Roll Cage Tie In Suggestions

[Artisan]

Any full time fabricators here?

Gents I need to weld a 1-3/4" x .120 wall tube to a 3" x 3" x .25 wall Square.
The tube sits 7* off perpendicular . It is for a roll bar for a tractor. External
gussets, well, maybe 3 at wierd angles.
I want a very strong connection, not being a "pro" cage builder I am grasping
left and right looking for a good solution.
What if I got a piece of 1.5" OD x .25 wall x .75" tall, DOM, cut it to my angle,
set it on the 3" square and weld INSIDE that, then slip the 1-3/4" that has
an ID of 1.51 OVER the DOM and weld the outside of it to the 3" square?
If OK should I add maybe 4 plug welds as well?
FWIW, the existing 2 U-Bolts you see go away and we will marry this rear
roll bar anchor to the OE ROPS w/ 6-8 1/2" Pro U-Bolts, tall nuts, heavy washers.

[Shield Arc]

If I'm understanding this correctly, I think the web of the original ROP box tube is the weak zone. I would add a doubler plate to thicken the web of the box tube of the ROP. Make sure the doubler plate is big enough to catch the heel of the box tube. Gussets are always a good idea!

[Artisan]

No...I don't know how I made that seem to be my question...ummm lemme see here...

OK, the OE ROPS is A-OK, I want to attach the short pieces of tube you see sitting on
the anchor I welded up. That is all.

[Shield Arc]

So the round tubes will not be welded to the ROP?

[Artisan]

OK, Now I see what's going on.

OK, look at the short tubes, now look at what they are on.
That is a piece of 3" x 3" x .25 wall Square tube. I Radius-Boxed
the ends of the 3" Square, see that at the end?, welded things
up so that 3" x 3" tube will fit up into
the OE ROPS. I will attach the 3" x 3" to the OE ROPS w/ 6-8
.5" U-bOLTS....

DS= Drivers Side PS = Passenger Side UP as in not DOWN
That 3" Square tube w/ rounded / radius'd ends fits up under
the ROPS and will attach w/ U BOLTS.

[Shield Arc]

OK, I got cha now! So you want a weld procedure / joint design for the round tubes to the 3 x 3 x .250 square tube? If so, I would gap them with some 1/16 Mig / Tig wire, or 16-GA tie wire. Make four small tacks, say at 2, 4, 8, and 10 o'clock. Weld from 3 o'clock to 6 o'clock, weld from 9 o'clock to 12 o'clock. Grind and feather the starts and stops of these welds. Then make the other two welds. A weld sequence like this will eat up the tacks when you run over them.

[Artisan]

Ummm. Well, no I know how to sequence as you say, I am looking
for a stronger method of connecting it, more shear and more melting
if you will.

Here, this is from post #1;

I want a very strong connection, not being a "pro" cage builder I am grasping
left and right looking for a good solution.
What if I got a piece of 1.5" OD x .25 wall x .75" tall, DOM, cut it to my angle,
set it on the 3" square and weld INSIDE that, then slip the 1-3/4" that has
an ID of 1.51 OVER the DOM and weld the outside of it to the 3" square?
If OK should I add maybe 4 plug welds as well?

[Shield Arc]

How strong does it have to be for .120 wall tube?
Only thing I can think of is drill holes and insert the round tubes through the box tube, and weld both sides. Or use gussets to pick up more weld volume on the one side.

[tinman565]

Maybe we could help you out more if we knew exactly what your final idea/outcome is. Whats this added piece for ? What are you going to be doing with it ? Future plans for it ? More info would help...then maybe more ideas will come from members as to how you can make it stronger, how to weld it better, or if your even possibly going overboard with the strength issue here.

[Artisan]

It is a roll cage for a BX25, imagine those 2 tubes going forward,
then maybe angle down on a 45, then another 45 to make
A Pillars for a roll cage.

Me explaining more will just complicate the matter I think.
It is for a roll cage, I want to afix the short pieces you see
exactly where they are on that 3" square.


What if I said this.

Forget EVERYTHING I said.

Now this;

I want to attach the round tubes you see to the 3" x 3" square tube
they are sitting on, in the strongest manner possible.

I am sorry I guess I am not communicating good enough.