RIM SPROCKET SYSTEMS

[fencerowphil (Phil L.)]

Since I am faced with buying a few 404 chains for my mill, I am planning to change over to the rim sprocket system.  The idea will be to have three chains, each with its matched replacement rim(s), so that they will wear together.

My first Stihl chain lasted far longer than the teeth on the original spur gear on my Stihl 090.  This was in spite of the fact that I cut at least sixty pieces of nail and fence with that chain.  By the time I had ground away half the teeth on the chain,  the spur looked awful.  My question for you guys is this:  
     Should I team up a pair of rims for each chain, rather
      than one rim for each chain?   In other words, how will
      the rate of wear on the rims compare to the rate of wear
      on the chain.
     
Phil L.

[Kevin]

 Phil;
I think Rob mentioned this the other day but it's geared to two chains per rim.
The problem with milling is the chains get loose with heat and the wear is more severe than normal use as I am sure you are well aware.
Rims are cheap, I think all you can do is watch for the wear when you clean the saws after each use.
Dressing the bar and proper chain tension is a must when milling, that alone will save the chains, bar and rim.

[Kevin]

... and lots and lots of bar oil.  

[blue_eyed_devil]

Just curious if you have compared cutting rates between  .404 and 3/8 pitch ?
I always thought .404 would bag out even the biggest saws!

[fencerowphil (Phil L.)]

The original Stihl brand ripping chain lasted so long, that this is the first time I have had reason to change chains.  Over the period of a year and a half, I have probably cut between sixty and seventy small nails and pieces of fence, as well as screws and a few 12penny and 16 penny nails with this 404/.063 gauge chain!  Tough chain on a 41" bar.

Of course, bear in mind that the Stihl 090 power head is 137cc.  - big and heavy.    I think I am right in thinking that I can simply change a rim (without changing the clutch hub), and be able to try smaller chain.   The question is whether rims will be available for the Oregon 12004 rim system for that 3/8 chain.

Thanks,  Phil L.

[woodbeard]

Yes, indeed. You can get 3/8 rims in 7 or 8 tooth for that drum. Also .404 in 7 or 8 tooth and .325 in 9 tooth.
I have basically the same setup, and have been using the .325

[fencerowphil (Phil L.)]

 
I found out that Madsen's in Oregon had the Oregon brand goods I needed for the Stihl 090:    The rim sprocket system was #12004, available with a variety of rims.  (This number does not show up on Oregon site.  While the rims were on sale, I ordered two .404 7-tooth, one .404 8-tooth,  one 3/8 8 tooth, and two .325 9-tooth.  Oregon also has set-ups for the old Stihl 075.  (I have one of those, also.)  #22271X is the system which includes a 3/8" 8-tooth rim for the 075.

Woodbeard,
The idea of the .050 GB bar with  .325 / .050 ga. chain and a 9 tooth rim is still something I want to try.  I'll have to wait a month or so and come up with the coins for that, too!  Thanks for the info.!  Even Madsen's guys were not aware of this option.   One word of caution, which I hope I remember:   I would definitely save the .325 set-up for metal-free logs.
Phil L.

[Oregon_Rob]

Yes, indeed. You can get 3/8 rims in 7 or 8 tooth for that drum. Also .404 in 7 or 8 tooth and .325 in 9 tooth.
I have basically the same setup, and have been using the .325

Please expound on your work with the .325 chain on the big saw. I have been contimplating giving it a try on my "Big Orange Dog" 2100

[fencerowphil (Phil L.)]

Hey Oregon!

I'm just too good (at expounding).    

The first step would be to find the Oregon rim sprocket system to match your 2100.   If the Oregon (brand)  site doesn't have it listed,  Madsen's in (the state of) Oregon can tell you what it is, and they will probably have it "on the shelf".   The most flexible category of their rim drive splined cups(drums) is called "7-spline standard".   Available tooth counts for the rims, which slide onto the cup/drum, range from 7 to 9, with nine available for the .325 only.  Chain pitches range from .325 to .404.  GB also makes some rim sprocket systems, but not as many different types to fit particular crank dimensions.   When you first purchase a "system", you get the splined cup and one rim.  This system has a particular model number, applicable to your saw model.

Kornfused yet?    

The diameter and length inside the collar where the needle cage resides is matched to your particular crankshaft, so that the rim sprocket splined cup replaces your existing clutch cup/drum.  On the other hand the rims, which slide onto the cup, are interchangeable, letting you change bars and gauges and chain pitches by merely changing the $4 rim.  Neat, huh!

Below are some notes I made about the bars for my saw :

[  Note:   GB makes a .050 bar which will fit a Stihl 090, available thru Foster's.
       You can use a .325 chain, .050 gauge and use a 9 tooth Oregon .325
       rim.    This would only be feasible on a certified metal-free log!
       36" GB bar for .325, .050 ga.  $55.00  shpg.  $7.00
       42" GB bar for .325, .050 ga.  $75.00      "           "]

Kevin has a quick set of links to all these.  Go to . . .

http://www3.sympatico.ca/kvn.rob/millingmasters.html

Note that Foster's is in his group of "Chainsaw Mills" and the others fall under "Suppliers".
Phil L.
        P.S.  Well, you said "expound"!  

[fencerowphil (Phil L.)]

Oops, I'm sorry, did you mean for Woodbeard to expound?

He musta' been busy!

Phil L.

                You probably already knew most of this, but
             others may be curious about this topic.  I had to
            learn a lot, QUICK, when I got into the stuff.                     Woodbeard helped.

[Oregon_Rob]

Phil,
I thank you for your great knowledge of the conversion. I was really wanting to know about the differences in cutting/milling with .325 and what improvements and or problems were encountered in going with the smaller chain set up.

Best regards,

Rob

[fencerowphil (Phil L.)]

I know the feeling.

You might try a direct contact with Woodbeard.   He claims good experience, faster feed, etc.   He also said he has not hit any metal, however.   Another very experienced miller is Ralph Foster, owner of Foster's Sales:

Ralph@fosterssales.com

His comments appear widely on the Yahoo Milling Group:
http://groups.yahoo.com/group/milling

When I ordered the rim system from Madsen's,  the guys there were very skeptical about using .325 on big bars.   They did not know about the GB bars made to fit the 090 at .050 gauge, either.  This is understandable.   After all, the heritage of the Northwest includes big timber and big saws, running .404 and 1/2" pitch chains.  To them 3/8" pitch is probably small.  (In contrast, my local Stihl dealer thought that I had to mean the 009 model, not the 090, when I recently ordered flocked air filters.  Different type demand in our area.)

Here is an example of Ralph's work, dated 12/2/03 on Yahoo:

[   Hello Rob

  You have been posting some great stuff lately.

  I have been using .325 for milling for a couple of years now.
  It's great stuff. I've used it on my 088 and it stretches but does not
  break.

  .325 chain comes in professional grade chain, unlike 3/8 Low Profile chain.

  It cuts about 25% faster than 3/8 50 gauge chain and about  10% faster than 3/8 low
   profile chain with out any of the negatives associated with it.

  Big saws cross cut faster with standard 3/8 chain.

  For milling I use the same file or stones I'd use with standard 3/8 chain, I believe it opens    up the chain and allows it to move more saw dust.

  .325 chain cuts faster and smoother than any thing I have tried so far and I've tried
   everything I could think of except 1/4" chain. And that should work well on saws that are    border line for the job they are doing now.

  Ralph ]

You can get more info there, for sure!
Phil L.

[fencerowphil (Phil L.)]

Aha!

I see we are meeting ourselves coming and going.

You're in two places at once!

Phil L.

[Oregon_Rob]

I jsut know there is a WILD GOOSE around here somewhere.
I'll just keep hunting till I find it.

[fencerowphil (Phil L.)]

Well, at least we now have a good bit of information "in black and white" for others to use.   It will save them a good bit of time.

Got to go to work.  

Or, as Maynard used to say to Dobbie Gillis ,   "WORK!?"

Phil L.
               P.S.   See Bailey's cat.# CA25

[Gus]

Good coverage guys,
I was going to put .325 on my 2100 when I started milling and the guy at the saw shop talked me out of it. Thinking the screamer would break it I suppose. If you can run it on a 090 or 088 I would certainly think we could run it on a 2100.
Thanks guys,
Gus

[Bobcat_pa]

PHIL L:  the .325 does not hold up too well to metal ?   3/8 better ?

[fencerowphil (Phil L.)]

Hey Bobcat!

The .325 pitch comes in at least these flavors:  .050 gauge. .058 gauge, and .063 gauge.   I have ordered some of the heavier ga., since it will go right on my bar.  Also,  the thicker gauge should be strong.

What I have my doubts about is how the .050 ga. would handle hitting an ingrown eyebolt, for example.    If the kerf is smaller,  I would like to use this thickness for metal free wood, only.

Before I learned how to properly tighten the Alaskan mill to my saw,  I cut half way through one of the grade six hardened bolts which clamp the frame onto the saw bar.  The .404/.063 ga. Stihl chain not only did not break;  it didn't even lose a tooth!  Now that is what I call tough.

Yep, I wondered where all the smoke and noise was coming from.  Yikes!
Phil L.

[woodbeard]

Well, I've cut into the bar clamps on mine with a chain that got a little loose. Not the same as a bolt, but the chain was fine, just chipped some teeth.
Now that I've been getting into some wider cuts, I'm starting to notice the saw bogging down a lot more. Wondering if maybe the .325 can't clear the chips out fast enough.
Another thing I often think about is that Ralph Foster's experience with .325 has been on an 088 which is a much faster saw. Even with the 9 tooth rim, the chain speed of the 090 is much less than the 088.
 Sorry I've dropped out of these discussions lately. Been kinda busy and also not sure where I'm at with the chainsaw mill right now. Fried the clutch pretty good recently, so she's on the sidelines for a while.

[fencerowphil (Phil L.)]

Since I usually cut big stuff,  and with .404,  that tired, bogged-down feeling is familiar to me.   ;)Because of this, I am looking to the .325 to get that improvement in speed and reduction in bogging,  compared to .404.  From the quote above, from Ralph Foster,  it looks as if the ripping speed could be about 40% faster, comparing .404 to .325.

I have found that I can bog down anytime I want.  It's a combination of four factors:  The hook angle on the teeth, the filing of the depth gauges, and the pressure applied, and, finally, the width of the cut.  So, in other words, you can bog any chain.   A few times I have had the depth gauges filed a little too deep and had trouble avoiding bogging down.  

Strangely enough,  "bogged down" sometimes actually cuts faster, but there is a ripple/washboard effect on the board surface which is bad, especially if the chain has become a little loose.  When the 090 is running slower at max. torque, it seems that a time coefficient comes into play, allowing each tooth time to dig deep, rather than "skate".   As a chain dulls, this effect is more pronounced.  (It skates worse at high speed, but cuts at lower speed.)  Just don't like the look of the cut and don't like the "grunt" of the engine, when this is going on.  But the 090 will surely grunt right along!

I "spun" my clutch and am waiting on the rim system.  All UPS orders should converge on Dublin Dec. 11.  Hope to be cutting Dec. 13 with .0325
More later.
Phil L.