"Winch-bit" drill-powered winching

[Heckler]

We have had a WinchBit, teamed up with a Makita 18v cordless drill, in use since 2008. The Makita drill hoists our fully battened mainsail five times before the battery needing re-charging.

Which model is it please?
Stu

 

[Zing]

I've got a Cranker bit on a top end Makita brushless drill driver. It works perfectly and puts out enough torque to break your wrist if you are not paying attention. A spare battery ensures I never run out of power. The best Dewalt or similar will be fine too.

I think an impact driver is a terrible idea unless you want to punish your winch, if so a sledge hammer would do a quicker job.

 

[AntarcticPilot]

There is an issue that I don't ever see addressed on these devices.

You STILL have to hold the drill to provide the torque to turn the winch! Action and reaction are equal and opposite, so you actually have to provide exactly the same force to hold the drill or whatever against the torque turning the winch. OK, it's probably a little easier to hold something still than it is to turn a winch handle, but the force required is exactly the same, for the same length of handle. I can only imagine the force being less if there was some way of jamming the drill (or whatever) so it could not turn relative to the winch.

Either I'm missing something, or there isn't really any significant advantage to these devices?

 

[mjcoon]

Either I'm missing something, or there isn't really any significant advantage to these devices?

Is there no point in an electric screwdriver or drill, either?

Effort = force x distance

No distance, no effort (in a manner of speaking!)

Mike.

 

[AntarcticPilot]

Is there no point in an electric screwdriver or drill, either?

Effort = force x distance

No distance, no effort (in a manner of speaking!)

Mike.

Good point. Still not sure - for me it is applying the required force that is the problem, and I don't think it reduces that .If the force required isn't too great, I can easily apply it by pulling on the rope; it is the torque that I find hard to apply.
After all, the torque required by a screwdriver or drill isn't all that great.

 

[penberth3]

There is an issue that I don't ever see addressed on these devices.

You STILL have to hold the drill to provide the torque to turn the winch! Action and reaction are equal and opposite, so you actually have to provide exactly the same force to hold the drill or whatever against the torque turning the winch...

Good point. And if you're using maximum torque from the drill it's probably a two-handed job to hold it engaged with the drive square, in line, and resisting the reaction.

 

[Zing]

There is an issue that I don't ever see addressed on these devices.

You STILL have to hold the drill to provide the torque to turn the winch! Action and reaction are equal and opposite, so you actually have to provide exactly the same force to hold the drill or whatever against the torque turning the winch. OK, it's probably a little easier to hold something still than it is to turn a winch handle, but the force required is exactly the same, for the same length of handle. I can only imagine the force being less if there was some way of jamming the drill (or whatever) so it could not turn relative to the winch.

Either I'm missing something, or there isn't really any significant advantage to these devices?

I think you need to think more in terms of power rather than just torque. Torque is important, but what makes you really sweat is power and that is torque x speed.

 

[Cantata]

I use a WinchRite and you obviously do have to hang on to it but the overall effort seems much easier than winding.
SWMBO can't get on with it, though, and her inclination is to fly round the winch while the drum remains stationary........

 

[rogerthebodger]

Is there no point in an electric screwdriver or drill, either?

Effort = force x distance

No distance, no effort (in a manner of speaking!)

Mike.

Don't know where for got that formula from but

Torque = force x distance

or force = torque / distance

so if distance is zero the force required to home the drill would be infinity.

 

[davidej]

I think you two are using distance rather loosely.

Torque = force x distance (of application of the force)from the fulcrum

energy = force x distance moved by the force or
=torque x anglular distance moved

If you hold the drill steady it is correct that you have to apply the same force as you would in turning the handle but the drill will supply all the energy

 

[mjcoon]

I think you two are using distance rather loosely.

Of course! Who likes a pedant, even/especially one with a physics degree...

Mike BSc.

 

[mjcoon]

Don't know where for got that formula from but

Torque = force x distance

or force = torque / distance

so if distance is zero the force required to home the drill would be infinity.

True, but who was talking about torque? The missing words were: "distance - through which the force is applied" which would have been too boring... (And "effort" was intentionally non-jargon; maybe "sweat" would have been even better, per Zing.)

Mike.

 

[rogerthebodger]

True, but who was talking about torque? The missing words were: "distance - through which the force is applied" which would have been too boring... (And "effort" was intentionally non-jargon; maybe "sweat" would have been even better, per Zing.)

Mike.

I considered the word effort to mean reaction force countering the torque provided by the drill so wished to correct effort (force) = torque x distance. in your post #24

I know "effort" can have several differing interpretations.

effort
ˈɛfət/Submit
noun
1.
a vigorous or determined attempt.
"in an effort to reduce inflation, the government increased interest rates"
synonyms: attempt, try, endeavour; More
2.
technical
a force exerted by a machine or in a process.


BTW I made my own winch bit from a piece of 16mm square stainless bar turned down to 12mm dia to fir in mt drill chuck some years ago

Roger Shaw B Sc Mech Eng. (Aston)

 

[JumbleDuck]

That's what I was thinking, and referring to, earlier. I'm glad to hear the Winchrite has effectively cornered this market, but for less cash, some dazzlingly torquey - over 1,000Nm - cordless impact wrenches are available.

The clue is in the name ... impact driver. They don't produce a constant 1,000Nm, just intermittent whacks. Very intermittent, on the cheaper ones.

 

[JumbleDuck]

I've no idea how much of an impact wrench's torque, comes from the motor's actual turning power, and how much comes from its rotation simultaneously hammering down on the nut, such that it is momentarily, fractionally looser on the thread and easier to turn?

The electric ones use the motor to spin up a flywheel. When it's going fast enough, a centrifugal sprag clutch engages and it gives a wallop. The motor's output is irrelevant at that point, are determines only the time between wallops, which can be seconds, compared to the constant rattle of blows from an air-powered one.

I can't see why a slightly less highly-specified impact wrench couldn't effectively turn a winch. 300Nm, perhaps?

Because they might give you 300Nm for 10ms every second or so, if you're lucky.

I don't know how different the action of an impact driver is - but I've assumed that again, there is a 'ramp' inside the chuck so for every turn the screw-bit makes, it is also thrust forward or downward

Yes, more or less. A pair of ramps inside the outer casing and a pair of projecting lugs from the inner part which get driven round the ramps, against a spring, when the end is hit. The turning force comes from the wedge effect while the main effect of the axial force is to prevent the bit from jumping out. Does this help?

But do the high torque ratings of these machines express what their motors produce ...

No.

 

[JumbleDuck]

Good point. And if you're using maximum torque from the drill it's probably a two-handed job to hold it engaged with the drive square, in line, and resisting the reaction.

I recently put up an oak-framed garage, for which I had to drill a good number of 20mm holes. An auger and an SDS drill (with hammer action off) did it very nicely, but I had tennis elbow by the end ...

 

[JumbleDuck]

If you hold the drill steady it is correct that you have to apply the same force as you would in turning the handle but the drill will supply all the energy

That's OK for purely mechanical considerations, but human muscles do work when a applying a stationary force. Try holding a 20kg sack of coal at arms length above your head while telling yourself that it's not moving so there is no work involved ...

 

[JumbleDuck]

Of course! Who likes a pedant, even/especially one with a physics degree...

I occasionally introduce myself when giving public talks by saying "I'm an engineer. That's a bit like being a physicist, only with communication skills and friends."

 

[mjcoon]

I occasionally introduce myself when giving public talks by saying "I'm an engineer. That's a bit like being a physicist, only with communication skills and friends."

In what way is it like being a physicist?

Mike.

 

[JumbleDuck]

In what way is it like being a physicist?

There is more to being a physicist than having poor communication skills and no friends. I expect.