I'm getting back into more gymnastics-styled fitness and decided to fabricate some training equipment. Practicing circles on a pommel horse is a great way to workout groups of muscles dynamically. Since I cannot afford an actual pommel, or even the practice "mushrooms" I figured I'd try and make one on my own. I scoured the internet for tutorials and wasn't able to find any so I just winged it. Feel free to loosely follow my instructions and add, subtract or modify as you see fit. I'm sure there's an easier, more effective and probably cheaper way to make these and I'd like to know how to improve upon it, so feel free to share your input.
An adequately sharpened pencil
Piece of string at least 16" long
Staple Gun and staples
Box of 3" and 1 5/8" screws
Circular saw or Chop saw
Sanding device (I used a Metabo Compact sander with a rough sanding stone and 220 grit sandpaper)
Two sheets of 3/4" plywood 24" x 24" (~$6 from Home Depot)
4' of 4" x 4" (7' piece ~$7 from Home Depot)
12' of 2" x 4" (7' pieces ~$6 from Home Depot)
24' of 2" x 6" (8' pieces ~$6 from Home Depot)
12' x 1' of outdoor carpet (~$19 from Lowe's)
36" x 9' of rubber carpet padding (would've been $38 from Lowe's, but it had a couple holes and I was given a half-off discount, schyeah!)
4' x 4' of vinyl fabric (faux leather, you can get it cheap by the yard from a fabric distributor)
Since I already had all the tools I needed except for some screws, this instructable cost me approximately $90, which is by no means cheap, but if you search for them online they sell for anywhere from $250-$400.
Note: When completely finished this sucker weighs....a lot. I would assemble it where you plan to use it, and if you absolutely need to move it, turn it on its side and roll it. I am not responsible for any bodily harm including hernia, constipation, rug burns, or shattered expectations resulting from performing the outlined steps or while using the mushroom. Play safe.
Step 1: Cut the Base and Top Out of Plywood
1. Tie a piece of string to your pencil.
2. Measure the length of the string to 12".
3. Use a thumb tack to fasten the string to the center of the piece of plywood.
4. Pull the string taught while holding the pencil and draw a circle on the plywood.
5. Using the jigsaw, cut the freshly drawn circle from the plywood.
6. Repeat steps 1-5 for the remaining piece of plywood.
Step 2: Cut the Support Legs and Attach Them to Base and Top.
1. Using the chopsaw or circular saw, cut four 12" long pieces of 4" x 4"
2. This part is purely arbitrary, feel free to choose your own placement. I went with 4" from the edge for each leg and I tried to have them as evenly spaced as possible.
3. Using your 3" screws, attach the legs to the base. I used 4 screws/leg.
4. Place the top so it lines up with the base and screw the top to the legs the same as you did the base.
Note: In the last picture I attached a couple shims to one leg that was slightly shorter than the rest. If you want a level mushroom you can do the same, or not.
Step 3: Cut and Attach All Outside Legs
1. Cut twelve 12" tall pieces of 2 x 4"
2. These go on the outside as a second level of support. Try to place them evenly apart, whether by eye or measuring and use to 1 5/8" screws to attach them to the top, two more screws for the bottom.
Note: I placed the legs approximately 1/2" from the edge of the base and top so that when you put the rug on later it will sit flush, rather than stick out.
Step 4: Cut and Shape the Mushroom
Bare with me, here's where it gets complicated and, like an idiot, I forgot to take lots of pictures.
1. Cut three piece of 2" x 6" 25" long. Place it on top of the base, centered for reference.
2. Now working from the middle outward measure the length of the diameter of the circle and add an additional inch. Use that measurement to cut from the 2" x 6." As you work your way out each piece should gradually get shorter. My bad on not writing down the measurements.
3. Lay the middle 2" x 6" down horizontally and measure up 3" and mark a line, do the same on the other side. Now, lay the base on top of the 2" x 6" and trace the circular arch centered on the 2" x 6." Cut the shape using your jigsaw. This will serve as the basis for our mushroom shape later.
5. Once you have all the 2" x 6"s cut, use your 3" screws to attach each piece to the one next to it. The objective is to have the 2" x 6"s as a single piece that you can pick up without them moving.
6. place the giant amalgam of 2" x 6"s on the ground, place the mushroom on top of the 2" x 6"s and trace the circle onto the 2" x 6"s.
7. Using the Sawsall cut the circle shape out of the 2" x 6"s. BE CAREFUL to avoid cutting into any screws that are holding the pieces of 2" x 6"s together, you might have to move screws as you cut.
8. Now that you have the same circular shape of the 2" x 6"s to match the base you can attach it to the base by using your 3" screws and screwing them from the bottom of the top piece of plywood into the bottom of the 2" x 6"s.
9. Now that the 2" x 6"s are fastened to the base, use your Sawsall cut the basic dome shape out of the mushroom, by using the already cut middle piece as a guide. Since the middle piece was only marked for an arch on one side you will need to carve the arch on the opposite side by eye. But fear not, once the first arch is done, matching the second arch to it is easy sauce.
10. Great! Now the hard part is over. Put a sanding stone on your sander and get ready to sand your hineys off, sand. Work back and forth gradually smoothing out both the arch on top and the outer circular shape of the walls of the mushroom. When you're satisfied with the shape stop.
Step 5: Attach the Padding and Vinyl Covering to the Mushroom
1. Cut your rubber padding into 3' x 3' squares and staple it to the mushroom.
Note: This is easier than it sounds because the circular will cause the padding to bunch up rather than lay flat. To avoid this cut slits where the padding tends to bunch and restretch. Continue to cut away bulges until it lays as flat as you want it to.
2. After you have the first layer stapled to the mushroom you will do the same thing with the second and third layers of padding, BUT you need to tape them to the layer below it because the staples are not long enough to reach the wood. I found the best way to tape the layer of padding down is by starting the tape on the leg and pulling it tight across the mushroom to the leg on the opposite side.
3. Continue taping from leg to leg until the padding is flat and even.
4. Tape down another layer of padding so that you have three layers total.
5. Now cut the vinyl 3' x 3' and use the staple gun to staple it down to each leg. Try and keep it as taught as possible and fold the bulges to flatten them out where they appear.
Step 6: Attach Carpet to Legs
1. Your carpet should already be cut to 12" tall by 12', so all you need to do is turn the mushroom on its side and screw the carpet to one of the 2" x 4" legs using your 1 5/8" screws.
2. Now that the carpet is started, roll the mushroom slowly on its side while flattening the carpet to the legs. Attach screws along the top where needed. I placed them around every third leg.
3. After the top is done, do the same for the bottom.
4. Turn the mushroom back up and do a victory dance.
Step 7: Resources
If you're itching to learn circles here's an intro video on the basics behind getting them down:
Knowing the mechanics are great, but that won't get you anywhere without the proper conditioning, which means shoulder strength primarily, but also bicep, tricep and abs. According to Coach Sommer of GymnasticBodies, one of the best exercises you can do to build shoulder strength is Handstand Wall Runs. Check them out here: http://www.youtube.com/watch?v=1okSA32sFWs&feature=channel
He suggests that you do them for ten minutes twice a week, so I tried it and was barely able to do five. Then I realized, I can't even hold a handstand against a wall for more than a minute. So clearly, I have some basic training to do before I get to that caliber. I'm guessing after you're able to hold your weight on your hands for that long while alternating arms you'll be able to support the weight of your lower body fairly easily while doing circles.
Another neat training trick I found are "bucket circles." http://www.youtube.com/watch?v=EoToS8bCOlc&feature=related
For more training videos check out the GymnasticBodies Youtube page: