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SF33 - Wing Imperial Measurements

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Steve Naidamast
Posts: 22
Joined: 25 Jun 2021, 17:51
Location: New York, USA

SF33 - Wing Imperial Measurements

Post by Steve Naidamast »

For those model builders who live in the United States and would like to build Cliff Charlesworth's, Schriebe SF33, the first issue that one will be faced with is the Metric measurements that Cliff's plans make use of.

Though one can easily use an online conversion tool or calculate the Imperial measurements by hand, I have already done that for you. And as I found, direct equivalents to what the plans provide for will not be found for all of the needed measurements. As a result, some slight adjustments have to be made to come up with the optimum measurements when using the Imperial system.

To begin with, here are the following baselines I used for for all my calculations...
  • 1.5mm = 1/16inch
  • Fractions are rounded up to the next highest number so that they are divisible by 2 thus allowing for common sizing found in the US
  • Sizes that are slightly larger than the original measurement in millimeters can be gently sanded down to afford equivalency
  • The main spars will be used as the primary guide for all other component fittings

And here are the conversions that one will require to purchase the necessary additional wood components...

>>>
Leading Edge (Balsa)
1/4inch x 1/2inch x 48inches

Main Spars (Basswood)
1/4inch x 1/8inch x 48inches

Main Spar Facings (Lite Ply)
1/16inch x 1/8inch x 48inches

Mini Cross Spars (Basswood)
1/4inch x 3/32inch x 24inches

Trailing Edge (Balsa)
1/4inch x 3/4inch x 48inches

Rear Rib Abutments (Optional; as strengtheners)
3/32inch x 1/2inch x 36inches
<<<

The last component, which I labeled as the Rear Rib Abutments, reflect what the author of the SF33 build-thread (Peter Balcombe - "SF33 1/6 scale") did with his SF33 kit. Where he added enough height to his abutments to assist in flaring out the Trailing Edge, my measurements are simply for additional strengtheners between the ribs, just in front of the Trailing Edge.

My Imperial measurements were submitted to Cliff just to get his opinion on them and he said they looked fine.

If you decide to build the Shcriebe SF33 and use these measurements, please check them against how you plan to proceed with your build project. You may want to make some adjustments of your own.

Stateside procurement of wood measured in Metric sizing is just about non-existent. However, National Balsa (National Balsa Website), provides all of the necessary wood for the measurements I provided. Please also note that the lengths I used may not be the lengths you would prefer. National Balsa offers lengths of 24, 36, and 48 inches for all Balsa that is categorized as "Sticks".

National Balsa also offers a manual, Balsa scoring tool that will allow one to create properly sized strips where such strips are needed.

I hope those that may use this information find it helpful...

:)
Last edited by Steve Naidamast on 26 Jun 2021, 22:38, edited 1 time in total.
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Cliff Evans
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Joined: 29 Dec 2019, 15:13
Location: Bristol
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Re: SF33 - Wing Imperial Measurements

Post by Cliff Evans »

I think your first measurement of .5mm = 1/16" is a little out, I think you will find that should read 1.5mm = 1/16"!
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Barry_Cole

Re: SF33 - Wing Imperial Measurements

Post by Barry_Cole »

Cliff Evans wrote: 26 Jun 2021, 09:30 I think your first measurement of .5mm = 1/16" is a little out, I think you will find that should read 1.5mm = 1/16"!
To be correct it shold be 1.6mm = 1/16"

:roll: :roll: :roll: :roll:

BC
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Steve Naidamast
Posts: 22
Joined: 25 Jun 2021, 17:51
Location: New York, USA

Re: SF33 - Wing Imperial Measurements

Post by Steve Naidamast »

Thank you all for noticing my typo...

The correction for the line item should read as follows...

1.5mm = 1/16inch
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