Van's Engineering Presentation - Laser Cut Parts

[@1hornet1]

I never doubted your testing and analysis from the first report. Sadly, that is not my concern despite having plenty of laser parts. I created a financial plan and timeline to build an RV-8 as I am just a blue collar guy. It was great and very doable. Since the moment I started ordering kits and tools, all of the costs skyrocketed to the point that this is just a rich person hobby now. The amount my project inflated is horrific and I have to give it up. I hope you get through this and can continue to provide awesome planes to people that can afford them. Good luck.

[@John-nc4bl]

Kit planes are too expensive. Buy a good used Cessna and fix it up nice.

[@1hornet1]

@John-nc4bl I have a Grumman Cheetah thankfully. My future hopes and dreams were all based on the capabilities of an RV though. LOL

[@usaerospace6707]

Build a Wittman Tailwind or some other plans built aircraft.

[@usaerospace6707]

On second thought. Make it a Thorp T-18.

[@davebeemer2834]

Man I'm so sorry! Have you considered a GoFundMe page? I've cancelled my QB wings saving $13,300 but mostly I discovered I like building and tank sealant?

[@toohip1959]

I appreciate the time, effort, expertise, and analysis of the testing Van's has put into ensuring their aircraft are safe AND explaining that to the builders and (like me) future builders. Well done.

[@kentcolgan6139]

With one caveat, this is what I needed to hear and see. As an RV9 builder (in progress) and a mechanical engineer for 40 years, I’m comfortable with your conclusions and recommendations. I expected that manufactured cracks would propagate. It’s a beautiful thing that the test results and analyses demonstrated otherwise. I’m impressed with the rigor and level of conservatism. It has taken a long time and I’ve been frustrated with the long periods of radio silence, but things are looking up. CAVEAT: The presentation didn’t address (I may have missed it) un-dimpled joints. In the absence of the compressive hoop stress near the edge of the hole (due to the absence of a dimple), the discontinuities in the LCP holes will not be isolated from the alternating stress of flight (or fatigue testing). Given some of the gross discontinuities that have been seen in delivered LCPs, I’d expect a much shorter fatigue life in LCPs than in punched holes in un-dimpled joints. Would love for Van’s to explain why this is not a problem.

[@ersinc9080]

I always had confidence in Vans engineering. This makes that confidence even more!

[@hexad3c1m4l]

Brilliant, an amazing analysis and presentation!

[@SI-lg2vp]

Amazing the engineering and design in every airplane.

[@damongulick4306]

Thanks so much for all your efforts and transparency!!! I really look forward to purchasing one of your kits/planes and hope to see your RV15 when it is ready!!!!

[@XXfea]

You guys are THE BEST

[@djquick]

😂😂😂

[@JRSoiseth59]

Excellent engineering work, really textbook approach. It would be interesting to know what the results would be with similar tests on professionally built airplanes. As a RV7 builder that finished the empennage kit in June, and that now knows that my two rear horizontal spars are laser drilled, I believe that drilling out the umpteen rivets to replace the spars would likely put more risk in the structural integrity than keeping the laser drilled versions in place. I'm sure the structure will outlive me. Looking forward to the fuselage kit!!

[@norwichcadet]

Have you guys thought about publishing this data as a white paper for the rest of the industry? The benefits or pitfalls of punched vs. laser cut parts?

[@rallyit671]

Thanks for publishing. Very informative and hopefully it can guide well informed engineering and business decisions now and into the future. With minimum estimated 13k airframe hours with half aero half training, maybe you can sell LCP kits heavily discounted and recoup some funds instead of a full inventory write off.

[@MatthewRuno]

Thank you!

[@pilotrhino]

Thanks for the expansion on your findings. I felt very confident after hearing your data and approach at Oshkosh this year.

[@usaerospace6707]

This should have been done from the get go. Quality control was a failure. Its better to catch things before they happen. Not after they happen.

[@DaveOfAllMasterOfNone]

Can you use magnaflux on non-ferrous metals? Sure would make it easier to see the severity of those cracks because sometimes cracks are damn near invisible to the naked eye.

[@klw141]

No, MagnaFLux only works on magnetic materials (iron), for Al you need to use die penetrant, Xray or Ultrasound

[@dlanderson2559]

Eddy current works on AL.

[@WiekingderViking]

Dye penetrant testing

[@WiekingderViking]

Have you considered contacting Fatigue Technology in WA state?

[@mathieusan]

Have you considered using water-jet cutter instead? This would avoid any heat effects and still keep production speed. An additional process would be to cut (drill, etc) the hole slightly smaller, and do a cold expansion with a mandrel tool in order to leave compressive residual stress on the edge of the hole, tremendously increasing fatigue life. Just ideas.

[@johnpiper82]

Well the RV3 is still alive with no structural failures, other than an Ad on the main spar, just like all the other airplane manufacturers 😊

[@haroldchapman8499]

Can you guys share the PowerPoint slides?

[@electoplater]

If you cut holes with a laser the thermal difference between the cool areas and hot areas cause and develop stress leads to cracking ,

[@davebeemer2834]

Bottom line, the stress area around a rivet is NOT the crack in the hole but the bend in the outer rim of the dimple. So... All of this is a lot to do about nothing but yet Van's stopped shipping LC parts. Van's also identified high load, high stress and critical parts to help builders make decisions. I've identified 72 LC parts in my fuselage kit of which 32 are red, yellow or purple. Nearly all the parts I'm replacing are visually inferior. It's interesting to note many of my LC parts are absolutely perfect, especially the thicker ones. However, some are just crap when compared to punched. How these parts passed QC is mindboggling. This is adding about $2,000 and 30 hours to my build. PS Please do not change the order of the parts list again or further reduce the font size...

[@damongulick4306]

I have made this comment in other locations, but are locations a possible solution or additional level safety. One the panelists on the kit Planes round table appeared to indicated that adhesives would almost make the rivets redundant. Some have commented that adhesives would make replacing parts difficult and add significant difficulty. It does not seem to me that two part or other possible forms of adhesives would be that more difficult and replacing structural parts is hopefully very uncommon. Overall that adhesives provided more than enough benefits relative to the few negatives.

[@builttofly3686]

So now that you've filed bankruptcy and have protection from the court, and the ability to void original agreements and contracts, all of a sudden laser cutting is fine! lol!!

[@hyperiondan]

Am I the only person wondering where that 1 hole at 150lb is at?

[@rianjohnson7484]

Top and bottom forward most hole on the main wing rib second in from the root rib.

[@djquick]

Vans - laser cut parts are safe! Also Vans - were no longer laser cutting parts. 😂😂😂

[@deeremeyer1749]

Punched hole shops had more work than they could keep up with. Laser cutter shops were twiddling their thumbs. Hmmm. Just a coincidence I'm sure. Yeah. Right. Lasers do not cut HOLES. They cut OPENINGS. Holes are MADE. Punching them is a "constructive" process because the dies CONTROL THE PROCESS. Lasers HEAT THE BASE METAL and an AIR JET does the actuall cutting. Much like Oxy-Acetylene cutting only the laser process uses atmospheric air which is not "PURE" like the oxygen cutting "jet". And there is no PRECISE CONTROL with a laser under "computer control" because current, air flow and "feed speeds" are not precisely and "infinitely" VARIABLE. No other shop CUSTOMER is using your dies IF your "engineering" is actually PRECISE. EVERY OTHER CUSTOMER THAT COMES IN THE DOOR USES "YOUR" TOOLS LASER CUTTING AND THERE ARE "CONSUMABLES" THAT ARE REPLACED ON A "TIME" BASIS VS. A "VOLUME" BASIS. MEANING YOUR "ENGINEERING" IS SUBJECT TO HOW LONG THEY HAVE BÈEN IN USE ON OTHER CUSTOMER WORK NOT HOW "WORN OUT" THEY ARE.

[@BartHull]

The end of Van's aircraft.