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Roll Cage Construction.


Risking

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Okay so there seems to be an increasing number of guys (and girls) who are wanting to get into entry level motorsport like the current MRA (motor racing aus) championship etc etc.

The one thing they all need and dont seem to full understand is rollcages and what they have to go through to get one fitted and log booked etc. The ammount of time and labour and why it cost what it does to have the cage fitted when they have purchased a "kit"

So I have a car here owned by the one John Boston. Its a little 180sx which we are building to run various events.

Im going to update this thread and start a bit of a cage log for the guys who are interested.

Basicly the idea is to show you what the car goes through and the entire process involved in fitting a weld in cage to a vehicle. From a complete car to a caged stripped interior.

The Basic kit has been purchased from Bonds roll bars. It contains the main hoop, pre bent front legs and enough material to fabricate full intrusion bars, hoop cross, rear legs and full cross, roof diagonal, harness bar, front leg supports and a dash bar.

Fairly extensive cage but also what I think is typical for the guys who are getting into motorsport to purchase and have fitted.

I want to show the process we use, the notching methods and tooling we use (both manual and CNC cut) The welding procedures and the assembly procedure required to weld the joints properly and well. there is more to it that throwing some tube in and welding it up.

The aim of this thread is not to start a cage war about procedures and whats the best way etc etc. I mearly want to outline the way it can be done and try to put some understanding out there for the guys who are thinking about caging a car but are not sure or have questions.

I know there is alot of guys out there who already know what goes on and have a good idea of how cages are fabricated, but after some searching I found there is nothing showing a cage from Virgin car to final product with detailed photos and outlines.

So thats what I think this thread can be for.

Ill get some photos up tomorrow night of the basic Bonds kit and the car as it stands now. Then if people want to see it grow then Ill keep the thread updated and explain whats happened as it goes along.

Hopefully it helps the community a little and inspires people to get their cars caged and out on the circuit.

And before anyone PM's me asking if ill cage their car, sorry but no. Im too busy, im doing this thread as I get PM's left right and center asking how much the car gets screwed up and what needs to be done etc.

So here it is in one thread.

Edited by Risking
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Nice one Brad!!! :P Should give us little guys a good understanding of what goes into making a cage...

I know cause I have seen you do it many a time and I have helped..it's not easy and very time consuming! :D

Please keep this thread updated step by step!

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Chris log books and cage certification are different but I'll cover both in this tread

I do my own certifications and have an engineer that I use when doing a Molly cage which is not oftern.

The process is very simple providing you follow the basic cage designs.

I'll put photos of everything up as it goes along

this thread is not about drumming up business so posts like above are not needed.

It's about the technical aspects of a cage and it's construction not making money or creating business.

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lol, after ANKs thread in FI i doubt anyone would be willing to use him.

Question about the kits though, I assume they arnt pre-fabbed for the specific car apart from the front legs?

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They are pre Bent hoops and front legs. The roof bars have slight bends and so forth but everything still requires tweaking to fit well.

The bolt in kits anyone could instal these require some thought and planning like you will see in a few days.

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great idea risking i cant wait to see all aspect of building a cage i think it will help me with mine just one question

what type of welder has to be used on a cage ive herd all different stories about what welder to use i would personally like to use a tig on mine thanks tim

Edited by timsr33
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What does everyone think of www.mmsport.com.au ??

4 Point

Including main hoop with tags to B pillars, single diagonal brace and 2 rearward diagonal stays $1050

6 Point

As for 4 Point but including forward legs, A pillar tags, windscreen header and a diagonal roof bar $2035

Comprehensive 6 Point

As for 6 Point but including second diagonal to main hoop, as well as standard double diagonal side

intrusions (single bent side elements reinforced at centre) to both sides of vehicle

$2950

Additional Bars

First (1 piece) diagonal side intrusion (both sides). $270

Second (2 piece) diagonal side intrusion (both sides). $485

Second diagonal to main hoop (2 piece) $210

Seatbelt bar to main hoop (2 pieces) with screw fittings $210

Seatbelt bar between rearward braces (1 piece) without screw fittings $95

Single diagonal between rearward stays $145

A pillar reinforcement bar (single piece) to floor ea $155

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For what you want to do with the car Zebra weld in is a MUCH better option.

Tim I used to mig weld all my cages but really dont like the finish.

I now Mig the bases and plates to the floor but everything else is TIG'ed. If you are carefull and have a good quality knotcher Tig welded cages look so much better.

One thing with this one is Boz will be using it as a promotional tool as well so it needs to be very presentable and look the part. Tig welding is the only option.

Okay this is the "kit" that bonds have supplied us with. Im not 100% sure what the retail on this particular kit is. Ill ask petter and let you all know though.

post-20349-1249638259_thumb.jpg

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All the lengths are cut to the right length they just need to be knotched out at the right angles and made to fit.

The legs will require some touching up around the bends to get them a little tighter to the pillars.

There's a few bars that will be added to this kit and Im considereing doing a fire wall penetration as well considering John wants to keep it for a while and the cars are known to flex in the front alot.

Everything is labeled, Pete and Allan spend some time getting the parts labeled and wrapped in pairs to make the job less jigsaw like come time to assemble it.

This is the donor cage that John has given up. Its a really nice expample but race rally only so its going to be a purpose built car. The cage is only the begining for this girl but thats not the point of this thread.

post-20349-1249638298_thumb.jpg

post-20349-1249638421_thumb.jpg

Tomorrow the car will be stripped to a bare shell and the work will begin.

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What does everyone think of www.mmsport.com.au ??

4 Point

Including main hoop with tags to B pillars, single diagonal brace and 2 rearward diagonal stays $1050

6 Point

As for 4 Point but including forward legs, A pillar tags, windscreen header and a diagonal roof bar $2035

Comprehensive 6 Point

As for 6 Point but including second diagonal to main hoop, as well as standard double diagonal side

intrusions (single bent side elements reinforced at centre) to both sides of vehicle

$2950

Additional Bars

First (1 piece) diagonal side intrusion (both sides). $270

Second (2 piece) diagonal side intrusion (both sides). $485

Second diagonal to main hoop (2 piece) $210

Seatbelt bar to main hoop (2 pieces) with screw fittings $210

Seatbelt bar between rearward braces (1 piece) without screw fittings $95

Single diagonal between rearward stays $145

A pillar reinforcement bar (single piece) to floor ea $155

That is a lot dearer that Bond. just a heads up. as i know this thread is not about who to buy them off but how to go about building them. but shop around as there is a few places that are around the same price as bond now.

I have just done this myself. im not a welder or machinist by trade but i can weld ok so i set about a bond weld in cage. I got the kit all labeled ect from bond. i then started on it and it was a far more daunting task than i had imagined. i had a few friend that had built cages come and give me a hand working it all ot but it soon became apparent that i had not done enough research on cage design and had not decided fully what i wanted. this meant that i was on the phone again ordering more pipe work to finish it off as i had added a few more "chassis strengthening" bars.

It took me about 4 weeks from the start to finish doing a few hours every night and i was working to a time schedule to get to another event in the car. after i had spent some wheel time in the car i then picked a few more faults with it and as it hasnt been log booked yet i will add the extra bits in when i get a chance.

so key things i learnt as a real amature.

Get the windows removed. it can be done with them in but not advisable.

Get some one that knows how to weld to do it. I got a welder mate to do it. far better job

Go to track days or any where where you can look at 10s of cages at once and take notes on what bits you like and dont like then talk to the drivers and ask them what they would change.

do your research even if you are taking it to a pro to do the job as they may do somthing that when explained you may think thats grate but when you pick up the car and start driving it you think gee thats a pain in the ass.

That last point i like as through my job i work on race cars frequently and its just getting in and out that shows the clever design and the not so clever.

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DJRIFT it depends on the type of car as to the windows coming out.

I agree it should be welded by someone very confident in their welding. Its not a job to be taken lightly.

There is procedures to follow which makes the whole job alot less stressfull all of which ill be sharing with eveyone in this thread.

The job can be very daunting, esspecially when it comes to knotching and calculating angles etc etc.

Today the car was Gutted and I mean gutted.

There is nothing left, not one trim clip or wiring loom. We stripped the sound deadening out and have a little bit left to finish off before the real work begins

Typically Idont do stripping its too much work and takes far to long. In this case I have made an exception and we did it today. Loads of work!

This si the 180 being stripped. Dash out and a few things removed.

post-20349-1249717940_thumb.jpg

This it it with everything just about removed and alot of the sound deadening taken from the body shell. Alot of work getting it to this point

post-20349-1249718063_thumb.jpg

Afterwards we toyed around with the hoop and made sure it was wide enough etc.

Basicly to begin with we hole saw holes in the body to allow the hoop to slide down through the floor. Not everyone does this but there is a few reasons I do it even when building a box section for the hoop to rest on.

*it lets the cage drop right down to get the roof bars welded perfectly

*if the holes are big enough you can drop the front more than the rear which lets you weld the intrusion bars and leg supports very easily. Important in a 180sx which has no room to weld around as the quarter windows are no where near the cage

*makes marking the desired hoop height very easy. We will left it up and hold in place with scissor jacks, mark off the cutting length of the hoop ends and that way I know the lengths are correct instead of measuring I can pysically see.

The bases will still be boxed into the corner and the hole plated up, but this method I like as it lets me raise and lower the cage alot more than without the floor holes. The easier it makes to weld the better the welding will be

post-20349-1249718129_thumb.jpg

post-20349-1249718605_thumb.jpg

More to come tomorrow, hopefully if im motivated Ill get alot of it done like the hoop and front legs etc

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Heya, very nice!

Im looking in to getting a bolt in half cage (want it street rego'd in SA) soon and am really interested in the process. I know that there is significant difference in bolt in/weld in but still good to know. Is there a possibility of including how many hours work each step of the process takes?

Keep us updated :down:

Edited by SkyHi_33
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