Sopwith Baby Project - Page 36

Joe Perkel · 19 July 2008, 08:21 PM

Nick,

To illustrate my previous post, here is tonights work with the short ribs "finished" off as the woodwork detail notation specifies.

I have also noted, that the center section plan view, calls for 1/16" 3 ply at this cutout location over the (shown on their drawing) extended short ribs.

This makes that notation particularly perplexing!

I will extend these ribs and modify to fit as per the Pup detail.

Thanks again!

Joe Perkel · 25 July 2008, 08:28 PM

Center section TE issues now worked out, thanks Nick. I confirmed what they did on the San Diego Pup, is what I modeled.

I still have to correct some details such as solid spars for this top wing and my now en route, original root details.

I also got a true appreciation of the work that lays ahead when I saw this rendering. Must say that I'm looking forward to it, one little piece at a time!

Joe Perkel · 28 July 2008, 03:32 AM

I'm not surprised how this is looking so much like your center section Nick, these rascals were brilliant businessmen, (convenient little war too), just look how they took this basic design and morphed it into the various famous end products.

Stuck here now until I get my missing details. If for some reason I don't, it's really fortunate for me that the Pup is so well documented and reproduced. Thank you Replicraft!

Nick · 28 July 2008, 05:27 PM

Quote:

Originally Posted by Joe Perkel

I'm not surprised how this is looking so much like your center section Nick, these rascals were brilliant businessmen, (convenient little war too), just look how they took this basic design and morphed it into the various famous end products.

Stuck here now until I get my missing details. If for some reason I don't, it's really fortunate for me that the Pup is so well documented and reproduced. Thank you Replicraft!

Joe,
Out of interest I presume the centre section joint boxes also have a socket to locate the drift struts. Do they have a bolt located though the centre of that socket? This is the case on the Snipe which poses a problem inserting the strut after bolting it up to the spar once the ribs have been put in place. I presume you have to slide all the ribs down one end so can get enough space to get the strut in , then slide them all back down the other end and do the reverse. Never was much good at puzzles

Cheers, Nick

Joe Perkel · 28 July 2008, 09:01 PM

Quote:

Originally Posted by Nick

Joe,
Out of interest I presume the centre section joint boxes also have a socket to locate the drift struts. Do they have a bolt located though the centre of that socket? This is the case on the Snipe which poses a problem inserting the strut after bolting it up to the spar once the ribs have been put in place. I presume you have to slide all the ribs down one end so can get enough space to get the strut in , then slide them all back down the other end and do the reverse. Never was much good at puzzles

Cheers, Nick

Nick,

Yes, I have not yet modeled the sockets / hardware. I can't answer the bolt question yet as I'm not quite sure what I have in my hardware drawings. Picking through these giant drawings late at night on a tiny surface cross eyed and bow legged,... is slow going at best.

I am at a bit of a disadvantage trying to do this work in my current conditions. The contractor has delayed incessantly, so my workshop and office space wont be ready until early next year now. Then my wife gets a hold of me for finish work,... god help me!

I see your point on the strut. It looks to me like it would be as you describe, so that center bolt would not be convenient! Those two inboard are 1" OD tube and the outboard are 1 1/4" square spruce tapered to 1", both (tube & spruce) in sockets. I was under the impression that these fittings were to be through bolted via tabs on either side of the member but, now you have me curious and will look for this.

Interesting how things are addressed from an engineering perspective in these center sections as the increase in drift strut sizing, positioning of same, increased wire sizes, are all very apparent.

Thanks Nick!

Joe Perkel · 28 July 2008, 09:11 PM

Found this truly lovely piece today and promptly ordered a print from the artist in the U.K. , Barry Weekley.

Mine is not the most popular WWI aircraft for builders, so I am extremely pleased to find a specific piece like this.

This print will be framed in my workshop with a wing rib mounted over it in short order when I finally get rolling on this.

Joe Perkel · 29 July 2008, 09:32 PM

Today I finally received my missing drawings and now have sufficient material to replicate this aircraft as original, excepting the engine and floats as previously noted. Several items worth noting....

- They did in fact (rabbet) the ends of the center section spars to accept the box hardware...(Huh!) More confusion here.

- I now have my tail float details! Interestingly, the designer I've commissioned for the main float internal re-design, predicts a lighter result by a clever use of thinner external marine ply skins backed up with a hidden layer of Kevlar fabric! Externally indistinguishable from the original but a neat marriage of WWI and space age technology! I am truly pleased as this and lack of military load hopefully makes at least matching the original performance specs a bit more attainable.

- I now have the center section lifting eye details. I really wanted this because besides authenticity, I can easily picture being lifted out by a large marina davit somewhere.

- I also now have the fuselage separation details for shipboard stowage that was also used on the 2F1 Camel. Not quite sure how I feel about this but, it would not be authentic without it. A bit unnerving to think that your fuselage comes off like a lobster tail!

womenfly2 · 30 July 2008, 05:00 AM

Awesome!

Quote:

- I also now have the fuselage separation details for shipboard stowage that was also used on the 2F1 Camel. Not quite sure how I feel about this but, it would not be authentic without it. A bit unnerving to think that your fuselage comes off like a lobster tail!

..... probably the same way Navy pilots felt about " folding wings "!

Great thread, thanks for sharing all this valuable information with us. Cannot wait to see the start of the first parts.

Keep the dream,
WF2

brisfitworks · 30 July 2008, 05:44 AM

Nick:

The Camel is the same on ctr-section and wings - the design implies you have to install the end spar boxes on first and then set the spars and drift struts in place and then assemble the wings.

It sounds like a Chinese puzzle! and I am not entirely sure of the process they used and suspect that we may find one day the drawings are not "as built".

On the wings you'd think you can just start at the root and work this way out to tip, but the center section has the same problem at both ends and I am in the same but worse bind as you - we already assembled the wings and centre-section without the end boxes installed!

The spar boxes were hard to make and confusing in assembly process at the roots, so that portion was left to last while people worked on getting all the wing panels done.

I have been pondering this issue, off and on, for almost a decade and it is one of those things I forgot to ask Fred Murrin when I last saw him.

That said, "Plan B" has been for the whole time: "screw it, I'm reinventing it.

What I have done is welded a nut in at the base of the drift strut socket!

Since the strut is a tube this works out well. Now one slips the strut between the boxes, slide the assembly over the end of the assembled wing and simple put the bolts in and tighten.

Another issue is the shape of the bottom of the socket compared to the tubular drift strut - the wire lug welded under the tube does not fill the bottom of the socket and leaves a step for the tube to rest on. Properly, the tube needs to be supported on its entire circumference and it either has to be cut to a complicated and hard to match profile or left with all the load on 25% of its shape. It is all quite wrong. Again an area that either the details were different as built or we are missing a detail. I am filling the socket base with "Liquid Steel" (steel reinforce epoxy) and spot facing it flat. Then the tube only needs a simple angled face to be cut.

Quote:

Originally Posted by Nick

Joe,
Out of interest I presume the centre section joint boxes also have a socket to locate the drift struts. Do they have a bolt located though the centre of that socket? This is the case on the Snipe which poses a problem inserting the strut after bolting it up to the spar once the ribs have been put in place. I presume you have to slide all the ribs down one end so can get enough space to get the strut in , then slide them all back down the other end and do the reverse. Never was much good at puzzles

Cheers, Nick

brisfitworks · 30 July 2008, 05:50 AM

Joe:

I am so glad that you indeed got what you needed; it is always such a crap shoot when ordering dwg's sight unseen.

When you say rabbet, do you mean tight fitting to the box? It still may be "as designed" versus "as built."

Definitely go with the split fuselage! As part of the conversion to steel tube I made our F1 Camel split in same place as the Navalized Camel. It has been a huge help in workability. You can work on sections separately. When, the tail portion is done, simply remove it and store it out of the way. It makes access to the front portion much easier for working on. It is a great bonus for construction especially in tight workshops.

When done, it makes transprtation easier too!

Quote:

Originally Posted by Joe Perkel

Today I finally received my missing drawings and now have sufficient material to replicate this aircraft as original, excepting the engine and floats as previously noted. Several items worth noting....

- They did in fact (rabbet) the ends of the center section spars to accept the box hardware...(Huh!) More confusion here.....

...- I also now have the fuselage separation details for shipboard stowage that was also used on the 2F1 Camel. Not quite sure how I feel about this but, it would not be authentic without it. A bit unnerving to think that your fuselage comes off like a lobster tail!