This section is for those of you who buy a kit and wonder when you get it... "where do I start"?
Normally this is done on the tractor, or on a flat surface, but in this case, the customer wanted it shipped already welded together. Since I didnt have the tractor, and the welding table was tied up at the time, I thought I would do this as you might, right on the floor.
So, using this kit, you can see how the parts fit and maybe get some ideas...
This will be a two bar cage. The spacers are already notched on 10° and will set the spacing for the hoops. This is usually a two person job to get it to this stage. Notice the spacers at the bottom to insure nothing moves as it is welded. (2 X 4's cut the correct length will work fine) Also there are temporary angle iron 'legs' to keep it upright and level. This is not the only way to do this, and you may find it is easier for you to do with the cage laying down.
It does make it easier to 'square' the hoops, or get them in line with each other by placing a straight edge across the front, and holding a carpenters square to the sides to get then in line. (or placing the square on the table and checking upwards if laying down) Do this on each side in case hoops are not exactly the same. If not, measure and split the difference, using largest at the front.
It is almost necessary to level the main hoops (and make sure they lay back 10°) when you get them tacked together before you start anything else. This will give a baseline for establishing level and plumb for the rest of the operations. Unless you have a super level floor, try not to move the cage until you are completely finished, otherwise you will waste time releveling and shimming to get it to sit still
The 10° spacers (sides) are tacked lightly in position and the top two straight spacers are left to 'float' . Yes, there is a reason for doing this as you will see later
It is a good idea to let the bottom two float until you see where the U shaped piece will be on the hoop. It is much easier to set this in place first then bring the spacers up level to it
If you are not familiar with notching pipe, you will be very soon! The U bend is good practice for the really tough ones...
make sure it is notched equally on each side, so the long flat runs parallel to the hoop
Notice the bar clamp to squeeze the U shaped piece - this was done because I wanted it to be a little lower (in the bend of the hoop)
The lower spacers are brought up at this point and tacked. If done correctly, it will look like one continuous line around the cage and will be level from all points.
Now cut the two uprights to length and notch to fit
Using a straight edge, (with the two remaining straight spacers in place) measure over to get equal distance from each side of the cage
Tubes will be plumb at this point
Now you can slide the top two into position and get them in line with the verticals
next, slide the back spacers into place and level
This is a good time to cut and notch the upright supports - ideally you want them vertical at the sides and blend to the uprights at the top. This may require a little 'tweaking' with a torch. Just dont get too wild and you won't kink the tubing if you heat evenly and make minor adjustments.
Note spacer at bottom between the upright and hoop. You may want to kick this back till it sits plumb - whatever looks good to you
Now comes the fun part... cutting and notching the rear 90s to make it look like a continuous line around the cage. I wish I could give you some hot tips here but the fact is, there isn't an easy way to do this. It just takes a lot of patience and time with a die grinder to make them fit. This is not a straight thru notch if you put the bars in the bends as shown, but a compound curve. I start out with a plasma arc (or torch) to get them close, then its check and grind for the next 30 minutes or so
Make sure everything is level as you check fits. It helps to have someone hold the 90 up while you stand at a distance and look at the alignment. A little grinding makes a big difference when it gets close, and you will know when it 'looks' right
when the 90s are tacked, it's time to put in the X at the rear. This is as much fun (maybe more so) as the 90s.
Here I use the plasma to 'shave' a little off at a time till it gets close, then get out the grinder
dont worry about the part that sticks out past the edge. When you get it welded most of the way around and it is still hot, hammer it flat.
SFI required plates to go around the bottom that also serve as spacers as you tack the cage together. These are the lightened version.
now it is time to weld it up using a MIG welder ( or TIG for moly )
every cage I build is TIG welded for looks and no cleanup of splatter that is inherent of the MIG process
Finished 2 bar moly cage ready to ship
a two bar moly cage weighs 100# as shown
3 bar is 140#
You still have to add the 1/4 X 6 plates and anchor it to the tractor according to SFI specs
optional removeable roll cage
this includes all the parts in a kit, plus three main hoops
five different style kits available in two or three bar
large octagon bullet
"Never tell people how to do things. Tell them what to do and they will surprise you with their ingenuity."
George S. Patton
Disclaimer: Ace Chassis will claim no responsibility for any problems or damage that may incur from building your own chassis. This includes but is not limited to: home incineration, joining fingers together, loss of hair, minor or major cuts, loss of sanity, solvent rushes, rashes, cuts in the floor, tape balls, or food and beer spills. The information above is what has worked for the Author, but building your own chassis, or any other project for that matter, has implied risks.