To Jig or Not to Jig...

[Terrance Medemblik]

We are moving along nicely on the H.S. but am wondering about whether to use a jig. We consult Dan's C.D. regularly and see that he constructed a jig out of 2x4's. Also Van's seems to be a proponent of jigs. But the -7 is almost all pre-drilled and everything matches up perfectly with little or no room for movement and there doesn't appear to be any calls for a jig in the plans...
Any thoughts?

 

[N908RV]

No jigs required

You don't need a jig.

With the newer matched hole kits, the holes are aligned in three dimensions. All you need to build a matched hole kit is a big flat table surface to work on.

Sometimes, you may find yourself wanting to use a jig or more precisely a holding fixture - such as when assembling the wing tanks, etc.
These help hold the leading edge shape, but other than convenience, there is no need to use a jig for alignment purposes. If the holes don't match, then you did something wrong. Nothing is perfect of course, but generally doesn't get much better than the matched hole technology.

Enjoy building your tail kit - build away!

-Rob

 

[Terrance Medemblik]

To Jig or not to Jig

Thanks Rob...you've confirmed my suspicions. Terrance

 

[Dave Taylor]

To jig or not to jig

Directly from Van's website:

But the biggest improvement ? some might call it revolutionary-- in Standard Kits is the introduction of "matched-hole" components. Made possible by advances in tools and techniques, components are now supplied with all the fastener holes punched ?and punched so accurately that the need for assembly jigs is eliminated. When the holes line up, the component must be straight!

http://www.vansaircraft.com/public/kit-std.htm FMI

 

[jmartinez443]

Don't need one, but it sure helps.

We are moving along nicely on the H.S. but am wondering about whether to use a jig. We consult Dan's C.D. regularly and see that he constructed a jig out of 2x4's. Also Van's seems to be a proponent of jigs. But the -7 is almost all pre-drilled and everything matches up perfectly with little or no room for movement and there doesn't appear to be any calls for a jig in the plans...
Any thoughts?

You don't need one. But it sure helps. You can check out what I did here: http://www.rv8alog.com/empennage/hstab/hs5.htm.

It really helps when if you are working solo. It's also a big help when you rivet half of the skin. The bucker can stand on one side and the riveter on the other. Those HS skins are pretty stubborn and refuse to just lay on the skeleton. Hard as I tried to talk them into it. Here's an easy way to "encourage" the skins to conform: http://www.rv8alog.com/empennage/hstab/hs13.htm.

When you are done with the HS, you can transform the jig into a wing craddle: http://www.rv8alog.com/wings/structural/s2.htm

 

[minute2]

I did not need a jig

I made a jig because I have experience with NC punch press sheetmetal and I know that it not necessarily as perfect as some think. The sheet could slip in the clamps, the setup for the brake could be off etc... However, after all the work I put into building and aligning a jig I discovered that - the stab assembled with less than 0.050 of twist I was/am impressed and was also depressed that my hard work on the jig was a giant waste of time (I could have been riveting).

FYI, My wing (only the left so far) also built up with less than 0.050 of twist !!!! Very impressive considering the tolerance stack involved.

Kerry Stevens
Riveting left wing top skin RV8A

 

[cytoxin]

my money

things can always be done to a closer tolerance. but i will put my money on no you dont NEED a jig. sure you could use one. i will go as far to say that you could drill dimple then assemble. i have in some cases. due to replaced parts. never been a problem. however some people want absolute perfection and i admire that. i just want a straight solid platform. and that is exactly why i built an rv. not saying its the best but is but it is predictable and stable as far as the build process goes. kinda like the small block chevy engine, the worlds most popular hot rodded engine. not because its the best but because its inexpensive, more parts availiable in the after market, lends itself to modification easily, and anyone can build it outside in a sand storm and it'll run for years.