Author Topic: Ben Feist's Curtiss R3C-2 (Read 24150 times)

bfeist · « **Reply #15 on:** October 05, 2005, 07:34:35 am »

quote:

Ben, you are going to have your hands full this winter.

That's it, i give up

Benjamin Feist - EMFSO Website Developer

mistairjoe · « **Reply #16 on:** October 05, 2005, 09:36:22 pm »

As far as i am concerned Ladie has the best beer,imported,Cech. hmmm how do you spell that, you know it use to and with Slovakia

bfeist · « **Reply #17 on:** October 10, 2005, 09:57:22 am »

Well, I'm making some half decent progress on the plane. Glenn Nikolaiko was gracious enough to go over the plans and short-kit parts with me and make some lightening suggestions (lots). As you've read above, if built as-is it would come out as a very heavy airplane. Glenn's hopeful that major modifications could take up to 1.5 lbs out of it--leaving me with an all-up weight of 6.5-7lbs.

Some of the main planned points:

Fuselage
- Discard 90% of laser cut fuse formers (boo). They're made out of very heavy 1/8" ply which is unnecessary for electric. I can use the ply ones as templates, and make 1/8" balsa sheeted with 1/64" ply formers.
- Change fuse to stringer construction rather than fully sheeting
- Modify firewall location to coincide with Axi 4130/16 location
- Completely redesign and rebuild the tail. Currently it's a thick 1/2" balsa construction sanded to contour. It also uses square structure pieces. I'll change these to triangle and will make it a 1/4" flat tail. The curve of the tail will be achieved by bending 1/32" balsa strips and laminating them together.
- Change top of rear fuse from sanded block of wood, to built-up construction.
- Create sloped battery tray through firewall.

Floats
- Partially sheet the floats (instead of full sheeting) if I can come up with a way to make them waterproof (Pike?).
- Drill lightening holes in float spines (it looks like swiss cheese now)
- Make floats removable and rig plane to accept gear of some sort (so i can fly it more than once a year)

Wings
- Partially sheet the wings (instead of full sheeting). Make them a D-Tube construction and use 1/4" cap strips everywhere.
- Revisit how the bottom wing is mounted (currently two 1/4" bolts). Might change this to a dowel off the LE and one bolt.

Benjamin Feist - EMFSO Website Developer

Martin Irvine · « **Reply #18 on:** October 10, 2005, 11:13:11 am »

Sorry you've had to do so much redesign but I think you are on the right track. I'd suggest you keep the fully sheeted floats. I'd think you would save very little by going to partial sheeting and they are going to be under quite a load when landing and taking off.

I really like the Curtis racers, and I'm glad someone chose to do one. (One of them was my #2 choice)

Martin

bfeist · « **Reply #19 on:** February 26, 2006, 09:25:19 am »

After a 3 month delay (stupid contract work) i'm back building this thing. I'm now officially worried that I won't finish in time. I'll be finished sheeting the floats tonight (took Martin's advice and went with fully sheeted 1/32" bottoms). Wings are next.

The manufacturer said that someone in the UK has electrified this kit. I'm going to try to get in touch with them to see what mods they made to do it and what power system was involved.

Benjamin Feist - EMFSO Website Developer

piker · « **Reply #20 on:** February 27, 2006, 12:32:27 am »

Hi Ben,

Glad to hear you're back at it.

I too have had a serious building delay. I've done very little since the first week of January. I plan to get back at it ASAP.

You still have 4 months. No excuses

Robert

bfeist · « **Reply #21 on:** April 17, 2006, 12:44:52 am »

Making good progress (thanks Pike!). Floats and both wings are finished contruction and now need sanding and covering. The fuselage is about half finished. I was planning on covering the fuse with monokote rather that 1/16" sheeting, but it looks like most of the strength is in the sheeting going to the tail, so i'll sheet the whole thing. The fuse is feeling a bit heavy...but i'm not used to building planes this big. it's probably just my own paranoia.

As for the power system, i've decided on:

Axi 4120/18 radial mounted
two 3s1p 3700mAh lipos for a total of 6s (20 cells equiv).
13x8 prop - should spin at around 9000rpm drawing 35A producing about 600W output.

These cells are very light. I got them from icare who provide very fast service and a resonable price (http://www.icare-rc.com/modelmotors_axi41.htm).

some modifications and deviations from the plans:
- sheeting with 1/16" balsa instead of 3/32"
- using 1/8" gear wire with rigging instead of 5/32"
- made mounting plates in the fuse for the gear wire to make the gear removable--mainly did this for portability reasons, but it also means i could potentially put undercarriage on the plane for non-float flying
- built up the wing tips by lamenating curved balsa instead of using blocks and sheeting
- modified the fuse to allow cowl removal all the way back to the leading edge of the top wing--mainly for easy battery access.

that's all for now

Benjamin Feist - EMFSO Website Developer

bfeist · « **Reply #22 on:** April 24, 2006, 09:50:06 am »

I've been cooking along--spend about 8 hours building this weekend.

Here are some pics of the work in progress

https://plus.google.com/u/0/photos/115501856346560787992/albums/5757076170782257457

found this awesome photo of a similar curtiss. looks sweet.
http://website.lineone.net/~roling47/SeaWings/Curtiss1a.JPG

Benjamin Feist - EMFSO Website Developer

piker · « **Reply #23 on:** April 24, 2006, 10:06:44 pm »

Great work, Ben.

That other photo....Is that full size? Looks like it.

Robert

bfeist · « **Reply #24 on:** April 25, 2006, 10:12:05 am »

I think it is. it might be a later model. the markings are slightly different.

Benjamin Feist - EMFSO Website Developer

gordonbw · « **Reply #25 on:** April 27, 2006, 07:57:32 pm »

Wow, Ben! Beautiful work, and I can see you've made major progress since the EMFSO annual meeting.

bfeist · « **Reply #26 on:** April 29, 2006, 08:56:07 am »

Glen from GDH has contacted me and told me that the photo above is actually of a 3/4 model that was built a few years ago. Oh well, still beautiful.

Benjamin Feist - EMFSO Website Developer

bfeist · « **Reply #27 on:** May 31, 2006, 09:07:28 am »

Painted the floats last night. They look awesome.

todo:
- put magnets into cowel for fastening
- sand and cover the fuse
- sand and cover wings
- bend the float strut wire again (and again) to get them symetrical and the right height.
- paint pilot
- get/make wing decals
- sand/cover wing struts
- mount electronics
- mount motor
- balance
- make battery tray

Benjamin Feist - EMFSO Website Developer

piker · « **Reply #28 on:** May 31, 2006, 08:26:30 pm »

You can see the light at the end of the tunnel. Keep going. There's only three and a half weeks.

Robert

bfeist · « **Reply #29 on:** June 18, 2006, 03:19:30 am »

Well, did a float test with Rob Pike this Saturday evening. It floats

We taxied around for a while and practiced getting up on step. I'm drawing 39 amps static with 6s1p lipos (750W). The Axi 4120-18 purrs like a kitten.

Here are some shots (with a picture of the real Curtiss for reference). I still need to add the markings, pilot and some of the rigging.

Rob convinced me (of course) to try taxiing one last time and I managed to flip the plane over. The Jeti Advance 70 Opto literally exploded--spewing smoke and whatever that black crap that smells like money is that comes out of exploded Jetis. The guts of the plane are now coated in tar. My lipos are fine thank god. The plan is to get a Phoenix 60 this time instead of a Jeti--Rob assures me they are "more water resistant". Well, anything is better than exploding on contact with water.

A Dali painting?

Benjamin Feist - EMFSO Website Developer