SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Sep 26, 2002, 02:39 PM
BEC
Registered User
BEC's Avatar
Auburn, Washington USA
Joined Jan 2001
12,937 Posts
Sure, that dam would trip the flow and make it turbulent (if it wasn't already), lowering the local air pressure which would encourage flow out of the vent....good idea. It needent be a 1/8 X 1/4 stick (that's about what it appears to be) - 1/8 square or even 1/16 by 1/8 edge on would have the same aero effect.

OTOH, this isn't that far behind the aileron servo and linkages sticking out from the bottom of the wing, so it may not be necessary as the airflow is probably already pretty turbulent here. Can't hurt, though.

The NACA shape is for intakes - it wouldn't help in this application.
BEC is offline Find More Posts by BEC
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 26, 2002, 02:51 PM
www.M-A-E.com
rcflyer11's Avatar
Lilburn, GA, USA
Joined Dec 2000
1,175 Posts
BEC,
Good guess! I measured and it is, indeed, 1/8"x1/4". Also, it's exactly 5" behind the rear of aileron servo to front of opening. What doesn't show very well in the picture is the taper on the air dam. The air dam LE is almost flush with the fuse bottom.

Randy
rcflyer11 is offline Find More Posts by rcflyer11
Reply With Quote
Old Sep 26, 2002, 02:56 PM
Registered User
markwild's Avatar
San Fernando Valley
Joined Jun 2002
444 Posts
RC,
My guess is that having the vent there is aerodynamically cleaner than without the vent. Without the vent, you're basically dragging a bag through the air, and with the vent it's like a bag with a hole. I don't know if you'd ever notice any difference (we're only human, after all), but intuitively it seems better. Maybe that's a mod that oughta make it into production.
--Mark
markwild is offline Find More Posts by markwild
Last edited by markwild; Sep 26, 2002 at 05:13 PM.
Reply With Quote
Old Sep 26, 2002, 05:05 PM
www.M-A-E.com
rcflyer11's Avatar
Lilburn, GA, USA
Joined Dec 2000
1,175 Posts
I actually test-flew the plane before I added the air exit. Can't tell any difference in flight performance.

Randy
rcflyer11 is offline Find More Posts by rcflyer11
Reply With Quote
Old Sep 26, 2002, 06:44 PM
89" Kool Aid drinker.
Smash McCrash's Avatar
United States, CA, Ventura
Joined Dec 2001
3,133 Posts
RClark: I don't know if the motor is getting warm, I didn't pull it out and check. I will next time. I think that the prop may have been coming loose, when I didn't grease the landing, like I ever do , the prop did loosen up a bit, so next time I fly I will have to see. BTW, what are the 1100's that you are using? I checked at the LHS yesterday and all they had were KR1200AE's in yellow wrap. I am interested in getting some higher cap packs for my SB and these sound like the ticket.

RCFlyer11: Like the exhaust... Going to have to cut into my SB and add it. Thanks for the inspiration.

Mike
Smash McCrash is offline Find More Posts by Smash McCrash
Reply With Quote
Old Sep 26, 2002, 07:04 PM
an earth bound misfit, I
Basketcase's Avatar
St. Pete, Florida
Joined Sep 2001
9,429 Posts
Thanks Randy, BEC and Mark, I'll definitely be adding one to my Switchback.

Should the air dam be tapered or blunt?

Wayne
Basketcase is offline Find More Posts by Basketcase
Reply With Quote
Old Sep 26, 2002, 09:09 PM
www.M-A-E.com
rcflyer11's Avatar
Lilburn, GA, USA
Joined Dec 2000
1,175 Posts
I would think it should be tapered, but in reality it probably won't make much difference.

Randy
rcflyer11 is offline Find More Posts by rcflyer11
Reply With Quote
Old Sep 26, 2002, 09:38 PM
A Clinger
rclark's Avatar
Butte, MT
Joined Sep 2001
7,073 Posts
Mike,

www.HobbyPeople.net has the 1100 Nimh packs I am using. I needed to 'fold' the pack to make a brick.

www.EdogFight.com has the loose cells.

I'll probably add an air exit port or two on my SB as well; now that I been shown how simple it can be Thanks Randy.... Course as we head toward winter, we may want to keep the systems compartment a little 'warm' when the temp is hanging around 0F .... Hmmmm...
rclark is offline Find More Posts by rclark
Last edited by rclark; Sep 27, 2002 at 10:37 AM.
Reply With Quote
Old Sep 26, 2002, 11:44 PM
89" Kool Aid drinker.
Smash McCrash's Avatar
United States, CA, Ventura
Joined Dec 2001
3,133 Posts
Thanks RClark. I know which ones you are talking about now. I think these will have to find their way into my box now.

2 more sorties on the SB last night and 2 more tonight. GAWD this is addicting. I dorked it in and bent the prop shaft. When I pulled the motor out to straighten it for the second flight, the motor was barely warm, but this was about 90-120 seconds after I stopped flying. I am also able touse less throttle for some of the flight, so that might be letting the motor and battery cool a bit. I know that my skills are progressing now. I can plant the plane on the road where I want it and feel comfortable enough to try snap rolls... I think that I am getting the hang of this flying thing.

Thanks for all of the information for the motor/prop/battery combination. I ordered the parts to make a C box and will let you know what the results are.

Mike
Smash McCrash is offline Find More Posts by Smash McCrash
Reply With Quote
Old Sep 27, 2002, 01:39 AM
BEC
Registered User
BEC's Avatar
Auburn, Washington USA
Joined Jan 2001
12,937 Posts
Did a static test with the 10X7 and 8X1100s - the plane wants to slowly climb when held vertically by one wing tip - but the motor gets hot in a hurry.... I'll have to fly it this way then decide if going to the "C" ratio isn't safer for the motor (and perhaps the battery).
BEC is offline Find More Posts by BEC
Reply With Quote
Old Sep 27, 2002, 06:45 AM
Space Coast USA
hoppy's Avatar
Space Coast
Joined Oct 2000
20,897 Posts
Anybody else wish HP would shut the opening music off?

Anyway, where are you finding those batteries on the HP website? Couldn't find them under airplane batteries.

hoppy
hoppy is offline Find More Posts by hoppy
Reply With Quote
Old Sep 27, 2002, 09:20 AM
89" Kool Aid drinker.
Smash McCrash's Avatar
United States, CA, Ventura
Joined Dec 2001
3,133 Posts
They are the Wattage 1100 2/3 AE's, PN 128554. Also, the second link is wrong, it should be EDogFight

Thanks for the info, I think I will have to get some of those single cells from EDog and build up a couple of packs... At $2 a cell, its a steal!

Mike
Smash McCrash is offline Find More Posts by Smash McCrash
Reply With Quote
Old Sep 27, 2002, 09:48 AM
www.M-A-E.com
rcflyer11's Avatar
Lilburn, GA, USA
Joined Dec 2000
1,175 Posts
BEC,
Have you taken any WhattMeter readings with this setup?

Randy
rcflyer11 is offline Find More Posts by rcflyer11
Reply With Quote
Old Sep 28, 2002, 06:21 PM
89" Kool Aid drinker.
Smash McCrash's Avatar
United States, CA, Ventura
Joined Dec 2001
3,133 Posts
Hrmmm... Lets see... Another 6 flights with the MiniAC 1215/16 in the B box with APC 107SF. Batteries not too hot, motor not too hot, life is good. I took 4 planes out with me today. BL SB, Wing-E, Gym-E, DT. I flew the SB 4 times and the others I only used 2 QC packs in. Hrmmm... I wonder if there's a pattern here. I sure am glad that I ordered those 25 NiMH 1100's from EDogFight. Can't wait to get them in and run 'em.

For anyone looking for a nice system, I really like the MiniAC 1215/16 in the GWS EPS300C-B gearbox with the APC 107 and a Castle Creations Phoenix 25(although putting something called the Phoenix in a plane just seems like bad juju.) Seems to work quite well here at almost sea level. Plenty of power and I am getting about 4-5 min runs with 8600AE packs. Nothing is too warm, but YMMV.

Mike
Very happy BL SB3D owner
Smash McCrash is offline Find More Posts by Smash McCrash
Reply With Quote
Old Sep 28, 2002, 08:40 PM
A Clinger
rclark's Avatar
Butte, MT
Joined Sep 2001
7,073 Posts
. Glad the 10x7SF is working for you (you now have the same combo exactly that I am flying). I thought It may be to much for the mini at sea level . Works good up here at 5000 feet I know . Yes, you DO need more batteries LOL ..... And so do I . Actually this is where the 600s work well as it takes only 10 to 15 minutes to charge them in the field. By the time I fly my 4 600s and my 2 1100s, I have 2 or 3 of the 600s ready to go again -- Yesss. Easy to get 8 to 9 back to back flights (7 *4 minutes + 2 * 8 minutes = ~44 minutes of actual flying at 'least' probably more) before having to wait for a battery....

Going to have to wait a bit though for more batteries as I just ordered the Flashback .
rclark is offline Find More Posts by rclark
Last edited by rclark; Sep 28, 2002 at 08:45 PM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Uh...need a little help. Maybe. Yet another XRB newbie thread... Harv Coaxial Helicopters 17 Apr 02, 2005 12:51 PM
Yet another Dave Drive thread!! Heli Mod Man Electric Heli Talk 19 May 18, 2004 12:20 AM
Yippee! Yet another Brushless SS question Kado Parkflyers 8 Mar 31, 2004 11:07 AM
Yet another what to buy thread... (SAL/DLG, long post) dimple Hand Launch 28 Dec 20, 2003 03:36 AM
Yet another Brushless SB Beachernaut Parkflyers 7 Jan 11, 2003 12:14 PM