Zenith Aircraft Builders and Flyers
Online Community of Zenith Builders and Flyers
Pre-drilled holes
I'm assembling the 650 horizontal stabilizer. I would like confirmation that "pre-drilled" means the holes are actually the correct final size and ready for riveting without any additional drilling. In other words, I don't need to "open up" any of these pre-drilled holes, right?
I hesitate to conclude that no additional drilling is needed for two reasons.
- It's too nice. Can't be this easy right? That rudder needed hours of measuring and drilling!
- All the holes align and allow for the final A4 or A5 clecos to pass and fasten parts and also A4 or A5 rivets fit thru the holes but my #30 or #20 drill bits appear to be every so slighlty larger in diameter than the pre-drilled holes.
Thus, it seems to me that I could go ahead with riveting without any drilling because everything seems to fit. But the pre-drilled holes are just slightly smaller in diameter than my #30 or #20 drill bits.
Replies to This Discussion
-
Permalink Reply by Don Morrisey on
-
Holes are correct if the rivets fit but you will need to debur the holes, both sides...
-
Permalink Reply by Stephen Larew on
-
Indeed, my next step was to disassemble the stab skeleton to debur and prime. I wanted to be sure I wouldn't need to do a bunch of drilling before disassembling though. Thanks.
-
Permalink Reply by Len Burgess on
-
They're most likely drilled to #40 and will need to be drilled to the correct rivet size. The exact location is drilled, but not to size.
-
-
He said the rivets fit. Pretty much everything Zenith does now is final size or at least much more than in the past
-
-
The holes are definitely larger than #40. For example, A5 rivets already fit in the holes joining the spar and doublers.
-
Permalink Reply by James Neirinck on
-
I'm building a Cruzer and in many places 'pre-drilled' does not mean they are the correct final size. Verify all holes sizes to your drawings and as Don M noted the holes are correct if the rivets called out on the drawing fit in the holes. If they don't fit of course you will need to cleco and drill to correct size as called out on the drawing. I was just riveting up some parts today and one was pre-drilled full size, A5, but the mating part was pre-drilled one size smaller so I had to cleco them together and match drill, then take apart to deburr, cleco back together and then rivet. As for the holes being slightly smaller than your drills if the correct rivet fits in the hole you are good to go. If they don't then you will have to cleco and chase the hole with the correct drill, and then deburr.
-
-
I think we have the same experience with the ZAC parts then. I agree with you, James, and Don that if the correct rivet fits in the pre-drilled hole, then no additional drilling is necessary.
On my horizontal stab skeleton, I checked all the holes against the drawings. The two places I found that needed drilling were:
- Ribs had all A4-sized holes but these needed to be enlarged for the A5 rivets along the spar doublers.
- L angles for tip ribs needed matched drilling. Fortunately the spars had #30 holes pre-drilled and the tip ribs had #40 holes pre-drilled. I simply needed to cleco the tip rib to the spars and clamp on the L angles for drilling.
-
Permalink Reply by Tim Jones on
-
James, I agree with you. On my Cruzer, I had to de-skin my flaperons to drill out A4 rivets "that fit" in the factory drilled holes on the internal skeleton because I failed to note that the plans clearly call them out at size A5. I contacted Roger about this, and he said the holes are now factory enlarged to the final A5.
But I would not and have not going forward assumed that holes are final sized from factory.
Tim
-
-
I agree, if the rivets fit, then they are drilled to the correct size.
New from Zenith:
Classified listing for buying or selling your Zenith building or flying related stuff...
Custom Instrument Panels
for your Zenith:
Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, Dynon and Garmin avionics, and more.
Zenith Homecoming Tee:
Flying On Your Own Wings:
A Complete Guide to Understanding Light Airplane Design, by Chris Heintz
Builder & Pilot Supplies:
Pro Builder Assistance:
Transition training:
Aircraft Spruce & Specialty for all your building and pilot supplies!
How to videos from HomebuiltHELP.com
Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.
© 2024 Created by Zenith.Aero.
Powered by
