What is the formula/trick to fitting tubes to other tubes in a cage? Like how do you know at what angle to cope it and what length to cut it, and end up with tight *** gaps to tig weld? Like what would an example of the process be when building the a pillar bars in a cage, and attatching them to the main hoop. What measurement process goes on here? I look at some of these cages and chassis built by http://www.ironworksspeedandkustom.com and it boggles my mind how everything is perfectly symmetrical and all the gaps are tight as can be. Im sure there is a lot of experience involved here, but theres got to be more to it.

And please no dick head responses, im sure there are alot of people out there who want to know the answer to this question.

 

i like solidworks, and measuring a few times.

 

seriously, you just gotta screw up a few times to learn

there are some formulas to calculate bends, but as far as getting everything parallel/even/symmetrical you just have to measure plenty, as dfoxengr said

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MajorPayne &raquo;</TD></TR><TR><TD CLASS="quote">seriously, you just gotta screw up a few times to learn

there are some formulas to calculate bends, but as far as getting everything parallel/even/symmetrical you just have to measure plenty, as dfoxengr said </TD></TR></TABLE>

I concur, I find the more I do the better and more efficient I become.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NaPiEr &raquo;</TD></TR><TR><TD CLASS="quote">

I concur, I find the more I do the better and more efficient I become. </TD></TR></TABLE>

i think thats how it goes with anything though....very few people jump in and are immediately great at building cages, but for some it takes longer to become proficient than others

to the OP, buy some EW tubing and start making some complicated projects (not necessarily cages in cars, just go wild with some small stuff, practicing bends mostly) and youll get better much faster

 

The right size tubing notcher and a quality notcher at that helps in the notch area. When I started cardboard papertowel roll tubes helped too, the majority of them are almost 1 3/4", did I mention they even slip over 1 3/4" .095 wall tubing

 

what would you consider a quality notcher?

 

JD2 (JD squared) makes great quality benders and notchers.

When it comes to bending, just remember that when you bend tubing that it tends to stretch when it's bent. You need to account for this when making a cage.

When it comes to notching, just get the alignment and angles correct and you're good. It helps to have a quality product that will show you angles of your notch so that you don't play the guessing game.

Either way the tubing is relatively cheap.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tepid1 &raquo;</TD></TR><TR><TD CLASS="quote">JD2 (JD squared) makes great quality benders and notchers.

When it comes to bending, just remember that when you bend tubing that it tends to stretch when it's bent. You need to account for this when making a cage.

When it comes to notching, just get the alignment and angles correct and you're good. It helps to have a quality product that will show you angles of your notch so that you don't play the guessing game.

Either way the tubing is relatively cheap. </TD></TR></TABLE>

Do you think building a quality, great fitting cage is that easy to do?

 

I wish it was. It still takes plenty of time to do, no matter how many times we do it.

 

I'm by no means a professional, but when i built my first and only cage, i found it helped using one of these for some joints that had multiple tubes going into the point.



Also, I measured twice and cut leaving a little extra length so I could put the peice in place and see if the coping was correct and overall length was good.

Not gonna lie, i ended up with like 5 peices where I cut the coping from the wrong side or did something else that was stupid and had to scrap the piece or use it for something shorter later. But by the end of the cage, I felt like I had learned a lot and got much more efficient.

 

There is as much eyeballing cage building as measuring. Cars are not perfectly symmetrical and therefor most of the time there is a lack of a good place to measure from equally on both sides.

It's always easier to take a little more off than to put a little more back on...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by miller &raquo;</TD></TR><TR><TD CLASS="quote">

Do you think building a quality, great fitting cage is that easy to do? </TD></TR></TABLE>

No... never said it was. Just trying to throw some pointers out there.

I have bent A LOT of tubing so I know what to look for. I do it all the time at work.

 

as a drafter, ive used acad, sw, and inventor for industrial stuff at work.
i am also a journeyman welder welding industrial pipe.

i have not welded a cage before, but
one can calculate and layout pieces perfect using cad or layout tools, and when it comes to fitment & welding... controlling distortion will own you!
hours of planning can all be screwed up just by one welded joint.

at work my welds are subjected to ultrasonic & radiographic inspection almost on a daily basis, though, my imperfections have pass code (api) so far.
no weld is perfect. theres a certain amount of defects you can have.

when welding a 4130 cage, some say skip the preheat & post heat because its only thin wall 4130. but if it was me, i wouldn't skip the procedure.
improper procedures are for 4130 pipe where I work.

fit as you go (experience will tell how much a pipe will move as you apply heat).
once you get a good fit, make your tacks strong, and check fitment again.
if pipe needs to move and the bigger hammer wont work,
a grinder w/ cutting disc is your friend ..
grind tacks so the joint can hinge where you want the pipe to go.
repeat the above

 

doing a bend in solidworks and repeating in the garage are 2 different things entirely. ...lol...

Go slow, don't get frustrated.

 

Bendtech software is your friend....

 

I've got Mittler's Pro bending software and i don't think i've ever used it to build a cage. It's great to make it all work on paper, but bending and test fitting in the car has worked great for me.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sims &raquo;</TD></TR><TR><TD CLASS="quote">There is as much eyeballing cage building as measuring. Cars are not perfectly symmetrical and therefor most of the time there is a lack of a good place to measure from equally on both sides.
</TD></TR></TABLE>

I agree completely, though i think it's probably more eyeballing than measuring.

 

It is more of a hands on thing. You can have good plan, but in the end it will come down to what fits when you start putting it in the car. I have killed my fair share of tubing. It is just something you learn with time.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vectorsolid &raquo;</TD></TR><TR><TD CLASS="quote">doing a bend in solidworks and repeating in the garage are 2 different things entirely. ...lol....</TD></TR></TABLE>

works well for me

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tepid1 &raquo;</TD></TR><TR><TD CLASS="quote">Bendtech software is your friend.... </TD></TR></TABLE>

That is the single most useful piece of software I have EVER USED. I have SolidWorks and ViaCAD at my disposal too, but bendtech was created by a CAD user, so it uses a CAD engine, but completely stripped away of anything non-tube bending/joint fitting related.

 

I used a 20" protractor/angle finder, some string, and a lot of walking back and forth to the notcher. Other than that it is some simple math, patients, and eyeballing more than anything.

 

a good angle finder and a bridgeport with a bit thats the size of the tube. Works great for notching stuff on the first try with out having to spend much time redoing it.
The bending part, ill get better at it eventually. I like measuring and eyeballing, after awhile you can almost mentally measure pieces

 

As most have said, nothing replaces experience. You will screw up TONS of tubing throughout your process of building cages. I can do the majority of tubes by eye now since Ive done them for awhile, but there are some tools that make the job a lot easier!
First, to find what angle to notch your tubing at you'll need a angle finder. Basically 2 flat piece that pivot in the middle. No angle marks are needed on the tool. Ill take a straightedge, and say on a door x-bar, clamp on end at the height you want the tube to fit to on the main hoop, and the other on the front a-pillar where ever you want it. Once its clamped in the there, take your angle finder and lock it in place in that exact angle...take it over to your notcher and go for it.
Secondly, I will usually leave the tube straight cut, butt it up to the tube it will be notched to fit, and mark a short line length wise with the tubing at the point where the "deepest" of the notch will be. Say for an a-pillar bar for example, butt it into the main hoop, then mark the a-pillar tube where the deepest part of the notch will be in order to line up with the main hoop. This will get the "rotation" of the tubing correct in the notcher.
Thirdly, when your notching, before you take your tubing out of the notcher, run a Sharpie or paint pen along some straight edge on your notchers clamp. This way if you need to make the same notch, but a little deeper, you can clamp the tubing in the same spot and keep your "rotation" of your notch the same.
Lastly, remember you can always take more off. If you make a notch and its really close, DONT TRY TO FIX IT IN THE NOTCHER! Alot of people will probably bash me for this, but a 4.5" electric grinder with a hard grinding wheel in it, will be much more precise to final fit your tube if need be. Usually its faster just to touch it up with a grinder. Also, trying to fix it in the notcher will probably lead to having to scrap the piece of tubing!
PRACTICE PRACTICE PRACTICE! GOOD LUCK!

Kyle

 

Temporary thread hijack, (no sense starting another thread with the same title)



I'm about to order tubing for my cage. No way this car is going to go 11.50 and be required. So I'm putting it in for some additional safety and some added cool factor on the street.

I see the NHRA is down on MIG welding Cro-moly. Does that also include annealed cro-moly?

And what about some 1.5" x .095 mild steel for a small little six point cage? I'm thinking it should be just fine, without having to weigh down the car with .120 wall 1.75"

Any thoughts on that?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vectorsolid &raquo;</TD></TR><TR><TD CLASS="quote">No way this car is going to go 11.50 and be required. So I'm putting it in for some additional safety and some added cool factor on the street.
</TD></TR></TABLE>

Good luck with a full cage in a street car that sees daily use. You gonna wear a helmet too?