dumb question on ripper chain

[Molecule]

I've never used ripper chain before, but need to chop up some large diameter disks, so I bought some WP375-38RP ripper chain, hoping it would be significantly faster, and put out less dust, than a std. 30° Carlton A2LM chisel.

I've never tried ripper chain before ... so I don't know what to expect. But I was surprised that on a 44" dia tulip magnolia (wood looks like/ feels like poplar), the ripper chains cuts slow as h3!! and produces mostly just dust and heat. On a 24" bar with 68cc saw, the cut speed is about 1" a minute. The same result was confirmed on a piece of 24" fir. (Both ends were cut 2 days ago, so they are maybe a little dry.) I quit after 3". Too much "push" was required on the bar to make progress (no natural draw of the bar into the wood), and my saw was running a lot hotter than I think I want to run it ...

Rakers are 0.025" so they seemed ok. The top angle is around 10°, and a 3/16" file seems to just fit in the side hook when held at 0° deflection (exactly 90° to bar). So that seems "normal" relative to specs in other posts for ripper chain.

Is there anything I can do to to this chain to make better progress ripping soft woods, or is this typical for ripping softwoods like poplar?

scans of the chain side and top --

 

[Lawn Masters]

Perhaps you should use a bigger saw with a 24" bar. What make/model of saw are you running?

 

[Al Smith]

I am not a fan of chainsaw milling,but that aside,if you look up "procut",which is a chainsaw mill,sold by a fellow by the name of Alan Combs,I believe,he lists different angles for milling different woods,speeds etc.

 

[Molecule]

oldsaw -- I'm using a Makita 6800i which I rebuilt ... new seals, piston&rings, carb kit, etc. Should be similar to a 120si, except (a) the fuel system on the 6800 has a return line from a vent on the HU carb back to the fuel tank, (b) the clutch has 3 shoes covering full circle on the drum, (c) the oil pump drive gear floats on the axle, being driven by the clutch drum and (d) the chain brake system. Other than that should be similar. It has good compression, and has no problem pulling 24" fully buried thru a cross cut ... but maybe it needs more for ripping. I was bearing down on the bar pretty hard during the attempted rip cut, and the saw had no quit in it. It's just producing about 100% fine dust ... there were a few strings but they came out on the far side (*?*)

would using too small a saw produce a tiny granule dust on a rip?

 

[Newfie]

It sounds like you are not milling lumber, rather quartering blocks down into more manageable pieces? If this is the case, ditch the ripping chain and put on whatever your preference for regular chain happens to be and THEN lay the rounds on their side like a log and cut it lengthwise parallel with the ground. You will produce big long curly fries but be able to rip right through the block/round a million times faster than cutting from the end.


When milling, rip chain produces dust,not chips.

 

[Molecule]

newfie -- the pieces I need to quarter up are 40+" in diameter. when I dropped the trunk, I set some roller logs on the ground, to hold it up for the crosscuts. Even "dropping off" the chunks in 10 inch thick pieces, they still weigh a proverbial ton. That's why I was hoping to be able to quarter them lying on their flatside.

I can't figure why it would make a difference with the saw held horizontal for the quartering operation? What that means is that I should try to do the quartering before I drop the pieces with the cross cut.

That is interesting ... that milling with a ripper chain produces mostly dust and not chips. So if a person is milling a log say 30" in diameter, say 12 feet long, it would take a while I guess. If my experience with this saw (new GB bar) and chain is any gauge, I also recon milling must take a fair amount of wear and tear out of the sawyer too.

 

[cbfarmall]

Anybody else notice in the side shot of the chain how the rivet spinner dug into the tiestrap?

Chris B.

 

[Newfie]

I can't figure why it would make a difference with the saw held horizontal for the quartering operation? What that means is that I should try to do the quartering before I drop the pieces with the cross cut.
If my experience with this saw (new GB bar) and chain is any gauge, I also recon milling must take a fair amount of wear and tear out of the sawyer too.

It's all to do with how the chain is attacking the grain structure. Milling is hot tiring work, many find it rewarding. My operation got to big for it to be "fun" anymore so I bought a woodmizer.

 

[ErrolC]

Dear Molecule:I think there is some confusion about the problem, and suggested solutions if I am understanding things correct. As I understand it Molecule is cutting the disks as they stand flat onthe ground with the grain vertical and trying to saw 90 deg across the grain, which will of course produce lots of dust. Try cutting with the tip of the bar (assuming its penatrating right through, don't try this if the tip is still buried) leading the cut down so the chain is cutting back along the grain. The same applies to carpenters hand saw ripping timber, as with chiseling. This creates more of a slicing action through the grain and allows the grain to peel away from the edge of the cutter rather than bunch up and plough through. Better yet as has been suggested, put the disks on their side (grain horizontal) and slice along the grain with a regular cutter and watch the spagetti peels fly..this is how I cut NZ native logs into halves and slabs..If I've done it right - see the attachment (Husq 50cc/20" bar - the log is NZ totara 40" across the cut 5.5mtrs long & took about 40mins to split.. for furniture table tops).
I would give the cutters more hook for soft wood!

 

[Molecule]

I see exactly what I was doing now, and it's like ... Duh! Geometry, of nature, takes precedence over false assumptions, of the mind. I had been looking into portable mills, and had falsely assumed that the alignment of the chain's cutters with the grain, as shown in their "cool" advertising pictures, would be an efficient orientation for a ripper chain.

It's obvious now, that no matter how the cutter is ground, when the grain is going to be cut end on, then all each cutter is going to get is a "nibble" on a little 0.025 piece of end-grain. Dust!, with no ripping action at all.

Thanks for the geometic wake up Newfie and ErollC - ripping is much more efficient when running with the grain -- which raises the latent question, do any ripping mills allow for angling the bar, to say 30°, so that it can cut somewhat with the grain?

ErollC--WOW! nice work ... in fact ... totally amazing work! How did you cut that log? It looks like you had to freehand the saw from two sides. That's mission impossible: how did you get cuts to exactly match up (let alone each be flat! for a length of 18 ft!!-- just awesome), with just a 1" piece standing in the center. Were you cutting horizontally from left then right sides and using wedges to support the top piece? Is that some kind of coating you put on the cut, to help it in drying or just ooze from the wood ... I have a mighty purdy piece of dramatically grained wood here (with 1/2" to 1" growth rings), with a 14" dark center 15" light periphery, and the whole which has a very perceptable dark purple-dark blue hue in the sap ... I caught the tree just as it was flowering, so I guess some of the color was coming up from the darkness of the roots. I don't know where it came from, but I sure hate to just haul it to the dump. No way I can afford a mill and saw right now. If there is some way I can do what you did with this log, I'd like to know how. Thanks.

 

[scottr]

Angled Ripping

Bert , 21 Saw Shop makes a bandmill that cuts on an angle and Hudson makes a chainsaw mill that also cuts on an angle . When ripping with a manual bandmill I can angle the blade and feel the feed rate increase . The same is true when using a chainsaw to rip firewood bolts. Gypo posted a video of him ripping a bolt of firewood into quarters and used the angled cut method .

 

[bman]

My 2 cents. I cut about 6000 bdf of 8X8 timbers thus far since starting chainsaw milling from scratch since about the first of the year. I have tried a couple of chian mods and chain styles on a 3120. My observations/experiences are as follows; If I am makeing "dust" and not small chips when milling then something is wrong. Most common problem for slow milling/dust producing cuts is a LESS THAN REALY SHARP CHAIN. 0 deg. top plate on full chisel full skip cuts smoothest and fastest and also DULLS the quickest. Big difference between .025 and .035 raker depths, deeper rakers=bigger chips. Sharp chain with .035 rakers and cutters identical lenghts will easly load the 3120 with a little "push pressure" causeing the saw to almost feed its self. Angleing the mill to talke advantage of "angle of attack" to grain of wood also means that you have effectively increased the "width" of the cut, the biggest killer of milling speed (compare milling a 8" wide cant to a 24" wide cant and you get the idea! Did I mention that you need a realy sharp chain? bman

 

[ErrolC]

bman's right in that a sharp chain is key..and this was a problem for me and the work I do in extracting NZ native timber (some of them carbon dated over 2000 yrs old..thats right 2k) from rivers. Its quite valuable and as you would imagine...rather gritty on the outside so portable mills are next to useless because the drit from one side is pulled right through the cut..about 4" between sharpen ups, hence other millers have tried to recover this timber and the time and cost in equipement has proven frustrating to all. These logs are very durable (obviously) and also saturated (heavy..I mean heavy)..they sit on the bottom of the rivers and in snag beds and shingle bars and move down a little with each occational flood and as the river beds move and expose ancient buried trees...email me and I'll tell you more [email protected] quote arborist and your id or I won't open your messages (my protection)

 

[mackie]

you might try a Granberg rip chain. someone told me a regular chain could be ground to rip and you dont need ripping chain, but i tried regular chain ground to rip and it didnt work at all. now i only use granberg rip chains, i have 3 chains so i can bring one or two to the sharpening shop every week. you must keep the chain sharp.

(i mill only spruce and fir softwoods up to 24" dia., so this may not be true for hardwoods)