No Screws or Holes Pull Up Bar / Door Gym

This is a tutorial on how to make a doorway pull-up bar that does not require holes in any door frames or walls to mount it; which makes it perfect for college dorms or other temporary living quarters. It pushes against the door at two different points when weight is applied to safely wedge itself into the frame without the use of screws or bolts. It has an estimated maximum capacity load of 300 lbs. It allows for wide, regular, close, and hammer-grip pull-ups and chin-ups. Some of the work for this instructable are inspired by Shenandoah of http://www.angelfire.com/ny5/shenandoah/Grunt/Bodyweight.html and other commercial products on the market.

Step 1: Measurements

We need to measure the width and depth of the door to be used. Most door frames will more or less have the same general dimensions, but it is important for weight distribution. Look at the pictures for more details.

Step 2: Materials

Now that we have our measurements, we need our materials:
-3/4" galvanized steel pipe (Length will be determined from door measurements)
-2 x 4-directional coupling
-2 x 3-directional coupling
-2 x 45 degree coupling
-4 x 90 degree coupling
-2 x close nipple (meaning no pipe between threads)
-2 x 3/4" x 3" nipple
-2 x 3/4" x 4" nipple
-2 x 3/4" x 5.5" nipple (Length will be determined from door measurements. This is dependent on the depth of the door.)
-6 x 3/4" x 6" nipple
-duct tape
-sponge
-detachable links
-Pipe wrench
-measuring tape
-pipe insulation
-athletic tape*
-painters tape*
*=optional

NOTE: I could not find any stores that would cut and thread pipe in lengths shorter than 12". That is why I had to purchase individual nipples. If you can find a store or are capable of cutting and threading pipe in small increments, the cost of the project can be cut significantly.

Step 3: Construction

A couple of things to keep in mind before constructing this build is that it takes a lot of leverage to put these pieces together so using baby-oil or WD-40 or some other type of lubricant may be necessary. I also used a longer pipe to use a leverage while constructing the pull up bar, just be careful not to strip the threads.

1) I started with the two 4-way directional pieces. I started by fitting one of the closed nipples to the 4-way directional coupling and then attached a 45 degree coupling to that piece. Make sure to align the 45 degree appropriately. The pictures show better detail. (Picture 3)

2) Then I attached 6" nipples to the 45 degree sections. These will be the wide-grip handles. (Picture 4)

3) I took 3" nipples and attached it to the top of the four-directional couplings. Apply a 3-way directional coupling to the end of the 3" piece so the perpendicular feeder points outwards. Another 6" nipple will be installed here. (Pictures 5 and 6)

4) Then I took two of the 90 degree couplings and attached 5.5" nipples to them. (Pictures 7 and 8)

5) Taking the pieces from the above step I then attached 4" nipples with 90 degree couplings on top. (Picture 9)

6) I attached the pieces made in steps 4-5 to the pieces from steps 1-3. This finishes the majority of the project. (Picture 10)

Step 4: Finishing Touches

1) I put pipe insulation on the two 6" nipples that are positioned parallel with the floor, then wrapped it in duct tape to prevent movement. Masking or painter's tape on top of the duct tape could help with preventing marks on the door frame. I did not choose to do this however. (Picture 1)

2) I took an industrial sponge and ripped it in half. (Picture 2) I shoved the sponge into the 90 degree coupling that will hook onto the door frame lip. (Picture 3) Then I secured it with duct tape. (Picture 4)

3) Then I added the last two 6" nipples to the 4-way coupling to finish off the hammer-grip handles. (Picture 5)

4) You can choose to add athletic tape to the bar to improve grip.

Step 5: Conclusion

This is my first Instructable. I would appreciate any input that anybody has in order to help me improve my future Instructables. My future Instructables will include peripherals for this pull up bar to make it an entire home-gym system. I look forward to contributing more Instructables in the future.

UPDATE: I've included a picture of my pull up bar with athletic tape added for grip and comfort.