Issue with Sonerai Plans

[CdnMedic]

I called Sonex today to speak to tech about the wrong sized bolts I found on the plans and they essentially do not support the Sonerai, and they know nothing about them basically.

Here are the issues just on this one single page of the spar carry through for the 2L

Yellow is the wrong diameter, should read as 1/4".
Red should be 2" (I already saw this mistake and made them 2" anyways)
And blue, it SHOULD say 23-5/8 in both places as its the same piece. Except one gives the dimensions as 25-3/8.

If you have purchased your plans from Sonex, they are not to be trusted until they have been properly revised by someone that knows these airplanes thoroughly. But, considering the lack of support, do not expect that.

I'm now thousands of dollars in to the project in materials, easily 100 hours and have nothing to show for it. I hate to give up, but I don't trust the rest of my plans.

For reference, I am an aircraft structures tech by trade. I work on a 60 year old aircraft every day, I'm used to old drawings and information. But, rarely do I find this much misleading information on a single drawing.

 

[KWK]

Well, that's weird. I listened to some webinar with Monnett and I thought I heard him say these are the old plans printed in a larger format. My 1993 set of 2LS plans show 1/4" holes there.

 

[soneraifred]

The error brought up by the OP is only found in the three page low-wing supplement to the Sonerai II Original plans. The error occurred when Great Plains Aircraft Supply went thru each of the plans sets to clean up some hard-to-read areas, and called out the hole size as 1/2” rather than the correct 1/4”. When I reviewed those updates, I missed the error, and I apologize for that. The drawings now being sold by Sonex have been corrected, and they’ve placed a notice of the change in the drawing corrections section of their website.

 

[BJC]

Are there any plans that never contained an error?

BJC

 

[soneraifred]

Are there any plans that never contained an error?

BJC

The original plans sold by Monnett Experimental were correct. The error was when the originals that were used to make copies were cleaned up to make portions of the text on the drawings easier to read.

 

[TFF]

Most plans on the market have issues. That’s what news letters were originally for, sharing the problems.

 

[BJC]

The original plans sold by Monnett Experimental were correct. The error was when the originals that were used to make copies were cleaned up to make portions of the text on the drawings easier to read.

What are the drawing changes referenced on their web site? See:

Please Note: The plans set is printed on 11” x 17” paper. They are the original hand drawn plans created in the 1970’s and 1980’s (they are not CAD drawings). All drawing changes are included and noted in the plans.

BJC

 

[Aesquire]

I'll point out that Chevy, Ford, etc. don't support any of the muscle cars made in the same decade as the Sonerai. Some parts are still being made, but if you call Ford, about your '77 Mustang with questions, the guy there doesn't even know what it looks like.

 

[cluttonfred]

The error brought up by the OP is only found in the three page low-wing supplement to the Sonerai II Original plans. The error occurred when Great Plains Aircraft Supply went thru each of the plans sets to clean up some hard-to-read areas, and called out the hole size as 1/2” rather than the correct 1/4”. When I reviewed those updates, I missed the error, and I apologize for that. The drawings now being sold by Sonex have been corrected, and they’ve placed a notice of the change in the drawing corrections section of their website.

Here's a link to the drawings revisions for the Sonerai II and other aircraft on the Sonex site: Drawing Revisions

 

[David L. Downey]

I'll add that while it does nothing to solve actual engineered feature discrepant callouts, this is exactly why I reverse engineer/re-design everything I build from the original plans/manuals. Helps you find the bugs before they find you.

 

[Vigilant1]

Here's a link to the drawings revisions for the Sonerai II and other aircraft on the Sonex site: Drawing Revisions

It appears that Sonex has identified a pen-and-ink change for the hole size discrepancy ("1/2" should be "1/4”) for the Sonerai II (here: Drawing Revisions ) . There are other plans changes shown there, but not the ones identified by CdnMedic.

 

[KWK]

The drawings now being sold by Sonex have been corrected, and they’ve placed a notice of the change in the drawing corrections section of their website.

I checked the Drawing Revisions page, which covers changes since Sonex acquired the plans. Has anyone compiled a list of changes over the years? My set was acquired in late 1993, according to the post mark, and was shipped from Sterba.

 

[mcrae0104]

I hate to give up, but I don't trust the rest of my plans.

I think that would be your best option.

Also, I will pay for postage if you want to send the plans to me for proper disposal.

 

[Tiger Tim]

I think that’s just par for the course for plans-built airplanes. It didn’t hold back however many hundreds of Sonerai builders who have finished their planes, though.

 

[Hot Wings]

I think that’s just par for the course for plans-built airplanes.

Maybe for modern plans. Some of the older plans didn't even have all of the dimensions.
Lots of notes on the old plans saying things like "drill to final size on assembly".

 

[Tiger Tim]

Maybe for modern plans. Some of the older plans didn't even have all of the dimensions.
Lots of notes on the old plans saying things like "drill to final size on assembly".

I wonder which is ultimately better, one’s that give lots of info at the risk of being wrong or ones that have a lot of ‘you can figure it out’ dimensions? I know my Wag Aero Sport Trainer plans are only something like nine pages. Nine pages for a whole Cub!

 

[cluttonfred]

I think that’s just par for the course for plans-built airplanes. It didn’t hold back however many hundreds of Sonerai builders who have finished their planes, though.

I agree, plans are never perfect but folks still manage to build from them.

 

[Hot Wings]

I wonder which is ultimately better

Depends on the goal of the designer/builder?

If you only have room to work and a limited budget then the plans should be as clear and precise as reasonably possible so the sub-assemblies can be built and stored with assurance that they will fit the other sub-assemblies when they are combined. Having to rework wing attach fittings because of a deviation in the plans could get expensive and time consuming if one depends solely on the plans.

On the other hand the lack of dimensions for the same fittings forces the builder to build one part and then the second to fit what - they - created. I'm perfectly comfortable with this method but I'm also of a different time when we didn't have the precision of CAD. We were lucky if we had jig built parts.

 

[crusty old aviator]

I'll point out that Chevy, Ford, etc. don't support any of the muscle cars made in the same decade as the Sonerai. Some parts are still being made, but if you call Ford, about your '77 Mustang with questions, the guy there doesn't even know what it looks like.

Probably doesn't want to know...the mid/late 70's Mustangs were pretty ugly...uh-oh! THREAD DRIFT!

 

[crusty old aviator]

I agree, plans are never perfect but folks still manage to build from them.

I remember receiving my set of Smith Miniplane plans. There was a note from Dorothy on the first page, "You can do it, Andy, don't give up!" or something to that effect. I thumbed through the drawings and thought, HUH??? Just my luck: there was a very kind and patient man in town who had built two of them, back in the sixties, and his shop was empty. He became my mentor, and soon the plans made sense.
Martin Hollmann gave me the prints for the Cringely Plane Crazy design, and there was a note to replace the 4" wide main gear (Grove built, Wittman type), as drawn, with a 6" wide leg. It was sandwiched between two vertical bulkheads and didn't say if one or both bulkheads had to be moved and by how much. When I asked Martin for clarification as to which bulkhead(s) would be moved to accomodate the extra 2" of width, he basically told me to study it and figure it out on my own, so I kept the main axles in place (for CG purposes) and moved both bulkheads. He got screwed over by the production company so was done with the design, and he trusted my ability to run the FEA to verify she wouldn't snap in half. I never built her, as Cringely specified an Eggenfeller Subaru conversion, and Jan had a checkered reputation then.
Paul Poberezny gave me a set of Acro Sport II drawings (serial #2). I never built her, but the drawings that Paul had Bill Blake draft (IIRC) for the design were very nice, with lots of text for guidance. They had a LOT of errors on them. Fortunately, I was registered as #2 and received the newsletters with the changes/corrections for a couple years.
So, bringing this ramble back to the thread: who needs Sonex when you have generous, knowledgeable people like SoneraiFred and type groups who support each other? It's not enough to formulate a good question, you need to know whom to ask.