Well, I've gone and done it. Isaw a brand new Guillow's B-17 on Craigslist and Icouldn't help myself. After thinking about it for a week and doing some research, Ihad discovered that these are fun kits to build and turn into great RC planes. I know they are quite challenging due to their size and complexity (for their size), but every bit rewarding for it. So Ibought the kit and have continued reseraching the details of the build before Istart building. So Idecided to start a thread to share my progress, challenges and to ask for help, as Im' sure I'll need it.

This is certainly not my first build, so I feel quite comfortable biting this project off. Not to mention that Iam a mech/aero engineer when Im not tinkering with the RCstuff... But here's where Iam so far, and the questions Iam currently looking to answer.

Power: Brushless - 4 motors ~ 9-10 oz thrust each to be very conservative. Something similar to an E-Flite Park 250. Each with a 10A ESC. Still deciding on exactly what motor/esc's any recomendations? I've checked out some of the Motrolfly, MicroDan, Trinitiy, and other types on Hobbycity... (and of course Hacker, scorpion and the other nicer/expensive ones)
Batteries:A final decision will be made based on motor selection, but Iam thinking 2 x 3S ~1000mah packs (one for each wing)
Servos: 8g servos HS-55 or S75s (I have a bunch from old projects)
Retracts: Not sure about this yet. I've seen some posts on rcgroups that included them, but didn't mention what they were. However, they did mention they were a big PITA (what retracts aren't?!)
Flaps: IKNOW it doesn't need them. IKNOWit will add complexity. But IkNOW it WILLlook so much cooler... Ihaven't seen anyone do this on a Guillow's B-17 yet though... anyone?
Sheeting: Ithink some sheeting is a good idea. Iplan to do a lot of lightening so there will need to be some re-strengthening to compensate. Iwas thinking some thin (1/32 or 1/16) sheeting on the empenage and wing would be a good idea to add stiffness and will help the appearance when its covered.
Covering: This one I'm really not so sure about. I want to be pretty scale with the plane, so color is required. Use the tissue and dope it? Use some sort of plastic covering (monokote/ultracote derivative, solite, microlite, etc?)
Hardware: Most likely dubro 2-56 in combination with CF rods (for torque-tubes, push rods)
Wheels: Du-Bro 2" Super lite wheels for the mains, Not sure about the tail - depends on how the tailwheel is set up (retracts, steering etc)... any suggestions?

In general Iam estimating that my finished weight will be under 30 oz. I'm aming for that just for conservatism, but hope to be in the 26oz range. Anyways, I'd appreciate any thoughts or insight from other builders experiences. Thanks!

Cheers,

Kyle

been one of my favorites ever since 12 O'clock High aired back in the 60's.
having been inside a real one though tells the real truth about this gladiator, and the men who crewed these in the scariest of times.

this will be enjoyable to watch

Boy you sure took on a project didn't ya....  With sheeting on such a delicate airframe, I would do a lot of pre bending with water and ammonia rubber banded to tubes to get the shape you need. I think it would be hard to keep everything straight if you don't.. This will be a fun one to watch, looking forward to your build... I love how they say "Giant scale" on the box, Rc planes have sure gotten a lot bigger over the years....

plans.....check, glue.......check, box-o-wood....check, box-of 5hr energy drinks.......check

I prefer Rockstar myself. 5 hour is ok, but I like that cranked out feeling from waaaay too much caffeine. No building done today, more research. Found some threads on where people used Solite to cover. That seemed to work decently well for them. I really like the colors available for Microlite. Has anyone used it before? It has a great areal weight (0.6 oz/yrd^2, 18-22 g/m² )
http://www.coverite.com/covering/covq0240.html
Those same builders also used HeadsupRC for motors and speed controls. Never heard of them before. Anyone else?
http://www.headsuprc.com/servlet/the...lectric/Detail

Kyle

Saw this in another forum and thought I'd share as well... enjoy!

http://www.pacificflyer.com/2010/03/...th-scale-b-17/

No building yet... more reserach. Been thinking about retracts and motors. Anyone use the Robart 123 micro retracts before? They look like they might work...

Motors I have nailed down to one (or four) of the following

Motrolfly DM2205-1800 or 2800KV
Turnigy Park 250-2200
Turnigy 221-2300
Headsup RC 2712-17

Any thoughts on these motors? Thanks!

Cheers,

Kyle

I think they fly pretty hot... http://www.youtube.com/watch?v=zzG8IOtKIUI

I have one all framed up, and sheeted..I just need to finish it sometime...its a show model only..started it back when those b17 kits were like 25 bucks ! hahaha

I've read through that guys thread on another forum... he used the Headsup RC motors. Thats actually where I originally heard of them. He did a decent job building the plane, but didn't lighten it up too much. As such he needed a little more power than I'm hoping to need.

A friend of mine at work turned me on to the Hobbyking digital servo-less/electric retracts.. at  1.25 oz each and $8.. they might be worth the gamble!

http://hobbyking.com/hobbyking/store...dProduct=12883

Finally got my building space clear so Ican start working on the Fort... had to build a bridge for work. Tthis coming week in National Engineers week and we have some events and such were they try to remind us that work can be fun... Anyways, got that done, made some new building boards out of scrap sandy ply Ihad laying around from other projects and got the fuse keel beams cut out, sanded and glued. Started working on the bulkeheads, but Ineed to figure out where my servos battery are going to go and make mods to them before Iglue them in so its not as much of a delacate proceedure later on. Here are some pics... Any opinions so far?!?!?

After a very long week of work, Ifinally was able to get some building in (and post about it!) Ifinished cutting out the fuselage bulkheads, trimmed out the stringer notches and then sanded them all down. Ithen glued them in place and have gotten the fuselage framed up. Ihaven't gotten the stringers on yet, but Imight get to that later tonight. So far at 1.5 oz.

Afriend was cleaning out some smaller electrics, and decided to make a donation to my build. He gave me two scorpion 2208-32 motors, two no-name similar motors, and two 10 amp speed controls. Not a bad freebe! Woohooo! Abit more muscle that is necessary, but it will work for sure!

Ihave been thining about the retracts more and more, and as much as Iwant them in, unless Ifind someone who has done this and can tell me exactly what retracts they put in, and how well it worked (ie would you do it again?) I think Imight forgo them. It is sad, but we'll see...

Anyways, here are some pics of the bulkheads, first half of the fuse, and the full framed fuse.

Kyle

I got a bunch of the stringers put in, the wing roots glued on and the stab saddles glued on. Now I'm at a point, where I can use some helpfull ideas...  What to do with the tail wheel?!?

I figured this would be a good time to get that sorted out before I finish framing that all in and it turns into a nightmare to work around. I'd really like a stearable tailwheel. I've heard of some using the ParkZone Corsair tailwheel, or similar things... any other ideas? Anyone? Help?

I'll get some pics up tomorrow.

As promised, here are some pictures. Ihave added more stringers to the top hemisphere of the fuselage. It is nearly complete - for this stage anyways. I've got an idea for the tail wheel. Very simple, but in engineering, simple is better. Less room for errors and mistakes right? Have to wait till Ihave time to go to the LHS to get a wheel and what not for that. In the meantime, I will probably finish what Ican on the fuse, but leave the bottom half without the stringers. If I'm still looking for something to do, Imay start cutting wing ribs. I'm sure that will take up my time!

Well, work has gotten in the way of fun lately. But I've managed to get some more work done. After several iterations, Iput a tail wheel configuration in that Iam happy with. It is stearable via a seperate push-rod. Ialso removed part of the top section to form a hatch to access the area Iintend to put the servos and batteries. I have also bought two Maxxamp 2S 3100 batteries that were on clearance at the LHS. But after getting home and running some numbers through the calculator it seems these are just not going to work. Ihave since bought two sets of 3S 1400mah LiPos that will work out great and should give a good 8 min flight time and with a 6in 3 blade prop provide more than adequate thrust ~ 13 oz per motor at full throttle. More work will be completed this weekend and I'll get some more pictures up then. Should start working on the vertical and horizontal and soon the wings... feel free to leave comments!

More progress to report. Ihad to buy new batteries. The MaxAmps that Ibought were just too big, physically and capacity wise. After running a prop calc Idecided to buy some smaller 3S 1300mah batteries. So now Ihave two 2S 3100mah LiPo's if anyone is interested, just PM me.

As for building, Ihave finished the fuse and started building the left wing. Need to add stringers nd the pylons and that should be about done. Still not sure about retracts. Afirend might have some extra electric ones so that may be too tempting to pass up. So far the building is going very well and seems to be very light. Ilightened most of the ribs with holes and small cut outs. I'm also using a CF torque rod for the aileron which can be seen in the last pic. Post your thoughts or comments! Thanks!

More work on the left wing has been completed. I have installed the two wing joining roots which attach to the fuselage. I added the additional partial wing ribs and cut the front spar in the two locations for the pylons. I have added additional gussets and some balsa at the end to help blending from the front and rear spar to the wing tip. Very minor additional weight but I thinnk the strength and astetic benfits gained far outweigh the several grams I added.