Sleeving Box Section Steel

[scotslad]

Alright

 

I was just wondering how/wot more experienced engineers/fitters do when they need to sleeve 2 pieces of box section together so 1 can move over the other?

 

I've done it before easy enough with small box say 20mm-30mm as i've bought different thickness to give me the right sized dimensions of internal diameter.

No idea if thats wot 'proper' fitters would do?

 

The projects i'm looking at now really should be in 50mm x3mm box range so the next nearest size up or down i'm worried going to leave it to slack (talking a 4mm gap) or should

Would welding a strip of flat bar on work? or be a lot of work? Or should i just step up to 4mm thickness? But trying to keep wieght down if possible

I know a 2mm gap each side isn't massive but i think for wot i'm trying to do they'll move aabout and end up with wear as wellas a noisy trailer

 

"1 of the projects i have are for an ATV trailer,, 1 is so the axle could slide up/down trailer body/chasis to balance logs (fixed with either ppins or bolts/nuts) or for tow bar to move for transport

another idea for the same trailer was to have the axle interchangable. I weld a solid box in as axle (which can slide/move as above) but i then can slide anther piece of box in with stubb axle/wheel attached, be handy either for transport lifting if i could take wheels off plus got a set of twin bogey wheels i could rob of another trailer when needed so could convert into a twin axle. (TFM do a similar axle set up with pipe in there lightwieght quad trailer, a really nice little trailer)

 

Cheers for any avice

[bornfree]

The problem with trying to sleeve box in box is the internal ridge inside it. So it's difficult to get a tight fit.

[Old farrier]

Have you there about pipe inside the box section 

problem can be to much friction/dirt paint etc for box to slide inside box 

just a thought 

of 

[scotslad]

It probably doesn't want to be a tight tight fit but worried that 4/2mm play wil be too much, but possibly i'm worrying over nothing.

 

Aye bornfree had that problem in the past esp some of the small box sizes, i have ran a grinder down 1 face before just to create a wee groove so that goes wher ethe joint is. Sort of works. Althou only done it for relatively small lengths

Am i right in saying some types of steel (more expensive) ERW? or something is formed without an inside ridge.

Don''t really buy that much steel and until now my 'projects' have been a good bit smaller and less complicated

 

OF  Does pipe sleeve nicely into box section?? Not something i've ever thought about or even seen..

I just thought box in box u'd have no room for play/wiggle if the pipe tried to rotate, or even the hassle of trying to spin the frame round to get holes alinged

 

How do agricultural engineers/fabricators do it as quite often see 2 box sections sliding ontop of each other and adjusted with pins.

[ljaddy12]

In the outer box drill 10 or 12mm holes at 100 mm intervals find the difference between outer box and inner -1mm and cut either steel plate or bar depending on thickness to right width to go inside the outer sleeving effectively packing out to the width you need then plug weld through the holes you drilled to the new plate or bar inside grease up the inner box section hard part is making sure the bar/plate you weld inside is tight to the face before welding if you have access to taps and dies you can drill and tap the bar and put bolts in and pull tight for welding then remove and weld up holes and grind off flush few more ways to do it but id say that was easiest not knowing what gear you have access to hope that helps

[la bala]

6 minutes ago, ljaddy12 said:

In the outer box drill 10 or 12mm holes at 100 mm intervals find the difference between outer box and inner -1mm and cut either steel plate or bar depending on thickness to right width to go inside the outer sleeving effectively packing out to the width you need then plug weld through the holes you drilled to the new plate or bar inside grease up the inner box section hard part is making sure the bar/plate you weld inside is tight to the face before welding if you have access to taps and dies you can drill and tap the bar and put bolts in and pull tight for welding then remove and weld up holes and grind off flush few more ways to do it but id say that was easiest not knowing what gear you have access to hope that helps

A method I have used successfully 

[Potter64]

Just put some small welds on inner box until you get the fit you want start first one just below the point it's fully extended. Hot formed is formed without a seam if I recall 

[bornfree]

6 hours ago, scotslad said:

It probably doesn't want to be a tight tight fit but worried that 4/2mm play wil be too much, but possibly i'm worrying over nothing.

 

 

 

How do agricultural engineers/fabricators do it as quite often see 2 box sections sliding ontop of each other and adjusted with pins.

Most setups I've seen like this have a fabricated outer box made of two channel pressings welded together.

[scotslad]

Cheers to everyone, i must admit i thought there was some steel maker making custom sizes for this and just hadn't found out where yet.

I have sort of managed at smaller sizes by altering thickness and does ok for wot i was needing

 

Bit of work involved to get it right then, cheers lj12 never heard of doing that before.

Born free Quite a lot of work welding and i imagine cutting to channels/angles together to get a box that fits

But my weldig a bit of flat bar on along the box idea wasn't that far away.

 

I'll get my design's measured up and steel ordered and have a play with the steel and see how it fits and wot sort of play i have in it.

I think for the axles it will need to be a far tighter fit but might get away with more slack/play where the axle brackets slide on the trailer body as it wil be covered in mud most of the time anway

 

Cheers again to all

[owdnorthener]

Could you manage with box section being the same dimensions, but on one, weld flats the same size as the box width, (ie, fabricating your own box section)  on all four faces and long enough to support the moveable box section.

That should remove any slackness, as your box is the same size.

[figgy]

Just weld small spacers along the outside of the smaller box section to give you the fit you desire. You can grind them down to as tight a fit as you want and being small will be easier to slide with less friction. 

You could fix PTFE to it if you wanted.

Or as above make the outer section out of flat bar to suit the smaller box.

One other way I'd get all the bits hot galvanized dipped this would take up the slack and stop corrosion.

Edited February 8, 2019 by figgy