Tip: 60 Second Fluting
 

Many builders obsess way too much when it comes to fluting. I haven't seen an RV rib yet that I could not flute to acceptable flatness in a minute or less. Remember, fluting is done "as required." The primary goal is to have the rib holes line up with the mating holes in the skin without bending, forcing or preloading anything. In many if not most cases, fluting is not required between every single hole. What I usually do is lay the rib web side down on a flat surface and take a moment to observe its unique profile. As the second photo illustrates, I start fluting at the bows highest point without lifting the rib off the table. As I squeeze the pliers, I watch the flute work its magic and draw the rib flange toward the table. Right out of the crate, as you probably know by now, some ribs are bowed more than others. With a little practice, you can intuit which flutes should be made deep and those which are made shallower. Observe the last photo. With the rib now flipped over, note that a relative few flutes were actually required to sufficiently flatten it and in a minute or less, that rib is done. BTW, to make things a bit easier, don't forget to FIRST debur the rib before doing your 60 second flute. As with fluting, if it takes more than a minute or so to break the sharp edges and thoroughly debur each and every rib, you are courting mindless tedium and wasting valuable time, but that is another subject altogether.

Rick,
Thanks for the quick lesson on fluting. I've been spending between 3-5 minutes per rib, and thought that was pretty good. I'll try your method next time.

How about 631s?
 

Rick,

Thanks for posting that lesson. Any comments on fluting the 631s (these are the heavy 063 arches on the back of the tipup canopy frame)? Mine were flat as delivered, but the instructions say to increase the flange angle from 88 to 92 degrees (presumably to be parallel to the plexiglas canopy). Once one adds that bend to the flanges, the flatness goes south fast. I eventually was able to make enough flutes to get it somewhat flat, but the edges look like lasagna! Any insights would be appreciated.

greg

Greg,

Your question would be better answered by someone with real time experience working with that particular assembly. I'm a slider type of guy. :)

[quote=Rick6a;207970]I haven't seen an RV rib yet that I could not flute to acceptable flatness in a minute or less.

Rick:

That's assuming the holes are pre-punched. Back in the old days, like 1999, the holes weren't drilled for you, so figuring out where to flute took a little longer.:)

Chris

Chris,

I agree. Back in the day, my 2000 vintage -6A kit, as yours did, included a fluting pattern DWG. Laying out and drilling hole patterns and fluting was far more time consuming and required considerable thought and planning. But that was prior to the computerized era of prepunching we enjoy today. This tip was directed towards the newer kit crowd which arguably represents the dominate segment of the market today.

Scary!! Strangely enough, I have been fluting my wing ribs and this is the EXACT same method that occurred to me.

Couple of things to note. Firstly (on the -10 at least) the bottom profile is less curved than the top so needs less fluting - took me a couple of ribs to work that one out. Secondly, after fluting the flanges bend out again slightly and need to be hand-seamed back to square again.

Must be a million different ways to do these things. Anyway, 20 down, 10 to go..........

Rick,

What's your secret for quickly deburring between the tiny little "fingers" at the ends of the flanges of each rib? Getting those smooth is the part that slowed me down.

Thank you,

Mark

Not Rick, but I got myself a set of small files (about 8, all different profiles) from a model shop. The round one gets into the gaps really well. Then just finish off with a rub of a scotchbrite pad.

first off, this is how I did my fluting, and deburing. For the small areas, a roll of emery cloth worked great, use it like dental floss.