Another Large Revolve on a Budget

[jstroming]

Just out of curiosity, how do you trace and cut out a circle that big? Some kind of a wooden arm bolted to the center of the deck, then a pen on the end that rotates around center? Cut it with a jig saw?

 

[scrogers]

Just out of curiosity, how do you trace and cut out a circle that big? Some kind of a wooden arm bolted to the center of the deck, then a pen on the end that rotates around center? Cut it with a jig saw?

You basically hit the nail on the head. I first laid out the two layers of ply on top of each other in a 24ft x 24ft square, then put a few screws in every sheet just to keep it together during the process. I then took a 14ft piece of strapping and drilled a hole just a little smaller than a sharpie, and screwed it in the exact center of the square. Then spun it. A couple of sharpies later... I had a rather perfect circle.

I then took a jig saw (or really, two) and starting cutting (one from one direction one from another). We had helpers slide 2x4's under the edges as we went around the circle so the blade didn't collide with the floor while cutting. It admittedly took a while since I wanted an accurate cut, which is why I added a second person and saw.

I actually snagged a some pics of the cutting, but we'd already made the circle when these were taken...

 

[jstroming]

Very nice. I own a 4x8 CNC router so it could make a pretty accurate turntable in no time! But interesting how to make it without one.

 

[scrogers]

Very nice. I own a 4x8 CNC router so it could make a pretty accurate turntable in no time! But interesting how to make it without one.

Oh nice! Yeah, we have a decent shop and tools etc, but afraid not quite a CNC router table... I imagine you could make the outside pieces of the disk very accurately with the right math. Overall, while certainly not perfect, the jig saw and 2x4 method worked out pretty well for us. Thanks!

 

[jwh78]

I'm so fascinated by this. VERY cool build!

 

[Scott Growdon]

Question: What was your final cost for the revolve? Looks great!

 

[scrogers]

Question: What was your final cost for the revolve? Looks great!

Thanks for the interest Scott. I just went back to look at some of the numbers-

All in, I was right about $2750 for this project, BUT- I already had some parts from a much smaller prior turntable project years ago. The casters are the big thing, and I wanted good quality, quiet casters, which aren't cheap. I already had about 50 of them, but, as this saga unfolded, I needed many more (nearly another 70). I also had all the rope leftover from a rigging project a few years ago. It also should be noted that there is a considerable amount of time and labor, but I sorta see both of those as "free."

So, if I was starting this exact project with nothing, I'd estimate the costs closer to $4000(+).

There are ways to make it cheaper, but I think it would be at the cost of quality of the end product, and in the end, I was also marketing this as a longer term investment since it'd all be stored for future use. You could use cheaper 4in casters, and I actually even experimented with some knock-off "blue" casters in the beginning. I actually couldn't believe how noisy they were and poorly they rolled. There was just no comparison to the Blickle casters, other than they looked similar. Also, that much AC ply isn't cheap, but again, you want a really nice smooth rolling surface, so I needed AC for at least one layer.

The quotes I was getting to rent similar revolves weren't terrible by the week... but my people wanted the unit for 5+ weeks and with delivery etc, those costs became extremely high, not to mention I lose all the long-term investment into a short-term rental.

Looking back on it all, it was a great project and a good experience. Plenty of stress and hiccups along the way, but in the end, it was very successful.