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. ullinghair:

 

[tinman565]

Ok...now I see where your going with this. For some reason, I thought the round pieces were going to be facing backwards...like shooting out the back. As suggested earlier...if you have longer pieces of the tubing available, I would cut holes in the boxed piece, and slide the tubing thru it, and weld on BOTH sides of each tube. Little more work, but will definately be stronger.

Look at it this way...if you roll this over, or it flips and hits something (tree, large rock, falls off a cliff, etc.)...the weakest thing in your whole setup will be the U-bolts sir.

 

[Artisan]

Ok...now I see where your going with this. For some reason, I thought the round pieces were going to be facing backwards...like shooting out the back. As suggested earlier...if you have longer pieces of the tubing available, I would cut holes in the boxed piece, and slide the tubing thru it, and weld on BOTH sides of each tube. Little more work, but will definately be stronger.

Look at it this way...if you roll this over, or it flips and hits something (tree, large rock, falls off a cliff, etc.)...the weakest thing in your whole setup will be the U-bolts sir.

No, not out the back, thats why I labeled UP, PS, AND DS to try to convey the orientation.
Obviously I am doing a really bad job at conveying my ideas.
OK, there is a suggestion, drill clear thru, but, it is on a 7* angle, I would have to figure
out how to strap it to the drill press and drill "Clear Thru" It would be very hard to do, twice,
and do it to the acuracy I want. Sure I could drill at a 90 and then wiggle it back to the 7*
I need to counter the OE ROPS angle.

Ya really think 6 or 8 .5" Diameter U'Bolts, pro U Blolts not Home Depot specials are weak?
By "Pro" I mean fine threads, tall nuts, and extra thick washer with backing plates.
I think that will be the strongest part! Heck Axles on huge trucks use U-Bolts...

Oh well. I appreciate the input.
Obviously I am doing a really bad job at conveying my ideas.
Here is a quick sketch.

 

[Shield Arc]

You're kidding about drilling the holes at 7-degree offset, correct?

Two Way Milling Machine Vise

Magnetic Universal Protractor- Craftsman-Tools-Measuring, Levels & Stud Finders-Angle Finders & Protractors

 

[tinman565]

You could drill the holes slightly bigger...then do your little offset...then weld. If your decent with a torch (plasma cutter would be even nicer), you could cut them out that way also. Another idea is to drill them straight then shim the upper part of the insert you made on one side (front long side). Another idea is to drill them straight...then put the 7* angle on the flange...then weld the flange. If you have a friend that has access to a bridgeport mill, he could put the holes in easily on the angle you require.

I meant that the u-bolts are the weakest link meaning in a worst case scenario. The u-bolts you see on truck axles are not/were not designed to take a monster hit. They are basically holding the axle in position while the wheels roll. In your case, you may end up flipping a one ton tractor over on its head numerous times (on a hill, it could roll over a few times before coming to rest). Obviously your thinking/looking to take this tractor to some unlevel places. This is a small tractor, and easy to turn over with the bucket raised up high in the air on unlevel ground. Just be careful sir...and know your tractors limitations.

Please dont take this the wrong way...I dont mean it to be offensive...but your trying to make a tank out of a chevette. Try not overthinking too much sir.

 

[Artisan]

You're kidding about drilling the holes at 7-degree offset, correct? snip

I apprecaite the drill idea, thank you so much, I sure would like more ideas.
There is a simple and elegant way to do this, unless my "plug" method is
indeed it. I do not want to drill this member. I want to attach to it.
Again, THANK YOU for that idea. This makes a total of two ideas.
My plug and weld and the drill and weld clear thru.

 

[Mace Canute]

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.

X 2. I'd suggest doing both. Cutting the hole on an angle isn't all that difficult. You could make up an angled drill bushing/jig that would give you the centers of both holes and then you could hole saw them both out or you could cut the one hole just large enough to stick the pipe into and cut the other hole smaller so you could see where to enlarge it until the pipe will exit it at the correct angle. You could even use trig to figure out where the second hole should exit! (For seven degrees angle on a three inch separation, the difference would be .4 inches btw...that means if the center of the entry hole was .5 inches from an edge, the center of the exit hole would be either .1 or .9 inches from the edge, depending which way you wanted the lean of course!) You could also just cut one hole and angle the pipe end so it makes full contact on the end when it bottoms out on the hole. It would probably be stronger than if you just surface mounted the pipe and welded it on unless you are a good welder...no offense meant but not everyone is. If you decide to surface weld it, adding gussets would increase the strength of the joint by a very large amount. So many options!

 

[radioman]

I been watching this thread- and I am starting to think you are oveer thinking it a little. I agree with sheild arc to drill holes and put dom tubing into that member. Plus I wouldnt worry a hair about the angle since you just need to ovalized the hole and you are welding everything up. Thats the beauty of welding. it will hide your cutting mistakes or such and its stronger then before IMHO.

 

[Artisan]

FWIW;

Prior to posting this post I thought about drilling one side and both sides.
I decided against it for this reason. I am taking a VERY strong member
and making it REALLY week by drilling all those holes! Now I stick my
tube in it and expect it to take up all the slack. What do I know...
thats why I ask q's. I would rather be accused of overthinking
it then underthinking it! :mickeymouse:

I really do appreciate the input. You will learn I rarely settle for "Status Quo". :blacksmith:

Over the top, slightly Askew, Bold and Obnoxious makes me smile!

 

[Shield Arc]

I drew this up on AutoCad, mainly because I'm a picture kind of guy:laughing:, and I wanted to see what it would look like if you decided to drill through the box tube.

 

[Artisan]

Cool...thanx for the CAD drawing... I look at that and imagine what
it will look like after drilling. This is hard for my untrained eye to call.
I am going to take these pics and email a pro cage builder and see
if I get a reply.

ToShea!

The red is my 1-3/4" OD Tube Cage Material

TheYellow is my 1.5" OD Tube Inner Plug

The Magenta is welds, including 4- .3"OD Plug welds thru outter tube connecting to inner tube.