75mm draw bar --- 100mm draw bar

[craigtempo]

looks like im going to get a trailer made to put a camper top on and a question just comes to mind .

would a 75x 50 mm x 3mm draw bar that goes right to the end of the trailer [ tailgate ] be stronger than a 100x 50 mm that goes to the springs ?4 touring and general off road stuff . thinking weight and strength .

draw bar length would be 1800 ish .

im going to get a base trailer .. good suspension .. and stuff but very basic and add stuff myself .

or is it a .... how long is a piece of string question .

craig

[Jon]

Depends on how well your design is balanced. Generally 100mm is better as the box section has the depth to maintain rigidity, whereas the drawbar is just a beam and requires extra strength at the forward end of the trailer tub where the most strain will be located.

Alternatively, you could use the 75mm right through and integrate the tub to a tapered box at the front, thereby extending the body and stiffening the drawbar.

Ahhh, decisions, decisions

[gronk]

The drawbar on a KK is 130 mm ( used to be 150 ) and it only goes to just in front of the wheels.  ( never heard of one breaking ) ....

Comes down to knowing how to knock up a box trailer or knowing how to make an off road trailer ??

Depends on where you want to take it. ?

When you look under a KK ( and not saying they are a be all and end all of trailers. ) , they really are a work of art compared to a " normal "  trailer ( the later laser cut ones anyway!  )

Make sure you get someone who KNOWS how to make a trailer. !!

[dno]

Would be worth buying Aussie made steel or at least making sure the steel meets AS1450.

[craigtempo]

yeah im just thinking out loud .i will get one custom made from somewhere around Newcastle.
looked at a 2 today but i dont think they were strong enough .one even had a 10mm gap between the bottom of the tailgate and the floor of the trailer  ???and it was $2500 .

craig

[dazzler]

75 x 50 x 3mm is fine in the usual A frame arrangement tied into the front spring hangers.

There is no need IMO to run it through to the back.  From an engineering perspective the drawbar pulls the trailer along through the springs to the axles/hubs wheels.  Has nothing to do with the back of the trailer, it just comes for the ride .

Have you thought of designing it using googlesketchup (googlesketchup.com).  You can then take it to the trailer bloke as a plan and should get what you want how you want it.