The Length of the inside pipe is EXACTLY 40 3/4 inches (fourty and three quarters). 1/2 inch inside diameter blackpipe. Threaded on both ends. The exact cut of this pipe is important because the more precise it is the better able you will be to screw the plate ends on without having slack between the reducers and the Soloflex barbell arm. I screw my plate arms on and off as I need them. This will make more since later if it doesn't now.
Once you have the inside bar cut you will need to wrap it with duct tape. Not the entire bar. You will wrap it In sections. Remove all oil from the bar with alcohol or some other degreeser. After the degreeser on the pipe drys stick the ducttape to the pipe and begin to wrap the tape over itself. Just like it is on the cardboard spool you are removing the tape from.
What you are creating here is a shim (a spacer) for when you insert the pipe inside the Soloflex barbell arm. You want to stop taping the pipe when the taped pipe will barely slide into the Soloflex barbell arm. Repeat this about six times down the length of the pipe. Space the tape evenly along the pipe.
When you are finished slide the taped pipe into the barbell arm. It should be slightly difficult because the tape should be barely allowing the pipe to fit inside. When you are finished with this part of the assemebly you can check if you have done it right by spinning the barbell arm.
The barbell arm will be heavier because of the additional weight. Hold it with one hand on the top of the bend in the neck and spin the entire thing 360 degrees a few times. The pipe inside should stay put. If it doesn't remove it and add more duct tape. Make it stationary inside the barbell arm but removable in case you decide to use the machine in 100% classic mode.
The plate pipes should be cut 15 inches long. 3/4 inch galvanized pipe. You will need two, of course. Thread one end of each pipe. DO NOT REAM the uncut ends of the pipes. Reaming expands the ends and will prevent certain small holed plates from sliding onto the pipe. I had this problem in the beginning.
Add a 3/4 X 1/2 inch reducer to the threaded end of each pipe and tighten with the pipe wrenches.
Now screw these onto the pipe inside the barbell arm. At first REALLY tighten the plate pipes onto the barbel arm. I mean crank it down! Then, remove both plate pipes, reducers and all from the inside pipe. Take them off completely. Screw them on again. Repeat the tightening steps. Really crank it down for a second time! Remove the plate pipes again at the reducers.
From now on you will be able to tighten the ends down hand-tight.
Here are the hand-tight steps:
Make sure you have the same amout of thread sticking out on either end of the barbell arm. Screw the plate pipes onto the ends of the barball arm pipe. Stand in the middle of the barbell arm. Grab the plate pipes and turn in the the opposite directions Really handtight. They will hold. I have used up to 200 lbs with handtight torque. For heavier weight just attach the pipe wrenches to the Reducers and do the same opposing motion.
Thats it. Enjoy your workouts and have a great day.