1/3 Scale Pratt Ried

[Tom]

I've been working on the Pratt Ried on and off since April of 2007....5 years so far! Damn.....

The first part of the build can be found at RCG here:

Pratt-Ried

I have been assembling the wings for a couple of months now and need to get them together so I can move them off the bench they are on so I can finish my Duo-Discus wings.....so....what was holding me back was the spars...they are 96" long and have a double taper from 34" out to the tip.....I did a write up here on how I tapered these spars that can be found here:


Tapered-Wood-Spars-for-Large-Scale-Aircraft

So tonight I set about to start putting the spars together...at the root the spar is built solid and then a 1/4" plywood shear web will go to where the taper starts and then 1/8" ply out to the tip.....the spar will also get a 1/16" exterior shear web on both front and back from root to tip....overkill? Why yes...thank you!

Here are the parts to make up the root area of the right hand spar...



All together...



Where the joiner brackets will attach.....



All epoxied up.....

[cpdude]

Yes, very nice. I love all of that wood!

Brian

[Tom]

Thanks! Just like the full size!

[yyz]

Plastic cloth on the workbench is for chicks... Nut up, dude!

Nice work on bookmatching the endgrain on the spars. Those things are ginormous!

Mike

[Len]

And i thought I had a bunch of projects going!
Will that one make the aerotow this weekend?

LEN

[stihac]

Are you sure this is a 1/3 scale? looks bigger then that
Great stuff, looking forward to this build!

Petr

[Tom]

Plastic cloth on the workbench is for chicks... Nut up, dude!

Nice work on bookmatching the endgrain on the spars. Those things are ginormous!

Mike

It was either that or make the work bench part ofthe spar!

And i thought I had a bunch of projects going!
Will that one make the aerotow some weekend?

LEN

Yes, it will.

Are you sure this is a 1/3 scale? looks bigger then that
Great stuff, looking forward to this build!

Petr

Yep....third it is...thought about 40% but designed this before I truly fell off the deep end.... 216" wing span and 35 - 40 lb flying weight.

[stihac]

Yep....third it is...thought about 40% but designed this before I truly fell off the deep end.... 216" wing span and 35 - 40 lb flying weight.

That's all? 216"? I can't beleive you wasting your time with something this small

Petr

[ARUP]

Where'd you get those fancy schmancy metal joiners?

[Tom]

Where'd you get those fancy schmancy metal joiners?

Laid them out in AutoCad......export to "dxf" file.......went and got a "drop" of 1/4" 6061 aluminum sheet.......took it to my local water jet guy...... $75 later I had 4 - joiners.