how to stop roller swing arms 'tipping over'?

[steve-ribnet]

Hi all,
I've got a roller coaster trailer - probably their "roller coaster 10" or similar .
ROLLER COASTER 10 | Roller Coaster | Marine | Leisure | Trailer Range | Indespension
I've just been replacing all the split pins, washers and bolts for the rollers and swing arms as they corroded through and I lost a roller. (these things: NA026 | Ribbed Parts | Boats Pads & Rollers | Marine Spares | Trailer Parts | Indespension )
Winching the boat back onto the trailer is now a breeze, but I had unknowingly been relying on the seized swing arms from stopping
waves flipping them over when recovering the boat back onto the trailer. Now that they all swing/pivot freely, it is a P.I.T.A to recover the boat in wavey conditions as you have to keep flipping errant arms back to sloping inwards. I have now twice inadvertently winched the boat onto an end-on roller that had flipped over in a wave (local slip is v.exposed).
Has anyone got any tips for stopping them tipping over? I was thinking perhaps small lead weights bolted to the inner side of the swing arms, or perhaps bungee chord to loosely tie them down, or even weld pins across the outside edge of their clevis mounting brackets so they cannot rotate too far (they need only rotate perhaps 45 degrees max from their rest position when the boat is recovered).
I am reluctant to simply tighten the swing arm brackets to increase friction as this sounds like a recipe for corrosion and seizing.

The trailer is perhaps 15 years old - not sure if the latest designs suffer the same problems?
any tips welcomed..
thanks
steve

[Chris Caton]

sounds like the rollers weigh more than the swing beam, so with the help of a wave it's just over balanced, mine does the same while being reversed into the water but swings back the right way up when the trailer stops moving, I'd try the bungee to see if that does the trick.

[Festinghouse]

is it the the 'dumbell bars' that keep moving? if so, i have the same problem with mine as the rollers float level and easily rock over towards the outside of the trailer. my solution is to leave the trailer in much shallower water and put a bit more effort into winching! i find this also keeps the boat firmly located within the rollers even in heavy waves.

[biffer]

You can weld or make a bolt on bracket to stop that, it's quite common

[steve-ribnet]

Originally Posted by Festinghouse

is it the the 'dumbell bars' that keep moving? if so, i have the same problem with mine as the rollers float level and easily rock over towards the outside of the trailer. my solution is to leave the trailer in much shallower water and put a bit more effort into winching! i find this also keeps the boat firmly located within the rollers even in heavy waves.

Yep that's it ( you put it better than I did)
Sounds sensible to keep the rollers shallow-I do try not to put the trailer in too deep - but if the waves are over a foot high they still flip the rollers. That and it is sometimes the wife doing the winching!

[Dhf]

I use those really tough bungies of a trampoline, all the rollers pull in, and the swing bar is forced to face rear when unloaded.

[steve-ribnet]

Thanks for the photos Dragonhawk ficht - that makes sense. I'll give this a go first.

now I've gone and dug myself into a hole and feeling a little ignorant:
I was referring just to the 'dumbell' bits with the two rollers, and how they would flip outwards - see photo below...


but..I just assumed the transverse beam holding the roller sets was rigid, but
now you all mention it, I guess this should be pivoting too - and I've never noticed. See photo below - the beam outlined in RED should be swinging too?

Now the bungee running along the line of the keel in Dragonhawk's photo makes sense! This beam doesn't budge on my trailer (never has - 2nd hand to me)

Now I'm looking closely, I have the same coupling for the beam at the front too - which is also seized and should be pivoting too?


It recovers so well without these beams swinging - I'm tempted to leave them alone...especially as the hook on the bottom of the swing beam is a great tie-down point at the transom

[Chris Caton]

ah, I see it all, a picture paints a thousand words if it were me, n I know I'm gonna get shouted down, but who cares I would nip the bolts up on the dumb bell fixing just enough to stop the waves moving them but still allowing them to self adjust, and I would deffo get the swinging beams moving again, they make recovery so much easier if they can self adjust to the hull climbing into the rollers, but heh, I know nowt, I get Chris Ty Calch n his team to launch n recover our rib

[Dhf]

Hi Steve,
Yes as Chris said your swing beams should be loose enough to swing freely, especially the rear one, which will help with displacing the wieght of your bow as you winch or power your rib on, also offering a much better angle of approach, otherwise you would be putting a lot of pressure on those first two rollers, of course this wouldn't matter if you could always guarantee the ideal depth, often I'm faced with having to power or winch on, so having all the rollers forced to face in, and beam forced to face out helps loads, to get those rollers facing in you need some short lengths of tough bungie.

[steve-ribnet]

Originally Posted by Dragonhawk ficht

Hi Steve,
Yes as Chris said your swing beams should be loose enough to swing freely, especially the rear one, which will help with displacing the wieght of your bow as you winch or power your rib on, also offering a much better angle of approach, otherwise you would be putting a lot of pressure on those first two rollers, of course this wouldn't matter if you could always guarantee the ideal depth, often I'm faced with having to power or winch on, so having all the rollers forced to face in, and beam forced to face out helps loads, to get those rollers facing in you need some short lengths of tough bungie.

Thanks for this. Yes sorry I should have posted a picture earlier.

I shall attack the swingarm pivots at the weekend. I can't see any replaceable parts available on the internet for these pivots- no nylon bushes or washers to replace are there? (new split pin of course)

The photo of the bungee is good - I will do something similar too. Thankyou.

I am looking forward to recovering the boat with a working swing arm and without the irritating misaligned dumbells!

Thanks all.

[Chris Caton]

Originally Posted by steve-ribnet

Thanks for this. Yes sorry I should have posted a picture earlier.

I shall attack the swingarm pivots at the weekend. I can't see any replaceable parts available on the internet for these pivots- no nylon bushes or washers to replace are there? (new split pin of course)

The photo of the bungee is good - I will do something similar too. Thankyou.

I am looking forward to recovering the boat with a working swing arm and without the irritating misaligned dumbells!

Thanks all.

the swinging arm should just swing, may be seized but also worth checking that both clamps are in same position on the frame, if they aren't square to each other that could cause beam to bind on the pivots

[steve-ribnet]

Originally Posted by Chris Caton

the swinging arm should just swing, may be seized but also worth checking that both clamps are in same position on the frame, if they aren't square to each other that could cause beam to bind on the pivots

Good point I will check. Thanks Chris

[steve-ribnet]

Swinging beams freed up with a bit of persuasion. The whole beam is quite stable and resists flipping over.

Barbells all stripped down and new washers and split pins all round ( original barbell just had a crimped section of the aluminium holding the inner washer in place - replaced with drilled hole and split pin)

New part-threaded stainless bolts to hold barbells to clevis bracket- nice and loose but not too much play.

Most importantly, bungee straps to hold the barbells in the correct position- this is a godsend!

Thanks all for your ideas. The wife launched the rib for the first time today and had no difficulties pushing the boat off, and I recovered the boat by driving straight on to the trailer for the first time ever- much less faff!

[Chris Caton]

Originally Posted by steve-ribnet

Swinging beams freed up with a bit of persuasion. The whole beam is quite stable and resists flipping over.

Barbells all stripped down and new washers and split pins all round ( original barbell just had a crimped section of the aluminium holding the inner washer in place - replaced with drilled hole and split pin)

New part-threaded stainless bolts to hold barbells to clevis bracket- nice and loose but not too much play.

Most importantly, bungee straps to hold the barbells in the correct position- this is a godsend!

Thanks all for your ideas. The wife launched the rib for the first time today and had no difficulties pushing the boat off, and I recovered the boat by driving straight on to the trailer for the first time ever- much less faff!

excellent news, the power of RIBnet strikes eh, glad you're sorted

[Dhf]

Originally Posted by Chris Caton

excellent news, the power of RIBnet strikes eh, glad you're sorted

+1
Great job done with the bungees, and good to hear you managed to power your way on too. many can't perform this delicate operation, proclaiming winching on is the only way, you are obviously a natural, well done sir.

Regards
Paul.

[HughN]

Originally Posted by steve-ribnet

New part-threaded stainless bolts to hold barbells to clevis bracket- nice and loose but not too much play.

I'm not sure stainless and zinc like each other? Doesn't the zinc leach metal from the stainless?

[steve-ribnet]

Originally Posted by HughN

I'm not sure stainless and zinc like each other? Doesn't the zinc leach metal from the stainless?

In theory there would be bimetallic corrosion between the stainless and the zinc, but because there is so little surface area of the stainless vs the much much larger surface area of zinc, and it is the zinc that would be 'attacked' / made to corrode by the stainless, I'm not too worried.

In practice...I've not had problems in the past with stainless split pins on galvanized box trailers, - the hardness of the stainless makes them easier to extract if seized too!

Here's a good article

http://www.galvanizeit.org/hot-dip-g...-other-metals/

And here
http://www.galvanizeit.org/hot-dip-g...lvanized-steel

[steve-ribnet]

Oop 2nd link broken

http://www.galvanizeit.org/education...lvanized-steel

[steve-ribnet]

Originally Posted by HughN

I'm not sure stainless and zinc like each other? Doesn't the zinc leach metal from the stainless?

...and I put copper grease on the stainless parts passing through the aluminium dumbells for the same reason

[Chris Caton]

I guess main thing is to rinse salt water off after recovery