Car ramps - Page 3

Sargan · 29 March 2021, 10:29

The axle if looked at in cross section is diamond shaped, without a flat top.
So the usual bo;t on rollers & pads for box section tube wont work.

Contacted SBS ... they offered a rivet on pad, but don't want to be drilling holes in the galv or having pop rivets in salt water.
Anybody see a suitable pad that can be fixed .... even if by cable ties ...... the keel may never touch the pad, its a 'just in case' prevention.

Pikey Dave · 29 March 2021, 10:50

Quote:

Originally Posted by Sargan

The axle if looked at in cross section is diamond shaped, without a flat top.
So the usual bo;t on rollers & pads for box section tube wont work.

Contacted SBS ... they offered a rivet on pad, but don't want to be drilling holes in the galv or having pop rivets in salt water.
Anybody see a suitable pad that can be fixed .... even if by cable ties ...... the keel may never touch the pad, its a 'just in case' prevention.

Without seeing it in the flesh, it sounds to me like the trailer isn’t setup correctly. The stern shouldn’t be higher than the bow when the boat is sat on the trailer (that’s if I’ve understood your description). Also, as soon as the boat starts to come off the trailer, the bow should be lifting, not dropping. Lastly, the keel shouldn’t be able to get anywhere near hitting the axle. Personally I’d get the trailer sorted before adding bits to cure setup issues.

jeffstevens763@g · 29 March 2021, 10:56

wrap it in carpet until you get it off then as Dave says set it up properly post some pics when you get it off people can help then

Pikey Dave · 29 March 2021, 11:00

Quote:

Originally Posted by jeffstevens763@g

wrap it in carpet until you get it off then as Dave says set it up properly post some pics when you get it off people can help then

Wot he said^^^^^
Also post some side on & end on pics of the bow & stern showing the current setup & position of rollers.

Limecc · 29 March 2021, 11:03

I agree with PD and pics would help tremendously.

Somebody set my trailer up that the rollers were on the inner chines not the outer ones so the stern was sitting higher and it also made it less stable for towing. The thinking was it self-centred the boat better on recovery. I've got them in line with the front ones now but have yet to try it because of lockdown and it was out of season.

Sargan · 29 March 2021, 11:13

Quote:

Originally Posted by Pikey Dave

Without seeing it in the flesh, it sounds to me like the trailer isn’t setup correctly. The stern shouldn’t be higher than the bow when the boat is sat on the trailer (that’s if I’ve understood your description). Also, as soon as the boat starts to come off the trailer, the bow should be lifting, not dropping. Lastly, the keel shouldn’t be able to get anywhere near hitting the axle. Personally I’d get the trailer sorted before adding bits to cure setup issues.

No the boat is perectly level on trailer when fully on.
When removing trailer form under boat it come off 'level', until the hull is no longer supported by rollers at that point it starts dropping (which I can undertasnd) as there is nothing supporting it at the front, and rear bogey at back can swivel - so that is what happens.
Bogey cant swivel down as props in place at stern. Hull is strapped so it can't go forwadrd but that does not stop up or down movement (within limits)

Once you pull trailer out a bit more (increasing trasom overhang, then at that point weight at transom become heavy enough and bow comes back up to level .. and pushing stern back down solid onto supports.

Sargan · 29 March 2021, 11:14

Quote:

Originally Posted by Pikey Dave

Wot he said^^^^^
Also post some side on & end on pics of the bow & stern showing the current setup & position of rollers.

I posted pictures 2 days ago - post #38 - though I can take more

Sargan · 29 March 2021, 11:17

Quote:

Originally Posted by Pikey Dave

Without seeing it in the flesh, it sounds to me like the trailer isn’t setup correctly. The stern shouldn’t be higher than the bow when the boat is sat on the trailer (that’s if I’ve understood your description). Also, as soon as the boat starts to come off the trailer, the bow should be lifting, not dropping. Lastly, the keel shouldn’t be able to get anywhere near hitting the axle. Personally I’d get the trailer sorted before adding bits to cure setup issues.

It was set up by dealer & SBS jointly ..... I have no one to go to for more experince.
I'll post some pictures

willk · 29 March 2021, 12:02

Quote:

Originally Posted by Sargan

Anybody see a suitable pad that can be fixed .... even if by cable ties ...... the keel may never touch the pad, its a 'just in case' prevention.

a coupla of turns of old carpet around the axle, secured with cable ties will prevent damage for a few passes. Works best wet.

Sargan · 29 March 2021, 12:12

Maybe an off-cut of marine carpet will do - if I can find some.
I don't think it ever gets touched in use ..... just a safety belt.
Or maybe some sheet rubber if I can find some, wrapping it around about 82 wide and cable tied would do the job
Thick enough to protect, flexible enough to wrap.

Sargan · 29 March 2021, 13:00

As requested 4 pics ... front on, close up, side on & rear

Hull has a planing pad so rear rollers are under transom.

jeffstevens763@g · 29 March 2021, 13:18

could do with a pic like this

Sargan · 29 March 2021, 13:45

Can’t do that sorry .... boat is winterised, it’s not coming out of boatshed until ready to use (at least another month)

jeffstevens763@g · 29 March 2021, 14:21

you'll have a fair idea looking at my old boat if your rollers are in the correct position i use to take mine off onto a dolly 5 foot long just by pushing by hand 6m boat bit lighter than yours of course

GuyC · 29 March 2021, 17:03

I wonder if the LCG of your boat is forward of the aft set of rollers before the bow has contacted the forward set of rollers.

This would cause the bow to dip as the boat is pushed on to the trailer.

You could move the forward set of rollers aft a bit so that the boat contacts the rollers rather than the axle. This will tend to lift the front of the boat up a bit and I'm not sure you have the height.

I think the carpet solution is probably the neatest for now.

Pikey Dave · 29 March 2021, 17:58

Quote:

Originally Posted by jeffstevens763@g

could do with a pic like this

First impressions are that the front sets of rollers are set too wide. If you moved them inboard, closer to the centre line of the trailer, you would close the gap & stop the keel dropping between them. I’d be setting them so that the inner rollers closest to the centre line are the other side of the chine.

jeffstevens763@g · 29 March 2021, 19:29

It’s hard to tell but I’d be a bit worried that pulling the rollers in at the front not having balance sideward OMO personally I’d go and try to fit a keel roller just to keep the keel off the axle at that crucial point to stop it dropping.

Sargan · 29 March 2021, 20:48

That was my first thought ..... but Keel rollers are made to clamp onto square sect tube.
The axle tubes are diamond shaped .. i.e. not flat at the top

My thought now is to take some 5mm rubber sheet (or simila) fold a piece like a 'tent' and cable tie to axle. Providing a buffer if required.

jeffstevens763@g · 29 March 2021, 21:09

Drain pipe split down once, open up push over axle tape round it until it’s memory comes back it will act as a roller then. Or an engineering plastic such as HDPE formed into a diamond and bolted at the bottom like a horse shoe, HDPE a certain amount of lubrication and hard wearing. A heat gun to form it.

Sargan · 29 March 2021, 21:21

I think uPVC drain pipe may be too hard to provide protection, but HDPE would be softer.
You need something with a bit of give. Have to think where I can get HDPE from.

I did think of a piece of rubber conveyor belt 'tented over the peak of the diamond and cable-tied in place may work.
I'll measure axle tomorrow and get some idea of sizes.