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Post by chesterwin on May 11, 2009 15:10:22 GMT -5
OK folks. Here goes a show of ignorance. I can't find a thread on here and have had no luck trying to google an explanation. What exactly is a "direct drive" saw? Does it have a clutch and sprocket setup? Or, is it a gear drive or something else? Sorry about such a rookie question but the only saws I've dealt with to date have a clutch and sprocket. I suspect it's direct drive off the crankshaft with the clutch and sprocket but want to be sure what I might be getting into. Thanks.
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Post by chainsawwhisperer on May 11, 2009 16:27:36 GMT -5
Perfectly valid question
Direct Drive saws have a clutch on the end of the crank. When the clutch is engaged you have a 1:1 ratio between the crank and the sprocket.
Gear drive/ reduction drive saws are just that, there is a some type of ratio reduction unit between the crank and the sprocket.
CSW
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Post by redsqwrl on May 11, 2009 17:01:15 GMT -5
I just learned this one within the last year,
Perfect explanation CSW, remember CW both have clutches.
Sometimes the GD saws run in an opposite direction CW vs CCW.
Also some models have or had multiple ratios available.
RS
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Post by MCS on May 11, 2009 17:57:44 GMT -5
chester, As RS said, both configurations have a clutch and in both setups, the clutch is mounted on the crankshaft - we need full engine RPMs to expand the clutch. The difference starts at the clutch. In a direct drive saw, the clutch and sprocket drive the chain directly - the chain is mounted on the sprocket. In the gear drive setup, the clutch has a gear welded to it and this gear is the first gear in the gear train. Since we added a gear, the engine rotation has to be opposite to have the chain run correctly.  |
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Post by chesterwin on May 11, 2009 18:21:28 GMT -5
Thanks guys. I got it now. I'm considering buying an older Homelite that is labeled "direct drive" and wanted to be sure I wasn't jumping in over my head. Interesting to know the engines on the gear drives run in the opposite direction. A7E, a hunting buddy recently emailed me a clip of the white deer herd you have up there at Boulder Junction, MN. Beautiful animals. If I hadn't seen that clip I would have sworn them to be albinos but they don't appear to be. This herd must be what the old indian legends are all about.
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Post by OBR on May 11, 2009 20:31:10 GMT -5
Somebody's buying themselves a c-series...eh chester???
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Post by chesterwin on May 11, 2009 20:34:23 GMT -5
;D
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Post by billg on May 12, 2009 0:44:28 GMT -5
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Post by lesorubcheek on May 12, 2009 9:13:56 GMT -5
You'll love those C series chester. Built like a tank and easy as pie to work on. A few parts can be tricky to come by, but as well as those things were built, ya probably won't need too many parts to keep her running.
Dan
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Post by MCS on May 12, 2009 19:44:01 GMT -5
You'll love those C series chester. Built like a tank and easy as pie to work on. A few parts can be tricky to come by, but as well as those things were built, ya probably won't need too many parts to keep her running.. if the starter works so you can get her started ;D |
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Post by billg on May 13, 2009 0:54:44 GMT -5
You'll love those C series chester. Built like a tank and easy as pie to work on. A few parts can be tricky to come by, but as well as those things were built, ya probably won't need too many parts to keep her running.. if the starter works so you can get her started ;D I fully agree the starters are a real pain. I should be seeing some more parts C series show up at the end of the week. I would bet the starters will be all screwed up. Too many differences between the models Bill |
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Post by lesorubcheek on May 13, 2009 7:16:25 GMT -5
I must just be lucky so far. The 3 C-91s I have all use the sprag-type one-way over-running bearing starter and they all work pretty good. Once in a while, one of them slips initially. I just make sure its grabbing before I pull it hard to start.
Since the C52/72 uses the modern style starter pawls, I'd guess they are fairly reliable. The C5/7/9 used the Fairbanks-Morse type, so I'd guess the biggest problem there would be slipping in the cup, but this can be fixed by grooving it.
So, I suppose the starters that are so problematic must be the over-running bearing types when they don't work properly??? If this is the case, then chester just be alert if you're looking at a C51,71, or 91, or a C series that was fitted with one of these via a parts swap / frankensaw event. Otherwise, I can't understand what the b!tching is all about ;D.
Dan
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Post by chainsawlady on May 13, 2009 10:44:40 GMT -5
lesoreubcheek
I have several overrunning starter bearings 58480-A but they are rather expensive.
chainsawlady
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Post by lesorubcheek on May 13, 2009 12:21:57 GMT -5
Thanks chainsawlady.
Again, I'm doing OK so far with the few I have. I wouldn't be surprized if somebody else around here would love to know there's some available.
Dan
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Post by blazer296 on May 19, 2009 6:55:01 GMT -5
I have a c-71, got it free because the starter was messed up. Where the recoil spring "hooks" in, was worn and kept slipping off. A bit of cleanup with a file to fix the rounded edge, and it has worked great for 9 years. Starts first pull every time, and runs like a champ. I bet you will love you'r new c-series.
Jim
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