correct.



I think sprocket size is only one input to the causes of washboarding. I reckon is related to a synchronization between the chain speed, width of cut, raker depth and cutting speed. The only time I see it in Aussie hardwoods with the 880 is in narrow (<18") cuts. If anything, going to bigger sprockets will require rakers to be set higher which will make smaller chips so the chances of washboard are even less.

The main problem I see with very large sprockets is whether the chain will still ride back onto the bar correctly after passing around the sprocket. The bars the racing boys use these sprockets with are usually modified to help them do this. A chain jumping the bar ay WOT at the start of the bar aint a pretty sight. I have a couple of 9/10/11 tooth sprockets I should drag out and mock up to see what they look like.

your first and third points are right on the money! I'm hoping the high(er) chain speed of the 8 pin will mean I don't have to lower the rakers too much, but I really want to know how far I can take them without bad surface finish. I haven't come across washboard yet... fortunately! Sounds like I don't want to either.

Simon - the standard 7 pin on an 090 is too small in most timbers today. I've actually got a blank splined clutch drum so there is no standard. But unless you're running a 50" plus bar I think a 7 pin is unsuitable for an 090. You'll be hitting the limiter the whole time or will need to drop the rakers a lot resulting in increased stresses on the chain. I'm sure it will mill 40" oak with an 8 pin no worries, it's not very hard timber really and 40" is small/medium on an 090 cf what it was designed for. Looking forward to your pics though, how about a video? Have you got an 090AV or fixed handle?

 

[Big Beech]

your first and third points are right on the money! I'm hoping the high(er) chain speed of the 8 pin will mean I don't have to lower the rakers too much, but I really want to know how far I can take them without bad surface finish. I haven't come across washboard yet... fortunately! Sounds like I don't want to either.

Simon - the standard 7 pin on an 090 is too small in most timbers today. I've actually got a blank splined clutch drum so there is no standard. But unless you're running a 50" plus bar I think a 7 pin is unsuitable for an 090. You'll be hitting the limiter the whole time or will need to drop the rakers a lot resulting in increased stresses on the chain. I'm sure it will mill 40" oak with an 8 pin no worries, it's not very hard timber really and 40" is small/medium on an 090 cf what it was designed for. Looking forward to your pics though, how about a video? Have you got an 090AV or fixed handle?

Hi Harry,

did not mean my response to come across perhaps as a noitall, dam internet!
at present I only have the option of a seven pin as I am still running the original spur sprocket. though another uk chap on another forum has just purchased a batch of drums and rims from your neck of the woods. when that arrives and is installed I will have more options as you do!
the saw is on its maiden tree cut on Monday on a 5ft Oak fell with a 48" duro sthil bar and was tached up this morning running 7.5 - 7.8K and cuts nice on the 30" bar and chain that it came with. so I am quite excited about using it proper since its been rebuilt. there are a few of my posts knocking around showing from start to finish on the chainsaw forum.
I have probably an early AV model as there is a STIHL emblem and an 090AV sticker on the top casing rather than name plates, which I would presume are later?
as for a video, yes hopefully if the rain holds of Monday, footage will be recorded for prosperity :smile2:
as for a 50"+ bar I would love one but really would not need a bar that big, even 48" is big by UK standards. anything over that is for gloating purposes but you never know, but not only that they are so expensive over here.

good luck and again any info I can learn re milling with the 90 much appreaciated :msp_thumbsup:

Simon

 

[harrygrey382]

Hi Harry,

did not mean my response to come across perhaps as a noitall, dam internet!
at present I only have the option of a seven pin as I am still running the original spur sprocket. though another uk chap on another forum has just purchased a batch of drums and rims from your neck of the woods. when that arrives and is installed I will have more options as you do!
the saw is on its maiden tree cut on Monday on a 5ft Oak fell with a 48" duro sthil bar and was tached up this morning running 7.5 - 7.8K and cuts nice on the 30" bar and chain that it came with. so I am quite excited about using it proper since its been rebuilt. there are a few of my posts knocking around showing from start to finish on the chainsaw forum.
I have probably an early AV model as there is a STIHL emblem and an 090AV sticker on the top casing rather than name plates, which I would presume are later?
as for a video, yes hopefully if the rain holds of Monday, footage will be recorded for prosperity :smile2:
as for a 50"+ bar I would love one but really would not need a bar that big, even 48" is big by UK standards. anything over that is for gloating purposes but you never know, but not only that they are so expensive over here.

good luck and again any info I can learn re milling with the 90 much appreaciated :msp_thumbsup:

Simon

No worries simon I reacted a bit too strongly anyway... I'm actually from west sussex, moved here a couple of years ago (well I'm dual citizen in fact). Where abouts are you? You do still see the odd tree I guess but people are normally a bit touchy about doing things like testing an 090 on them!
I lucked out a few years ago and bought a NOS oregon clutch drum for rims for 12 pounds. I didn't have an 090 at the time but thought it might come in handy later I had a look at your 090 electrix thread, remember it from before actually but I had nothing to add after the experts chimed in. Not sure when they changed to name plates over castings, could it have been when they went to "type 2" AV?
That was a steal on the bar, 48" should be fine with an 8T in in 5' cut. Not sure about the 7.5-7.8k tuning though. Was it tuned via the extended edition manual? That is - disconnect governor, tune to 11k, reconnect governor, set to 8k. I'd say your 7.5-7.8 is good enough. But if you/they didn't disconnect the governor when tuning the actual mixture could be anything. Or if it was set at 7.5-7.8 without the governor it'll be insanely rich and you risk scoring/massive carbon build up.
I don't have a tach, I tune in the cut - timed cuts and in this saws case dogging the sh*t out of it to load it up. Then for milling I richen this by 1/8 - 1/4 of a turn. Looking forward to the video btw!

 

[Big Beech]

Horsham is my home town. where were you based?

as for tuning, yes as you noted. but did not disconnect the vane, as I would of presumed that was untouched when it was running correctly. I would of hoped

what should I do or change, just check plug colour? last thing I wanna do is bugger her up on Mondays big job!!!!

 

[harrygrey382]

Horsham is my home town. where were you based?

as for tuning, yes as you noted. but did not disconnect the vane, as I would of presumed that was untouched when it was running correctly. I would of hoped

what should I do or change, just check plug colour? last thing I wanna do is bugger her up on Mondays big job!!!!

as I noted - as in tuned with a tach without touching the vane? If so then it's not tuned correctly at all. How much smoke does it put out at WOT? Checking the plug won't tell you a whole lot, unless yo use a new plug, make a few long cuts, then kill it while cutting, then have a look.

The best would be tuning on the job with it in the cut. See what the H screw is set at now - if it's much different from 1 turn out and my first assumption is correct, reset to one turn out. Warm it up, if it idles and revs up well you can assume the L is correct. Make a cut - tuning while making the felling cuts might be a bit hairy though If you've loaded it up well (this bit is probably the hard bit, you have to decide what makes an 090 load up) and it is not four stroking, richin it until it does. Then lean it until it just doesn't four stroke in the cut. Might be best to either disconnect the vane or stiffen the spring right up so you're not confusing the governing with four stroking.

If all else fails and you're just felling and making a few cross cuts, 1 turn out will probably be ok. But if milling you want to get it just right, then richen a little bit.

I grew up between midhurst and petersfield, my family are still there. Still love the place but I need the space and wildness of this place

 

[Big Beech]

When it first came to life we tuned to the fourstokibg sound as best we could.
Thsn when tried in wood if just bogged out woulndt hold revs n died. Was a bastard to restart. So went bak to basix 1 turn on eacch n got it runninv again.
When i tunex it on saturday initial readinv was 5.8k. Turnd h until revs lifted.on tic over a little smoky. Backex tbe L back idle rose turned that bac tik over now at 1.8k.checked on tach to the current 7.5k. No smoke on idle snappy pikup too.
Ran it in log along the grajn. Pullslike a train and held revz niceley whilst doggin in too!
Currently living in Bedham near petworth.

Cheeds S

 

[harrygrey382]

When it first came to life we tuned to the fourstokibg sound as best we could.
Thsn when tried in wood if just bogged out woulndt hold revs n died. Was a bastard to restart. So went bak to basix 1 turn on eacch n got it runninv again.
When i tunex it on saturday initial readinv was 5.8k. Turnd h until revs lifted.on tic over a little smoky. Backex tbe L back idle rose turned that bac tik over now at 1.8k.checked on tach to the current 7.5k. No smoke on idle snappy pikup too.
Ran it in log along the grajn. Pullslike a train and held revz niceley whilst doggin in too!
Currently living in Bedham near petworth.

Cheeds S

Not sure what's up with your phone Simon but its quite hard to make out what you meant! Or are you on the piss? Either way, kind sounds like everything is good if it's got heaps of grunt and doesn't smoke. I'm still not totally sure if you tuned it with the vane disconnected though? You can't tune with a tach and not disconnect the vane...