Don Smith B-17 Project
 

I'm ready to commence my B-17, and am wondering about which engine(s) to use. My inclination from a reliability point of view, is to use gas engines. The drawback with them is the diameter of the nacells would require that the engines protrude outside of the cowls. I want to avoid that. I am considering the RCV 90-sp glow engines. These would swing scale 16 inch 3-bladed props, and be fully enclosed in the cowls. The downside is the presumed decreased reliability of glow engines as compared with ignition engines. Anybody have any opinions they would like to share?

Another concern I have is Don Smith's fuselage construction. He uses the old Guillio methood of building half of the fuse flat on a board, removing it, and then building the other half on to it. I don't like that at all, as it is extremely difficult to build a true structure that way. I much prefer Ziroli's crutch method of construction, and I plan to employ it on the b-17, if I can figure out how to redesign the fuselage formers to accomodate it. Has anyone done a similar thing?

The last issue I have to figure out is a 3 piece wing, and 2 piece stab design, as the model must be transportable in a minivan. The main concern i have is having the outboard engines on plug in wing pannels. Will the vibration of the engine cause any problems over time with the plug in joint?

Any thoughts you may have regarding these and any other Don Smith B-17 issues would be appreciated.

Don Smith B-17 Project
 

Fly Doc,

It might be possible to trim down the side pieces of the nacelles and push the firewall back. Perhaps you could then make a retaining ring to attach to the firewall that will hide that you have moved it back. There are two different construction views of the nacelle on Don's plans, if you look at the one with the 1/2" balsa rings, you might be able to modify this to your needs.

The "clam shell" construction of the fuse can be a pain in the ass, but if done carefully, it will make for a more accurate fuse than full formers. My employee, Butch, is currently tackling the problem right now with Don's B-24, give me a call at the shop one morning and I will put you in touch with him.

Lastly, Don's wing is already a 3-piece, but the split is outboard of the nacelles. I don't think I would change the split line to have the outboard nacelles on the outer wing panels.

Mace Gill
The Aeroplane Works

B-17....
 

Fly Doc.....One of the guys in our warbird group is flying the DS B-17 with close to 300 flts on it.......you'll be hard-pressed to get it into a Mini-Van.......3-piece wing is a piece of cake...the fuselage is where you'll need to be "creative"......The B-17 is powered by G-23's and although they don't fit in the cowl completely..they sound real and it flys very well as I've flown the plane myself....He has 3-blade 16x8 props...2-batteries and 2-recievers.....ck out CONDORSRC.com and click on the "Condors Project Planes" and then click on "SHOO SHOO BABY.....plenty of pictures for you to get what you might need to know.....Bill.... :D

Don Smith B-17 Project
 

Flydoc,
The best and easiest way to do the fuse is to build it with stand offs. I will try to explain the best I can. First lay the plan on your table and draw a line about an inch under the fuse the whole length of the plane. Next measure from that line up to where the side stringer notch is on each rib. Next cut some 1/4 X 1/2 stock to match the measurements. Do ths for each former and make 2 stand offs for each as well. Now draw a long line on a good flat building surface. Mine is glass, but most anything will work. Now fold your plan over so that all the formers show at the top edge. Lay this against the line you drew and mark off where each former needs to be on the table. Glue the former halves together and add the stand offs so that they are lined up with the stringer notch as you measured them. Almost done here!!! Last thing to do is to line up each former with the place it belongs vertical and side to side and glue the stand offs to the table. Do this for each former and they will be in perfect alignment and in the right spot. Now add the top and bottom keels and the side stringers and sheet or plane the fuse as far down as you can. Now just rock the whole thing and the standoffs will pop off the table. Just twist them off the formers and finish planking the fuse. Ta Da!!! A perfect fuse evry time.

I will show photos as soon as Mace gets my kit out to me of my B-17. What's the skinny on that Mace?

As far as the engine thing. Don't ever believe the tales about glow not being as reliable as gas. It is not true at all. A glow engine is every bit as reliable as a gasser. Go to a contest and count engine outs for yourself. You will see just as many gassers fail in flight as glow.

Being that this is a 4 engine plane, if you loose one you may not even know it until you come around and see the prop not turning. The 17 flies just as good on 3 as it does on 4 and it does a pretty good job on 2! I know a guy that got his around the pattern and landed his on 1!

As for transport, well it won't be easy. I'm not sure I will be able to get it in my long bed pick-up and still close the tail gate!

Good luck on the 17. I can't wait to get started on mine!!!!!

Hans

B-17
 

Thanks for the input, guys. As far as transport of the plane in my minivan goes, the fuse will fit as long as no part of the structure is wider than 48". I have enough length as long as the rear and middle seats are removed. I intend to transport the plane on its wheels, with the center section of the wings attached, that's why I need to design a wing separation point between the nacelles, and have plug-in stab halfs.

As far as the fuse construction method, after studying the plans last night, I decided to try to use a 1'' dia length of pipe as a fixture to build the fuse on. I'll try to explain: I'll support an approx. 9' length of 1" pipe a foot or so above my work surface. I'll modify the fuse formers so that each is cut out with a "web" with a 1" hole on the centerline of the fuselage for each former station. Then I'll thread each former in sequence on to the pipe fixture, and install stringers and planking. The webs for each former will be scored so that when the pipe is finally removed, they will break off relatively cleanly. What do you think?

For those of you familiar with this plane, how do people handle fuel tank placement? Especially in the case of the inner nacelles, the is no room within them for a decent size tank. How far from the engine can the tank be located in the case of glow engines, and still have reliable operation?

B-17
 

If your budget allows the use of YS 4 stroke engines, the placement of the tank(s) is not critical. You could place the tanks just about anywhere there is room so long as they are not too far from the CG point. YS engines put a lot of positive pressure in the fuel tanks and there is never a fuel draw problem with them.

B-17......
 

Fly Doc...You're gonna have some problems with splitting the wing between both i/b and o/b engines.....a wing tube needs to be long enough to support the weight and aerdynamic forces on the o/b panel...you'll invariably be short changed due to retractable gear in the i/b nacelle aft towards the trailing edge.....you'd be better off picking up a used trailer to accomodate your new project.....Bill.......

Don Smith B-17 Project
 

Heavy Date,

The kit is done, but I am waiting on sockets. They should come any day, do you want me to send the kit to you with no sockets and then send the sockets when they come?

Mace Gill
The Aeroplane Works

Don Smith B-17 Project
 

Mace,
Might as well wait awhile. I am in NY working until the 8th anyway. I'll call you when I get home and you can ship it then.

Flydoc,
Sorry to use your thread to talk to Mace. I have never tried your pipe method before. The only thing I see as a possible problem is the formers could twist around the center a bit. Not sure how you plan on making sure all is square during the build.

As far as tank location, most use single tanks outboard and a large tank aft of the landing gear with a small header tank either next to the gear or above it. One thing to remember with the YS engine is to wrap the tanks with fibreglass shipping tape. They put out enough pressure to blow the tank.

I'm not sure about spliting the wing between the engines as I have never tried such a thing. I guess it is doable, but I would really look into it good and be triple sure that it will be strong and safe. You could just take the center section out in transit, but would mean more set up time at the field. That also may give you more angle options for stowing the fuse in the van as well.
Hope that helps out some.

I will have photos up in a few weeks of the stand off method on my website. After you see it in practice you may want to try it. If I can answer anything about it please feel free to email me.
Hans

Don Smith B-17 Project
 

Warbirdz,

I don't see a problem with room for a wing tube behind the gear. The tube must be behind the main spar, and all of the gear assembly is in front of the spar. I think the main problem with splitting the wing between nacells is one of vibration's effects on the tightness of the socket and allignment pins over time, not one of stregnth.

Hans,

Good point about keeping all the formers vertical and not letting them rotate on the pipe. I'll have to think about that.

Don Smith B-17 Project
 

A friend of mine had a RCV engine on a Ryan st and it had a lot of vibration. You might want to think about that with four of them.

Also Going to Build One
 

I've got all the accessories and most of the wood to build a Don Smith B-17. I was going to use G-23's which I have 4 of, but am about to change my mind to RCS 140's. They won't stick out of the cowl as much and I might be able to build scale exhaust for them. I'm building a Top-Flite T-34 presently and will finish it first. I needed something smaller to practice Flite-Metal on before the B-17. I'm going to build mine as "Starduster" which carried Lt. Gen. Ira Eaker all over the world. He was commander of MAAF at the time. The reason I'm doing this plane, is that my Dad was his flight engineer. Good luck with your B-17.

Jerry

Don Smith B-17 Project
 

I've now got my fuselage framed up. The method i described previously (building the fuse on a 1" pipe ) worked better than i hoped. I'll be able to plank 95% of the fuse before I remove it from the fixture, and it will be absolutely straight and true. I've also finished the stabilizer and elevators. I've made the stab so that I can plug in the right and left halves onto the center section, and also built fabric covered elevators with scale rib spacing and trim tabs.

I've got a quote for a set of matched RCV 90's to power this plane from Otto. Unfortunately, he's been called up by the Marines, so who knows when he will again be able to devote any time to servicing these engines. I'm considering other powerplants for my '17, but am still leaning towards the RCV's.

Howard Kahn
Fairfax Station, VA

Don Smith B-17 Project
 

Great news Flydoc,
When can we see some photos?

Hans

Don Smith B-17 Project
 

Sorry about the lack of photos, but i'm still in the dark ages, and don't have a digital camera. As soon as i get access to one, I'll take some and post them.

Don Smith B-17 Project
 

Paul hauls his 13 foot B17 in a Suburban, wing is 3 piece, all engines are in the center section. He cut some cheap styrofoam coolers to make a stand for the fuse, the center section goes in first, then the fuse on the stand and then the wing panels at the rear, to man operation to load, but all fits

photos of pipe construction method
 

Here are a few shots illustrating the method i used to construct my B-17 fuselage:

Don Smith B-17 Project
 

Here is anothe showing the stab center section mounted on the fuse:

Howard's 17 "pipeline"
 

Excellent work Howard!

That is going to be one beautiful bird when she's finished. Straight as an arrow to boot! Which B-17 are you replicating?

Operating temperature would be my only concern with the RCV's. In the stream of user data I have read they have a problem with heat disapation due to their linear design.

Rigging cowl flaps to the throttle linkage on each engine would go a long way to do as good a job of dealing with that as anything.

Don Smith B-17 Project
 

Hi Ed,

I inteng to model a particular B-17, which was flown by a friend of mine, Col Floyd Mason. It was #42-97555, a G model with the unromantic name of "Island F for Fox". It was downed on a mission over Meresburg on July 28th, 1944. The problem is I have no photos or documentation as yet regarding this plane, other than access to Col. Mason's logbook. He was a group leader in the 349th bomb group of the so called "bloody 100th".

If anyone out there has any leads regarding this plane, I'd love to hear about it.

No Docmentation...
 

Red flag going up..... ;^)

I shudder at the thought of you doing all this work without any documentation other than a generic G model...

By chance does the flight log have any photos of the airframe? It is possible to search for that S/N on both the web and within the USAAF archives in Dayton.

Before you go beyond sheeting the fuselage and wing you should gather docs of that specific airframe. You can use the Doc-U-Link section of ScaleAero.com to conduct your documentation search. I have the USAAF Assn, Boeing, 8th AF, USAF Museum, Paul Garber,
and other B-17 resources there for you to use in your search.

http://www.scaleaero.com/docpath.htm

This doesn't take very long since Doc-U-Link is already indexed to provide easier searching. I can imagine there are members of the USAAF Assn with resources beyond the web which can be of help.
Each AF Wing has a documentarian out there on the web.

Is Col Mason an active member of his wing's historical assn?. It will be easy to find out if there are photos of 42-97555 if you get to the unit's historian. If he remembers his tail code that vividly it sounds like he might be able to lead you to crew members, ground crews, etc who can provide photos.

Don Smith B-17 Project
 

Flydoc,

B-17 42-97555 is a B-17-G-20-VE Built by Lockheed-Vega. Give me a few days till I get home and I will see if any photos are available.


It took me 3 years to find them but I did get photos of my B-17 Heavy Date from 5 places including a bunch of crash photos.

It can be done if you really want to do the research!

Take care, Hans

RE: Don Smith B-17 Project
 

i have ds b17 and im having a terrible time building the stab,so far ive built it 3 times the first time i built it was by laying it over the planes and then removing it and building the other half,the result was warpped. the next 2 time i built the ribs as a whole and the leading and trailing adge then i assembled it,measured front and back got the same measurements and then sheeted it the result was warpped what do i do help thx bob

RE: Don Smith B-17 Project
 

Bob,

I'm sorry that you have had some difficulty building a straight stab. I'm no fan of Don Smith's technique of building structures in halfs. The way to solve the problem is to build the stab in a conventional manner, and make sure that you sheet it while it is pinned to a flat surface. First build the structure of the stab. Remove it and sand it so that all the ribs an spars are even. Make a full size skin by edge gluing the approprate thickness of balsa sheet together. Lay the skin in the jig you used to build the structure and place the structue on the skin. Glue the structure to the skin. Then apply the upper skin while the strtucture, with the lower skin attached is still on the flat surface. Once the top skin is attached, the stab will be locked in and absolutely straight, assuming that the building surface and jig is true. I hope this helps.

If you are interested, check out this thread on RC Scalebuilder, where I have documented the build of my B-17. Its a great flying plane, and well worth the effort to build.
http://www.rcscalebuilder.com/forum/...p?TID=723&PN=3

RE: Don Smith B-17 Project
 

thx howard 4 the info but im not sure of what you mean by building the frame work first ? do i build the leading edge by putting both 1/2" pieces toghter and doing the same with the trailing edge and then install the ribs as a whole? what do i do with the outside edge,put a tempoary piece of wood on the out side edge to hold it in place and then installing the ribs ? i looked at your pictures of your b17 (GREAT JOB) if you would like to call me my number is 408-248-0238 i live in ca.(pacific time) best time to call is around 6:00 pm thx look foreward to hearing from you bob