A Caravan forum. Caravan Banter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » Caravan Banter forum » Caravan, Motor Homes and Camping Newsgroups » UK Caravanning
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

UK Caravanning (uk.rec.caravanning) A forum for the discussion of caravanning undertaken by residents of the United Kingdom, whether in the UK or abroad. It encourages the interchange of views on the merits of models of caravan, makes of tow car, accessories, caravan sites, caravan clubs, and other related topics. The term caravan is to include trailer vans, motor caravans and trailer tents.

Levelling Aid - More!



 
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old June 8th 09, 05:08 PM posted to uk.rec.caravanning
Harry Bloomfield[_2_]
external usenet poster
 
Posts: 278
Default Levelling Aid - More!

I would like to make an apology for my comments about this item last
week. It seems the author of the OP was simply trying to gauge interest
in such a device. Since when I have exchanged a series of emails with
the OP.

The outcome of which has been that I have come up with something which
potentially should work much better, better more repeatable accuracy
and uses electrickery.

Basically a short length of plastic drain pipe with a plumb bob
suspended from a conductive wire inside it and four contact points
around the bob weight. It should fit under a bed locker with a thin
ribbon cable linking it to a five LED display. Four provide indication
of fore or aft/ left or right lean arranged in a square, the fifth in
the centre will provide indication of power on and also provide a
reference point so you know which of the other four are lit.

Due to the way it works, and the tiny gaps between the bob and the
contact points - the only feedback you get is when the lean swaps over
from leaning one way to the other, there will be no null point. There
is no indication of degree of lean or amount of correction needed - you
just adjust until one LED goes out, and its opposite number lights up,
as it does so - you are spot on level.

Its an idea I formulated several years ago, but never got around to
testing. The entire accuracy of the device depends on using very small
gaps between bob weight and the four contact points. I'm thinking of a
suspended length of around 300mm and a contact point gap of around
0.5mm would someone like to do the maths on the potential degree of
accuracy?

The display can be put in the front window when needed and you just
switch the power on to use it.

I have offered the OP the description above, suggesting he might like
to make free use of it and I'll make the same offer to members of this
group for their own personal non commercial use.

This evening I shall make a start turning the idea into something which
works.


--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk


Ads
  #2 (permalink)  
Old June 8th 09, 10:31 PM posted to uk.rec.caravanning
Harry Bloomfield[_2_]
external usenet poster
 
Posts: 278
Default Levelling Aid - More!

Harry Bloomfield was thinking very hard :
This evening I shall make a start turning the idea into something which
works.


I have made up the 'sensor' and it seems to be extremely sensitive to
level.

http://myweb.tiscali.co.uk/m1byt/P1010108.JPG

http://myweb.tiscali.co.uk/m1byt/P1010110.JPG

I used a bit of 35mm OD plastic drain pipe, as used for domestic sink
drainage. A 32mm push fit joint, cut in half to make the bottom end
more rigid plus thick enough to take a thread. 4x brass 4mm (I think)
screws and nuts, with the ends ground to a sharp contact point. An
undersize drill bit (to the one you would normally use for the tap) to
make the four holes then tap them. Being plastic and flexible, it
doesn't make a clean thread - the screws need some force to screw them
in and the stay put where you set them without need for a lock nut.

The plumb bob is made from brass, with a 0.5mm hole drilled down the
centre. That is about 25mm high by 25mm diameter. It is crucial that is
made up accurately so it hangs straight. I made it up on my lathe. To
that I soldered some fine flexible wire. A plastic pop bottle top was a
perfect fit to go in the top end, with a tiny hole made in its centre
to support the wire and bob at the top.

The circuit is...

Connect battery negative to bob weight, then each of the four contact
screws goes via a ribbon cable to a super-bright LED x4, then in series
with a suitable resistor to a switch. Other side of switch goes to a
fused positive 12v supply.

A 'power on' LED (also serving as a centre of the display reference
point) is wired between negative and the switch, via a suitable value
of resistor.

In total, six wires are needed from the sensor to the display, to feed
the 5x LED's. The grey ribbon cable as used in computers is perfect for
the purpose.

If you prefer, low wattage 12v lamps can be used instead of LED's. The
five LED's (or lamps) are set out on a small piece of black plastic in
a diamond shape, with the 'power on' LED in the centre, which needs to
be a different colour to the other four LED's.

Two small bits of thin ply, with a hole drilled in the centre of each,
to match each end of the sensor pipe, tacked to the floor and the
underside of a bunk support timber, keep the sensor in place. The
screws are screwed in until both sides touch, then just backed out
enough for one of each directional lights to go back out. Line it up
initially with the caravan perfectly level - small adjustments can then
be made via the screws.

The unit fits in a front bed locker, with a long enough ribbon cable to
allow the display to be fitted when needed in the front window. When
not in use it all goes out of sight, in the locker.

If you use LED's they MUST be fitted in the circuit with the correct
polarity and they MUST be wired in series with a resistor of the
correct value.

My preliminary tests suggest that contact resistance will mean that a
sort of null point (neither side lit) will be provided when it is in
perfect balance.

Now should the light come on when that side/end is high, or low?

I'll post more pictures as I progress with the 'electronics'.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk


  #3 (permalink)  
Old June 9th 09, 06:19 AM posted to uk.rec.caravanning
Roy[_3_]
external usenet poster
 
Posts: 111
Default Levelling Aid - More!

Harry Bloomfield said the following on 08/06/2009 23:31:
Harry Bloomfield was thinking very hard :
This evening I shall make a start turning the idea into something
which works.


I have made up the 'sensor' and it seems to be extremely sensitive to
level.

http://myweb.tiscali.co.uk/m1byt/P1010108.JPG

http://myweb.tiscali.co.uk/m1byt/P1010110.JPG

I used a bit of 35mm OD plastic drain pipe, as used for domestic sink
drainage. A 32mm push fit joint, cut in half to make the bottom end more
rigid plus thick enough to take a thread. 4x brass 4mm (I think) screws
and nuts, with the ends ground to a sharp contact point. An undersize
drill bit (to the one you would normally use for the tap) to make the
four holes then tap them. Being plastic and flexible, it doesn't make a
clean thread - the screws need some force to screw them in and the stay
put where you set them without need for a lock nut.

The plumb bob is made from brass, with a 0.5mm hole drilled down the
centre. That is about 25mm high by 25mm diameter. It is crucial that is
made up accurately so it hangs straight. I made it up on my lathe. To
that I soldered some fine flexible wire. A plastic pop bottle top was a
perfect fit to go in the top end, with a tiny hole made in its centre to
support the wire and bob at the top.

The circuit is...

Connect battery negative to bob weight, then each of the four contact
screws goes via a ribbon cable to a super-bright LED x4, then in series
with a suitable resistor to a switch. Other side of switch goes to a
fused positive 12v supply.

A 'power on' LED (also serving as a centre of the display reference
point) is wired between negative and the switch, via a suitable value of
resistor.

In total, six wires are needed from the sensor to the display, to feed
the 5x LED's. The grey ribbon cable as used in computers is perfect for
the purpose.

If you prefer, low wattage 12v lamps can be used instead of LED's. The
five LED's (or lamps) are set out on a small piece of black plastic in a
diamond shape, with the 'power on' LED in the centre, which needs to be
a different colour to the other four LED's.

Two small bits of thin ply, with a hole drilled in the centre of each,
to match each end of the sensor pipe, tacked to the floor and the
underside of a bunk support timber, keep the sensor in place. The screws
are screwed in until both sides touch, then just backed out enough for
one of each directional lights to go back out. Line it up initially with
the caravan perfectly level - small adjustments can then be made via the
screws.

The unit fits in a front bed locker, with a long enough ribbon cable to
allow the display to be fitted when needed in the front window. When not
in use it all goes out of sight, in the locker.

If you use LED's they MUST be fitted in the circuit with the correct
polarity and they MUST be wired in series with a resistor of the correct
value.

My preliminary tests suggest that contact resistance will mean that a
sort of null point (neither side lit) will be provided when it is in
perfect balance.

Now should the light come on when that side/end is high, or low?

I'll post more pictures as I progress with the 'electronics'.



Great idea, but any problems with vibration or having to wait for it to
stop swinging - presumably the LEDs will flash until the steady state is
reached. Possible solution is to use a less flexible pendulum wire.

Roy
  #4 (permalink)  
Old June 9th 09, 12:16 PM posted to uk.rec.caravanning
Roger Mills
external usenet poster
 
Posts: 418
Default Levelling Aid - More!

In an earlier contribution to this discussion,
Harry Bloomfield wrote:

Harry Bloomfield was thinking very hard :
This evening I shall make a start turning the idea into something
which works.


I have made up the 'sensor' and it seems to be extremely sensitive to
level.

http://myweb.tiscali.co.uk/m1byt/P1010108.JPG

http://myweb.tiscali.co.uk/m1byt/P1010110.JPG

I used a bit of 35mm OD plastic drain pipe, as used for domestic sink
drainage. A 32mm push fit joint, cut in half to make the bottom end
more rigid plus thick enough to take a thread. 4x brass 4mm (I think)
screws and nuts, with the ends ground to a sharp contact point. An
undersize drill bit (to the one you would normally use for the tap) to
make the four holes then tap them. Being plastic and flexible, it
doesn't make a clean thread - the screws need some force to screw them
in and the stay put where you set them without need for a lock nut.

The plumb bob is made from brass, with a 0.5mm hole drilled down the
centre. That is about 25mm high by 25mm diameter. It is crucial that
is made up accurately so it hangs straight. I made it up on my lathe.
To that I soldered some fine flexible wire. A plastic pop bottle top
was a perfect fit to go in the top end, with a tiny hole made in its
centre to support the wire and bob at the top.

The circuit is...

Connect battery negative to bob weight, then each of the four contact
screws goes via a ribbon cable to a super-bright LED x4, then in
series with a suitable resistor to a switch. Other side of switch
goes to a fused positive 12v supply.

A 'power on' LED (also serving as a centre of the display reference
point) is wired between negative and the switch, via a suitable value
of resistor.

In total, six wires are needed from the sensor to the display, to feed
the 5x LED's. The grey ribbon cable as used in computers is perfect
for the purpose.

If you prefer, low wattage 12v lamps can be used instead of LED's. The
five LED's (or lamps) are set out on a small piece of black plastic in
a diamond shape, with the 'power on' LED in the centre, which needs to
be a different colour to the other four LED's.

Two small bits of thin ply, with a hole drilled in the centre of each,
to match each end of the sensor pipe, tacked to the floor and the
underside of a bunk support timber, keep the sensor in place. The
screws are screwed in until both sides touch, then just backed out
enough for one of each directional lights to go back out. Line it up
initially with the caravan perfectly level - small adjustments can
then be made via the screws.

The unit fits in a front bed locker, with a long enough ribbon cable
to allow the display to be fitted when needed in the front window.
When not in use it all goes out of sight, in the locker.

If you use LED's they MUST be fitted in the circuit with the correct
polarity and they MUST be wired in series with a resistor of the
correct value.

My preliminary tests suggest that contact resistance will mean that a
sort of null point (neither side lit) will be provided when it is in
perfect balance.

Now should the light come on when that side/end is high, or low?

I'll post more pictures as I progress with the 'electronics'.



Ingenious - but I can't help thinking that you really need something which
is more 'analog' in nature, so as to give an indication of *how* unlevel you
are - like a spirit level does(!)

It would obviously require a lot more electronics, but have you considered
using variable gap capacitors rather than contacts as the sensors? You could
possibly then use longer intersecting rows of LEDs to indicate how large the
error is in each plane.

Having said all that, I'm not quite sure why you *need* to see a level
indicator from the driving seat. If setting up single-handed, a side-to-side
indicator may be useful - but fore-and-aft levelling won't be done until you
unhitch - at which time it's very easy to look at a spirit level on the
A-frame as you wind the jockey wheel up and down.

I have a 2-axis spirit level inside my front locker, which is visible with
the lid open. My levelling process is:
* Get in approx the right position, and see how unlevel we are side to side
(from which I can estimate how many steps of my stepped ramp I need to use)
* Drive forwards or backwards onto the ramp (as appropriate) with SWMBO
counting steps
* Re-check side to side level, and do one more/less step if needed
* Unhitch and do fore-and-aft levelling on the jockey wheel

The whole process takes far less time than it has taken me to type this!

Am I missing something?
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!


  #5 (permalink)  
Old June 9th 09, 04:33 PM posted to uk.rec.caravanning
Harry Bloomfield[_2_]
external usenet poster
 
Posts: 278
Default Levelling Aid - More!

Roy wrote :
Great idea, but any problems with vibration or having to wait for it to stop
swinging - presumably the LEDs will flash until the steady state is reached.
Possible solution is to use a less flexible pendulum wire.


Basically, it cannot swing at all - it is trapped between the contact
points, there is only enough of a gap for the bob to clear one contact
before touching the other. The worst you will get is a little bounce
and for a brief amount of time. Anything less than absolutely flexible
suspension will distort the bob weights position.

The only problem I foresee at the moment is poor contact between brass
bob and the screw points, as the brass builds up an insulating coating
over time. Which is why they use gold plating on points of contact
where low resistance is needed.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk


  #6 (permalink)  
Old June 9th 09, 04:45 PM posted to uk.rec.caravanning
Harry Bloomfield[_2_]
external usenet poster
 
Posts: 278
Default Levelling Aid - More!

Roger Mills was thinking very hard :
The whole process takes far less time than it has taken me to type this!

Am I missing something?


I was looking for something which would produce a more accurate level
position and which gave SWMBO easier to follow feedback. I have lost
count of the number of times she has misunderstood a bubble level and
had me cranking the caravan the wrong way. She reads the level and
tells me which way it needs to go.

An analogue output of the error would be much better, but then it
becomes complex for the non technical to build. I was trying to put
together something which almost anyone could build and cheap. The only
real difficulty is the brass bob weight, which has to be made up
accurately on a lathe. Perhaps someone with more time than me and a
lathe could perhaps put together a kit of parts?



--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk


  #7 (permalink)  
Old June 9th 09, 04:49 PM posted to uk.rec.caravanning
Harry Bloomfield[_2_]
external usenet poster
 
Posts: 278
Default Levelling Aid - More!

on 09/06/2009, Roger Mills supposed :
Having said all that, I'm not quite sure why you *need* to see a level
indicator from the driving seat. If setting up single-handed, a side-to-side
indicator may be useful - but fore-and-aft levelling won't be done until you
unhitch - at which time it's very easy to look at a spirit level on the
A-frame as you wind the jockey wheel up and down.


I forgot to mention...

I'm looking for better accuracy than my present T level provides,
because we tend to have problems with drainage unless we hit just the
right spot.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk


  #8 (permalink)  
Old June 9th 09, 05:44 PM posted to uk.rec.caravanning
Lofty
external usenet poster
 
Posts: 155
Default Levelling Aid - More!


"Harry Bloomfield" wrote in message
k...
on 09/06/2009, Roger Mills supposed :
Having said all that, I'm not quite sure why you *need* to see a level
indicator from the driving seat. If setting up single-handed, a
side-to-side indicator may be useful - but fore-and-aft levelling won't
be done until you unhitch - at which time it's very easy to look at a
spirit level on the A-frame as you wind the jockey wheel up and down.


I forgot to mention...

I'm looking for better accuracy than my present T level provides, because
we tend to have problems with drainage unless we hit just the right spot.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk


Get a longer spirit level, and it will be much more accurate

lofty




  #9 (permalink)  
Old June 9th 09, 06:58 PM posted to uk.rec.caravanning
Tom[_10_]
external usenet poster
 
Posts: 27
Default Levelling Aid - More!


"Harry Bloomfield" wrote in message
k...
on 09/06/2009, Roger Mills supposed :
Having said all that, I'm not quite sure why you *need* to see a level
indicator from the driving seat. If setting up single-handed, a
side-to-side indicator may be useful - but fore-and-aft levelling won't
be done until you unhitch - at which time it's very easy to look at a
spirit level on the A-frame as you wind the jockey wheel up and down.


I forgot to mention...

I'm looking for better accuracy than my present T level provides, because
we tend to have problems with drainage unless we hit just the right spot.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk


What's wrong with 1/4" translucent tubing filled with water and
positioned -say around a front window on the van in the shape of a "U" leave
about half of the uprights in the "UP" empty of water leaving the two ends
of the tube open mark the tube both sides when you initially set the water
level and all you have to do when setting the van up is make sure the water
line is level with both marks on the tube for the van to be level. If you
then want to add lights or whatever you can by positioning the electrodes at
water level on both sides to make a circuit.

May be crap but simple and would work.

  #10 (permalink)  
Old June 9th 09, 08:12 PM posted to uk.rec.caravanning
a. clarke
external usenet poster
 
Posts: 10
Default Levelling Aid - More!


"Tom" wrote in message
...

"Harry Bloomfield" wrote in message
k...
on 09/06/2009, Roger Mills supposed :
Having said all that, I'm not quite sure why you *need* to see a level
indicator from the driving seat. If setting up single-handed, a
side-to-side indicator may be useful - but fore-and-aft levelling won't
be done until you unhitch - at which time it's very easy to look at a
spirit level on the A-frame as you wind the jockey wheel up and down.


I forgot to mention...

I'm looking for better accuracy than my present T level provides, because
we tend to have problems with drainage unless we hit just the right spot.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk


What's wrong with 1/4" translucent tubing filled with water and
positioned -say around a front window on the van in the shape of a "U"
leave about half of the uprights in the "UP" empty of water leaving the
two ends of the tube open mark the tube both sides when you initially set
the water level and all you have to do when setting the van up is make
sure the water line is level with both marks on the tube for the van to be
level. If you then want to add lights or whatever you can by positioning
the electrodes at water level on both sides to make a circuit.

May be crap but simple and would work.



"gadgets are great"

Al C


 



Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT. The time now is 04:24 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.Content Relevant URLs by vBSEO 3.0.0 RC6
Copyright 2004-2019 Caravan Banter.
The comments are property of their posters.