Milemarker Question

[LR90]

Other than Mr Murray's elect bad, hydro good 'facts' I can't turn up any real tech on the MM winch so I'll have to ask, where is the brake on the MM? Just curious.

I was hoping to find an exploded parts diagram but couldn't turn one up. Does anyone have a link to one?

[TomG]

There is no brake in the winch, it relies on the hydraulic fluid stalling the motor when the control valve is closed, although you can mechanically lock the winch by using the two hi/lo levers in combination.

Have a look at the thread: Fast Hydraulic winch build for photos of inside one.

[BogMonster]

To add to that, there is a valve in one of the hoses which provides "braking" on power out e.g. for lowering, so the fluid flows freely in one direction but in the other direction a plate drops over the fluid inlet from the motor so the fluid all goes through a tiny hole, this provides a strong braking effect and then when you take your finger off the button the valve closes and stalls the motor as Tom said.

[LR90]

I did wonder so that's why the safety valve thingies HFH fitted are so important in the event of a burst hose then.

But if MM don't have a brake why do other hydraulic winches have brakes just like their electric brethren? Would seem like an unnecessary complication and added production cost.

[BogMonster]

I did wonder so that's why the safety valve thingies HFH fitted are so important in the event of a burst hose then.

But if MM don't have a brake why do other hydraulic winches have brakes just like their electric brethren? Would seem like an unnecessary complication and added production cost.

Don't know, I suppose if a hose bursts its all very well having the winch lock solid but you may need to let the load down? in which case a brake would be required

I haven't really done any lowering in mine but you can hear the power it soaks up when you winch out just to pay line out, so I think it does absorb a lot of energy and I should think it is very controllable on lowering out.

[madmatt]

As said above, the MM requires an additional valve to act as a brake, These are called load hold valve or over centre valves. I use my winch for tree work and the last thing I want is the winch tyo drop the tree if we have a hose go. Interesting your comments about other Hyd winches having brakes can I ask which ones youv'e seen please??? I know the Superwinch H range use the irreversability of the worm gear as a brake rather tha having a seperate brake as such.

Matt

[LR90]

Well, I'm just browsing but there are the Superwinch H8/10P and Come-Up HV series which come with 'integral, automatic' brakes external to the drum and the Champion CH series which come with an automatic failsafe brake in the drum. I was wondering how suitable these might be with plasma (maybe its not an issue with hydraulic) and as I started, I could find no info on the MM to compare and contrast with.

Maybe these brakes are only failsafe brakes and whatever the design would not come into effect during a normal lowering operation?

[Bush65]

I did wonder so that's why the safety valve thingies HFH fitted are so important in the event of a burst hose then...

Depending on the application, there are a number of slightly different devices commonly used in hydraulic circuits that are required to stop and hold a load.

pilot operated check valves, usually used for near horizontal loads

counterbalance valves, for downward acting loads

overcentre valves, for loads which can runaway when lowering or going overcentre

It is normal in industrial applications to use these alone, without any other mechanical device. For example, mobile cranes, which even in the largest sizes, use hydraulics for winding the hoist rope and elevating the boom.

Although I have a hydraulic mile marker winch, I haven't (because I don't use it), examined the supplied directional control valve, with combined brake valve, to see how they work or how well they are made. It is obvious from the number of these winches in use, that they do work when used with a power steering pump. But I have heard that they are not as well made (read cheap) as the usual proprietry devices mentioned above for industrial use. The mile marker control valve is not suitable for higher flow rates than the usual power steering pump.

Nige and myself (among others), use proprietry overcentre valves in the circuit which controls the winch. Where possible it is best to mount these directly on the motor.

They can be remote from the motor, but if the connecting hose is damaged and fails, the motor will not be able to hold the load. For some industrial uses, they must be directly mounted on the motor or actuator which supports the load.

...But if MM don't have a brake why do other hydraulic winches have brakes just like their electric brethren? Would seem like an unnecessary complication and added production cost.

You are implying than mile marker winches don't have a brake and all others have a mechanical brake! This is simply not the case. Although some hydraulic winches do have mechanical brakes.

[Bush65]

Well, I'm just browsing but there are the Superwinch H8/10P and Come-Up HV series which come with 'integral, automatic' brakes external to the drum and the Champion CH series which come with an automatic failsafe brake in the drum. I was wondering how suitable these might be with plasma (maybe its not an issue with hydraulic) and as I started, I could find no info on the MM to compare and contrast with.

Maybe these brakes are only failsafe brakes and whatever the design would not come into effect during a normal lowering operation?

Maybe they only use a counterbalance valve or similar device for hydraulic braking.

Because they are described as you have stated, does not necessarily mean that they have a mechanical brake.

Also I should point out that many mechanical brakes on electric winches used for 4wd vehicles are inferior to a properly installed overcentre valve on a hydraulic winch.

I used to design mine winders and haulages for raising/lowering men and materials up to 80 men, and 90 tonnes and at high speeds. We never used mechanical service brakes.

[LR90]

Thanks John.

I'm not wishing to suggest mech brake is better than hydraulic, just learning. The pros/cons of brakes WRT plasma on elect winches has been discussed in some depth so I am just trying to understand the various braking types on the hydraulic winches and in turn their impact in the use of plasma. Maybe they just don't matter (when it comes to plasma).

Of course along the way I'll learn a lot more too

The come-up manual has an exploded parts diag that might give more clues to its brake.

[Hybrid_From_Hell]

Hi All,

Bear in mind my MM JUST is the winch unit itself, with none of the normal MM stuff.

As such I have a dual Over centre Valve on BOTH my winches, the MM is a industrial one, set up for both ways, and was not a fortune, I can dig the PN out if anyone wants, around £90ish

This is not made for the unit, so I have it mounted around 5 inches of pipe from the motor, being as close as I could get it, and should either of those 2 pipes go then its useless, but if not it will give some protection.

The front winch (a ka a "The Thing") has a motor mounted one, which, if you can do it is obviouly better still (LHS on the winch top just below the 2 1/2 bsp pipes)

I would seriously advise anyone with a Hyd set up to check if they have got such an item within there system - if not then its a damned good idea to fit one, many winches do them as options (esp industrial stuff) and they are less expensive and better as they are ON the motor.

Nige

[Bull Bar Cowboy]

Trev,

Yes, John has just about said it all……………..

The valve supplied by MM has a washer in one port with a 3mm hole in it to limit the flow. This also contributes to the MM being slow when driven from a steering pump ( apart from the fact that there is no where near enough flow)………….and yes the MM valve block is not of high quality………

Whilst Nige has his OCV on the winch …………. Mine is just behind the Rad with 2 very short pipes feeding the winch motor.

Ian

[Bush65]

Thanks John.

I'm not wishing to suggest mech brake is better than hydraulic, just learning. The pros/cons of brakes WRT plasma on elect winches has been discussed in some depth so I am just trying to understand the various braking types on the hydraulic winches and in turn their impact in the use of plasma. Maybe they just don't matter (when it comes to plasma).

Of course along the way I'll learn a lot more too

The come-up manual has an exploded parts diag that might give more clues to its brake.

I had a look at that manual for the comeup winch.

It shows a mechanical brake outboard of the planetary gearset.

It also states that the hydraulic system must have an overcentre valve.

The problem with some winch brakes and synthetic winch rope is:

Some winches have brakes that act on the inside of the winch drum (Warn low mounts for example). These brakes are simple, cheap and automatically apply when the winch drum direction reverses (except while in free spool). Because the brake is applied automatically, when the winch is powered out, it is driving against the brake and the heat generated is dissipated through the drum and can damage synthetic rope.

Neither mechanic brakes outboard of the winch drum, or hydraulic winches with overcentre valves (or counterbalance valves) will generate heat which can damage synthetic rope.

[Bush65]

Hi All,

Bear in mind my MM JUST is the winch unit itself, with none of the normal MM stuff.

As such I have a dual Over centre Valve on BOTH my winches, the MM is a industrial one, set up for both ways, and was not a fortune, I can dig the PN out if anyone wants, around £90ish

This is not made for the unit, so I have it mounted around 5 inches of pipe from the motor, being as close as I could get it, and should either of those 2 pipes go then its useless, but if not it will give some protection.

The front winch (a ka a "The Thing") has a motor mounted one, which, if you can do it is obviouly better still (LHS on the winch top just below the 2 1/2 bsp pipes)

I would seriously advise anyone with a Hyd set up to check if they have got such an item within there system - if not then its a damned good idea to fit one, many winches do them as options (esp industrial stuff) and they are less expensive and better as they are ON the motor.

Nige

Although, a winch may rotate in both directions, the rope load on the drum can only be in one direction - because rope is flexible it only carries tension, and will buckle if the load direction reverses (compression).

Therefore it is only necessary to have a single overcentre valve (for one direction of rotation).

In your thread for installing the electric fans in front of your radiator, there is a pic from above your front winch. This pic clearly shows only one overcentre valve cartridge.

Unless a hydraulic winch is used to lower a load (eg. lower own or another vehicle by powering out), an overcentre valve is not necessary and a counterbalance valve will do as good a job.

[LR90]

I had a look at that manual for the comeup winch.

It shows a mechanical brake outboard of the planetary gearset.

It also states that the hydraulic system must have an overcentre valve.

The problem with some winch brakes and synthetic winch rope is:

Some winches have brakes that act on the inside of the winch drum (Warn low mounts for example). These brakes are simple, cheap and automatically apply when the winch drum direction reverses (except while in free spool). Because the brake is applied automatically, when the winch is powered out, it is driving against the brake and the heat generated is dissipated through the drum and can damage synthetic rope.

Neither mechanic brakes outboard of the winch drum, or hydraulic winches with overcentre valves (or counterbalance valves) will generate heat which can damage synthetic rope.

Cheers John. The Come-Up looks nice but if a hydraulic winch had an in the drum brake (which I suspect is what is in the much cheaper Champion C10000NH) could it be dispensed with and an overcentre valve used instead?