Has anyone made or use one of these, I do not have the space to store a ridged one, I have seen the leisure trailer http://www.leisure-trailer.co.uk/index.htm but it is far to expensive for me, this got me thinking that I would be able to build one myself and use aluminum instead of stainless steel box section, this would keep the cost down and also the weight, I think I would be able to modify the design to utilize bunks instead of rollers to give more support, I have already drawn the hinges and the brackets for the axle on Cad and would cut these out of Stainless for the additional strength and wear resistance, all of the other fittings would be bolted on to avoid any welding, any input and ideas on unforeseen problems would be most appreciated.
I haven't built one, but I do own one, exactly that make, and and have used it throughout the summer. It's a well made, very good piece equipment. Quite a pain to collapse completely, but when we go away with the caravan, it means we can take the boat and trailer too with just one car, which means we can trailer the boat about to different places once we've unhitched the van and set up. Let me know if you need any bit photographing !
Making your own and getting it approved might present extra challenges.
Aluminium is "bendy-er" if I'm not mistaken. And you will have to have some plain steel parts which will introduce galvanic corrosion headaches. Aluminium boat masts with stainless fittings screwed in are a real world headache. I imagine this would be similar...
It will be a small market for the RIB world... you still need to store the boat. I can see a market for the small open boat world that sits on a swing mooring during summer and comes out at winter. But on the whole trailer storage costs at harbours etc are relatively low...
Aluminium is lightweight but you do have to be a bit careful with joint details and geometry. Try to ensure that that you don't have any sharp (particularly internal) corners or abrupt discontinuities as aluminium is more susceptible to cracking than steel.
The grade of aluminium is also important. Some grades are not corrosion resistant at all. 'Standard' marine aluminium is generally 5083 for plate and 6082 for sections.
You could consider getting it hard anodised. This will make it tougher.
Aluminium is at one end of the galvanic table and stainless is at the other. As a result you should try and keep the two materials isolated from one another - plastic washers, plastic film or where stainless fastenings are involved - Duralac painted on to the surfaces reduces corrosion.
My De Graaf trailer is put together with U-bolts which might be a route you could consider taking.
Thank you for all your input, I had not considered the galvanic problem, I have had a look and it appears that titanium is ok with aluminum and I have access to some, so I think I will go with that for the hinges and the axial bracket, thank you for your offer PeteG, I would like some dimensions if possible from the hitch to the axial also the width as I'am aware that if it is to long it will not follow the towing vehicle round a corner, my SIB is a Honwave T38IE 48Kg and need a trailer for the same reasons PeteG, my next dilemma is what suspension units to go for and wheel size I think the smallest i have seen are rated at 150kg and the next size up would be 250kg, I would not be carrying the outboard on the back but would have the fuel tank, life jackets etc so I think the 150KG would be superficial but do you think this would make it bouncy when being towed, I have included my drawings of the hinges and axial plates.
Hopefully i have managed to attach the photos of the hinge and axial plate, I have put some bolts through the hinge to show how it should work, the bolts that go through the box section will have a tube sleeve on the inside to stop it compressing when tightened up, I will put some more photo's on when I have attached the parts to the box section.
Ok a quick update if any one is interested, I have attached the brackets to the box section and the hinges appear to be working, please ignore the bolts I have used these were left over from a previous project, when I have it fully assembled I will order the correct size for each location.
Ok back on the trailer project, I have now assembled the axial, suspension units and mud guards fitted, I am now thinking of the length of the bunks, as I have never use a trailer before do they need to run the full length of the tubes, I have fitted three keel rollers so they will take the majority of the weight, I was thinking around 1mtr to 2mtr as the Honwave is 3.8, any advice on this would be appreciated.
I have seen some with full length bunks and then some with very short ones. I suppose if it was me would try and make them long as possible which isn't going to be a nightmare when folding.
I suppose it all depends how far you plan on trailering it tomorrow short distances across campsites ect won't need much support but 50mile + journeys it needs to be well supported.
Only other thing I can add is to also ask you to build me one at the same time I want a trailer for my t38
Had another look at it today, I think about 2mtr would do it as I have used the keel rollers, the rear of the honwave projects about 400mm past the axial, so if I let the bunks finish level with the hydrofoils I could then attach a couple of brackets and fit the light board to them using sword pins to attach it.
You could use mine when it is finished, Most of the summer it is tied to a pontoon floating at the side of my other boat in a marina, really only need it when going on holiday, war department needs the kitchen sink in the back of the car when we go away for some reason.
Ok final adjustments made to the bunks and rollers, I have three ratchet strap points and an eye at the front to keep the bow down, when loading/unloading I need to chock the wheel if it is not attached to a vehicle but it is a one handed job to pull it on to the trailer if i use the transom wheels, I have not tried loading with the engine mounted yet but i do not foresee any problems, I have been on line and the Tyre pressure calculators are advising 17psi for the load and wheel size, any advice welcome, just the lighting to put to assemble now.
Yes a lot less but it is time consuming, I have only worked on it as and when as I was in no hurry, if I do have to make any modifications it would be very simple the way it is constructed, have a look at my other posts the info is there if you shop around you can get the parts at a good price.