Hi team ….. I have a boat trailer (twin axle) which has a boat on it weighing 1600Kg.
On the flat I can happily pull & push trailer is a straight line - so rolling resistance is not too high.
I have to manoeuvre the boat into a boat shed after each use … and for a number of reasons I can’t use a car other than for getting in aprox right position.

The problem is 2 fold … there is a slight incline until the wheels get onto the boatshed floor (requiring a lot of effort) …. And being a twin axle trailer it is very hard to move it ‘sideways’ on single axle it’s fine, you simply see-saw back and forth over a short distance to move sideways - but on twin axle the rear wheels ‘crab over’ as front one trace the arc, and then it is very hard to move.

If I have a mate with me it’s fine, but it certainly can’t be done single handed.

An option I have thought of is using an electric winch, clipping winch cable onto rear axle … my thoughts are that the winch then provides the effort of the ‘pull’ .. and all I have to do is then put the effort into steering the jockey wheel.
I have 220V ac there so ‘maybe’ I could use a remote control mains ‘lift/hoist’ …such as … http://www.silverlinetools.com/products?search=264782

I could even set a single snatch pulley block into a fixing into concrete floor to make pull ‘better’

My Q is …. Does this sound logical ? ………… for these winches they quote vertical lift load of 250Kg … (to 11.5m high) so not sure how (if it does) relate to a horizontal pull capability …. This is a rolling load not dead lift, but hard to know how to estimate how much ‘pull’ force would be needed.
The other option is the 12V 4x4 recovery winches … more than enough pull, but as this would be fitting in building (not on a vehicle) no high current 12V source (OK I could buy a battery… but 240V seems so much easier)

I did ask a question a while back, and that sent me in direction of ‘Powered jockey wheel’ & caravan ‘power movers’ … but all suitable ones were in the US only.
Such as these - http://youtu.be/qOWHNYa80y8

Unless anybody has an interesting way of making a powered version of one of these ? ….. http://tinyurl.com/bpbl7jf

On Tuesday, November 6, 2012 10:48:06 PM UTC, Osprey wrote:

Hi team ….. I have a boat trailer (twin axle) which has a boat on it weighing 1600Kg.
On the flat I can happily pull & push trailer is a straight line - so rolling resistance is not too high.
I have to manoeuvre the boat into a boat shed after each use … and for a number of reasons I can’t use a car other than for getting in aprox right position.
The problem is 2 fold … there is a slight incline until the wheels get onto the boatshed floor (requiring a lot of effort) …. And being a twin axle trailer it is very hard to move it ‘sideways’ on single axle it’s fine, you simply see-saw back and forth over a short distance to move sideways - but on twin axle the rear wheels ‘crab over’ as front one trace the arc, and then it is very hard to move.
If I have a mate with me it’s fine, but it certainly can’t be done single handed.
An option I have thought of is using an electric winch, clipping winch cable onto rear axle … my thoughts are that the winch then provides the effort of the ‘pull’ .. and all I have to do is then put the effort into steering the jockey wheel.
I have 220V ac there so ‘maybe’ I could use a remote control mains ‘lift/hoist’ …such as … http://www.silverlinetools.com/products?search=264782
I could even set a single snatch pulley block into a fixing into concrete floor to make pull ‘better’
My Q is …. Does this sound logical ? ………… for these winches they quote vertical lift load of 250Kg … (to 11.5m high) so not sure how (if it does) relate to a horizontal pull capability …. This is a rolling load not dead lift, but hard to know how to estimate how much ‘pull’ force would be needed.
The other option is the 12V 4x4 recovery winches … more than enough pull, but as this would be fitting in building (not on a vehicle) no high current 12V source (OK I could buy a battery… but 240V seems so much easier)
I did ask a question a while back, and that sent me in direction of ‘Powered jockey wheel’ & caravan ‘power movers’ … but all suitable ones were in the US only.
Such as these - http://youtu.be/qOWHNYa80y8
Unless anybody has an interesting way of making a powered version of one of these ? ….. http://tinyurl.com/bpbl7jf


Re how much pulling force, if a person can lift 50kg, 2 people can exert 100kg force. A lot of people max out at less. Its quite approximate of course, but a 250kg hoist should provide enough force, I don't think there's much likelihood of each person moving it with 125kg of force


NT

On 7 Nov, 00:17, wrote:
On Tuesday, November 6, 2012 10:48:06 PM UTC, Osprey wrote:
Hi team ….. *I have a boat trailer (twin axle) which has a boat on it weighing 1600Kg.
On the flat I can happily pull & push trailer is a straight line *- so rolling resistance is not too high.
I have to manoeuvre the boat into a boat shed after each use … and for a number of reasons I can’t use a car other than for getting in aprox right position.
The problem is 2 fold … * there is a slight incline until the wheels get onto the boatshed floor (requiring a lot of effort) …. And being a twin axle trailer it is very hard to move it ‘sideways’ on single axle it’s fine, you simply see-saw back and forth over a short distance to move sideways - but on twin axle the rear wheels ‘crab over’ as front one trace the arc, and then it is very hard to move.
If I have a mate with me it’s fine, but it certainly can’t be done single handed.
An option I have thought of is using an electric winch, clipping winch cable onto rear axle … my thoughts are that the winch then provides the effort of the ‘pull’ * *.. and all I have to do is then put the effort into steering the jockey wheel.
I have 220V ac *there so ‘maybe’ I could use a remote control mains ‘lift/hoist’ …such as …http://www.silverlinetools.com/products?search=264782
I could even set a single snatch pulley block into a fixing into concrete floor to make pull ‘better’
My Q is …. Does this sound logical ? ………… for these winches they quote vertical lift load of 250Kg … (to 11.5m high) so not sure how (if it does) relate to a horizontal pull capability *…. This is a rolling load not dead lift, but hard to know how to estimate how much ‘pull’ force would be needed.
The other option is the 12V 4x4 recovery winches … more than enough pull, but as this would be fitting in building (not on a vehicle) no high current 12V source * (OK I could buy a battery… but 240V seems so much easier)
I did ask a question a while back, and that sent me in direction of ‘Powered jockey wheel’ & caravan ‘power movers’ … but all suitable ones were in the US only.
Such as these -http://youtu.be/qOWHNYa80y8
Unless anybody has an interesting way of making a powered version of one of these ? …..http://tinyurl.com/bpbl7jf

Re how much pulling force, if a person can lift 50kg, 2 people can exert 100kg force. A lot of people max out at less. Its quite approximate of course, but a 250kg hoist should provide enough force, I don't think there's much likelihood of each person moving it with 125kg of force

NT

Caravanning types sometimes have remote control gubbins which allow
them to steer the caravan around very easily. obviously you'd need a
battery on the trailer, but I don't know how the rest of the gubbins
would compare time / price wise with what you are proposing.

C

In message
,
Chris Holmes writes
Caravanning types sometimes have remote control gubbins which allow
them to steer the caravan around very easily. obviously you'd need a
battery on the trailer, but I don't know how the rest of the gubbins
would compare time / price wise with what you are proposing.

I'm always too wordy.

I've been asking about winches here (and there!) so this is a little
story about how far I've got. I just needed something to help move a
4-wheel trailer without the boat on it over some rough ground into and
out of a good winter storage space.
To park it last winter we used the Disco in low range, with a bit of
help from a manual chain hoist used horizontally to a tree. This worked,
but was annoying because the chain kept jamming.
I asked here about "Champion" aka "Warrior" winches to mount on the
towbar of the Disco. These seemed excellent, but the towbar mounting was
almost as expensive as the winch, so I went onto ebay and bought a very,
very cheap Chinese towbar winch.
The seller had modified it to use as a hoist to get a log splitter into
the back of his van, but had found it to be too slow. As a hoist, he had
made it reversible (by swapping polarity of the 12volts), and disabled
the clutch and ratchet. With help here I found a clutch material
manufacturer to provide the replacement for the pad that had stuck to
the plate, and have modified it back to winch. As a winch I can
declutch and pull out the cable, then hook up, engage the clutch and
pull away.

The basic winch comes with a wired remote control, and a power cable
with 2 croc clips to connect to the battery. The power cable is about
1/4 the length of the Disco, which appears to be about standard for
these winches, and pretty stupid.

I've tested temporarily using jump leads and it works fine, and the sort
of keyhole plate that hooks over the towbar seems good and simple,
although the winch does droop alarmingly until under tension.

At this stage, the day came when we had to get the trailer out, so I
brought the jump leads, the winch, a pulley and a strop for round the
tree. This last was actually a luggage strap from Poundland - big
mistake as the sewing on it is poor and erratic and SWMBO seems to have
taken her bat and needles home wrt anything to do with boats.
The concept was to tie the rope to the back of the trailer, take it
through the pulley on the tree and lead it to the jockey wheel where a
son would pay it out and fine-steer. I would juggle the Disco and winch
to pull forwards and coarse steer.
I had just got the admittedly tangled rope out, and the jump lead
assembly onto the path when son declared that it was too difficult to
sort the rope out and he didn't mind me demolishing a few of his bushes
to do a straight tow out with the Disco, so we tried that and about an
hour later, we had juggled the trailer out onto the path.

Really, I was overtaken by time and hadn't got anything fully ready, but
the dummy runs indicate that this should be feasible next year.
Internally, the winch seems hardly used, and this towbar mounting means
that for light loads, the Disco doesn't have to be absolutely straight
with the pull. I'm trying to find a cheap way of wiring up the Disco
permanently for a winch at the back, but everyone seems to have had the
battery cables out of old Mini's already.

We all thought that the electric jockey wheel movers were a bit
lightweight, and dangerous for use on rough ground. I looked at the
wheel driven caravan mover of a nearby caravanner, but it was very
expensive and during the parking of our trailer at one stage we had just
one wheel and the jockey wheel touching ground.

I realise none of this answers the question, but maybe it will trigger
some sort of thought. One question that springs to my mind is whether
the hoists pointed to by the OP work well as winches, or are there
differences in the clutch/control mechanisms. As you can tell, I'm no
expert.
--
Bill

On 07/11/2012 08:40, Chris Holmes wrote:


Caravanning types sometimes have remote control gubbins which allow
them to steer the caravan around very easily. obviously you'd need a
battery on the trailer, but I don't know how the rest of the gubbins
would compare time / price wise with what you are proposing.



I somehow don't think that caravan movers would take very well to being
submerged in salt water every time you launch/recover the boat!
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 06/11/2012 22:48, Osprey wrote:

I did ask a question a while back, and that sent me in direction of ‘Powered jockey wheel’& caravan ‘power movers’ … but all suitable ones were in the US only.
Such as these - http://youtu.be/qOWHNYa80y8



You can get similar ones in UK. Which ones did you look at, and why were
they unsuitable?

With a powered jockey wheel, you *do* have to make sure that you've got
enough weight on the hitch to prevent wheelspin - but that shouldn't be
too big a problem if you're on firm ground and only trying to move up a
gentle slope.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 07/11/2012 08:40, Chris Holmes wrote:


Caravanning types sometimes have remote control gubbins which allow
them to steer the caravan around very easily. obviously you'd need a
battery on the trailer, but I don't know how the rest of the gubbins
would compare time / price wise with what you are proposing.


You are right there are caravan units these bolt onto axle and drive the
wheels via a knobbly roller .... but Because the trailer gets dunked in
sal****er I ruled out these.

On 07/11/2012 10:49, Bill wrote:


I realise none of this answers the question, but maybe it will trigger
some sort of thought. One question that springs to my mind is whether
the hoists pointed to by the OP work well as winches, or are there
differences in the clutch/control mechanisms. As you can tell, I'm no
expert.


so not just me looking for such a solution.

On 07/11/2012 16:26, Roger Mills wrote:
On 06/11/2012 22:48, Osprey wrote:

You can get similar ones in UK. Which ones did you look at, and why were
they unsuitable?

With a powered jockey wheel, you *do* have to make sure that you've got
enough weight on the hitch to prevent wheelspin - but that shouldn't be
too big a problem if you're on firm ground and only trying to move up a
gentle slope.

I found units that have to permanently attached to trailer (no good for
launching) ... the only other was quoted for a caravan weight that was
much less than trailer .... if you know of any UK ones let me know.

A powered mover / jockey wheel would seem to be best solution ... a
240v one would be even better

On 07/11/2012 20:24, Rick Hughes wrote:
On 07/11/2012 16:26, Roger Mills wrote:
On 06/11/2012 22:48, Osprey wrote:

You can get similar ones in UK. Which ones did you look at, and why were
they unsuitable?

With a powered jockey wheel, you *do* have to make sure that you've got
enough weight on the hitch to prevent wheelspin - but that shouldn't be
too big a problem if you're on firm ground and only trying to move up a
gentle slope.

I found units that have to permanently attached to trailer (no good for
launching) ... the only other was quoted for a caravan weight that was
much less than trailer .... if you know of any UK ones let me know.

A powered mover / jockey wheel would seem to be best solution ... a 240v
one would be even better

Is this any good? http://www.shifta.co.uk/industrial_mover.html

It appears that the basic caravan mover isn't made any more, but
second-hand ones are bound to be available on Ebay.

My interpretation of what it says is that they will still make one-off
industrial movers - doubtless at a price!

I don't know whether the industrial ones can be mains operated. The
caravan ones pretty certainly can't - because people need to use them in
the field, so to speak.

If you're only using it on firm ground with only a slight gradient, it
may not matter if your trailer is above its official weight limit. At
any rate, it wouldn't do any harm to discuss your application with these
people.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

Bill wrote:
In message
,
Chris Holmes writes
Caravanning types sometimes have remote control gubbins which allow
them to steer the caravan around very easily. obviously you'd need a
battery on the trailer, but I don't know how the rest of the gubbins
would compare time / price wise with what you are proposing.

I'm always too wordy.

I've been asking about winches here (and there!) so this is a little
story about how far I've got. I just needed something to help move a
4-wheel trailer without the boat on it over some rough ground into and
out of a good winter storage space.
To park it last winter we used the Disco in low range, with a bit of
help from a manual chain hoist used horizontally to a tree. This worked,
but was annoying because the chain kept jamming.
I asked here about "Champion" aka "Warrior" winches to mount on the
towbar of the Disco. These seemed excellent, but the towbar mounting was
almost as expensive as the winch, so I went onto ebay and bought a very,
very cheap Chinese towbar winch.
The seller had modified it to use as a hoist to get a log splitter into
the back of his van, but had found it to be too slow. As a hoist, he had
made it reversible (by swapping polarity of the 12volts), and disabled
the clutch and ratchet. With help here I found a clutch material
manufacturer to provide the replacement for the pad that had stuck to
the plate, and have modified it back to winch. As a winch I can declutch
and pull out the cable, then hook up, engage the clutch and pull away.

The basic winch comes with a wired remote control, and a power cable
with 2 croc clips to connect to the battery. The power cable is about
1/4 the length of the Disco, which appears to be about standard for
these winches, and pretty stupid.

I've tested temporarily using jump leads and it works fine, and the sort
of keyhole plate that hooks over the towbar seems good and simple,
although the winch does droop alarmingly until under tension.

At this stage, the day came when we had to get the trailer out, so I
brought the jump leads, the winch, a pulley and a strop for round the
tree. This last was actually a luggage strap from Poundland - big
mistake as the sewing on it is poor and erratic and SWMBO seems to have
taken her bat and needles home wrt anything to do with boats.
The concept was to tie the rope to the back of the trailer, take it
through the pulley on the tree and lead it to the jockey wheel where a
son would pay it out and fine-steer. I would juggle the Disco and winch
to pull forwards and coarse steer.
I had just got the admittedly tangled rope out, and the jump lead
assembly onto the path when son declared that it was too difficult to
sort the rope out and he didn't mind me demolishing a few of his bushes
to do a straight tow out with the Disco, so we tried that and about an
hour later, we had juggled the trailer out onto the path.

Really, I was overtaken by time and hadn't got anything fully ready, but
the dummy runs indicate that this should be feasible next year.
Internally, the winch seems hardly used, and this towbar mounting means
that for light loads, the Disco doesn't have to be absolutely straight
with the pull. I'm trying to find a cheap way of wiring up the Disco
permanently for a winch at the back, but everyone seems to have had the
battery cables out of old Mini's already.

We all thought that the electric jockey wheel movers were a bit
lightweight, and dangerous for use on rough ground. I looked at the
wheel driven caravan mover of a nearby caravanner, but it was very
expensive and during the parking of our trailer at one stage we had just
one wheel and the jockey wheel touching ground.

I realise none of this answers the question, but maybe it will trigger
some sort of thought. One question that springs to my mind is whether
the hoists pointed to by the OP work well as winches, or are there
differences in the clutch/control mechanisms. As you can tell, I'm no
expert.


make one of these.
http://www.youtube.com/watch?v=SF8PU77eyCo

"Osprey" wrote in message
...

Hi team ….. I have a boat trailer (twin axle) which has a boat on it
weighing 1600Kg.
On the flat I can happily pull & push trailer is a straight line - so
rolling resistance is not too high.
I have to manoeuvre the boat into a boat shed after each use … and for a
number of reasons I can’t use a car other than for getting in aprox right
position.

The problem is 2 fold … there is a slight incline until the wheels get
onto the boatshed floor (requiring a lot of effort) …. And being a twin axle
trailer it is very hard to move it ‘sideways’ on single axle it’s fine, you
simply see-saw back and forth over a short distance to move sideways - but
on twin axle the rear wheels ‘crab over’ as front one trace the arc, and
then it is very hard to move.

If I have a mate with me it’s fine, but it certainly can’t be done single
handed.

An option I have thought of is using an electric winch, clipping winch cable
onto rear axle … my thoughts are that the winch then provides the effort of
the ‘pull’ .. and all I have to do is then put the effort into steering
the jockey wheel.
I have 220V ac there so ‘maybe’ I could use a remote control mains
‘lift/hoist’ …such as …
http://www.silverlinetools.com/products?search=264782

I could even set a single snatch pulley block into a fixing into concrete
floor to make pull ‘better’

My Q is …. Does this sound logical ? ………… for these winches they quote
vertical lift load of 250Kg … (to 11.5m high) so not sure how (if it does)
relate to a horizontal pull capability …. This is a rolling load not dead
lift, but hard to know how to estimate how much ‘pull’ force would be
needed.
The other option is the 12V 4x4 recovery winches … more than enough pull,
but as this would be fitting in building (not on a vehicle) no high current
12V source (OK I could buy a battery… but 240V seems so much easier)

I did ask a question a while back, and that sent me in direction of ‘Powered
jockey wheel’ & caravan ‘power movers’ … but all suitable ones were in the
US only.
Such as these - http://youtu.be/qOWHNYa80y8

Unless anybody has an interesting way of making a powered version of one of
these ? ….. http://tinyurl.com/bpbl7jf

Neither will withstand continued immersion, but one of these might

http://www.powrlaunch.co.uk/

On 08/11/2012 01:57, F Murtz wrote:
Bill wrote:



make one of these.
http://www.youtube.com/watch?v=SF8PU77eyCo

Yep ... I know of that I posted the link in thread above.
If I could find a suitable gearbox it would be a good winter project

On 07/11/2012 22:48, Roger Mills wrote:

Is this any good? http://www.shifta.co.uk/industrial_mover.html

It appears that the basic caravan mover isn't made any more, but
second-hand ones are bound to be available on Ebay.



Swapped a mail with the company this morning .... he gave a really good
response ... see below ....
He does not make these any more ... looked on eBay £500+ for 2nd hand
........... seems crazy price
Maybe I need a retired fitter ... who wants a manufacturing project



I understand your problems completely, they have been there ever since
twin axles were introduced. I have attached some details of the problems
of moving trailers. Until trailer manufacturers accept that turning a
vehicle with four fixed wheels is like trying to drive a car with no
turning wheels! it is amazing that we all continue to buy such a
ridiculous piece of kit.
Lunar caravans did offer a few years ago a twin axle caravan with a
hydraulic system that pushed one pair of the wheels downwards, enough to
lift the other two off the ground. This made it as easy as any single
axle caravan/trailer to manoeuvre.

It didn't catch on, no doubt due to the added cost. It doesn't need a
hydraulic system, all it needs is for one pair to have a free steering
motion which can be locked into a straight position once any manoeuvring
has been completed. To my knowledge this has never been produced,
perhaps one day the trailer manufacturers will catch up with the demand
for a four wheel
system that can be steered easily.

Using one of our Shifta's may help you if you address the rotating hitch
problem and convert it to "fixed" which is what all modern caravans are.
Hitch and trailer manufacturers carry on making rotating hitches without
any knowledge as to why they rotate, Avonride even make a model which
does not rotate but when asked why? They have no idea, it seems someone
who has long since left the company designed it and it was not used on
all the other heads they make. The mind boggles!!

So Rick I am afraid you are one of thousands of trailer owners who have
a serious problem that the industry does not want to address as long as
people still buy what they choose to make.

I once asked Al-Ko Kober who buy our machines and make 90% of all
chassis on caravans, why they still fitted rod and drum brakes instead
of discs and hydraulics as all cars since the 30's have converted to
hydraulics and discs have been around since the 70's, so 40+ years ago.
Their answer was that "it would cost a lot for tooling to change the
system" I pointed out that surely after 50+ years they could do with new
tooling anyway, they just laughed. It is apathy in the industry and it
is the same disease that brought about the downfall of the motorcycle
industry here.

One day some enterprising company will design a new breed of
trailer/caravan chassis which will incorporate modern brakes and hitch
heads with all round suspension and damping just the same as the most
basic cars. Plus a steering mechanism for the four wheeled versions.
When this happens I am afraid it will come either from Germany or even
the Japanese who seem to be the inovaters these days.

I know a lot of this will not help you at all but it just illustrates
how we have lost our lead in the industrial world and I am sure that
neither of us can do anything about it.

We no longer manufacture our Shifta machines as I have retired, your
only chance of buying a machine is to buy a used one. You will need at
least a Shifta2 or 3 as the original machine would not be powerful
enough for the weight of your trailer. Please read the attachment as
trailers are fraught with problems as you can see.

On Thu, 08 Nov 2012 13:09:44 +0000, Rick Hughes wrote:

On 07/11/2012 22:48, Roger Mills wrote:

Is this any good? http://www.shifta.co.uk/industrial_mover.html

It appears that the basic caravan mover isn't made any more, but
second-hand ones are bound to be available on Ebay.



Swapped a mail with the company this morning .... he gave a really good
response ... see below ....
He does not make these any more ... looked on eBay £500+ for 2nd hand
.......... seems crazy price
Maybe I need a retired fitter ... who wants a manufacturing project

Personally it's the sort of thing I'd probably use an old lawn tractor
for (ditch the mowing deck) as they'd got masses of pulling ability for
their size - but then I am in the land 'o big lawns, so there's a ready
supply of almost-free old ones that are past their best but would happily
do the job.

Huge wrote:
On 2012-11-08, Jules Richardson wrote:

Personally it's the sort of thing I'd probably use an old lawn tractor
for (ditch the mowing deck) as they'd got masses of pulling ability for
their size - but then I am in the land 'o big lawns, so there's a ready
supply of almost-free old ones that are past their best but would happily
do the job.

Forget it in the UK. Even elderly knackered ones are Much Moola here.

They may be cheap in the YooEssHay but they seem expensive all across
Europe. My own full size tractor cost me £4500 and it was "quite old" when
I got it.

--
€¢DarWin|
_/ _/

On Wed, 7 Nov 2012 00:40:00 -0800 (PST), Chris Holmes wrote:


Caravanning types sometimes have remote control gubbins which allow
them to steer the caravan around very easily. obviously you'd need a
battery on the trailer, but I don't know how the rest of the gubbins
would compare time / price wise with what you are proposing.

Caravan types now seem to be migrating to those driving the
trailer wheels these days. At least this type avoids the
wheel-slip the motorised wheel tow-bar types are prone to,
due to lower towbar nose weights. Note that the demo of the
one posted earlier only shows it used on concreted flat
ground...

I see Powrwheel, who advertise in Caravan mags., do a fully
submersible version for boat trailers. see:
www.powrlaunch.co.uk - Probably not cheap though... I've not
seen one in use and would personally go for a towbar mounted
winch on a well anchored tow car to pull the lot up a
launching ramp. That way, the motor could be powered as
required - and well clear of the water, unless it ended up
pulling the tow-car down the ramp :-)

--
John W

In message , Rick Hughes
writes
On 08/11/2012 01:57, F Murtz wrote:
Bill wrote:



make one of these.
http://www.youtube.com/watch?v=SF8PU77eyCo

Yep ... I know of that I posted the link in thread above.
If I could find a suitable gearbox it would be a good winter project

I love the way he in the video has no shoes on. To hold the trigger on
the drill, steer and look where you are going would be hard enough. To
control a 4-wheel trailer up even the slight slope and crest into the
garage/boat shed would certainly scare me. It would be off the ground
one minute, bursting its tyres the next.

I honestly think that a towbar mounted or fixed mains winch and a bunch
of rope to the other end gives more control and some hope of stopping a
runaway trailer.

OT: In the other branch of this thread the Mr Shifta man sounds very
like the designer of the small Petter industrial diesel engine(s) we had
originally in our boat. The next boat in the yard had Volvo power, and
cooling part prices were up in the clouds. My Petter used standard pipe
threads, so I just had a trip to B&Q to plumb the exhaust. The retired
Petter designer went though all the problems with me and suggested the
answers, while bemoaning the state of British engineering companies.
Petter had at the time been taken over by Lister and had been run down.
Now many years later we are on a Mitsubishi diesel.


--
Bill

On Thursday, November 8, 2012 3:59:18 PM UTC, Steve Firth wrote:
Huge wrote:
On 2012-11-08, Jules Richardson wrote:

Personally it's the sort of thing I'd probably use an old lawn tractor
for (ditch the mowing deck) as they'd got masses of pulling ability for
their size - but then I am in the land 'o big lawns, so there's a ready
supply of almost-free old ones that are past their best but would happily
do the job.
Forget it in the UK. Even elderly knackered ones are Much Moola here.
They may be cheap in the YooEssHay but they seem expensive all across
Europe. My own full size tractor cost me £4500 and it was "quite old" when
I got it.

Mini tractors are diyable. I recall seeing a simple homemade design that pivoted the 2 halves of the chassis, with each half having a fixed axle, and used a hydraulic pump to power both wheels and to steer by changing the angle between the front & rear half. I can't find the link though.


NT

On 08/11/2012 06:23, Nthkentman wrote:

Such as these - http://youtu.be/qOWHNYa80y8

Unless anybody has an interesting way of making a powered version of one
of these ? ….. http://tinyurl.com/bpbl7jf

Neither will withstand continued immersion, but one of these might

http://www.powrlaunch.co.uk/



Contacted powrlaunch .... they want £2,500 ..... too expensive

This option http://www.youtube.com/watch?v=LBdYG...eature=related

could have merits but told trailer hitches that swivel (normal in UK)
don't work well and you would have to prevent the swivel.

I may be back to plan A ... a winch inside the boat store pulling the
trailer in.
Can get these for around £25

My concern is the vertical pull is stated as 250Kg (twin wire pull) I
could arrange that using a snatch pulley .... but is 250Kg going to be
enough .......... can't really think of a way to estimate the pull required.

On 06/11/2012 22:48, Osprey wrote:


Unless anybody has an interesting way of making a powered version of one of these ? ….. http://tinyurl.com/bpbl7jf


here is one I won't be building

http://www.youtube.com/watch?v=V3AM8...ture=fvwp&NR=1

On Fri, 09 Nov 2012 05:51:34 -0800, meow2222 wrote:

On Thursday, November 8, 2012 3:59:18 PM UTC, Steve Firth wrote:
Huge wrote:
On 2012-11-08, Jules Richardson wrote:

Personally it's the sort of thing I'd probably use an old lawn
tractor for (ditch the mowing deck) as they'd got masses of pulling
ability for their size - but then I am in the land 'o big lawns, so
there's a ready supply of almost-free old ones that are past their
best but would happily do the job.
Forget it in the UK. Even elderly knackered ones are Much Moola
here.
They may be cheap in the YooEssHay but they seem expensive all across
Europe. My own full size tractor cost me £4500 and it was "quite old"
when I got it.

Mini tractors are diyable.

There is that, although they typically seem to be based around car parts
(wheels and axles in particular), and so end up a little larger than a
typical garden tractor (and possibly with a far larger turning circle too
if using a car's steering system)

I recall seeing a simple homemade design that
pivoted the 2 halves of the chassis, with each half having a fixed axle,
and used a hydraulic pump to power both wheels and to steer by changing
the angle between the front & rear half. I can't find the link though.

Hmm, shout if you do! I've seen a few early (ish) commercial tractors
which achieved four wheel drive by essentially coupling two regular
machines together (minus their front axles) at a pivot controlled by
hydrualics, but they were standard geared drive to the wheels rather than
hydraulic.

cheers

Jules

On Fri, 09 Nov 2012 16:25:18 +0000, Rick Hughes wrote:
here is one I won't be building

http://www.youtube.com/watch?v=V3AM8...ture=fvwp&NR=1

The go-faster version uses an angle grinder ;-)

wrote:

On Thursday, November 8, 2012 3:59:18 PM UTC, Steve Firth wrote:
Huge wrote:
On 2012-11-08, Jules Richardson wrote:

Personally it's the sort of thing I'd probably use an old lawn tractor
for (ditch the mowing deck) as they'd got masses of pulling ability
for their size - but then I am in the land 'o big lawns, so there's a
ready supply of almost-free old ones that are past their best but
would happily do the job.
Forget it in the UK. Even elderly knackered ones are Much Moola here.
They may be cheap in the YooEssHay but they seem expensive all across
Europe. My own full size tractor cost me £4500 and it was "quite old"
when I got it.

Mini tractors are diyable. I recall seeing a simple homemade design that
pivoted the 2 halves of the chassis, with each half having a fixed axle,
and used a hydraulic pump to power both wheels and to steer by changing
the angle between the front & rear half. I can't find the link though.


NT

A friend made a very usable lawn tractor out of a Reliant Robin
it had i think a 4:1 reduction box bolted on the diff and mini tractor
wheels.
I have a photo of the thing if i can find it.


-

In message , Jules Richardson
writes
There is that, although they typically seem to be based around car parts
(wheels and axles in particular), and so end up a little larger than a
typical garden tractor (and possibly with a far larger turning circle too
if using a car's steering system)

I recall seeing a simple homemade design that
pivoted the 2 halves of the chassis, with each half having a fixed axle,
and used a hydraulic pump to power both wheels and to steer by changing
the angle between the front & rear half. I can't find the link though.

Hmm, shout if you do! I've seen a few early (ish) commercial tractors
which achieved four wheel drive by essentially coupling two regular
machines together (minus their front axles) at a pivot controlled by
hydrualics, but they were standard geared drive to the wheels rather than
hydraulic.

I have the use of a micro digger (Steelfab?) which uses hydraulically
powered wheels for manoeuvring. It may be based on *dumper truck*
technology.

--
Tim Lamb

On 09/11/2012 16:19, Rick Hughes wrote:


My concern is the vertical pull is stated as 250Kg (twin wire pull) I
could arrange that using a snatch pulley .... but is 250Kg going to be
enough .......... can't really think of a way to estimate the pull
required.


Well, it ain't rocket science!

To pull a trailer up a slope you need a horizontal(ish) force equal to
the rolling resistance plus the component of the trailer/boat weight
acting along the slope (weight multiplied by the sine of the angle which
the slope makes with the horizontal)

You measure the first of these by pulling the trailer along a horizontal
surface by means of a spring balance. You can calculate the second.

For example, if the all-up weight of the boat plus trailer is 2000Kg, I
would expect the rolling resistance to be around 25Kg. If you pull it up
a 5 degree slope (approx 1 in 12) the component of the weight along the
slope will be about 175Kg - i.e. 200Kg in all.

When the hoist is laid on its side, it should be able to exert a similar
horizontal pull to its rated vertical lift when used normally. So 250Kg
should be ok for a 5 degree slope. If it's steeper than that, you might
have a problem - so make your own measurements and do your own
calculations with the actual data.
--
Cheers,
Roger
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