Box Trailer Rebuild

Post any other rides you have here
Site Admin
User avatar
Posts: 5297
Joined: Sat Feb 28, 2009 8:34 pm

Re: Box Trailer Rebuild

Postby antus » Sun Sep 23, 2018 6:15 pm

That came out pretty nice. Almost a new trailer but quite cool that its still got the soul of the original where it made sense. Should last a long time.
Have you read the FAQ? For lots of information and links to significant threads see here: viewtopic.php?f=7&t=1396

User avatar
Posts: 256
Joined: Mon May 28, 2018 5:05 pm
Location: Country Victoria on a direct road to WINTON

Re: Box Trailer Rebuild

Postby oldn64 » Mon Sep 24, 2018 9:18 am

Looks great there firebug.

However, sorry to be the bearer of bad news but you have welded your draw bar the wrong way. By welding across the drawer bar you actually create a stress concentrator and it will generally crack right along the weld. This is a very common mistake and can lead to a serious failure.

I know you have painted the trailer and all BUT, to fix weld the drawer bar to the front support along the length of the drawer bar and then cut the welds you have done on the front and rear of this join. This will stop the stress riser and therefore allow it to have a great life. If you need extra strength in this area then place an upright between the front support and the drawer bar vertically and weld only in the vertical plain.

Above all the trailer is very neat. Also so glad that the angle grinder did not cause any human damage. That could have been nasty.

cheers
oldn64

User avatar
Posts: 1424
Joined: Tue Apr 26, 2011 9:52 pm

Re: Box Trailer Rebuild

Postby psyolent » Mon Sep 24, 2018 7:24 pm

man that come out awesome.

However, sorry to be the bearer of bad news but you have welded your draw bar the wrong way. By welding across the drawer bar you actually create a stress concentrator and it will generally crack right along the weld. This is a very common mistake and can lead to a serious failure.

wow thats interesting, i guess my 6x4 i've had for the last 20 years is doomed huh? is there any FEA or engineering articles to support this dude?
Cheers,
Greg aka Sir Burnie Tanington

VX1 Berlina V6, VX2 Berlina V6, VT1 Berlina V6 (Track), VN1 S V6, Hilux RN105 GMV8, Ford XP 170.

User avatar
Posts: 1424
Joined: Tue Apr 26, 2011 9:52 pm

Re: Box Trailer Rebuild

Postby psyolent » Mon Sep 24, 2018 7:30 pm

Cheers,
Greg aka Sir Burnie Tanington

VX1 Berlina V6, VX2 Berlina V6, VT1 Berlina V6 (Track), VN1 S V6, Hilux RN105 GMV8, Ford XP 170.

User avatar
Posts: 100
Joined: Tue Dec 17, 2013 1:05 am

Re: Box Trailer Rebuild

Postby Ken » Mon Sep 24, 2018 10:03 pm

Good looking trailer indeed, good for another 25 at least. :thumbup:

psyolent wrote:man that come out awesome.

However, sorry to be the bearer of bad news but you have welded your draw bar the wrong way. By welding across the drawer bar you actually create a stress concentrator and it will generally crack right along the weld. This is a very common mistake and can lead to a serious failure.

wow thats interesting, i guess my 6x4 i've had for the last 20 years is doomed huh? is there any FEA or engineering articles to support this dude?

I stuck an SBC in a HR early 80's, had to get it engineer approved, which led to understanding of the do's & don'ts regarding welding of anything chassis related, welding across ways was one of the no-no's, welding had to be front to back only, actually found some of the relevant paperwork in the last cleanup here.

Engineer_Mods_01.jpg


Engineer_Mods_02.jpg

User avatar
Posts: 1424
Joined: Tue Apr 26, 2011 9:52 pm

Re: Box Trailer Rebuild

Postby psyolent » Mon Sep 24, 2018 10:18 pm

bewdiful. thanks ken.
Cheers,
Greg aka Sir Burnie Tanington

VX1 Berlina V6, VX2 Berlina V6, VT1 Berlina V6 (Track), VN1 S V6, Hilux RN105 GMV8, Ford XP 170.

User avatar
Posts: 9491
Joined: Sat Feb 28, 2009 9:05 pm
Location: Tenambit, NSW

Re: Box Trailer Rebuild

Postby Holden202T » Wed Sep 26, 2018 11:54 pm

wow you've done a great job! :thumbup: :thumbup: :thumbup: certainly alot more effort than i put into it!!

to be fair i wanted a larger trailer so found it hard to justify any time spent when it would never be larger, and going to a larger width meant a new axle, and basically a whole trailer which made the cost not worth it.

at one point i recall having 2 x v6's, 1 x T700, 1 x 202 and various heads and parts to fill the gaps when i was moving house, so im not at all surprised if there is any bends in chassis hehehe

and to answer your question, straps under the front sides, around the draw bar then back on themselves (there is a gap between the draw bar and floor)

there also used to be bolts through the sides to hold the guards, this gave 3 points, front, top centre and rear of the guards.

at the rear there was bumper things to stop the trailer hitting the ground, these were good for attachment points also.

lastly was the number plate holder frame it was handy for attaching hooks etc to :)

and from memory the year on the rego papers is 1978 so its been around for a while!

User avatar
Posts: 256
Joined: Mon May 28, 2018 5:05 pm
Location: Country Victoria on a direct road to WINTON

Re: Box Trailer Rebuild

Postby oldn64 » Wed Oct 03, 2018 2:35 pm

psyolent wrote:wow thats interesting, i guess my 6x4 i've had for the last 20 years is doomed huh? is there any FEA or engineering articles to support this dude?


I Have seen way too many accidents that are caused by welding the drawbar across the front. This does not mean every one will but it give a higher stress concentration. To err on the side of caution it is best practise to not weld there. Yes there is many documents on this and I could dig up the actual trailer standards which I have seen it is previously.

Here is a prime example. There are alot of people who state that HQ pattern is the same as commodore. It actually is not. The commodore is the closest metric equivalent but is not exactly the same. What this means is that HQ rims on a Commodore rotor stresses the stud in the worse way (shear). Unfortunately stud have stress concentrators in them due to the threads so any force in shear can result in the stud breaking through the threads. Does every stud break when hq is used, no. Has it happened where the studs do break, certainly, and have I experienced this.... YES.

All I am saying is being the mechanical eng and electrical eng I am there are some things i have just learnt to do a certain way to remove the risk. After all how would you feel if your draw bar fractured off and it ran into a human???

Cheers
oldn64

User avatar
Posts: 1424
Joined: Tue Apr 26, 2011 9:52 pm

Re: Box Trailer Rebuild

Postby psyolent » Wed Oct 03, 2018 7:23 pm

not doubting you mate, i question everything its just the way i am wired - as you can see above both myself and ken researched to backup your claim which is completely valid dude.
Cheers,
Greg aka Sir Burnie Tanington

VX1 Berlina V6, VX2 Berlina V6, VT1 Berlina V6 (Track), VN1 S V6, Hilux RN105 GMV8, Ford XP 170.

User avatar
Posts: 256
Joined: Mon May 28, 2018 5:05 pm
Location: Country Victoria on a direct road to WINTON

Re: Box Trailer Rebuild

Postby oldn64 » Fri Oct 05, 2018 12:25 pm

psyolent wrote:not doubting you mate, i question everything its just the way i am wired - as you can see above both myself and ken researched to backup your claim which is completely valid dude.


:thumbup: All good was not offended more adding to the discussion :)

cheers
oldn64

Previous

Return to Other Rides

Who is online

Users browsing this forum: No registered users and 2 guests