RE: Composite ARF 2.1M conversion  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       



All Forums >> Electric Aircraft Universe >> Glow to Electric Conversions >> RE: Composite ARF 2.1M conversion Page: <<   < prev  1 [2] 3   next >   >>  

Login
Message << Older Topic   Newer Topic >>
RE: Composite ARF 2.1M conversion - 2/19/2008 3:12:21 PM   
BaldEagel



Posts: 4232
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: offline
quote:

ORIGINAL: RC Accessory

Can anyone recommend carbon fiber props in the 17" diameter? This will be used in a Showtime 902 electric conversion, 2000 watts approx. I have the APC 17x10e props to test.


Mejzlik have just started making electric props, if the IC versions are anything to go by they will be top quality, I don't know the sizes available in your area, suggest you do a google search.

Mike

_____________________________

No matter what anyone says 100% is the maximum you can get.

(in reply to RC Accessory)
       Post #: 26

RE: Composite ARF 2.1M conversion - 2/21/2008 10:39:58 AM   
BaldEagel



Posts: 4232
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: offline 		Ok guys what do you think? do I put the front former on at an angle to try and mitigate the side thrust? or do I put it all on nice and straight and keep the spinner in the middle and put a rudder too throttle mix in to compensate?

I have done the mix solution before and you can get it very accurate, in fact more than putting side thrust on the bulkhead, its also easier to modify if needs be, when you change prop or C of G. I think I have just answered my own question, but any thoughts would be appreciated.

Mike

_____________________________

No matter what anyone says 100% is the maximum you can get.

(in reply to BaldEagel)
       Post #: 27

RE: Composite ARF 2.1M conversion - 2/29/2008 2:49:45 PM   
BaldEagel



Posts: 4232
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: offline 		Anyone?

Mike

_____________________________

No matter what anyone says 100% is the maximum you can get.

(in reply to BaldEagel)
       Post #: 28

RE: Composite ARF 2.1M conversion - 3/4/2008 4:29:34 PM   
BaldEagel



Posts: 4232
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: offline 		Not much interest here, anyway the rear bulkhead and horizontal support are now fitted I have placed the rest in position to get an estimate of the final C of G, I am still not convinced on the motor angle and will probably go with a straight firewall and mix the rudder and elevator to compensate, it will just look better.

Mike

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


_____________________________

No matter what anyone says 100% is the maximum you can get.

(in reply to BaldEagel)
       Post #: 29

RE: Composite ARF 2.1M conversion - 3/5/2008 8:12:54 AM   
Dave Wilshere


 

Posts: 1399
Joined: 6/12/2002
From: Watford, UNITED KINGDOM
Status: offline 		I've been flying a 2 x 2 Extra with an AXi 5330/18 for 2 1/2 years.
It has 6000 prolite TP cells 10s and a Graupner 20 x 10 G Sonic prop.
This prop hangs at mid stick and pulls well out of the hang. Flight times are 10 minutes, with mixed 3-D and 11 minutes IMAC style.

I use a ACRO 90 Jeti controller and it hardly gets warm.
I'm using the new Spin 99 in my Spark EDF and it works well, but is more sensitive to temperature-only at higher current draws.

The 2 x 2 is quite a bit lighter than the 2.1, though the fuselage is the same. the wings and tail are heavier due to more cloth giving a tough surface that does not mark as easily.

Dave W

_____________________________

Motors & Rotors. UK JetCat, BVM, Airworld, Eurokit & Graupner agents. Comp ARF Rep UK.Pull Over Products.

(in reply to BaldEagel)
       Post #: 30

RE: Composite ARF 2.1M conversion - 3/5/2008 10:48:52 AM   
BaldEagel



Posts: 4232
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: offline 		Dave

Thanks for the information its usefull to know of other configerations.

I thought the 2.1 was lighter than the 2x2 with a bigger wing area, I must of misunderstood all the blurb when they brought this out, do you know what the weight difference is?

Interesting that the Spin 99 gets hotter, as you say this may be because of the ducted fan drawing more amps, what sort of amp draw is it compared too the 2x2?

What would you do with hindsight about the side thrust, would you build it in, or use a mix on the Tx? I would appretiate your comments.

Mike

_____________________________

No matter what anyone says 100% is the maximum you can get.

(in reply to Dave Wilshere)
       Post #: 31

RE: Composite ARF 2.1M conversion - 3/5/2008 1:15:52 PM   
didiwatt


 

Posts: 497
Joined: 2/3/2002
From: Walla Walla, WA, USA
Status: offline 		Dave:

Any idea of how many watts you are putting out on your 2X2? I would also be interested in what kind of motor mount you are using. I don't see where AXI makes a mount with a support for the rear of the motor.

I am working on a twin and would like a system capable of 3,000 watts per side on 10 cells.

Thanks, Paul

(in reply to BaldEagel)
       Post #: 32

RE: Composite ARF 2.1M conversion - 3/5/2008 1:55:01 PM   
BaldEagel



Posts: 4232
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: offline 		AXI do this type of mount for all their motors, go to the "Model Motors" web site and you can down load their catalogue that has all the information you will possibly need from prop size too amp draw.

Mike

Attachments
Click to see fullsize image.
Click for fullsize


_____________________________

No matter what anyone says 100% is the maximum you can get.

(in reply to didiwatt)
       Post #: 33

RE: Composite ARF 2.1M conversion - 3/5/2008 2:00:48 PM   
BaldEagel



Posts: 4232
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: offline 		Paul

If my calculation are correct you are building a twin which is going to weigh 40Lb @ 150watts/Lb (generous) that is some twin you are building what is it?

Mike

_____________________________

No matter what anyone says 100% is the maximum you can get.

(in reply to BaldEagel)
       Post #: 34

RE: Composite ARF 2.1M conversion - 3/5/2008 5:06:24 PM   
BaldEagel



Posts: 4232
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: offline 		Few more pic's, the first shows the Plett in the conventional position without the front former fitted, this allows me the choise if the C of G is too far forward, will have to take out the front former that is now fitted and shown in the second pic, I will brace this back too the mid former, the next two pic's show the range of battery position I have by making the tray movable, again for C of G adjustment.

Mike

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


_____________________________

No matter what anyone says 100% is the maximum you can get.

(in reply to BaldEagel)
       Post #: 35

RE: Composite ARF 2.1M conversion - 3/5/2008 5:30:41 PM   
BaldEagel



Posts: 4232
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: offline 		Further pic's showing the Plett in position on its temporary mount to get the spinner clearance.

Mike

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


_____________________________

No matter what anyone says 100% is the maximum you can get.

(in reply to BaldEagel)
       Post #: 36

RE: Composite ARF 2.1M conversion - 3/6/2008 1:13:54 PM   
didiwatt


 

Posts: 497
Joined: 2/3/2002
From: Walla Walla, WA, USA
Status: offline 		Mike:
Round #2 of this baby which only lasted 4 flights. At 40 to 45lbs, I figured I would need 150 watts per lb to take it off the grass.

Paul

Attachments
Click to see fullsize image.
Click for fullsize

(in reply to BaldEagel)
       Post #: 37

RE: Composite ARF 2.1M conversion - 3/6/2008 1:42:14 PM   
BaldEagel



Posts: 4232
Joined: 10/12/2005
From: Wychling, Kent, UNITED KINGDOM
Status: offline 		Paul

This may interest you: http://www.modelmotors.cz/odkazy/01/index.htm half the expected weight of yours, but if you double up, way over powered I think.

Have you downloaded the Model Motors catalogue yet?

Mike

_____________________________

No matter what anyone says 100% is the maximum you can get.

(in reply to didiwatt)
       Post #: 38

RE: Composite ARF 2.1M conversion - 3/6/2008 5:58:10 PM   
BaldEagel