Jerk Box Construction has moved!
These plans have been upgraded and now include step-by-step photos and instructions. To download the new plans, please visit: DIYGARAGEGYM.com.
Start this blog at the bottom. My first post was the beginning of the project, but because its a blog, the last post appears first.
Sunday, January 30, 2011
Sunday, January 23, 2011
Finishing Touches...
The last part of the project was screwing thin pieces of plywood at each end of the boxes to prevent the weight from rolling off. I had two lengths of plywood leftover that when cut in half would serve this purpose perfectly. I also plan on putting a couple of handles on the boxes. I'll probably use rope since I think I have some laying around and that's the inexpensive option compared to buying gate handles.
A few final thoughts to add...
After you've screwed the boxes together with the deck screws but before you lag them together, stack them to make sure they all line up and fit. This is especially important after screwing the tabs in place. That way if something is off you wont have to go back and undo any lag screws. Also, do what you can to buy 16' lengths of 2x12s. Its a long piece of lumber but it is more economical and the spare wood I had in the end saved me from having to buy more. I even had one center support split and was able to replace it and have wood to spare in the end.
Overall I'm pleased with the end product. I only spent $164 which is almost half of some estimates. It took several hours to complete - I ended up building it over the course of a week, working on it here and there after work at night. If I had to guess total time spent I would say between 6 & 8 hours.
Before you begin make sure you read the instructions at Catalyst Athletics and review what the guy at Auburn did. I posted links to both those sources in my first post below. There is valuable information in both sources that may help you with the project.
A few final thoughts to add...
After you've screwed the boxes together with the deck screws but before you lag them together, stack them to make sure they all line up and fit. This is especially important after screwing the tabs in place. That way if something is off you wont have to go back and undo any lag screws. Also, do what you can to buy 16' lengths of 2x12s. Its a long piece of lumber but it is more economical and the spare wood I had in the end saved me from having to buy more. I even had one center support split and was able to replace it and have wood to spare in the end.
Overall I'm pleased with the end product. I only spent $164 which is almost half of some estimates. It took several hours to complete - I ended up building it over the course of a week, working on it here and there after work at night. If I had to guess total time spent I would say between 6 & 8 hours.
Before you begin make sure you read the instructions at Catalyst Athletics and review what the guy at Auburn did. I posted links to both those sources in my first post below. There is valuable information in both sources that may help you with the project.
Building the Platform...
To save money, my original idea was to use a piece of 3/4" plywood covered with three layers of carpet pad and then covered with another piece of 3/4" plywood for my platform. I thought this would be strong enough because of the cushion the pad created, and I wouldn't have to buy any extra lumber to beef it up. I got the carpet pad for free from a local carpet store and even if you did have to buy it the pri
ce is around .17 cents/sq ft for "good enough" pad for this type of project. Really nice carpet pad can cost .90 cents/sq ft but for this project i didn't think that necessary. After constructing the box this way I decided it wasn't sturdy enough though and instead used plywood, 2x12's and then more plywood stacked into a platform. Fortunately for my wallet, I ended up having enough spare 2x12 left to go between the plywood and beef it up sufficiently (still sitting at $164 for the project!!).
After cutting the 3/4" plywood
layers, I screwed 20" piece 2x4's to the bottom of the plywood as tabs that would prevent the platform from bouncing around when the weights are dropped. Then I laid down two 40" 2x12 planks side by side on the first bottom layer of plywood. From there the top piece of plywood is screwed down on the 2x12's.
ce is around .17 cents/sq ft for "good enough" pad for this type of project. Really nice carpet pad can cost .90 cents/sq ft but for this project i didn't think that necessary. After constructing the box this way I decided it wasn't sturdy enough though and instead used plywood, 2x12's and then more plywood stacked into a platform. Fortunately for my wallet, I ended up having enough spare 2x12 left to go between the plywood and beef it up sufficiently (still sitting at $164 for the project!!).After cutting the 3/4" plywood
layers, I screwed 20" piece 2x4's to the bottom of the plywood as tabs that would prevent the platform from bouncing around when the weights are dropped. Then I laid down two 40" 2x12 planks side by side on the first bottom layer of plywood. From there the top piece of plywood is screwed down on the 2x12's.
Building Begins...
The dimensions I decided to go with were 40" lengths with 20" center supports. So the final dimensions were 40"x 24". The Catalyst Athletics boxes were 48" x 24" and the Auburn guy was 40" x 20". I thought the 48" length boxes were unnecessarily long and meant heavier boxes and needing more lumber.I made all my 2x12 cuts first. Each box had two 40" lengths and four 20" center supports. The next step was putting the frames together. I used the 3" deck screws at first to hold the frames together. It is probably worth noting that I bought "star drive" screws as opposed to phillips head. In my experience phillips head screws strip way too easy. I also pre-drilled all of the holes before screwing the deck srews in and then used liquid nails to help hold things together. I placed two deck screws in the center of each board so the lumber would not twist or go off center later on. After each frame was made using deck
screws, I pre-drilled the holes for the lag screws. I decided to go with a lag screw at the top and the bottom of each board as opposed to three. The idea was to cut cost by not having to buy as many .29 cent lag screws, plus I believe the strength of the deck screws plus the lag screws is plenty to withstand the force of weights dropping from overhead. the structure itself once put together is what will take the brunt of the dropped weight.The next step was the center support pieces. I marked 13" from each side of the box, drew a line and place the 20" 2x12 piece on the inside of the line. From there it was just making sure I was consistent with my measurements to ensure each box and all its supports would line up precisely on top of each box.
Next I used the 2x4 lumber to make the tabs so the boxes stay on top of each other. I centered them inside the boxes so i would have a little wiggle room when placing them on top of each other. Each tab sticks up an inch from the box.
These tabs are what I ended up having to shave a little with a hand planer. My poor measuring skills or slightly off lumber caused this (probably my poor carpentry skills). In the end they ended up stacking just fine on top of each other.
Tools...
This project does require the use of some basic tools that most people will already have...
I also used a Bosch 18v drill for conveniences sake so I wouldn't have to switch out bits as often. The use of an electric drill is a must for the lag screws. Another tool I ended up using was a hand planer and sander - at the end I had to shave a few edges to make everything fit right. This was probably due to me making un-precise cuts or lumber that wasn't quite the exact size as what was claimed when purchased. Not having true cut lumber is a problem - a 2x12 isn't really a 2x12, and each 2x12 is not the same as the next. I did my best to examine each piece of lumber before I bought it but evidently I wasn't as careful as I should have been.
- Circular saw
- Electric powered drill
- Tape measure
- T square
- Saw horses
I also used a Bosch 18v drill for conveniences sake so I wouldn't have to switch out bits as often. The use of an electric drill is a must for the lag screws. Another tool I ended up using was a hand planer and sander - at the end I had to shave a few edges to make everything fit right. This was probably due to me making un-precise cuts or lumber that wasn't quite the exact size as what was claimed when purchased. Not having true cut lumber is a problem - a 2x12 isn't really a 2x12, and each 2x12 is not the same as the next. I did my best to examine each piece of lumber before I bought it but evidently I wasn't as careful as I should have been.
Buying Materials...
Looking online at different pictures I saw a lot of different ways to go about building my jerk boxes. Most designs included stacked boxes made of 2x8's, 2x10's, or 2x12's. One design included 4x4's placed vertically as piers with a platform on top (http://carpeferrum.blogspot.com/). I decided to go with what the pictures at California Strength showed and use three stacks of 2x12's and a what looks like a about a 4" platform built up with plywood and 2xsomethings. If that's what Donny Shankle, Caleb Ward and Jon North use then it would be good enough for me. So here's my materials list:
- Six 2x12x16 untreated lumber
- One Sheet 3/4" plywood
- Three 2x4 untreated lumber
- One box 2.5" deck screws
- 100 3" lag screws
- One box 3" deck screws
- Two tubes Liquid Nails
Project Jerk Box...
I've thought for a while now that my weightlifting progress has been at least somewhat hindered by not training jerks and other overhead work enough. The solution was building jerk blocks, but from everything I read they were expensive to build which is a problem with a limited budget. My primary sources of how to build them came from Catalyst Athletcis (http://cathletics.com/articles/article.php?articleID=52), a guy at Auburn that built them (http://www.eng.auburn.edu/~simonrl/wl/jerkboxes/), California Strength (http://www.eng.auburn.edu/~simonrl/wl/jerkboxes/), and some pictures at USA Weightlifting (http://weightlifting.teamusa.org/). I started pricing the materials needed for the project and the price tag of $300 claimed by Gregg Everett and Catalyst Athletcis seemed a little high compared to what i was coming up with. So my goal in all of this was to build quality jerk boxes that would hold up and last years but not cost a hefty $300. Then I figured if the price tag was holding me back from building them, then there were probably a lot of other people out there holding back as well. This blog was created to show that quality jerk boxes can be built for almost half the cost of what others have done it for.
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