Caravan motorised mover.

[DAPPH]

I purchased a single axle Rhyno motor mover for the caravan about seven years ago .
The caravan has only done four trips out with it on till disabilities took me off caravan for a couple of years , none of the trips was in wet weather. Sold the caravan & got the mover transferred to the new caravan three years ago only one trip since due to more operations & recuperations I used it once a two weeks ago for three days to go to the film studio cum the world of Harry Potter( Magic ).

It didn't not much rain either but it seemed difficult to park it up so on coming home I reversed it into it's position then my lass & 16 yr old daughter pushed it to its final resting place as the parking is on flat floated concrete.

Came to start checking it over & servicing it for a run down to Devon on Monday The rhs mover would not work , I could hear it singing as the power went through the windings but not a fraction an inch of movement .

Ha ha I thought the dreaded grit in the bearings seizure I've heard so often about .
2x 17 mm , 2x 10 ,, 1x 8mm socket & driving ratchet and a 4 mm Allen key pus a pair of nippers to snip the cable ties . 20 min later it was free dangling by it's wires. Another 1/2 r and copious cooling drinks & that too is sorted the baby is free,trailing 12 feet of umbilical cables in black & red ….. Yeah! ..success .
It took longer to get the gear together & find something comfortable to lay in in the boiling hot sun than to get it off.

It was boooooger to strip apart , I found put why. The ferrite magnetic strips that should have been fixed internally to the motor body casing had all come free & attached themselves to the stator.
Careful examination revealed one magnet had a deep water stained crack in it & it was in two pieces at the crack .

On looking at what should have held the magnets in place I was dismayed to find the remnants of what looked like Evo Stick contact adhesive or Copydex rubber glue , It had been brushed on over a coat of paint .. every bit of the paint had lifted off because it was full of rust under the paint.
I'm in the pocess of using some paint stripper to remove the glue residues & the paint . then I'll poish the body tube on the lathe till there is no evidence of paint or rust .
Then I'll rust treat it & use araldite to put the magnets back in place .. Hope I get the polarity right or I'll have to swap the live & negative wires round at the control box ….

Do any of you have any tips as to how I should put the magnets back in ... say for instance go clockwise & have the north end of the magnets at the leading edge ?

Some thing to do with Maxwells law me thinks .

 

[colnerov]

I wouldn't mind betting that Sods law will come in to play as well.

 

[wristpin]

Can’t advise on polarity but I’d use an adhesive with a bit more flexibility than Araldite. Loctite Multibond is my choice for such jobs.

 

[DAPPH]

Now you tell me ,


Two hours ago,
I scraped , sanded & polished then cut it with a roughing wheel , used an araldite type poxy two part resin from the pound shop . had to fine cut the magnets with a rough wet & dry to get all traces of the Copydex & paint off them .

Had a bit of fun setting the magnets in as I slid them into place on a bed of poxy resin ,using strips of square 3" white plastic down pipe as spacers ( three between each row of three magnets worked out almost perfect .

The broken magnet was initially stuck together with a strong super glue , it flew apart as soon as it was introduced to the others even though it had spent half an hour glued & lightly clamped up in the vice & felt solid .
( My lass has asked to be applauded by you guys for doing this …….. as I held things in place using both hands, she used a very light touch & some folded tissues to clamp it in the vice without damaging the ferrite ) .

I cleaned the faces of super glue using a secial super glue solvent , put it back in a different place on a bed of poxy resin & it hugged up to its mate like it was a single magnet .

As I was looking at the four carbon brush holders ( 90 degrees apart ) I noticed that there is large pale blue currant sized Tantalum bead capacitor on one of them … ha ha .
I seem to recall from my long long distant past that means the magnets don't have the polarity as I'd imagined, but that it's internal & external curved faces that are all that matters , the capacitor is what gives the motor out of true DC to kickstart it. As Tantalum bead capacitors are very polarity sensitive I'll not be reversing the leads me thinks, unless I want hear one heck of a loud bang & add everything to the scrap heap .

Currently the magnet housing is sat on some kitchen roll in the airing cupboard as it's a wee bit warmer in there than the 25 oC we have outside , the resin should be well & truly cured by tomorrow morning when I try to remember how to put the thing back together & test it before re-fitting it .

 

[voipio]

Can you be sure that the magnets are back in exactly the same place as they were originally? They will be poled NSNS around the circumference and, if the poles are in the wrong place relative to the brushes, the motor won't rotate, or will pull into a position and not move from it.

 

[DAPPH]

Got up early had a cuppa & went out to the garage to reassemble the motor . On giving it the test fire up it ran like a dream whizzing round exceedingly quietly .

Put it on the gear box , Yeah ! it works & it runs in the correct direction .. it's saved me between £678 & £900 , I'll be fitting it a bit later today as I've been to theh dentists and my face is quite numb at present .

As I said earlier the N&S of the magnets appears to be on the curved surfaces not the ends as I'd first thought . Nothing flew apart after the initial opposition jobby on the broken magnet . That was solved easily enough by putting it in somewhere else after turning it through 180 degrees .

I used strips of plastic cut from some scrap 3" square white down pipe to get the spacings between the rows of magnets as equidistant round the circumference as possible .. ( got them within 12 thou it seems )

I've also slathered all the possible points of water ingress to the motor & it's mounting flange with 1/4 of a tube of red silicone joint sealant .

No doubt the right hand motor will soon need the same sort of attention , if it survives the failure of the magnets to stick to the steel casing . .. Might even do it as a preventative maintenance task once things get a bit cooler ...… after returning from our holiday .

 

[DAPPH]

Oh woe is me , WOE , WOE is me ! Like £ 700 to £900 Woe is me.

After testing both movers without engaging them on the wheels , on manually engaging them on the tyres . .. I noticed the controller unit kept flickering even before operating a mover .
The caravan would not move ( yes hand brake was of & the steadies were raised ) . So I replaced the controller battery with a proven new one as this often was a sign it needed replacing ..still the same result. Waaaaaagh !

Ledger battery 13.1 volts, all cells with plenty of electrolyte over the plates in them & able to take a 10 amp loading. Got my lass to operate the controller on each mover in turn whist I was inside the caravan with the cover off the power control module. I found very little voltage drop across the battery supply .. conclusion .. Perhaps the control panel got wrecked due to the overload that happened when the first mover failed . There are so many surface mounted micro electrical components jam packed on the 120 x 120 mm printed circuit board that it would be foolish to try & repair the board .

Ah well the repair had a fifty /fifty chance of turning up trumps .

The caravan is now booked in for a complete new remote engaging mover when we get back after our holiday …. for after several hours of searching the internet it seems no one supply's them as individual parts only & there's now way I'd ever think of shoving a second hand set on the van . ( Used chainsaw , good working, order £335 collection at such & such motorway services , comes to mind ) .


Do any of you guys & gals have any recommendations for brand name new ones or points for me to take in to account ?

Dave

 

[Rig Pig]

Bit late maybe but this just popped up on Facebook, I haven't had any dealings with the gent.

 

[TechnicAl]

Ive got a ENDURO....it was 649 fitted by Auto Additions last July.....not long but works perfect...my van is 1550Kg