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mcchaddy
19th Jun 2009, 09:38 PM
Hi All,

I have been toying with building something like (photo 1) for quite a while now. After the last caravan and camping show I decided it was time to make a start and the fact I think most trailers there were way over priced. The boat I have is in photo 2. The trailer is a brooker, not sure who makes them but it is a bit light to put a camper on top. My plan is to make the camp tent so it can be removed from the trailer and put onto the back of the ute when we want head for the hills

Total weight of boat, motor and accessories(fuel, water, safety etc) is approx 350kg. Camp tent weighs approx 120 - 140 kg i think. The frame to hold the camper will be made out of 50x50x2shs and it will have adjustable legs so i can remove it when I need to use the boat. The bed size will be 2100 x 1600 sitting on a 2100 x 1800 base.

I have a couple of questions.

1. What size sections do you think I should use for the trailer. I was thinking either 75x50x3rhs or 65x35x2.5rhs.

2. What size axle(not length) and springs

3. what size rims and tyres would be suitable. I may be taken off road on ocasions and on sand.

Look forward to peoples input on this

Cheers

Michael.

jatt
19th Jun 2009, 11:26 PM
Did u hit the search function? Type in boat camper if interested.

Will have to forgive my mixture of imperial and mtric.

Yes I do work for a canvas business that makes canper tents.

I make bed bases for the place I work at. Mine are 1710 x 2200. This will happily fit an off the shelf 6 inch queen sized mattress.

Posted a couple of fotos there of the boat camper I built a little while ago. (Aug 08)

1. Used 75 x 50 (2.0 wall from memory) but I recon I could have gotten away with 50 x 50 for everything except for the a frame. Thinkin about the weight factor. Ideally if the whole thing is under 750 Kg, then there is no need for brakes.

Used gussets on the uprights. A 50 x 50 frame under the bed base is sufficient. Run another piece (50 x 25 should be enuf) to support the join if u are gunna use 8 x 4 sheet.

2. Went 5 leaf for springs. 50 x 50 x 4 mm for axle, cause I dont like to see em bend.


3. 15 inch Ford or Holden rims would be my pic. Recon holden stuff might come in cheaper. Thinking the extra height created by using 4wd rims would be a bugger when it comes to launching the boat. Gotta take trailer in deeper. If u are towing trailer with a 4wd this might not be a problem. Only my opinion.

Pay attention to clearance around and above the boat. Remember you do have to launch and retrieve it in the water.

Whatever u do, pay close attention to the camp tent u put on top. Remember u have to live in it. The girls in the shop do repairs to other breeds of camper quite regularly and there are some, in my opinion, no so good designs out there.

Last of all BEWARE of the cheap Chinese stuff. I have yet to see one that is made from decent quality canvas/PVC.

I will watch your progess with interest. Lots of fotos :D

jatt
20th Jun 2009, 07:54 AM
Oops almost forgot. You will have to pay close attention to the floor drop, as in the height from the top of the bed base to the ground. If both confurations; ute back and above boat arent the same then I see problems.

Did a ute top recently. The floor drop was 1600 off the ground. Of course the higher one goes the more fun it is to get into bed. Other issues come about too if u wanna attach an awning roof. Ours zip on following the contour of the roof. Not sure what your setup is like, but in the above mentioned case the peak of the roof obviously was higher than off a conventional box trailer. The tradeoff of course then is allowing enuf fall in the roof for water drainage, without making it harder to attach the awning.

Axle placement on the trailer of course is important. Personnally recon closer to the back is better for launching/retrieval, however the tradeoff is the increased weght on the tow hitch. If I was going to build the trailer again I would bring the axle foward a bit from what I have done.

I'm sure there is other stuff to consider that eludes my memory at present, but if u have more questions feel free to ask. Will do my best to answer them.

Calm
20th Jun 2009, 08:14 AM
I have a cousin in Kallangur that is contemplating the same exercise but he intends to back it into the water and launch the boat without removing the camper. At the moment he is towing a boat and either makes a second trip or finds someone else to tow the camper. His is not a tent it is more like a type of pop top camper.

He runs his own aliminium welding business from home and I could put you in touch with him if you liked.

Cheers

mcchaddy
20th Jun 2009, 06:47 PM
Hi All

Thanks for the replies.

I will not be using a chinese version of a camp tent. A mate has had one for approx 2 years now and it is falling apart. I will have one made locally. I had considered the height issue. I will make it to suit the height on the boat. Then i will adapt it to suit the height on the back of the ute. The back of the ute will have a box on it with storage and the tent will sit on top of it. The height of the box will be dictated by the height it is on the boat trailer.

WHat type of springs are better, slipper or Eye to eye.

I was talking to a trailer builder today about launching the boat while the camper was still on top. He said it was possible but it would mean raising the height of the tent a bit more. Not sure if i want it to be any higher. It will be around 1600 to 1650 as it is. I asked if it would be possible to make the trailer a tilt one. He said that it could work but said the trailer would have to be further in the water. I like to keep the axle/bearings out of the water if possible.

I'm sure there is a way it can be done. Will have to give it some more thought. I have been making a list of all the little things that i want to incorporate into the trailer and the tent.

Thanks for the offer Calm. I might take you up on the offer when i make the Box for the back of the ute. I want it made from Ali to keep wait down.

I have almost finished a CAD Plan of the trailer. Will post it when it is complete.

Cheers

Michael.

mcchaddy
21st Jun 2009, 12:16 AM
Hi All,

Here is a drawing of the boat part of the trailer so far.

Let me know if there are any glowing errors like drawbar to long etc.

Cheers

Michael

jatt
21st Jun 2009, 11:04 AM
I put gas struts on the bed base. Helps when packing the boat with gear and makes it a bit easier wrt handling it in the water. Have to be careful tho with strut placement. Remember nothing is perfect. It still beats taking 2 vehicles.

Yeah wouldn't advise going too much over 1600.

Struts are easy to remove for when u put the camper onto the ute. Best to take the pressure off em first ie have them in the extended position before removal.

Springs: just used slipper myself. Seems to work fine.

Assuming u are using bows to support the canvas tent bit. Best to make them adjustable as canvas does shrink a bit over time. Little things like taking the sharp edges off the bow pivet points can make a big difference to how well your canvas work survives.

mcchaddy
21st Jun 2009, 11:22 AM
Hi Jatt,

Thanks for the reply. I was thinking about putting struts on the camper. I will investigate further. Good tip about filing rivet heads back as well.

I guess my next big question is "Where to position the axle". Do the same rules apply for a Boat/Camp trailer as they do for a box trailer. I was thinking of making the axle/spring assembly on a sliding chassis so it will be adjustable. It will be made from 50x50x5 angle. Makes it easier adjust loading on the ball and weight distribution.

Is this the way to go. I should i look at making it a permanent placement.

Cheers

Michael.

glen boulton
21st Jun 2009, 11:33 AM
someone told me that on a car float the axle position is 25mm back for every 600 m of deck to half way.... don't know if that helps or is confusing.

i think your idea of making a carriage for springs and axle is a great idea. just in case you change boats, motor or even the canvas section.

look like a fantastic set up...good luck with it.

jatt
21st Jun 2009, 12:06 PM
Its a bit hard to make out detail of the complete boat camper in the pic, but from what I can see it looks like a close fit with the boat. Does this unit have a name? Get enquires from folks about this kind of setup, so am always on the lookout for inspiration.

Biggest headache I see for u is doing the framework along where the centre roller sits, as in the V bit. Someone has posted their boat trailer build previously with a similar set up.


I guess my next big question is "Where to position the axle". Do the same rules apply for a Boat/Camp trailer as they do for a box trailer. I was thinking of making the axle/spring assembly on a sliding chassis so it will be adjustable. It will be made from 50x50x5 angle. Makes it easier adjust loading on the ball and weight distribution.

Cant see why not. It seems to be quite common on conventional boat trailers.

To help with guard to boat clearance I would suggest u get the boat mocked up on the trailer frame at the earliest possible opportunity, ie before u make up the axles. I had to make up spacers to fit between the chassis and guards for support on another trailer I worked on.

dazzler
21st Jun 2009, 06:29 PM
Hi Michael

Slipper springs are fine.

I like to match the wheels to the tow vehicle (what are you towing with?).

Also weld on electric brake plates so you can add brakes later if need be.

mcchaddy
21st Jun 2009, 08:18 PM
Hi Dazzler,

Current tow vehicle is a rodeo 4x4, but will be upgrading in the next 12 months(maybe). The trailer will also towed by a mazda cx7 when not camping. So I will probably have to have room for a spare on the trailer somewhere. I will probably go with a 15 inch rim. Not sure what size tyre.

Good tip about welding brake plates on in preparation for brakes another tip to add to the list of things to add to the setup.

cheers

Michael

mcchaddy
21st Jun 2009, 10:40 PM
Hi All,

Couple of different views of the boat/camp trailer so far.

Cheers

Michael.

Yonnee
21st Jun 2009, 11:42 PM
For what my opinion is worth, I'll put forward a few comments.

Electric drum Brakes and salt water do not go together. If you're going to put this boat anywhere near salt water, then there are a couple of other options. While not cheap to begin with, you'll be thankful in the long run.

Slipper springs will be much less maintenance hassle. Only 1 moving part.

While Glen is correct with his axle location calculation, this is usually not correct for boat trailers. The amount of overhang the boat has past the rear of the boat trailer, combined with the weight of the outboard, usually requires the axle to be set much further back than on a normal trailer. The way to get this right is to attach your spring hangers to a piece of angle iron, with a 2 holed plate welded at each end to allow the angle to be 'U'bolted under your chassis. This allows you to slide the axle position up and down the trailer to get the correct towball weight. You also attach your guards to this angle so that they move too. (having a re-read looks like you might have that under control. But NO, don't make it permanent.)

Yonnee
21st Jun 2009, 11:46 PM
Oh, and why not use the rims you have on your existing boat trailer? Unless you intend selling the current trailer to partly fund the new one.

mcchaddy
22nd Jun 2009, 10:15 AM
Hi Yonnee,

Thanks for tips. I will not be using drum brakes. I will go with disc's. Although the drawings dont show it, I will be doing exactly what you said about mounting the spring hangers to some angle iron as well as the mud guards so I can slide them along the chassis if needed. Is there anything i need to weld on like brake plates as Dazzler suggested if I use disc brakes.

The old trailer will be used for another boat I have just bought. It fits it perfectly but is fibreglass. So i will have to replace some of the poly rollers with a softer compound roller. Also remove the skids and put wobble rollers on. I can use the rollers and skids off this trailer on the new one.

Cheers

Michael.

Yonnee
22nd Jun 2009, 06:25 PM
Yeah, you can order an axle with disc brake flanges welded to it, even if you don't have the brake to start with, you can add them later.
BUT...
Discuss with your trailer parts supplier/axle manufacturer your requirements as there's a couple of different options. My choice for long term longevity, would be the Marinised Commodore caliper, and the Dexter Electric over Hydraulic system for the front of the trailer.
The reason for going the Commodore caliper is the ability to fit standard calipers at a pinch, or if it rarely sees salt water. And the Dexter system (http://www.dexteraxle.com/electro_hydraulic_actuators) will work off any brake controller on the market, whereas if you got to AL-KO in Brisbane, their Electric/Hydraulic system will only work with itself, and uses a pressure pad system fitted to your brake pedal.

The Dexter system is distributed by Melbourne Trailer & Caravan Supplies (http://www.melbournetrailers.com.au/) down here in Melbourne, but they can either sell interstate, or contact them to see if there's a Qld outlet they wholesale to.


Also, with your rims. Get some galv'd rims with the same stud pattern to put on your old trailer, and use the flash alloys on the camper. Reason being, those alloys are rated higher than a steel rim, not that your going to be excessively heavy anyway.

mcchaddy
23rd Jun 2009, 09:55 PM
Hi Yonne,

Thanks for the info on the brakes. I haven't decided on what brakes to go with yet. I'm not sure what weight the trailer will end up yet. I'm hoping to keep it under 1000kg. It will definetly be over the 750kg limit but. I will Melbourne Trailer & Caravan Supplies (http://www.melbournetrailers.com.au/) a call when i ready to order the brakes.

I like your idea about using the wheels off the other trailer but i was hoping to get a bit mor clearance under the axle for sand towing. So I will probably go with a 15/16 inch rim.

I started pricing steel in brisbane today. 75x50x2 rhs ranged from $110 to $155 a length exculding GST. 3mm thick 75x50 was only $1 dearer then the 2mm at one place. Would this be right. Would I be better off using 3mm if this is the case

Anyone know a cheap place to buy steel in brisbane.

Also can i get the trailer certified before i get it galvanised in case i have to make any changes to it.

Cheers

Michael.

Yonnee
24th Jun 2009, 06:25 PM
Bear in mind, even with only 13" rims your axle will probably clear sand ruts before your diff pumpkins, and you can put tall light truck tyres on them.

For the extra $1, the 3mm will greatly increase long term longevity.

And you should be able to register it, then galvanize it after, as long as the changes you make aren't changing the external size of the trailer, or it tare weight too much.

mcchaddy
12th Jul 2009, 09:55 PM
Hi All,

Well I have been away for a couple of weeks. I have just got back and started on pricing trailer parts for my project. The list so far includes.

45mm round mechanical disc brake axle fully assembled $500
4 leaf shackle springs 45 x 8 non gal $147/pair
2 tonne mechanical overide coupling $125
hand brake plate & Cable $70
Fish plates, shackles etc $80
13" alloy wheel & tyre $175/each
mud guards $36/each

After some net research these prices look about average if not a little high. What do other people think. Can anyone recommend a trailer parts place in brisbane.

My other question is that most of the trailer parts place i have spoken to always promote that their equipment is not the cheap "Made in China" crap that is sold at larger chains.......

So the question is would you use equipment made in china on your trailer. Is there parts you wouldn't use that were made in china

Cheers

Michael.

wonka
13th Jul 2009, 11:11 AM
Hi

I have used a place at Beenleigh called active fabrications, I have built 4 car trailers and have found there products great for my intended use and very well priced, I think some of there stuff is made in China, no worries to me.

whitworthsocket
15th Jul 2009, 11:38 PM
For the extra $1, the 3mm will greatly increase long term longevity.
Yonnee.
I have to disagree. Thicker does not neccesarily mean stronger.
Micheal use 75x50x2 RHS over 65x35x2.5RHS The strength mainly comes from the size of the section. Using 2mm is plenty strong enough and it keeps the weight down.
See http://www.rorty-design.com/content/tube_size_vs._strength.htm
I would suggest cutting up some 50x 3 flat bar into say 300mm long flat diamond shape pieces and use these for doubler plates where the A frame joins onto the main frame. I would reccomend using 75x50x3 RHS for the central drawbar.
Slipper springs are OK if you weld a sacrificial wear block (reccomend 6mm thick) where the spring rubs on the angle iron.
Do some web research on design for galvanizing. Mt first reccomendation is to use a mitre joint acrross the back of the frame. Capping the RHS frame members at the rear can lead to the hot zinc pooling inside the RHS and inreasing your weight and galvanizing cost. If you use doubler plates drill a 6-10 mm hole near the bottom so that there is no problem (explosion in the zinc tank) during galvanizing.
Regards Whitworthsocket