We are thinking of changing our single axle for a twin axle - we have a carver mover on our existing caravan & think it is excellent. Does anyone have any experience of the twin axle mover? How dificult is manouevering?
Carver caravan movers - twin axles
- Thread starter mike_5066073
- Start date
Just bought a Compass Rallye 635 twin axle. Had a Carver mover fitted. Not a bit like the single axles. You can't do balletic spins with these. The mechanics is quite complex. Moving back and forth is simple. Turns evoke a rather odd behaviour. It looks as if one motor turns whilst the other breaks against the wheel on the opposite side. The motors pulse and the caravan sort of jerks in a long arch. No spins here. If you lean against the van you can coax it round a little quicker. I wonder how long the motors will last - but at the end of the day it does the job.
- Mar 14, 2005
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Hello Mike and Chris,
Firstly Mike you seem to appreciate that twin axle movers need to be a very different beast to a single axle, and Chris, your experience hints at why.
When a Twin axle is turned, at least two wheels will effectively be skidding sideways across the ground. If you have tried to do this by hand, you have the mechanical advantage of the distance from the wheels to the tow hitch, compared to the distance between the axles, typically 3 to 1. Despite this it needs a lot of effort to overcome the friction between the wheels and the surface.
A twin axle mover has to do the same job, but without the 3:1 lever advantage so the motor/gearbox power needed is much greater than for a single axle system, To achieve this and to prevent damage to batteries, tyres and switch gear, the motors need to be sequenced in the way Chris described.
Firstly Mike you seem to appreciate that twin axle movers need to be a very different beast to a single axle, and Chris, your experience hints at why.
When a Twin axle is turned, at least two wheels will effectively be skidding sideways across the ground. If you have tried to do this by hand, you have the mechanical advantage of the distance from the wheels to the tow hitch, compared to the distance between the axles, typically 3 to 1. Despite this it needs a lot of effort to overcome the friction between the wheels and the surface.
A twin axle mover has to do the same job, but without the 3:1 lever advantage so the motor/gearbox power needed is much greater than for a single axle system, To achieve this and to prevent damage to batteries, tyres and switch gear, the motors need to be sequenced in the way Chris described.
A Powrtouch installation engineer was talking to my OH recently about installing twin-axle movers, whilst fitting one to our single-axle van.
I'm just a girlie so what would I know! - but I'm pretty sure he said it was necessary to raise the height of the jockey wheel so that the forward pair of wheels are raised clear and the mover can then work on a single pair. I believe this is why the mover is usually fitted behind the wheels on twin axles.
I'm just a girlie so what would I know! - but I'm pretty sure he said it was necessary to raise the height of the jockey wheel so that the forward pair of wheels are raised clear and the mover can then work on a single pair. I believe this is why the mover is usually fitted behind the wheels on twin axles.
- Mar 14, 2005
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Hello Mrs Hitchlock,
You are quite right, and yes it helps but in many cases the jockey wheel will only reduce the pressure on the forward pair of wheels, they rarley have enough movement to lift the wheels off the ground. Even with the reduced pressure, the drag is considerable.
You are quite right, and yes it helps but in many cases the jockey wheel will only reduce the pressure on the forward pair of wheels, they rarley have enough movement to lift the wheels off the ground. Even with the reduced pressure, the drag is considerable.
There's a letter in the May edition of the CC mag. The writer suggests using 2 pieces of plastic 4mm thick and about a metre square. They are placed one on top of the other on the side where the pivoting axles will turn. The caravan turns with "amazing" ease. Clever or what!
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