DR-1 (Sands): Builders Group

[Jeff Brooks]

Originally Posted by acwelder

What if the builder is using his own plans, derived from years of research studying a 90 year old German design? How does one get a design like this certified? Or do they allow a similar design a special waiver?

Don't you have to get your project inspected at certain stages of the build?

As far as using your own design, and research ... the answer is to load test the part to see if it can withstand the minium load for the design. That is probably why Achim did so much testing.

As far as getting a project inspected during construction, the FAA does not do this anymore. They want to see the finished product, a log book and paperwork. Any inspections done during construction are usually by an EAA technician and only if you want them. It helps get insurance!

[CORVUS]

Hi,

Thanks ACwelder for all those links. I just ordered the book on Steel Tube Fuselage Construction. I have all of the EAA books and a few others.

Very interesting article on Tig welding. After spending the last five years learning how to gas weld restoring an old WWII jeep I'm reluctant to switch to TIG welding but it sure sounds like a nice way to go. I know there's a lot of old timers that turn down their nose at Tig welding AC fuselages but it has been around for a while and as far as I know there have been no bulletins issued by the FAA restricting it's use.

I noticed on the Sands drawings he is saying to use Heli-Arc welding on a lot of the landing gear. What is the direction you guys are taking on this. Are you going to try and do it yourself or farm it out ?

Lou

[womenfly2]

Originally Posted by CORVUS

EDITED ....I noticed on the Sands drawings he is saying to use Heli-Arc welding on a lot of the landing gear. What is the direction you guys are taking on this. Are you going to try and do it yourself or farm it out ?

Lou

Point of interest .....

Back in the 70's, I worked for Linde welding in Florence SC, which was a division of Union Carbide. They produced gases, associated welding equipment, and did a lot of cryogenic work. Heliarc was the trade name of their GTAW (TIG) machines that was initially developed for welding aluminum, they used helium as the shielding gas. That trade name stuck to the process for a long time and still is use even now, some of the people who grew up during that period still call the process Heliarc and pass its name on.

I helped design and worked on a lot of the equipment in use today, TIG, MIG, Oxy-Acet torches and Plasma.

[baldeagle]

[quote=acwelder;369647]No one in the USA carries much if any aircraft grade 4130. Probably a European source, but I haven't located one yet.[quote]

You must mean in metric sizes? Inch sizes are available from a number of sources.

[Dogtail2]

Originally Posted by CORVUS

I noticed on the Sands drawings he is saying to use Heli-Arc welding on a lot of the landing gear. What is the direction you guys are taking on this. Are you going to try and do it yourself or farm it out ?

Lou

Lou

What WF2 said. For Heli-Arc read TIG.

Today I put the control cables in the top wing and also did the inter rib cotton tapes. This wing is now about finished and ready for covering.

[acwelder]

Originally Posted by baldeagle

You must mean in metric sizes? Inch sizes are available from a number of sources.

The topic was metric. Yes I meant metric.

I fixed it. Thx

[acwelder]

Originally Posted by CORVUS

I know there's a lot of old timers that turn down their nose at Tig welding AC fuselages but it has been around for a while and as far as I know there have been no bulletins issued by the FAA restricting it's use.

Lou

Restricting it's use????????

Why would the EAA give workshops every year for a possibly "restricted" practice?

TIG was invented originally for the very purpose of aircraft construction. "The TIG or GTAW, process was invented by the welding department at Northrop Aircraft Company in 1939-1941." See: TEC Torch Tig Welding Equipment

TIG welding is not some recent invention.

Modern manufactured aircraft are TIG welded.

[gipsymoth236k]

acwelder:

Thanks, I just ordered the "Construction of Tubular Steel Fuselages" book, and appreciate those other links to articles, books, and DVDs. I already have all the EAA books as well.

I learned to gas weld many years ago, but never applied it to aircraft tubing other than for practice. I like the idea of minimal distortion in the construction of the Fokker's airframe tubing, and it looks like TIG is a good choice for this purpose. I don't really care if gas welding was original, I want minimal distortion!

Not considering high cost as a factor, if I were to buy a Tig welder today, can you recommend which one is best for this type of airframe welding? I have found that "one usually gets what one pays for" so I want the best available for this purpose.

So, any help with a TIG welder of choice?

Thanks, Gary Sewall

[acwelder]

Originally Posted by gipsymoth236k

acwelder:
So, any help with a TIG welder of choice?
Thanks, Gary Sewall

The Lincoln Precision TIG 185 is a good machine for our purpose. Whole web site dedicated to it. Lincoln Electric - Precision TIG 185 Unfortunately it is no longer available. Good used machines can be had though. The new Lincoln Precision TIG 225 is the replacement for the old 185. The 225 is what I use.

Precision TIG 225

[gipsymoth236k]

acwelder,

Thanks! Hey, I think my flying buddy has one of those! I'll go over and check it out first, but I'd want my own new machine...

Regards, Gary Sewall