Our pullup station at CrossFit Impulse is unique. Actually, it’s one-of-a-kind. David and I developed the rough plan for it during our trip to Dallas for our CrossFit level 1 certification. With a sheet of engineer paper and a floorplan of our box (drawn to scale) we bounced ideas, calculated requirements, and I noted our results from the passenger seat. Two and a half months later, we are extremely pleased with the final construction, and thought we would pass on the information we learned and created for the rest of the CrossFit community. A complete drawing package for the pull up station is located here. You’ll also see the major assembly drawings pictured below. Please ignore all check marks and places where I marked the drawing or feature “DONE.” Read on for the full details on CrossFit pull up bar construction.
Background and Discarded Concepts:
We first explored a wall-mounted solution in order to save floor space. We wanted a bar mounted along the wall with triangular trusses at necessary intervals for support. We wanted to mount the bar far enough from the wall that wall ball shots could be done between the bar and the wall (kudos to Russell Berger of CrossFit Huntsville for that idea). However, due to the nature of our box, this proved infeasible. Permanently mounting load-bearing steel structures to a finished warehouse wall is very difficult to accomplish correctly and safely. Our walls are constructed with aluminum studs. Accommodating different bar diameters and heights would also be difficult. These considerations pushed us to designing a free-standing structure.
Assumptions and Requirements:
Our pull up station construction began with the requirement to accommodate at least six athletes at once. We quickly found that a rectangular, free-standing structure could accommodate many athletes. Our final product has space for 18 simultaneous athletes, assuming every space is occupied. We haven’t load tested it with this many athletes, but we are confident it would not fail.
We decided that an athlete needs a maximum of 4.5 linear feet of pullup bar to have adequate space and not “feel cramped.” We then determined that four pullup bar heights could accomodate 95% of athletes: 80″, 88″, 92″, and96″. We based this on reach measurements from Christina (5’1″), David (5’8″), and me (6’0″) and a statistical height distribution of American men and women from the Center for Disease Control. I based my calculations on the 95th percentile male and female. Yes, that’s probably a little overboard, and a lot geeky, but it worked. We also kept in mind that a short athlete can always use a plyometric box, bumpers, or trainer assistance to mount a pullup bar that is too high. However, an athlete that is too tall for a pullup bar will not be able to effectively kip under any circumstances.
Based on excursions to Lowe’s and steel vendors where we would go to “feel some pipe,” we determined four desired diameters: 1.05″, 1.32″, 1.66″, and 1.90″. These outer diameters correspond to inner diameters of schedule 80 steel pipe of 3/4″, 1″, 1-1/4″, and 1-1/2″, respectively. Steel pipe is named by its inner diameter, while we are concerned with its outer diameter. This is confusing at first. You’ll get used to it. This wikipedia page has a chart that can help. Our height and diameter choices yielded six total diameter-height combinations for athletes to choose from. Almost all athletes will choose the 1.32″ or 1.66″ diameter bars. We installed the smaller diameter for extremely small athletes and kids and the larger diameter for developing grip.
The basis of our design is a 9′ x 18′ freestanding rectangle. Bars are supported by 12 vertical beams constructed from 2.5″ rectangular steel tubing with 1/8″ (.125″) wall thickness. Beams are welded to 6″ x 6″ x 3/8″ steel plates that form the ground attachment point. The steel plates are anchored to our concrete floor using 1/2″ concrete anchors. Each bar fully passes through the beam(s) that supports it and is welded to the beam(s) at each intersection.
Total cost for our pullup station was $542 for steel, about $40 in primer and paint, about $40 to rent the concrete hammer drill and bit, and two cases of Bud Light for the welder. We scavenged or borrowed everything else. That puts the total cost at less than $650, assuming our time is free. From concept to completed product I estimate that David and I invested about 50-60 combined man-hours in this project. Adding help from others brings the total to roughly 80-100 man hours.
Constructing this pullup station was not complex, but it definitely wasn’t easy. Think about that subtle difference. All we’re dealing with is steel tube supporting steel pipe via some plates anchored to the floor. No part of that description is complex, but it takes some serious tools, experience, and effort to perform all the intermediate processes. You will need access to tools like a bandsaw, milling machine, and welder, and the knowledge to operate them. Conversely, you can also subcontract these parts of the construction for additional cost. You also need to know how to use a concrete drill, install concrete anchors, and read a mechanical drawing. Once again, not complex, just a lot of issues to address. Here is how to proceed.
First, purchase materials. We acquired all our materials from a local steel vendor and Lowe’s. You can see our receipt from the steel vendor on the last page of the attached PDF. Steel pipe only came in 21′ sections, so we had some excess when construction was complete. Below you can see our parts list
Raw Steel Parts List
|1||3/8″ thick x 6″ wide plate||6|
|2||1-1/4″ Sch 80 Pipe||21|
|2||1″ Sch 80 Pipe||21|
|1||3/4″ Sch 80 Pipe||21|
|1||1-1/2″ Sch 80 Pipe||21|
|6||2.5″ Tubing, 1/8″ thick||2|
Next comes cutting the steel to length. We used an industrial horizontal bandsaw with a hydraulic control system that lowers the sawblade onto the steel while flooding the cutting surface with coolant. You can see an example of a horizontal bandsaw below. A regular vertical bandsaw would work just fine. I do not recommend using a hacksaw. Even with a bandsaw, this takes some time. Remember, measure twice and cut once. First, cut the steel plates. The steel plate comes in one 6″ x 6′ section that must be cut to length. Cut it into 6″ lengths and you quickly produce the 6″ x 6″ plates. Our cuts added up such that the last plate was not exactly 6″ x 6″, but more like 6″ x 4.75″. This isn’t a big deal. We just moved in the bolt pattern on the plate (made it smaller than the 4.5″ square pattern on the attached drawing). You will see later that this doesn’t affect the construction. Next, cut the steel tube to length at 102″. Each 20′ length of tube produces two 102″ beams with 3′ of drop left over. Twelve total beams are needed. Finally, cut the pipe to length according to the attached drawings. Lengths range from 58.5″ to 220″.
If you’ve looked at the attached drawings then you may have noticed our pseudo-cryptic labeling scheme. Take a look at the plan view on page 2, also pictured above. Beams are labeled with letters A-J and enclosed by a triangle. Pipe sections are labeled with numbers 1-15 and enclosed by a circle. We kept this nomenclature throughout the drawing package. On page 6 you can see the drawing for Beam A (upper left hand corner when viewed in landscape). This corresponds to the beam that connects pipe sections 1 and 12 on the corner of the apparatus (see plan view). Drawings for these pipe sections are on pages 16 and 20, respectively. You should now be able to decipher the correct position for each part. Notice that the apparatus requires two iterations of Beam C and Beam G.
I digressed on the labeling scheme because now you need to start labeling your steel pieces. Mark each unfinished beam with its letter. This way when you work on the beam you know exactly which drawing to reference and the exact location and size of holes to be cut. You can also similarly label the pipe, although this is less necessary. Each base plate is identical, so no labeling is required.
Now you’re ready to start drilling/boring holes. This will likely be the most time-consuming part of the operation. We used a milling machine, and I highly recommend it if you have one available. If not, a drill press might do the trick. First, the easy part. Drill the clearance holes for the concrete anchors in the base plates. The drawing specifies four holes per plate. However, we ended up going with four anchors in each corner beam and two anchors in the remaining beams. Therefore, you can get away with drilling four plates with all four holes and the remaining eight plates can get only two holes (on opposite corners). This is an easy operation. It’s just a clearance hole, so drill 9/16″ holes on 4.5″ centers and you’re done. Location isn’t critical here, so don’t spend time precisely locating each hole, center-drilling, and then stepping up drill bits for a nice, clean hole. Just get in there.
Next comes boring holes in the beams. Most of the beams have two holes bored at right angles to each other a few inches apart. Some beams are exceptions to this rule, so play close attention to the attached drawings. Remember that you need two iterations of Beam C and Beam G. While dimensions are given from the top of the beam to the hole’s axis, you want to hold the distance from the bottom of the beam to the hole as constant, so measure from the bottom of the beam. Your resulting dimension will be 102″ minus the dimension given on the drawing. All holes are centered on the 2.5″ width of the steel tube.
Boring holes this large in steel is neither quick nor easy. We started with a ~1/4″ drill bit and stepped up to progressively larger drill bits. We had to finish each hole with a boring bit. You can see a picture of a boring head below. The largest drill bit we had available was 1.5″ diameter. Drill bits up to 2″ in diameter are available, but very expensive. The diameters that you need to bore are listed on the attached drawings. Each hole is 0.020″ oversized on the diameter for its corresponding bar. This ensures the bar will slide in easily, but prevents any noticeable slop. Debur the interior surfaces of the cut to ensure the pipe slides easily. Before cutting, always check that you’re boring the proper size hole in the proper place on the properly labeled beam.
After all the steel is cut the operation gets a little easier… if you know how to weld or have access to a welder. Weld the base plates onto the bottom of each beam, centered. Ensure that the four-hole base plates are welded to the corner beams if you decided to make different base plates for the corner beams. After that welding is complete you must clean the surface rust from the beams and base plates in preparation for painting. Paint will not stick to rust, and raw steel accumulates rust very quickly. I suggest using an electric grinder with a coarse sanding wheel of ~30-65 grit. You don’t have to get all the metal shiny, but it should be smooth and relatively uniform.
After the beams and base plates are welded and cleaned it’s time to prime and paint them. For best results wipe the beam down with acetone, allow the acetone to quickly evaporate, then prime, allow the primer to dry, then paint. You cannot yet paint where the bars will be welded to the beams, else the welding will be difficult or impossible, so leave about three inches of unpainted surface in each direction from the holes in the beam.
After the paint is dry it’s time to assemble the apparatus. Lay out the beams on your floor and insert the corresponding pipes. With ample help from others, stand up each side and progressively link them together. A hammer may be necessary to assist driving the pipe. Finally, you’ll have the complete apparatus assembled and standing on your floor. Be careful during this process. All that steel linked together is quite heavy. We recommend using four people, a minimum of one on each beam, to lift each side into place.
Now it’s time to anchor the pullup station to the floor. Use chalk lines to position the apparatus exactly where you want it. Ensure each beam is reasonably plumb and that the base plates align uniformly. Our floor is a concrete slab, so that is the anchoring method we will cover. We used 0.5″ concrete anchors and mounted them 1.5″ deep in the concrete. You will need a concrete hammer drill and 0.5″ concrete drill bit for this operation. Both can be rented at Home Depot for less than $40 per day. The anchors can also be purchased at Home Depot. Use the directions on the anchors to determine how deep you should drill. Using the base plate clearance holes as a guide, drill your anchor holes. Clean the concrete dust out of the hole using a shop vac and/or compressed air. Drive the anchor into the concrete with a large hammer. Tighten the nut with a 9/16″ wrench. Move to the next hole, rinse, repeat. Anchor the corner beams first, then anchor each intermediate beam.
Now the apparatus is assembled and anchored to the floor. Almost there! Now you need a welder to weld the joints between the pipe and beams. While full welds around each joint are not necessary, that’s what our welder did. We suspect that full welds at each end of each pipe and tack welds at each intermediate joint would be more than sufficient. After the welding is done all that’s left is final painting. Prime and paint the remaining surfaces of the pullup station. You may or may not want to paint the actual pullup bars. Schedule 80 steel pipe does not seem to rust as readily as raw steel. We left the bars unpainted, but did give them a thorough cleaning with sandpaper and acetone.
After much wailing and gnashing of teeth, the pull up station is complete. You can probably tell that the design is capable of modification for almost any bar diameter and height. Play with the design and modify it for your particular needs. By all means, improve on it and let us know how you did it.
I hope this article helps someone who is facing the same challenges in constructing a pullup bar for a CrossFit box. Perhaps you won’t have to work as hard as we did.
Update February 2011: Having worked with the pullup cage for over 15 months now, it’s still holding strong and sturdy as ever. We have discovered one way that we could have made it better. We should have positioned a few of the uprights closer together such that they could hold a barbell like a power rack. This would reduce the 4.5′ of space for each athlete, but we have found that is a little more than necessary anyway. We could have then cross-drilled the uprights to accept J-cups at varying heights to hold a barbell. We could have had several extra barbell racks from our pull up station, but such is the price of learning! Rogue has done something very similar with their Infinity Series of pullup rigs and rack hybrids. I highly recommend modifying our design in this manner if you plan to replicate it.