Anybody built or used one of these chainsaw winches?

[rogerflies]

I ran across this on ebay:
http://i15.ebayimg.com/04/i/000/ed/fa/d6c1_2.JPG

http://cgi.ebay.com/GAS-ENGINE-POWERED-SAILPLANE-TOW-WINCH-PLANS-on-CD_W0QQitemZ300243428519QQihZ020QQcategoryZ34056QQ rdZ1QQssPageNameZWD1VQQcmdZViewItemQQ_trksidZp1638 Q2em118Q2el1247

He makes some interesting claims about the use of a centrifugal clutch on an engine-driven winch.

I'll be in business if someone will just give me a chainsaw. Look how much mileage I got out of the old tractor someone gave me. :D

Roger

[atmosteve]

Holy smokes and far out!
Sorry Roger I know nothing worthwhile about this, but will be happy to learn something for sure if you go through with anything in this line. :)

[BrianSmith]

SMILE......... I want to see it Roger. :D Brian

[IBWALT]

If you build it I am sure they (or someone) will come. But in my opinion what a scam. Five pages of "digital" instructions and they want $2.75 to e-mail them to you and that's on top of the $5.95 they want for the plans. So for $8.70 you get plans that were obviously copied out of some old magazine.Give me a break.

Walt

PS: But if you build it you could always take it to your local power field. The slimmers would love the noise the thing would make and welcome you as a long lost brother.

[flystoolow]

Nice, but the bar and cutting chain should still be in place, and the drum could be bolted to the sprocket at the tip of the bar....

Just to make it more realistic you know, and put some fear into the eyes of the power flyers!!! :D :D

[dhauch]

Roger,
Have you ever given any thoughts on a brushless motor winch ?

If so, love to here the pros & cons.

dave

[Oldcoot2]

Tell you what, Roger,
Send me a drum, and I will modify one of my 4 chainsaws and we will see how it goes.

The idea sounds logical, but I seriously think that a 4 meter ship will stall the engine when trying a gorilla launch....well maybe not stall the engine, but cause the clutch to lose its bite as when you hit a knot hole on a log.

Also, those clutches are not cheap, and if you continue burning it then the heat will wipe out the needle bearings on the drive disk.

I agree that the chain and bar should be left on the rig so you could use it to intimidate the slimers!!!


Intresting.....
Gerald

[bobthenuke]

If you ever end up with a rat's nest of line you'll have something handy to deal with it. ;)

-bob

[talonxracer]

Dont forget, the "operator" must wear a hockey goalie mask.

[Jurgen]

....brushless motor winch ?Nice idea indeed, but to what advantage/benefits? Do the recent brushes compromise anything?

* wearing out they do yes, but replacements are rare and not expensive;

* overall heavier motor yes, but it keeps grounded, no big deal;

* any brushless concept depends on a turning magnetic field, so you need an electronic controller capable of putting trough the very high peak power of the winch, meaning big and a very expensive electronic components/circuit (try to find a controller that surges 600 amps :eek: ). Our brushed "controller" is compared to that a little cheap on/off solenoid, easy to take two for that in series as a safety;

* brushed motors come as starter motors, for us often little modified. So this is a big marked making the motors payable. A brushless motor adequate for the winch-purpose likely comes from a much smaller market = $$.

* I guess the biggest benefit for brushless winch would be the ability for a proportional power curve instead of the recent "stepping" technique. But managing that power curve with your foot will ask a dedicated learning process too, maybe even more difficult than just stepping on/off a solenoid.

* The whole discussion of standards will rise and "explode" with the coming of another technique, things are worse enuf in that field already. A brushless concept would imply a much better electrical yield factor (return), making the energy transferred to the plane much higher, with the same electrical draw from the battery.

So, out of pure technical reason it would be welcome indeed, but for economic and other reasons it would stirr us around seriously :)
Jurgen.

[TLyttle]

30 years ago, in our search for the Perfect Winch, one of the boys put together a saw-powered winch, ~9hp if I remember right. It was not worth spit. Our 6v Ford starter on 12v could out-pull it with no trouble.

[rogerflies]

I think the torque curve for the two-cycle engine is all wrong for our purposes. The drum would have to have a very small core, which means the line speed/tension would change quite a bit as the drum filled up.

I agree with Jurgen's assessment of the brushless motors. It would be wacko expensive, and you'd still have to buy batteries.

I'm thinking about ways to make a constant-speed electric winch. It would have a largish starter motor driving a small flywheel. An adjustable governor would turn the motor on and off to keep the flywheel turning at the same speed throughout the launch. The governor would be connected to the solenoids. An electric clutch connected to the flywheel and controlled by the foot pedal would drive the drum.

You'd set the governor prior to launching based on the plane, wind, and your preferred style. Then you'd step on the pedal, and hold it down for the entire launch. No pulsing would be required to keep from pulling the wings off your delicate woodie floater. Of course, you can always let off if the plane starts going too fast.

It wouldn't make much difference for the guys with the 50g moldies, but it would sure make it easier for the newbies and the guys with woodies.

I need to learn more about governors and flywheels, but it seems like something that would work.

Roger

[rdeis]

Read about the briggs winch in the sailplane talk forum.

Same principle, bigger motor.

[rogerflies]

Read about the briggs winch in the sailplane talk forum.

Same principle, bigger motor.

You're correct if you're referring to the constant-speed electric winch I was musing about. The Briggs winch is the first constant-speed winch I've seen, and it's got some really nice performance characteristics. But the noisy, smelly engine is a real drawback. It would be nice to have the same launch capability in an electric winch.

The chainsaw winch is a completely different animal. The picture shows a pedal attached to the throttle. It's used to control the speed of the engine during the launch, and the centrifugal clutch limits the line tension if the load on the engine causes the speed to drop below its lock-up speed.

The Briggs winch is set to the desired speed before the launch, and the governor maintains that speed throughout the launch. You can pulse the pedal to disengage the electric clutch that drives the drum if the plane looks like it's going too fast, but you can't change the speed of the engine.

Roger

[dlobbster]

What with the price of gas how many launches per gallon do you think
you would get?

[seanpcola]

Dont forget, the "operator" must wear a hockey goalie mask.


I was thinking the same thing right before I saw this post. :D

[rogerflies]

It takes about two minutes at idle to set the Briggs winch up, about a minute at some speed above idle for a launch, and about two minutes at idle to spool the line up.

So far I've bought two gallons total for the project. Most of that was used to get the engine into running condition. There's still some in the tank.

Chainsaws aren't very fuel efficient, but I doubt it'll run much more than the Briggs winch. Mixing the fuel is the part I don't like.

Roger

[rogerflies]

I did a little checking on the fuel consumption for the Briggs engine. A rough estimate based on what I found is that it'll use about a 1.5 gallons an hour at part throttle. That works out to about 90 launches. Subtracting some for set-up and spool-up, and figuring $4 per gallon gives about a nickel per launch.

How's that compare to the cost/launch for an electric winch? You'd have to include the cost of the battery and charger, plus the electricity for the charger.

(Don't forget the battery disposal fee. They tack that on here even if you bring in an old battery, and nobody "disposes" of old batteries anymore. :censored: )

Anybody done the math?

Roger

[GREASY]

BOYS; There is already a saw winch out there, I'm sorry I did'nt read all the threads on this topic so please bear with me. I'm from OREGON, and logged for years so I know a little about saws, and there use. About 30 years ago Iwas tired of packing out elk, so I started looking around and found a guy named FRED LEWIS, I think he was from CANBY, OR. any way, he built this winch for power heads and I bought one. Boys this is the most scookum tool you will ever use, iv'e yarded out elk, deer, trucks, quads, and logs for fire wood. and I moved, get this a 20x30ft. building Im not kidding we re enforced the inside and placed pipes under it and I yarded it over 100ft to were it sits today. ON THE INTERNET, LEWIS WINCH, I BET YOU'LL BE HAPPY WITH THIS ONE. :Don Fleming.

[Brady Baggs]

believe it or not!! I had a picture long ago of some guys in Europe launching a very large scale plane. They use what was a deluxe Mercedes winch. It was simple really they just jacked up the car put on a open rim with no tire. Some twine on the rim and what we have here is all the hp one could ever want. I guess they use 1st gear but who knows. I think it could be done today (BUT DONT GET ANY IDEAS)with a cable throttle linkage that could be operated from a foot pedal . a word of caution don't stand in front of the winch. Bob-Where did it go? Oh Man!!! it just went across the street and is heading into the subdivision . Bill-------------- how long before that thing runs out of gas? Bob-- I just filled it up. Bill-did you bring the shot gun. Bob- yep but its in the trunk.

[Libelle201B]

If you build it I am sure they (or someone) will come. But in my opinion what a scam. Five pages of "digital" instructions and they want $2.75 to e-mail them to you and that's on top of the $5.95 they want for the plans. So for $8.70 you get plans that were obviously copied out of some old magazine.Give me a break.

Walt

PS: But if you build it you could always take it to your local power field. The slimmers would love the noise the thing would make and welcome you as a long lost brother. IBWALT, LOL, you are absolutely right :)

[gyrokiteguy]

How many RPM does a Ford long shaft starter turn during launch (6V or 12V) ?

What sort of current and voltage does the starter motor see ? (How much power is it making ?)

Thanks

[eissmann]

I flew off a chainsaw winch in the late 70s, (that's 1970s to the younger crowd). Flyng an Aquila, it was a nightmare.

Maybe it would work on something where you never had to let off the winch, but somehow I doubt it.

With a floater, when you let off, 2 bad things happen.

First, it doesn't let off when you do. I suppose it's a relatively short period of time, but it seems like forever when the wings continue to flex.

Then, when you get back on the winch, it takes what seems like forever to get your tension back, after which it has too much tension again.

This isn't a new concept, and there's a reason why it didn't catch on.