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Tomhe design F18 Hornet

Started by VC, July 04, 2010, 10:52:10 PM

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VC

Hi All.

I just started building this model. I need some help in reinforcing the structure.

The attached diagram shows the reinforcement placements and I am planning to use Sheekh Kabab Skewers extensively. in fact for the wing leading edges (A) & (B), I have created long spars by cementing 2 skewers end to end. The joint is strong and the whole spar flexes well. Since they will be embedded in a furrow and covered with epoxy and set to cure overnight, I think this will provide sufficient strength and resilience against crashes.

These skewers are made of some kind of dense composite material (doesn't seem like bamboo, but I could be mistaken) which is very flexible yet strong. Takes a good deal of effort to snap or cut them. Does anyone have any experience with these type of skewers?

Any advice will be appreciated.

Regards,

VC
Growing old is mandatory, growing up is optional!

ujjwaana

Quote from: VC on July 04, 2010, 10:52:10 PM
These skewers are made of some kind of dense composite material (doesn't seem like bamboo, but I could be mistaken) which is very flexible yet strong. Takes a good deal of effort to snap or cut them. Does anyone have any experience with these type of skewers?

Regards,

VC

so After Tomhe's F-22, now F-18 Hornet!! great going VC!

Where did you get the Kabab skewers ? even I would like to preserve my CF stock for later...

Futaba 8FG Super | HK-450v2 | FA-22 Raptor |AXN Floater-Jet | FunJet | Black Horse Edge 540 | Amp Master 015 | 2.3M Big Brother

VC

Hi Ujj!

I just build them, never get around to flying them. You guys are the actual flyers, I am just a theoretical @$$****!

You want some kebab skewers? Let me have your address. I picked up mine from a shop that deals in party supplies like depron plates and stuff.

Cheers mate!

VC
Growing old is mandatory, growing up is optional!

VC

Administrator Sir, my apologies for the self deprecating description. I am just a wee bit frustrated with life today. Pardon me. :bow:
Growing old is mandatory, growing up is optional!

bmanoj2

Hi VC I have used the bamboo sticks. They are better than the Carbon fiber one for short spans (like up to 30cm) I have tried joining them by tying two ends with thread and gluing with epoxy. They work great. :thumbsup:
Here I have 2 sizes available here. One is aound 2 to 3 mm dia and the other about 5 to 6mm dia. I have used the small ones in all my foamies. :)
"Learn from yesterday, live for today, hope for tomorrow."

VC

bmanoj2 :salute: - Thanks Buddy! This gives me a lot of reassurance.

Here are some pics of the build in progress...........
Growing old is mandatory, growing up is optional!

bmanoj2

Looks Neat..What glue are you using to fix the bamboo sticks (I can't see any foam safe ca)? From the picture I think you have joined them too ??  I am not sure about the diameter of the sticks you are using but 3 mm will be great. If you feel that its more flexible just apply a thin layer of epoxy and allow it to cure before using them. But this will increase the weight of the model slightly. All the best and be little careful while launching the model as the propeller will be behind your hand. :)
"Learn from yesterday, live for today, hope for tomorrow."

VC

The sticks are less than 3mm and I have joined them with epoxy and standard CA glue. The groove that I will have to create along the fuselage will be filled with epoxy and these sticks will rest in them. 24 hours of curing should make them rock solid. BTW, I  don't have Foam Safe CA glue. Expecting it next week, courtesy Anam.
Growing old is mandatory, growing up is optional!

anwar

Hangar : Please see my introduction.
RC India forum and me : About this forum.

VC

Quote from: anwar on July 05, 2010, 01:09:15 AM
Why only pusher jets ? ;)

There is a FW 190 D similarly cut out and ready for assembly. It has a full profile fuselage. I plan to start on that after I finish this.
Growing old is mandatory, growing up is optional!

VC

The model now weighs 125 grams. Estimated AUW is below 350 grams.

This is what I plan to use:

EMAX CF2805 Outrunner Brushless Motor
6 X 4P prop
ESC - DYS 18 Amps
3S 1300 mAh LiPo
9gm Servo X 2

Experts please advise if my combo seems sound, I am looking for a moderately fast flyer - not aiming for crazy bursts of speed or fancy aerobatics to start with.

Cheers!

VC

Growing old is mandatory, growing up is optional!

ashJR7202

hi VC grt plan yaar!!!

i am going to copy this one for my next build!!!

Ashish
Hanger: Mini Yak-54| 210 Phantom | SU-47| F-15| EuroFighter|Scrappy|SU 27|Eurofighter|Sukhoi PAK FA
Blade MCX| Blade CP PRO
JR XP7202| DX7

VC

Should I send it to you, or do you already have it?
Growing old is mandatory, growing up is optional!

ujjwaana

Which EMAX CF2805 are you using ? 1600kV or 2840kv ?
6x4 would be fine for 1600kv. But just a little bit overkill for 2840. in later case try 6x3 or 5x4 and see the load on Watt Meter.

18Amp is okay if its not heating up much on static test. 25Amp would be safer option.
Futaba 8FG Super | HK-450v2 | FA-22 Raptor |AXN Floater-Jet | FunJet | Black Horse Edge 540 | Amp Master 015 | 2.3M Big Brother

VC

Thanks UJJwaana for the tip. I am expecting the  2840 Kv from Dinil and was planning to use that. Will now change the prop to 6X3.
Growing old is mandatory, growing up is optional!

ashJR7202

Quote from: VC on July 19, 2010, 04:18:40 PM
Should I send it to you, or do you already have it?
VC,
i just sayed 1st diagram, is it enough? can u pls provide dimension as well!!

thanks
Ashish
Hanger: Mini Yak-54| 210 Phantom | SU-47| F-15| EuroFighter|Scrappy|SU 27|Eurofighter|Sukhoi PAK FA
Blade MCX| Blade CP PRO
JR XP7202| DX7

VC

Hi Ashish, I have sent you a PM. Pl check.
Growing old is mandatory, growing up is optional!

ashJR7202

Quote from: VC on July 19, 2010, 05:23:59 PM
Hi Ashish, I have sent you a PM. Pl check.

PM not yet received !!! :-(
Hanger: Mini Yak-54| 210 Phantom | SU-47| F-15| EuroFighter|Scrappy|SU 27|Eurofighter|Sukhoi PAK FA
Blade MCX| Blade CP PRO
JR XP7202| DX7

ashJR7202

Hanger: Mini Yak-54| 210 Phantom | SU-47| F-15| EuroFighter|Scrappy|SU 27|Eurofighter|Sukhoi PAK FA
Blade MCX| Blade CP PRO
JR XP7202| DX7

VC

Growing old is mandatory, growing up is optional!

ashJR7202

hey VC any update on this.

are u able to put motor and fly it????

i do have FC 2805 2840Kv motor with me and i think ur also planning to use same motor. pls let me know the combination result!!!!!

i am planning to build eurofighter from the plans u sent me. if this motor is good then i will also use same one and will start building!!!!

Ashish
Hanger: Mini Yak-54| 210 Phantom | SU-47| F-15| EuroFighter|Scrappy|SU 27|Eurofighter|Sukhoi PAK FA
Blade MCX| Blade CP PRO
JR XP7202| DX7

VC

Ashish, will keep you posted on this. I plan to install the powerplant over this weekend. Wish me luck!
Growing old is mandatory, growing up is optional!

ashJR7202

All the best!!!!

let us know the good news!!! and some video as well!!!

Ashish
Hanger: Mini Yak-54| 210 Phantom | SU-47| F-15| EuroFighter|Scrappy|SU 27|Eurofighter|Sukhoi PAK FA
Blade MCX| Blade CP PRO
JR XP7202| DX7

VC

Construction of the model is now complete, with the exception of the hinges for the 4 control surfaces. AUW is 340 grams.

Final configuration as follows:

EMax CF 2805 (2840 Kv)
6X4 Pusher Prop
2s 1200 mAh LiPo
ESC 25 A (I can also use an 18 A) as suggested here:

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=5353

This combination should give me a thrust of approximately 413 grams at a current draw of 12 Amps.

Typical newbie question - 400 + grams thrust for an AUW of 340 grams - what kind of performance are we talking about here? Sedate, Moderate or Blazing fast?  ???

Please advise urgently, as I want to finish the model today and maiden her immediately.

Thanks!
Growing old is mandatory, growing up is optional!

ashJR7202

hey VC,

thats grt  :salute:!! would like to see it flying!!!!

abt performance i think it will give sedate flying!!!! i am using same motor on modified Phantom super 210, it has got 31" wingspan, havnt chk AUW!!! but it is giveing sedate/moderate flight chk my youtube video!! i am using 5x4 prop on this one!!!!


thougth it is mentioned 400+ thrust but i think it will not give that much!!!

but lets see hw it performs on ur plane!!!!!

Ashish
Hanger: Mini Yak-54| 210 Phantom | SU-47| F-15| EuroFighter|Scrappy|SU 27|Eurofighter|Sukhoi PAK FA
Blade MCX| Blade CP PRO
JR XP7202| DX7