abufletcher

I've been waiting all summer to start this thread!!! And now the time has come.

I'll be documenting here my build of a proto-type of the Sopwith Snipe kit designed and manufactured by CD ScaleDesigns in Germany. You may have run across Chris's site (http://www.cdscaledesigns.com./) or seen the photos that Chris posted here on RCU of his outstanding Sopwith Pup design. This kit really is hot off the presses and this is (I believe) the first online build of his Snipe (Chris tells me this is the second of five kits sold thus far).

The Sopwith Snipe is one of the great "what if" stories of WWI aviation. What if, it had come into production earlier? What if, the war had lasted longer? Opinions vary (ofter widely) as to how the Snipe compared to the more famous Camel (from which it was obviously derived). The Camel was a "pilot's pilot" sort of aircraft capable of great maneuverability -- but often a deathtrap for the novice pilot. It is a fact that more Camel pilots were lost in accidents than from combat with the enemy. The Snipe was a technical improvement in many ways and much more friendly to novice pilots. It could climb higher and faster than the Camel -- up to where the newest and fastest German aircraft were patrolling.

And then there is the tale of one of the most heroic air battles of the war with Major William Barker fighting a desperate single-handed battle with an "entire circus" of Fokker DVIIs.

http://www.constable.ca/barker.htm

So sit back and enjoy the action -- or chime in with questions and/or suggestions!!!

abufletcher

Here are some basic facts about the kit. This is a 1:6 scale design of the Snipe with a wingspan of 63" and total fuselage length (from front of cowl to end of rudder) of 37 inches. The plans show an OS 60-class FS but it should fly in a scale manner with something like a Saito 56 -- or you could move up to a 70-class FS.

Chris calls his series of WWI designs "sports scale" but it's a far cry from what we usually get in a sport scale kit. For starters the outlines are (as near as I can tell) 100% accurate when compared with the drawings in the Snipe datafile. That makes it a competition worthy design. Second, there are many ways in which the design has the feel of the original construction. For example, the way the wings are mounted (no underslung one-piece wing as on many "sport scale" kits). All in all, I think this kit has the potential to build into one really nice model. I only hope I can do it justice. BTW, I'm doing the prototype not because I'm the hottest model builder around but because I probably represent the prospective "target audience" of this kit: people who love to build and love to build scale but would just as soon start with a kit, if possible. People who might be a bit frustrated at always having to "kit bash" sports scale kits to get something reasonably scale.

At this point, the Snipe is available only in "short kit" form. Chris provides virtually all of the "shaped" wooden bits (including pre-cut firewall, tank and battery boxes, slotted hardwood rails, etc.) but doesn't include the stock "lumber" in order to reduce shipping costs. He may, if there is interest, eventually provide a full kit (along the lines of the nearly all-inclusive Flair kits). Some of the parts (for example, a polycarbonate cowl and decking) are still in the works. A metal cowl might even eventually become available. And this is a proto-type build so we might discover a few kinks. But the design looks well thought out and should build with reasonable ease.

Here's what came in my box:

abufletcher

Actually there are three LONG sheets of the plans. The second sheet shows fuse cross-sectons and the third has the top and bottom wing layouts.

abufletcher

I couldn't help getting ahead of myself a bit with some scale detailing while I waited for the kit to arrive here in Japan. So I set to modifying a set of WB 5" wheels to look more like the Palmer Cord Aero Tyres used on the Snipe (and other British aircraft). You can see the details on the "tricking out WB wheels" thread:

http://www.rcuniverse.com/forum/m_17...mpage_4/tm.htm

I also "pot-bashed" myself a nifty looking metal cowl -- since the kit's cowl isn't yet available. I'd like these bits to set the tone for the build.

abufletcher

OK, and here are a bunch of Snipe photos and drawings just to whet your and my appitite.

abufletcher

Oh, and one more thing: As of this time (October 2006) there are no instructions for this kit. So I'm going to be relying a lot on Chris' construction photos of his Pup and on his advice. You can find his construction photos (for his Pup) on the German side of his site (which thanks to years of German classes I can read):

http://www.cdscaledesigns.com./Germa...p%20Titel.html

The Snipe appears to have a similar construction. One of the hopeful outcomes of this build will be a useful set of instructions.

allanflowers

Bravo, Abu.
I am looking forward to your posts on this subject. Their Pup kit is at the top of my list so your build will be interesting.
Allan

abufletcher

Following Chris' lead, I'll begin with the fuselage. The first step to to create the two forward side panels by aligning the balsa parts with the 1.5mm ply doubler. The parts align flawlessly, BTW. And of course one needs a right and left version.

abufletcher

Next, positioning the left forward panel over the plans (ply side down) build the rear of the fuse frame. No wood is provided for this and the plans call for 6mm longerons and vertical formers. I used 1/4 square stock and that seems to work fine -- though I'll have to do a wee bit of sanding to get it all flush. I used the hardest balsa I could find for the longerons and vertical pieces.

The diagonal pieces are supposed to be 3mm square but I didn't have any of this -- so in an effort to economize I cut 3mm x 1/4 (I know, I know, mixed systems!) pieces out of the left over part of the 3mm parts sheet. This contained enough extra wood to do both sides easily with more left over.

In total I used three 36" pieces of 1/4 square stock to do both sides. I'm trying to keep a record of the wood used.

One minor note to Chris here: The line on the plan where the end of the longeron makes contact with the tail piece (this is why the end is built open for now) is exactly vertical. But I suspect that this really needs to be perpendicular to the longeron to fit flush with the 90 degrees of the tail piece.

abufletcher

Next, following the old modeling tradition to ensure equal sides -- and thereby a straight fuse, the right side is built on top of the left side. I used wax paper to separate the two sides but I guess saran-type wrap works just as well. This time the ply side ends up being on top.

You'll note that I haven't yet shaped the upper and lower longerons where they join the forward panels. I thought it would be easier to shape these together rather than trying to cut them ahead of time to the curved shape on the plans.

Well, that's it for now. Today is my 50th birthday!

BobH

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Don, Happy Birthday!! (mine's tomorrow.. I'm a lil older!)

khodges

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Welcome to the OFC! I got you by a couple of years, but as R/C'ers we are really only in our teens. Looking forward to this build thread. I've always liked the Dolphin. One thing I've noticed, though, and your pics point it out well. Every actual photo I've seen of the Dolphin shows a vertical tail very similar to the Camel, but drawings and paintings usually show it with the "notched" tail. Why is that? I profess to be much more familiar with the Pup and Camel, and BUSA's Pup is sitting in a box on one of my shelves waiting for its turn on my building table.

What did you make your metal cowl from? Looks great.

Also, what's the short kit go for? USD, not Yen, please

abufletcher

Maybe in 20 years I'll have the skills of Donnie Coe (over on RCSB) who seems to churn out prize-winning models 2 or 3 at a time!

The Dolphin had a serious dose of design "funk" (and to my mind a healthy helping of uuugly) but it would make an interesting model subject. I looks to me to be one of those "in-between" designs. The Snipe is, I believe, the later aircraft and benefited from the design innovations of the Dolphin. The prototype of the Snipe used stock Camel tail feathers initiially was was then given the notched tail rudder. Early production models also has the notched rudder. But this proved to be a bit ineffective and later production aircraft were upgraded to the larger rounded rudder.

Chris lists the price on his site at $200

Cowl started life as a 18cm cooking pot. I had to remove a bronze annodizing and then made the cowl reinforcement ring out of 0.5mm aluminum. This was first epoxied to the cowl and then drilled (140 holes with a 0.8mm drill). The "rivets" are standard sewing pins when I inserted, clipped off, and then finally fixed in place with a layer of epoxy along the back.

abufletcher

Next job is transfering all the former positions from the plans to the ply sides. It's best to line up the two halves and then draw the lines on both halves at the same time to make sure that everything lines up. It's important that the forward face of F3 is precisely aligned with the rear of the small hole as the wing tube will be bound with thread (and then epoxied) to F3.

Now is also the time to make the location of servo bearers onto the formers.

There are some other things to think about at this stage as well such as the size of the tank that's going to used and the material for the bottom hatch. On the plans Chris recommends a SLEC 6 oz. tank and the tank box is very tightly drawn to that tank's fairly narrow dimensions (1.82" according to the Hobby Lobby website). The Sullivan 6 oz. tank I bought is a bit wider (2.1" ) so I'll either have to order the SLEC tank or slightly enlarge the tank space and that will entail making a couple new parts.

Chris's plans call for the use of 3mm balsa for the bottom hatch. I usually use 1/16" ply for hatches but that would necessitate slight modificatons to a few pieces and/or their positions. To be honest, it's a bit like working on a 3-D puzzle trying to visual from two different views on the plan and it would be easy to goof up at this stage -- so I'm taking it slow.

franciscan

Hi Abu
Just a few points on your engine selection. I have a copy of the plans and write-up for a 62" Snipe by David Boddington in 1992. That aircraft was rated for 40 to 60 size engines. The final selection by the builder (prototype) was a 46 Enya four stroke in a 61/2lb model. His comments were `Providing you do not want an exhilarating aerobatic performance the Enya 46 (or similar output four stroke) will provide adequate power. In fact it gives a very scale like flying quality` He also states that by keeping the tank and battery pack in the cowling, fitting a relatively heavy dummy engine, having a four stroke motor and keeping the rear end of the model as light as possible, no further ballast was needed in the nose. This was quite an achievment with a short nosed Sopwith.
Depending on whether you want a more exhilerating performance and perhaps not fitting a heavy dummy engine you could use the heavier 70 class four stroke engine and kill two birds with one stone.
Nice looking kit. I will have to look into this one myself in the near future. Look forward to your build.

abufletcher

I've been thinking a lot of what to do about both the engine and the dummy. As you see in the photo below, I've definitely considered the idea of building a HEAVY dummy (these things by the way are called "3/4" close nipples"). I was basically thinking that all I'd have to build is the part that shows through the cowl opening.

But the other way I might go is to print a photo of the Bentley BR2 on something like a CD. I think the photo realism might actually compensate for the lack of depth. I could even add a few things like rocker rods to create some depth. Plus I've already done up both spinning and non-spinning versions of the photo. I paid a small fee (5 pounds) to the Museum of Science and Industry for a great hi-res photo of the BR2 explaining that it was strictly for personal use in a modeling project. So for that reason I shouldn't post the hi-res version. Actually, I had to do a fair bit of clean up work in Photoshop. Anyway, I can post the low-res version that is available in their picture library.

If I went with a lighter actually engine I might want to do the heavier dummy. But then I rather like the idea of using the photo.

allanflowers

I recently finished a VK kit of a Camel and had to add quite a bit of nose weight. The VK design was designed pretty light in the tail but the one you are doing looks far more robust than the VK. Tail weight is tough to compensate for, particularly if you want to have a neat tailskid and some wire bracing for scale realism back there.
I was unable to see the layout drawing very well in your earlier post. Would it be possible to shoot a pix of just the left side of the drawing and post it? I am quite interested in how they package everything up there, as well as what kind of functional access one has to that area. A little six oz. tank may be how they solved some problems but it could be a little small.
Allan

abufletcher

Here you go, Allen. As you can see Chris uses a computer cut out version of the solid core technique (same as on his Pup). This might look heavy, but that core is really wafer thin. Depending on the strength, I found I might even open up the holes a bit more. The edges are formed of laminated balsa. Since Chris has one of the VK Camels himself, I'm sure he's aware of the need to keep the tail area light. He used balsa for the rearmost fuse former and also lit ply plates imbedded in thicker balsa to hold the rudder post.

I'm been toying with the idea of building some functiional way to have variable tail incidence but only if doing so can eliminate some of the weight there already (for example the need to have the tail plane saddle).

Note that he also provides a plan for the early ("notched" ) rudder.

abufletcher

Next baby-step, while I'm getting my head around the tank wall placement, was to mark the locations of the servo beams onto formers F2 and F3 -- and then cut the beams from 8 x 10mm hardwood (not included).

Some care is needed in making sure that the "top" of each beam is where it should be since the bottom servo is mounted upside down. I haven't yet epoxied them on because it seems to me that I'll need to drill the starter holes for the servo screws first since afterwards I might not be able to get at them with my Dremel tool.

abufletcher

Franciscan, interesting that you should mention the Boddington model as Chris took the inspiration for his design from Dave's model! He even sent me a copy of the article you mentioned. It did make for interesting reading and it gave me a few things to think about (and discuss with Chris). For example, the article mentions the need for right thrust but Chris says he follows Dave Platt in not building in thrust on scale models. My own preference is also to not build in thrust from the get-go but rather make sure there's some option for adding it after the fact if needed. Fitting a dummy of a rotary engine if there's thrust angle used is a pain.

Anyway, I'll keep rereading the article as I build. I'm definitely leaning at this point towards powering it with a Saito 56.

khodges

My Feedback: (1)

This thread is confusing me (confusion is a normal part of being a 50+ old fart). Nothing you're doing, mind you. I've got all my BirdDog stuff out to start that build, but this is getting me pumped to build another WWI bird, and I've got 4 to choose from on the shelf.

I also misspoke on my last post. When I said Dolphin, I was thinking Snipe. You're right about the Dolphin and ugly in the same sentence. I guess it's the reverse stagger that does it.

The solid core tail is nice, and should be very durable. GP's now defunct DR-1 had a tail made this way, and we all know how much they wind up flipping and hitting the tail (at least mine does--must be the pilot) and this should be much more resistant to the inevitable flip-over damage. Once covered, you don't see the underlying structure anyway, so I certainly don't see this as a serious departure from scale. Something to consider for longevity of the rudder post is to laminate some thin carbon fiber down both sides from the top edge of the rudder past the lowermost hinge. A blow to the post in a flip-over shouldn't snap the post. It will transmit the shock to the hinges, which is an easier repair if they break. Ask me how I know

abufletcher

Yes, the Dolphin definitely belongs in the "Hall of Planes that Peformed Better than they Looked.

Definitely, go with the WWI model! What are your options? BTW, it's always amazing how small these 1/6 scale WWI models are after you get them off the building table and out to the field. Here in the house 63 inches takes up an awful lot of space in my Japanese sized home. Personally I like 1/6 scale (mostly an economy thing) but I can see the appeal of going bigger (expecially MUCH bigger). Anyone for a 1/3 scale Gotha?

kdc

Previously there was mention of the 62 inch span Sopwith Snipe plan by David Boddington. This was published as a free plan in the December / January 1991/2 issue of Radio Control Scale Aircraft. Also in this issue was a feature on the full size which contained lots of info, a 3 view & details of 5 different aircraft markings including 1with Soviet markings.

The second part of the plan & instructions was in the February / March 1992 issue.

For anyone who does want to build one there was a Sopwith Dolphin plan by Elwin Sapcote in the March 1987 issue of Radio Modeller . Span was 51inches span for Saito 45 4 stroke. The reduced size plan in the mag shows that the construction is nicely detailed on the plan. Its not that ugly.
Plan number is RM 322 and is listed by Xlist plans in their full list on their website [link=http://www.xlistplans.demon.co.uk]www.xlistplans.demon.co.uk[/link]

khodges

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My options are: BUSA 1/4 Pup, BUSA 1/4 Nieuport 11, BUSA 1/4 D-VII, or FunAero 1/5 SE5a. Pretty tough choice, eh?. I'm really in the WWI zone, though, I just finished my BUSA Bristol and have been flying the heck out of it lately, and am doing some repair work on my GP DR-1 after deadsticking/stalling into a cotton field last month (unbelievable--straight in from at least 60 feet, just bent the landing gear and broke the prop).

I love these stick-and-fabric planes, it would suit me to build nothing but WWI stuff, but I've wanted this L-19 for about 3 years now, and I have everything I need to put it in the air, so I guess I'll get it out of the way. Then it will be bipes and tripes forever!

abufletcher

So the article on the Boddington Snipe spanned two magazine? Any idea where I might be able to get a hold of backissues of these two?