Has anyone got or used one of these? I am thinking about getting one and would appreciate any feedback on what they are like. Thanks in anticipation.
Hitchdrive by Purpleline
- Thread starter CreakyKnees
- Start date
Hello Sean,
Having read your posting I think you should consider very carefully the potential dangers of using an A frame mounted mover when on an incline with an unstable surface.
When using a mover, you generally relinquish the pushing, and pulling of the caravan to the mover, but just as importantly, you also rely on the mover to stop the caravan.
It is a physical fact that the maximum force any type of wheel driven mover can exert (drawbar force) to pull, push or stop, is equal to the weight pushing it to the ground. Anything that degrades the friction between the wheel and the ground reduces the systems ability.
Now as a rough calculation, if you know the gradient (%) of the slope then if you take the weight of the caravan and multiply it by the gradient, you get a rough idea of how much push you need to move or stop the caravan on the slope. For example: if your caravan weighs 1000Kg and you have a 5% slope then you need 50Kg draw bar force.
Now let's apply this to the Hitchdrive, or any other nose mounted mover. Assuming a good hard surface like concrete, the power that a nose mounted mover can develop will be equal to the nose weight of the caravan plus the weight of the mover. Typically this will be about 70Kg nose-weight plus say another 20Kg for the drive unit a total of 90Kg. This looks fine, but now consider the gravel which reduces the friction by at least 50% which now gives an effective drawbar force of only 45Kg! Small wheels do not like gravel which further impedes the movers ability and you can see that we do not have enough force or any safety margin for a reliable safe process.
The same calculation can be applied to the movers that drive the caravan's main wheels; the difference here is that you have the bulk of the caravan weight on the driving wheels which radically increases the drawbar force available. 1000Kg less 70 nose weight (carried by jockey wheel) and the two main wheels give 930Kg drawbar force! Even allowing for gravel and wet surfaces this is 9 to 10 times greater than the force required to control the caravan. The bigger wheels also role over the gravel better than small ones found on the hitch movers.
Have you considered a winch that pulls the caravan up the slope?.
As you clearly want your father to continue caravanning in comfort and safety there are another couple of points that you may find interesting. A mover that fits to the main wheels is available even on difficult remote caravan sites, It dose not require to stored separately or lifted in and out of the caravan or car to be fitted for use and it is less nickable.
Having read your posting I think you should consider very carefully the potential dangers of using an A frame mounted mover when on an incline with an unstable surface.
When using a mover, you generally relinquish the pushing, and pulling of the caravan to the mover, but just as importantly, you also rely on the mover to stop the caravan.
It is a physical fact that the maximum force any type of wheel driven mover can exert (drawbar force) to pull, push or stop, is equal to the weight pushing it to the ground. Anything that degrades the friction between the wheel and the ground reduces the systems ability.
Now as a rough calculation, if you know the gradient (%) of the slope then if you take the weight of the caravan and multiply it by the gradient, you get a rough idea of how much push you need to move or stop the caravan on the slope. For example: if your caravan weighs 1000Kg and you have a 5% slope then you need 50Kg draw bar force.
Now let's apply this to the Hitchdrive, or any other nose mounted mover. Assuming a good hard surface like concrete, the power that a nose mounted mover can develop will be equal to the nose weight of the caravan plus the weight of the mover. Typically this will be about 70Kg nose-weight plus say another 20Kg for the drive unit a total of 90Kg. This looks fine, but now consider the gravel which reduces the friction by at least 50% which now gives an effective drawbar force of only 45Kg! Small wheels do not like gravel which further impedes the movers ability and you can see that we do not have enough force or any safety margin for a reliable safe process.
The same calculation can be applied to the movers that drive the caravan's main wheels; the difference here is that you have the bulk of the caravan weight on the driving wheels which radically increases the drawbar force available. 1000Kg less 70 nose weight (carried by jockey wheel) and the two main wheels give 930Kg drawbar force! Even allowing for gravel and wet surfaces this is 9 to 10 times greater than the force required to control the caravan. The bigger wheels also role over the gravel better than small ones found on the hitch movers.
Have you considered a winch that pulls the caravan up the slope?.
As you clearly want your father to continue caravanning in comfort and safety there are another couple of points that you may find interesting. A mover that fits to the main wheels is available even on difficult remote caravan sites, It dose not require to stored separately or lifted in and out of the caravan or car to be fitted for use and it is less nickable.
Sorry but I think Gerald Ratner designed this one!
I tried one of the proto-types and it was next to useless.
Save your pennies and go for a motor mover as a hitch drive or power touch for a fixed drive.
Second hand motor movers can be found in good order for
I tried one of the proto-types and it was next to useless.
Save your pennies and go for a motor mover as a hitch drive or power touch for a fixed drive.
Second hand motor movers can be found in good order for
They look impressive, specially the videos on their web site.However, I went to my dealer, who told me that they are a waste of money. He put me right off and saved me a few bob.
Hi There,
I have got a hitchdrive, which i am now selling as it was not suitable for my caravan, you need to check the distance from the bracket on A frame to the gas locker, i fitted the hitchdrive but the handle was catching against the edge of the gas locker, I cannot open the locker fully due to the height of the unit and when moving the caravan and turning the caravan the handle catches the gas locker, but then it depends on which caravan it is for, it may suit your caravan, i your still looking for one then reply to this message.
I have got a hitchdrive, which i am now selling as it was not suitable for my caravan, you need to check the distance from the bracket on A frame to the gas locker, i fitted the hitchdrive but the handle was catching against the edge of the gas locker, I cannot open the locker fully due to the height of the unit and when moving the caravan and turning the caravan the handle catches the gas locker, but then it depends on which caravan it is for, it may suit your caravan, i your still looking for one then reply to this message.
As stated in another thread. Have hitchdrive, FREE TO ANY HOME. just collect from Norfolk.
But for what its worth it is even less use than a cocolate fireguard.
ttfn
But for what its worth it is even less use than a cocolate fireguard.
ttfn
TRENDING THREADS
-
-
Bailey tech notes circa 2017 18.May apply to others..
- Started by toad a caravan
- Replies: 6
-
-
-
-
-
Facebook
Twitter