Learn how to fix your dings... it's FUN

[dietlin]

OK, look out for the drip...

[PonoBill]

It's pretty irritating that companies use those pieces of crap. Machining a two piece box is a simpler thing, you can do it without specialized tooling or a tool change, but it's really not that much easier or faster. A couple of bucks cheaper, that's all.

Ages ago I programmed a buddy's CNC mill to make a one-piece mast box. I was going to cast plugs and machine the slots--it's easier than you'd think, just four passes and one tool change. one vertical slot and then one T-slot starting with the head at 50 degrees and following the cut down to 90 (the path the slider plate follows), cut to the end then reverse and cut to the other end, reverse, stop the tool, move to the end of the 50 degree cut, rotate to 50 and extract. Then this guy showed me a chinook box and I quit fiddling. At the time the only criticism I recall was that I could see they didn't stop the tool to extract, and you could see a mark where the tool didn't quite clear the bottom of the 50 degree cut so it lopped off the end as the head rotated. For all I know that might be intentional. I never made one, it might make it easier for the slider plate to be extracted.

Even other one piece fin boxes seem more than a bit fragile to me. Chinooks are flat out stout, but not particularly heavy. I wish they didn't get so carried away with the channels and grooves to "hold" the box in better. I don't think it does anything. I sand the hell out of the boxes with 60 grit, getting as far into the channels as I can. That makes the boxes stick better to the epoxy. When I get my beadblaster running again I'm going to load it up with some nasty carbide grit and blast a lifetime supply of fin boxes, leash plugs and vents. I have a box of the stuff that I haven't used in twenty years. Finally a use for it.