It's not every day you see a Zenith CH-640 parked at an airport.

I `m just getting started plans building a ch640, are you still active on the forum? any hanged you might have done on your build looking back?

Very nice to meet you, I consider you part of the Golden Age of the CH-640. Ive read the complete Matronics old list and saw your errata. You were around when Jeff Paden and Mr Tremblay were active and building.

Ive looked at Jeff Padens site and Mr Tremblays on Archive.org but unfortunately the pictures are all missing.

I`m at the form block stage and I study the plans daily there is so much to learn. I have a few questions if you dont mind. I have a ton of them..but i`ll keep it short today...lol

I`m going over the Errata ....I have a question about this item

• Drawing 640V1, Revision 4 - Item 1, Wing Spar Extension. The plans dimension "~405" to the first lightening hole. Change this to 350 mm.

640V2 wing spar extension assembly shows the lightening hole half-way between the two (L) pieces.

Adding the dimensions: 25 mm for spar cap overlap + 225 mm from overlap bend to first (L) + 100 mm from first (L) to center of lightening hole = 350 mm

640-v-1-1.jpeg

On my plans the dimensions to the 1st hole(i` m assuming inboard toward out board) is 305mm. Did they revise the plans but not change the revision?..my numbers dont seem to match yours

I was also wondering how did you put that tight z bend in that part?

Like I said I have a ton of questions but I dont want to overload you so Ill keep it short today...lol

I`ve also been in contact with Dr Steve Adams(got his address from the CH-640 matronics list), he has been very helpful and answered many questions but he built his plane from a quick build kit so would not have the intimate knowledge that you and the other scratch builders do. But Steve and yourself are a great resource for when the plane is nearing completion and taking flight.