Shane's R2 Build Log
Body: The Frame
There is no standard frame in the R2Builders group. There have always been a lot of options, each with their own pros and cons. Ultimately which frame you decide to go with depends a lot on what your budget is and how sophisticated you intend your build to be. Frame designs usually have very distinctive names, typically associated in some way with the frame designer. This includes frames with names like T&J, Senna, and JAG. A very modern frame design is the COM-8, which is a beautiful and very expensive anodized aluminum frame.
The frame I used for this build is the A&A frame, designed by Andy Schwartz and Alex Kung (the A's in A&A). It's a budget frame made from PVC. It cost me just over $200 back in 2005. Unfortunately, the A&A folks aren't making it any more.
I put together an assembly tutorial for the A&A frame years ago. So I'm not going into any detail regarding the frame assembly here. You can download that HERE.
The frame was laser cut out of a couple of PVC sheets and shipped in a flat box. It was horrible mess when I first opened the box. Black powder went everywhere. I had to dump the whole kit into the bath tub and rinse everything off. My poor tub...
There were a lot of pieces to this frame. And the whole thing went together kind of like a jigsaw puzzle. You were supposed to glue everything together with pipe glue as you went. Because of that I think most builders ended up assembling this thing twice - once without the glue to see how it all fit together and then a second time with the glue and screws. You were also supposed to use a bunch of threaded rods to add in more structural support.
I glued most things on this frame, but not everything. I think I glued where it counts. I'm also not currently using the threaded rods. It's still pretty sturdy. The test, of course, will be once my little droid ventures out on a few field trips.
The A&A frame came with a few styrene pieces that, once assembled, provided compartment boxes that could be positioned behind the skin panels. I didn't particularly like the looks of them once they were assembled. I also didn't plan on building pop-out panels into my skins. So in the end, I simply threw them out.
One sad truth about PVC is that over the years it becomes brittle. I'm writing this 12 years AFTER I first assembled this frame. The PVC feels noticeably different. I dropped the backdoor from a height of about 2 feet and two of the hinges just snapped off. On another occasion, I was moving R2 after test fitting the legs and shoulders. The bottom ring caught on something and snapped into two pieces. Fortunately, there's a metal fabrication shop nearby and they were able to hook me up with an upgrade.
I'm a little bit worried about what PVC might mean for long term durability. I might actually find myself investing in a COM-8 frame before it's all said and done. I guess we'll see.