building a tray steel sizing (thickness)

[tomomatt]

hi all
been lurking for a while
got myself a shiny new 2014 sr dual cab late last year

im going to be building a tray in the not to distant future

now
what size wall are u guys using to build trays out of?
ill put my thoughts in and tell me if im wrong
65x35x2 for the sides and light 25nb tube tie rails
35x35x2 and 65x35x2 for the rear bar/light bar
65x35x3for the chassis (as in to link up the chassis mounts)
what makes a good strong chassis mount (i was thinking) 100x50x4 C channel with a foot plate for mounting
and what floor cross members spacings works for you 450mm?
lastly what thickness floor sheet 2.1mm or 3mm?

now i know theres 101 questions
but ive looked at all the "fleet" trays that ive seen in car parks
and they all look piss weak to my eye but they might be stronger than im thinking

thanks
Matt

[Alby]

I would stick closer to the sizes you see on the pro built trays. Be careful not to over engineer it as the bloody thing will end up too heavy and you will have a tray capable of handling 10 tonne but your GVM will only let you carry an esky

[tomomatt]

yeah i know haha
thats why i was putting the question out there

i think my sizes are a happy medium
based on meterige weighting i think the tray will weigh 200-250kg is that high? should i be looking at reducing weight?

[oggy]

They use 3mm checker plate in cattle crates in semi's , so might be overkill. As would be 100×50×4mm

[Bushbound]

Matt,
When I built the tray for my xtra cab, I used 75 x 50 for the outside rails and back of the tray, the cab guard and other mounting rails are all 50 x 50. I used 25 x 25 for the floor supports - chose to use 16mm form ply for the floor.
All the RHS was 2 - 2.5mm wall thickness. Its a solid heavy duty tray - right at the point of being too heavy but built for a purpose and works perfectly.
Consider mounting extra water or fuel tanks, tool boxes, battery's, spare wheel carriers etc, much easier to make them fit as you build the frame than modify it later. I now thinking about strengthing mine to mount an extra spare wheel on the back of the tray, I think this will require cutting the whole back off the tray and rebuilding it.
Geoff

[tomomatt]

thanks for the input guys
the 100x50x4 channel (maybe use 3mm) would only be very small just want a good footing as i have seen a tray with 100x5 flat mounts bend like a butterknife
maybe i could do some triangulated "feet" out of thinner steel to maintain strength

ok so 2mm wall is a good all round steel for tray
i know what extras im having and the list is short
2 underbody boxes
with provisions for undertray drawer

plan is to make tray out of 65mm (sides and headboard) as much as i can so that it matches my rear bar

[07luxyTD]

For your tray mounts you can fabricate some out of 75x8mm flat bar. Weld them in a right and then add triangle braces on each edge. Will be super strong and will save buying c section which isnt cheap.
Using 100x50 plus 65x35 will give you 165mm height of the chassis mounts if you lay your bearers over the top its going to be even higher. When I built my landcruiser tray I made it higher then normal to fit a certain size tank. From the mount to the bed is 170mm and its to high in my opinion.
With your tie down rails id be looking at atleast a medium wall thickness. If you use ratchet straps u will bend 25nb light wall

[tomomatt]

With the 100x50 I would buy box and using it upright,cut it about 125-150 long depending on height of finished tray cut diagonally from top to bottom forming a long triangle and then weld it to the side of my 65x35

Look at almost all the undertray drawers u need 190mm clearance but I understand that the tray mounts aren't the lowest point and there is about 30 mm of drop to the high crossmember above the spare winch

Thanks for the tip on the tie rail too
This is why I have put the feelers out

[cuzo4x4]

theres some stuff in my build if you want to check it out,

link is in signiture

[calis101]

Don't go crazy on your sizes unless you plan to abuse the tray. Remember most manufactures need to allow for people being rough. If your just going to put camping stuff n general use it wont need to be too strong. Two people can lift mine so it cant be much more than 100kg n it hasn't bent yet.

[cuzo4x4]

X2 2 can lift mine as well

[gregrobo]

most manufactures build to a price not quality you would be surprised at the corner cutting that they do

[packeteer]

fwiw, my all alloy welded tray is made from 3mm. so I'd go thinner if using steel

[tomomatt]

alright guys taking all of this into consideration
i think my tray was going to be a little machinery orientated where bigger is better and thicker is stronger
so based on that ill go to the lighter side of material and look around a bit more before i go building it too heavy and then trying to knock weight off it
thanks for the tips and comparisons guys

[bailey762]

That's how have my tray mounts done. Mounted to 75x50 for the main chassis rails, headboard is 75x50, sides of tray is is 75x50.
Cross rails checker plate sits on is 50x50


Think I used 3mm for the checker plate
Cheers ash

[angusjones8]

^^^^^^^^^^^^^ that looks awesome!


see my build thread



viewtopic.php?f=41&t=22769

[packeteer]

here is mine during build:


all 3mm thickness. 100x50 for the bearers and 50x25 for the joists. then checker for the top
edit: forgot to mention, the mounts were made from 10mm

[tomomatt]

what is a general height from top of chassis mount to top of checkerplate? by having a guess looking at your trays id be thinking around 200-250mm?

what method did you go about for choosing head board shape
dont want it to look like i have a gate welded to the front of my tray or make it look like my tray is off another brand of ute

[Bushbound]

what is a general height from top of chassis mount to top of checkerplate? by having a guess looking at your trays id be thinking around 200-250mm?

what method did you go about for choosing head board shape
dont want it to look like i have a gate welded to the front of my tray or make it look like my tray is off another brand of ute

I built my tray with the deck as low as possible as I carry firewood so the lower the better in my opinion. Measured from top of axle to bump stops and added 20mm, used this measurement from top of wheel to work out under side of the deck, then had to put 25mm packers under the feet when I fitted 75 litre water tank to get clearance for the tank over the back chassis crossmember, so consider what else you may want to add to your tray, tanks, toolboxes utc while you build it.
For the headboard I tacked the verticle section to the tray, suspended the horizontal in position on a couple of ropes from the shed and moved the angle bit till it looked right and followed the lines of the cab, mark cut and tacked it together, checked the look again, then welded it.
Geoff

[packeteer]

mine is 300, but it's at least 60mm too high. some people have even said "drop it 100mm"

really depends on what tyres you're running and how much under tray storage you want