SonexBuilders.net

Hi Folks
New to the forum and close to pulling the trigger on the either a Sonex or Waiex build. Nice to find such a great community!

I need your help understanding the latest Sonex kits, specifically the extent of their matched hole CNC capability.

Sonex says that of approximately August 2012, the Sonex and Waiex complete airframe kits employ CNC match drilled holds and approximately 115+ Matched hole formed parts. I don't have a sense of how complete this is, say compare to the completeness of the Van's RV-12 kit.

http://www.sonexaircraft.com/kits/match ... parts.html

Questions:
1) With the 'new' matched hole formed parts, do the holes still need to be drilled out to size for riveting?
2) For a given assembly of matched holes, is that to say ALL the holes (i.e. rib to skin) are already CNC punched?
3) Do the factory matched holes required deburr and finish?

Lastly- Assuming I purchase the Machined Angle Component Kit, how many parts can I expect that I will still need to fabricate?

Thanks in advance for any help you can provide :)

Philip

Philip,

Welcome to the forum! I represent a vote for the Waiex. Here are my answers:
1) With the 'new' matched hole formed parts, do the holes still need to be drilled out to size for riveting?
Answer: All the pilot holes are 3/32". These need to be run up to #30 for riveting. Some of the thick stuff, i.e. 1/8" angle parts generally need the 3/32" brought up to #40 for the clecos to happily go through them.

2) For a given assembly of matched holes, is that to say ALL the holes (i.e. rib to skin) are already CNC punched?
Answer: Much of the matched hole stuff has the 3/32" holes in both parts, so you cleco together and drill out to #30. Some places you are required to transfer one set of CNC holes to another part. Examples I can think of:
a. side and bottom skins to longerons
b. turtledeck skins to formers
c. machined angle parts to side skins
d. wing skins to ribs (I am not there yet!)
I would estimate about 75% straight matched hole, 25% transfer holes from the CNC pilots to the other piece.

3) Do the factory matched holes required deburr and finish?
Answer: Yes. They need to be drilled up, then deburred.

I have seen an RV12 up close, but have no idea how it compares to the Sonex as far as building. I am sure they are good airplanes.

I have the machined angle kit, the parts quality is excellent. Generally I don't need to do any edge finishing on those parts. That says a lot, as I used to work in Ground Test at Sikorsky, where we were all about fatigue. On the fuselage I have probably had to make 2 or 3 parts according to plans, typically shims or flat stock with two holes in it. I have made some more parts that I screwed up, or was unhappy with. So far I estimate less than 10 parts.

Overall I give the CNC holes in the Waiex (and the kit in general) an A-. I have found a few spots where the holes were not perfect, as have others. I am very happy with the kit in general though.

You can check out my build here:
http://www.sonexbuilders.net/viewtopic.php?f=39&t=578

I bought the Waiex to have an airplane to build with my 13 year old. He was 12 when we started. No regrets! It is a good kit.

Hi Phillip! Bryan did a great job addressing your questions and I don't have much to add. You did mention specifically rib to skin, and the answer is that the wing ribs do NOT have any pre-punched holes in them. The method is to "blue line" the ribs down the center, and drill pilot holes via the CNC holes in the skins during fitment. Also true as Bryan mentioned for the turtledeck formers, and a few other parts.

ALL holes in the kit will require updrilling and deburring. Every, single, hole will be up-drilled and deburred prior to riveting. I'm sure this is true for any airframe kit.

A good quality (high speed air) drill, a hole deburring tool and a scotchbrite wheel mounted on a grinder will pretty much take care of all of the issues you raised with your initial 3 questions. What other questions do you have?

Bryan and Ryan,
Excellent replies ! Very helpful!

I am sure to have more questions as I move forward. Not related to this thread would be how soon I would have to determine what engine and instruments I would install. I assume the engine could be decided some time later, but how long would you estimate the instrument selection should be locked down?

Welcome!

The Engine actually needs to be determined before instruments (due to the need to get an engine mount). Given the pace of improvement and pricing changes in modern avionics, I suggest waiting until the latest possible date before buying anything that's going to actually go in your panel**. And when it comes to the avionics/instruments themselves, you're probably going to want to test-fit everything before you wire it up - so again there's no reason to start buying stuff and implementing it before the actual cockpit is ready to have the panel built/mounted. When you get close to the end of the build there are inevitably lots of little details to tend to, so even if you *do* wind up stuck on a panel issue for a week or two, you can always use that time to make fairings, fittings, work on the engine, etc.

Take care,

--Noel

**Case in point: I bought my kit in 2010 and thought I was going to build the Sonex in 2-3 years... Then I got work promotions into management (stress and time commitments!) and found a wife... So things slowed down a little. ;-) If I'd bought avionics even in 2012 I would have missed out on newer items like the MGL Xtreme or the new Discovery Lite! I've put 480 hours in at this point and have the tail and wings essentially completed (note that I bought before the matched-hole improvements, and I'm making my Sonex with all-flush-rivets and wiring for lights in the wings; so I've added a fair bit of extra work for myself). I anticipate working on the aft fuselage this spring and the cockpit area this fall. So I'm probably not ordering avionics until Christmas! :-)

Noel makes an excellent point. A good buddy of mine and his dad built an RV4. Back in 1990 we flew out to Oshkosh, them in a guy's bonanza, me in a guy's cherokee 6. They bought a nice new Northstar Loran. Ten years later when they flew, there was GPS aplenty. Ten years ago or so they decomissioned Loran.

Phillip, , as mentioned the engine selection is best made early for the sole reason of having the correct mount included in the engine kit. That said, I was 600 hour into my project before actually attaching the mount, so that's when I locked in the engine decision.

As for instruments, I recently designed my instrument panel and ordered instruments, about 800 hours into my project. There was no need for me to make decisions before now, with one exception. I wanted to have a "lift reserve" indicator which uses a probe in my left wing, so that decision was made during my wing build.

Wow-- the quality of folks and replies on this forum is great. Noting that the engine choice precedes the avionics decision (makes a lot of sense) I am ready to have an engine 'conversation' now. I will post that query on a separate thread in the engines area. Thanks again everyone.