I had a chance to work on an old antique Fire Truck which needed the brake lines replaced however all of my supplies only sold the 5/16" steel tubing in straight lengths and some 90 degrees & 45 degrees needed to be made.
At first I tried using the current tube bending tool from Reilly’s auto parts which did not cost too much but soon found that the tool just kinked the tubing and ending up leaking fluid, so I decided to create my own tool which worked 100% and zero kinking and zero leaking. The use of a torch was also needed to soften the metal at the stress points prior to bending you will see the burned area on the wood surface where the torch lightly burned the wood in two area. But do not worry it was never held long enough in one spot to cause any worry.
The handle was a left over metal support for a wall shelf unit need to use sheet metal screws to mount it on the 3" metal wheel.
The tube holder was modified from the metal strap which came with the 3" wheel kit. See below step.
The plywood rectangular shape base is important because it will allow you to easily slip your 5/16" steel tubing with fitting attached so you can easily bend the tubing 90 degrees or 45 degrees which I need to do several times.
The spacing of the two wheels needs to be very close to what is shown in order for the tubing to be bent property.
Reilly's tube bender tool is the small wheel and the other is the 3" metal garage wheel kit from Ace Hardware.
Step 1: Gather Your Materials & Tools
The above is a garage door 3" wheel kit from Ace Hardware for only a few dollars the kit comes complete with a bolt and washers and nut. You will not need the bolt or nut but may use the washers.
Scrap plywood 3/4" thick about 18" long and about 12" wide but the exact dimensions does not matter just that the edges are square.
bolt 5/16" bolt x 2 1/2" with lock washer and flat washer
1) deck screw 2 1/4" long
1/2" space-( goes inside the small wheel)
1) Reilly's cheap tube bender tool
Portable drill or cord drill
1/8" 1/4" 5?16" drill bits
1 sheet of medium sand paper
1 sheet of medium emery cloth
1 hack saw
small vice press
small propane torch
5/16" Metal Brake line
Step 2: Metal Tube Holder Construction
The 3" metal wheel kit from Reilly’s has a metal strap which is used as a guide for garage door cables. This will be modified to a new purpose metal tube holder. The top of the strap will need to be cut diagonally using a hack saw held in a vice press. One side will only be used and the other discarded or recycled for future use. See photo
Step 3: Final Assembly of Parts
Whenever using tools that cause little bits to fly randomly about your workshop, USE EYE PROTECTION and gloves.
Mount the above cut metal strap now called Metal tube holder to the 3" metal wheel so the taper end is slanted down to the top of the 3" metal wheel. You will need to use center punch to mark the spot on the wheel and the above holder so you can use a sheet metal screw to attached it to the wheel. See photo
Then mount the metal shelf support to the 3" metal wheel to be used as a handle to turn the wheel hence bending the 5/16" tubing. The handle needs to be at right angle to the above metal tube holder.
Then the Reilly's metal tube bending tool needs to be put and held in a vice and made as round as possible using the hack saw to cut the handle off and the other holding tip which was all one piece before. Then use a flat file and emery cloth to sand all the sharp edges and burrs off.
Now assemble you wheels to the scrape plywood using the bolt with washers and deck screw to look like the finished photo.
Step 4: How to Use It
Once finished you can get a pre-marked with a sharpie pen where each bend needs to go insert the straight 5/16" tubing with fitting pre-attached easily slide the tubing so the holder can grab the tubing first for bending then bring the tubing down on the right side of the wheel against the 3" metal wheel then attach the final small wheel to hold the tubing tight against the 3" wheel with your pre-marked 5/16" tubing where each bend needs to go and in what direction fire up your small propane torch and heat the bend area until the tubing is good and hot then turn off your torch and bend the tubing using the handle mounted on the 3" wheel. By moving the handle in a counter clockwise motion down towards you keeping a close eye on the angle you are attempting to make 45 degrees is half of a 90 degrees. Once you bend the tubing unbending it is not advised so getting the correct direction and degree of bend is important first time. If you need to make a sketch first to give you the direction of what the final piece will look like that is the best way to keep track of your work do not rush on this because tubing is expensive.