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Old 06-04-2009, 08:10 AM   #1
William Valdez
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Concern for home-made pull-up bar

I notice heaps of crossfitters make their own pull-up bars out of rigid galvanize pipe and fittings.This pull-up bars are secured to the ceiling on the wood studs with flanges. However the flanges were not design for the shear force applied by the kipping pull-ups. You can do dead hang pull-ups all day long, but once you apply that shear force those threads are going to fatigue and give out in time.
There is a simple solution - seismic bracing! We use this in California in construction for earthquakes. Basically this designs adsorb the shear forces applied during earthquakes. You do not need to tear down your existing pull-up bars, just reinforce it. The easiest way to do this is use aircraft cable 3/8 or bigger. Use the power of the triangle, go from the bottom of your pull-up bar to the next stud in front at a 30 to 45 degree angle. Get the cable nice and snug,this should absorb the shear force applied during the kipping pull-up. If you find it still rocks reinforce it in the opposite direction. I hope this helps. Just constructed criticism.
I've seen a few affiliates guilty of this also. When they make the pull-bars with wooden post (4 x 4 or bigger) rigid galvanize pipe with flanges secured to the sides. Your applying shear force on those threads as well. To correct this just drill a hole through the post and install the flange backwards through the hole and then secure it with wood screws. Thread your pipe on and do the same for the other side. I know that most affiliates do this ,but they're still a few that do not. This well also keep your pipe from spinning. I do not want to hear about an affiliate getting sue for a falling pull-up bar.
I hope this helps.
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Old 06-04-2009, 08:13 AM   #2
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Re: Concern for home-made pull-up bar

nice advice. Although ive had mine on the flanges for a long time i like the way you recommend, maybe some day i will switch over
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Old 06-04-2009, 10:10 PM   #3
Mike Gin
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Re: Concern for home-made pull-up bar

Quote:
Originally Posted by William Valdez View Post
I notice heaps of crossfitters make their own pull-up bars out of rigid galvanize pipe and fittings.This pull-up bars are secured to the ceiling on the wood studs with flanges. However the flanges were not design for the shear force applied by the kipping pull-ups. You can do dead hang pull-ups all day long, but once you apply that shear force those threads are going to fatigue and give out in time.
There is a simple solution - seismic bracing! We use this in California in construction for earthquakes. Basically this designs adsorb the shear forces applied during earthquakes. You do not need to tear down your existing pull-up bars, just reinforce it. The easiest way to do this is use aircraft cable 3/8 or bigger. Use the power of the triangle, go from the bottom of your pull-up bar to the next stud in front at a 30 to 45 degree angle. Get the cable nice and snug,this should absorb the shear force applied during the kipping pull-up. If you find it still rocks reinforce it in the opposite direction. I hope this helps. Just constructed criticism.
I've seen a few affiliates guilty of this also. When they make the pull-bars with wooden post (4 x 4 or bigger) rigid galvanize pipe with flanges secured to the sides. Your applying shear force on those threads as well. To correct this just drill a hole through the post and install the flange backwards through the hole and then secure it with wood screws. Thread your pipe on and do the same for the other side. I know that most affiliates do this ,but they're still a few that do not. This well also keep your pipe from spinning. I do not want to hear about an affiliate getting sue for a falling pull-up bar.
I hope this helps.
Bracing is key to prevent shear - but I think with aircraft cable you suggest you would need to reinforce in both directions since it isn't rigid. A rigid rod/pipe running in one direction would do the trick (that power of the triangle you mention).

I really like the idea of drilling through the wood and extending your pipe through and then attaching the flanges (screwed down). That to me seems the most bombproof setup. Wish I had exposed beams in the garage. Don't know how to kip yet so not a big concern just yet. But some threads have made me think a little bit more about how I can design a better setup.
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Old 06-05-2009, 09:22 AM   #4
William Valdez
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Re: Concern for home-made pull-up bar

The reason for using aircraft cable because its the simplest and easiest to install and yet very strong. If in-doubt check out some bridges or utility-poles. Also since the cable is not super rigid it acts as a shock absorber.
You can install it in your garage. You'll need a stud finder to locate your beams. If you run it parallel to your beams you can install the flanges directly. If you run perpendicular use 2 x 4.
I wrote an article for the journal with all the details. I'm just waiting for them to release my home-made ring project article before I turn it in. They're a little backlogged.
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Old 06-05-2009, 12:54 PM   #5
Eric Terrell
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Re: Concern for home-made pull-up bar

Another cheap fix would be to weld it together prior to mounting.....no joke, we got a ton of welders and machine shops around here and it would take all of about five minutes. Just a thought.
I like your idea of the cable reinforcement. I may do that since mine is already mounted.
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Old 06-05-2009, 09:08 PM   #6
Mike Gin
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Re: Concern for home-made pull-up bar

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Originally Posted by William Valdez View Post
The reason for using aircraft cable because its the simplest and easiest to install and yet very strong. If in-doubt check out some bridges or utility-poles. Also since the cable is not super rigid it acts as a shock absorber.
You can install it in your garage. You'll need a stud finder to locate your beams. If you run it parallel to your beams you can install the flanges directly. If you run perpendicular use 2 x 4.
I wrote an article for the journal with all the details. I'm just waiting for them to release my home-made ring project article before I turn it in. They're a little backlogged.
Oh I don't doubt the strength of aircraft cable - stuff is crazy strong. But if you have it only going one direction it is tension as the energy goes away from it and then it is out of tension when the momentum swings the other way. Make sense? That will increase the shear load on the flange in one direction. If you have the cables going both directions to form a "V" then definitely you would have a sweet setup.

Are you securing the cables with eyelet/thimble thing or wire rope clamps?
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Old 06-06-2009, 05:25 PM   #7
William Valdez
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Re: Concern for home-made pull-up bar

Agree! Secure them to your studs (beam) with the eye-let lag bolt and to the pipe with a rigid pipe strap either electrical or plumbing. make sure is the heavy duty type. Create an eye on the cable, but of course run it through the eye-let and pipe strap. Then secure your loop with a wire rope clamp.
A picture tells a thousand words so check out my video from my past threads.

Last edited by William Valdez; 06-06-2009 at 05:47 PM.. Reason: not finish
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Old 06-07-2009, 08:15 PM   #8
Robb Breeden
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Re: Concern for home-made pull-up bar

This is a GREAT tip; it not only improves safety, but will also make your bar rock-solid. I just built my set this exact way yesterday. I used 4x6x12 posts with @120 lbs of cement in each hole and the whole setup is very stable. For 1" pipe use a 1 1/4 drill and use a wood file to get the hole snug (I didn't tap the pipe as with my luck I would have ruined the threads).

Quote:
Originally Posted by William Valdez View Post
I've seen a few affiliates guilty of this also. When they make the pull-bars with wooden post (4 x 4 or bigger) rigid galvanize pipe with flanges secured to the sides. Your applying shear force on those threads as well. To correct this just drill a hole through the post and install the flange backwards through the hole and then secure it with wood screws. Thread your pipe on and do the same for the other side. I know that most affiliates do this ,but they're still a few that do not. This well also keep your pipe from spinning. I do not want to hear about an affiliate getting sue for a falling pull-up bar.
I hope this helps.
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Old 06-07-2009, 11:06 PM   #9
Karl Eagleman
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Re: Concern for home-made pull-up bar

William, (or anyone else) do you have your own set-up of what you're talking about? I'll be installing my own soon and would like to see some pictures.

Great advice! Thanks!
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Old 06-08-2009, 07:39 AM   #10
Jason Murphy
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Re: Concern for home-made pull-up bar

Karl,
I posted pictures under the thread Monkey Bars / Pull Up Station just the other day for the pipe going through the wood and a flange on the outside. I did not use any cables however. That also seems to be a good idea. I was originally going to just thread the pipe into the flanges and attach to the posts until I started reading about the shearing off at the flanges. I'm glad I did some research on here first before completing the project. This site is great!
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