Roll Bar too

[voucht]

Hi,
I'm in a deep sh...t
I just finished my roll bar.

IMG_2751_1.JPG

But I have a problem: after fully weld the cross-bar, it looks like the whole thing shrieked. When I tried to fit the roll bar fully welded, it looks like each RB1 plate moved inward of about 3mm. So I can't bolt the roll bar on the chassis, it is of course not flexible enough to match CP3/CP4 hole pattern.

IMG_2747_1.JPG

However, to put everything together, I made sure that:
- I drilled plates RB1 at the same time as CP3/CP4, to make sure both hole patterns will be exactly the same,
- I tacked the man hoop on RB1 with RB1 bolted to CP3/CP4 on the chassis to be sure they will be exactly where they should be,
- I tacked the cross-bar and the back stays in the same way.
But I should have fully welded the roll bar with the plates bolted to the chassis too. I didn't expect it to move so much after being tacked.

What do you guys think? How can I solve the problem? I really don't want to cut RB1 plates off and weld new ones. I'm thinking about making “oval” holes on RB1 to match with CP4 hole pattern, but as the roll-bar is holding the seat belts, is this acceptable?
Any opinion, advice or comment is welcome. I'm so pissed-off
Thank you.

[K4KEV]

Sylvain....it does not look like it is much out, I would weld up the hole, grind it back and re drill to suit or you could make the hole oval and then weld up one edge of the hole and file to fit

[TheArf]

Could you warm up the tube where the upright and cross member meet and tweek it out wards with a bottle jack and a length of pipe, dont forget you only need to move each side half of the amount that its out if that makes sense

Arfon

[voucht]

Hello guys,
Thank you very much for the answers.
Arf, unfortunately, I don't have anything to heat-up the tubes, like a blowtorch (I just have my lighter, but I don't think it will be sufficient ) But thank you, it could have been an easy way to get rid of the problem.
I chose the option to enlarge the holes. Now they are oval, but at least the roll-bar fits. Actually, it doesn't move even move left and right, as the bolts are holding it on the "new" outside edges of the holes, on each side. I'm tempted to keep it like that, but I will try to weld up the edges and grind to go back to round holes as Kev adviced.
Thank you very much for the help.

[SeriesLandy]

That's what I ended up doing to my bar as it shrank.
Bit of a bodge but I'm happy with it still.

[voucht]

Hi,
I'm digging up this "old" thread just to update it. And because I'm very happy today.
First I want to thank you guys for your help, with special thanks to Kev' for his good advices (as always). Today, I could "repair" the fitting holes of my roll bar. As I said above, I enlarged them, and they were oval. Today, I finally decided to add some weld on the inner edges and grind them to recover nice and round holes. I delayed it because I was not sure if "I could do it". But it actually worked very well, and now, my roll bar fits perfectly!
So Thanks again to you guys for the help.
Here are a few pictures:

After I enlarged the holes two weeks ago.
RollBarForum01_1.jpg

Today I added weld on the inner edges. Grind flush, grind "round" (sorry, I can't find the English word for that)
RollBarforum02_1.jpg

All the holes are OK now and and the roll-bar fits !
RollBarForum03_1.jpg

[K4KEV]

Glad I could help mate.....now get some paint on it