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Old Nov 26, 2006, 08:32 PM
Watts Rule, Glows Drool
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I always lean towards spoilerons, instead of flaperons.....no chance of inducing tip-stalling. But I have not tried it on the 38. It already seems to float very well and landings are no problem, plus there are flaps already molded in the wing so if you really wanted flaps, I would try them.


BTW, the Ultrafly ESC's I am using have a nice soft-cutoff feature. they actually pulse the motors before they hit cutoff, so you know it's coming, and then the cutoff startes with a reduction of power (It'll only let you get to about 50% power).
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Old Nov 26, 2006, 08:50 PM
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Darwin Australia
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Quote:
Originally Posted by dogon1013
BTW, the Ultrafly ESC's I am using have a nice soft-cutoff feature. they actually pulse the motors before they hit cutoff, so you know it's coming, and then the cutoff startes with a reduction of power (It'll only let you get to about 50% power).
dogon 1013

The GWS 15 Amp ESCs have a similar soft shut down. They reduce the throttle as they aprouch the shut down voltage. The ESC takes about 20 seconds to reduce the throttle from WOT to almost zero and then the ESC shuts down the throttle completely.

I think that this was a deliberate design philosophy by GWS as they are featuring a lot of twins now.

Ken
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Old Nov 26, 2006, 09:01 PM
Lori, hey, you're home early
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I seem to remember reading that you can control two brushless motors from one GWS vrushless esc. I couldn't do it with my E-Flite esc's. Haven't tried the GWS's yet. Before anyone jumps all over me I know that the best thing to do is use two esc's but I'm curious.

Mike
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Old Nov 26, 2006, 09:14 PM
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From the pics of the underside of the wings, looks like the flap lines are nicely etched onto the underside of the wings. Won't it work better to put in one more servo and put the flaps in the scale location? I think it would work better too.

chewy
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Old Nov 26, 2006, 10:33 PM
Lori, hey, you're home early
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chewy-- No doubt about it. Individual flaps would be better than flaperons as they'd leave full aileron throw for better control. This 38 has a pretty nice size wing and a good bit of area so I bet in can stand a bunch more grams in micro servos and controls for rudder and flap. That's five micro servos now R x 2/A/E/F.

Mike
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Old Nov 26, 2006, 10:47 PM
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Quote:
Originally Posted by CarreraGTSCS
chewy-- No doubt about it. Individual flaps would be better than flaperons as they'd leave full aileron throw for better control. This 38 has a pretty nice size wing and a good bit of area so I bet in can stand a bunch more grams in micro servos and controls for rudder and flap. That's five micro servos now R x 2/A/E/F.

Mike

I think you would need a park BEC due to the nos of servos or maybe drive different servos from the two different BECs. Unless your BECs can be paralleled like Castle claims.

I think the last time I used flaperons, it caused a tip stall in my Cessna 5 feet from the ground. Total wipe-out. The plane landed just fine without the flaperons. I tried it two or three times with the flaperons on and they were all disasters. I think flaperons are a no-no in most cases. Maybe I just had the plane too slow, but flaps are supposed to help in that case, not causing tip stalls.


chewy
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Old Nov 27, 2006, 01:28 AM
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Quote:
Originally Posted by chewytm
I think you would need a park BEC due to the nos of servos or maybe drive different servos from the two different BECs. Unless your BECs can be paralleled like Castle claims.

I think the last time I used flaperons, it caused a tip stall in my Cessna 5 feet from the ground. Total wipe-out. The plane landed just fine without the flaperons. I tried it two or three times with the flaperons on and they were all disasters. I think flaperons are a no-no in most cases. Maybe I just had the plane too slow, but flaps are supposed to help in that case, not causing tip stalls.


chewy
I beg to differ. When I use the flaperons on my Formosa II I do not have tip stall problems. But I do need a shotgun to get it to land as it just floats forever. The secret is to have full span ailerons and not to have a great deal of flap movement compared to aileron movement. My Formosa II also has Elevator Flap coupling .

Ken
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Old Nov 27, 2006, 05:21 AM
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On my P-47 the flaperons go down only about 3/16 to 1/2" or so. I'll try to measure it tonight. The trick is to get the nose down when you apply the flaps. Flaps steepen the descent without adding too much speed and less floating unless you add power. Tip stalling is from slowing too much.

Yes to the BEC for me.

Mike
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Old Nov 27, 2006, 06:38 AM
Outcast outlaw
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Quote:
Originally Posted by chewytm
I think you would need a park BEC due to the nos of servos or maybe drive different servos from the two different BECs.
What's a good, inexpensive BEC to get?
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Old Nov 27, 2006, 07:45 AM
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Power Option

GWS-38 is on xmas wish list

I have 2 of these combo, do you think it'll work?

AM230811 Outrunner brushless motor + Jeti ECO 12 brushless controller
http://www.hobby-lobby.com/atlas2308.htm


Atlas 2308/11:
Motor weighs 43 grams (1-1/2 oz.), 28.5mm (1-1/8") diameter, 24.1mm (15/16") from back to front. Hardened 3.17mm (1/8") shaft with 2 ball bearings. Similar to PM220834

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Old Nov 27, 2006, 08:43 AM
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CaptEvo

Should work. HL says it is good for a 16oz plane and you are basically running two planes at around 15 oz each. Mine is on the heavy side at 36 oz. Just keep it on a diet when you build.

Jim
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Old Nov 27, 2006, 11:03 AM
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Quote:
Originally Posted by Red 61
What's a good, inexpensive BEC to get?
ParkBEC. http://www.dimensionengineering.com/ParkBEC.htm

I have 4 of them, but I've never used them. I have several planes that have multiple servos in them(more then 3 or 4) and have never had issues. I use mostly e-flite esc's, but do have several 18amp CC's , 3 x 25amp CC, and 1 60 amp CC. I have 5 servos in my GWS38. Not all servos get activated or used all the time at any given time. The two for elevator function at the same time and so do the two for ailerons, but the nose wheel servo is not in use while flying, so for me anyhow...only 4 servos will be in use while in flight.

Most of my electrics have 4 servos and I do not use the PArkbec in any of them and these do use the rudder while in flight. The PArkBEC is nice tho if your worried or concerned. I bought the 4 simply because I was going to use them in my 78" electric powered B-17, but have since decided that I will simply use a separate battery for the rx/servos.

If you want, I'll sell you one of the ParkBEC's I have.

BTW, my GWS38 is setup where both BECs are functional...neither of them has had the red wire cut....these are 18 amp CC's and so far no issues.
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Old Nov 27, 2006, 11:40 AM
Watts Rule, Glows Drool
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orlando, FL
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Quote:
Originally Posted by CarreraGTSCS
.....Flaps steepen the descent without adding too much speed and less floating unless you add power. Tip stalling is from slowing too much.

Yes to the BEC for me.

Mike
If you reflex the ailerons up, instead of down (spoilerons) you also increase the drag which will steepen the descent, of course you do loose some lift, which is actually a benefit for a very floaty model like the 38. and since you are decreasing the AOA (angle of attack) at the tips, the tips will NEVER stall before inside of the wings, so you eliminate the possibility of a tip stall.

Like KenSP said, flaperons is OK for full span ailerons (like formosa), but the 38 has tip ailerons only, so using flaperons on it would increase tip-stalling likely hood.

BTW 2-ESC's with BEC's paralleled eliminates the need for a stand-alone BEC....And since this is a twin, that works out well. Castle ESC's and Ultrafly ESC's can be paralleled (I have the Ultrafly) without any issues. Other brands may work too.
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Old Nov 27, 2006, 01:33 PM
Ship first, Improve often
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Virginia
Joined Apr 2005
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I'm using the CC ThunderBird ECS's and I believe they do not recommend using the thunderbirds in parallel. When I did my power setup tests I had forgotten to take the pin out of one of them but quickly rectified that before the next test. Not going to chance an overload
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Old Nov 27, 2006, 01:44 PM
Outcast outlaw
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Okay, a couple of responses:

Quote:
Originally Posted by kahloq
If you want, I'll sell you one of the ParkBEC's I have.
Cool -- you might have a deal if you also have a servo rate reducer you can throw into the deal. If not, I'll just order directly from their web site. (Thank you for the offer!)

Quote:
Originally Posted by dogon1013
BTW 2-ESC's with BEC's paralleled eliminates the need for a stand-alone BEC....And since this is a twin, that works out well. Castle ESC's and Ultrafly ESC's can be paralleled (I have the Ultrafly) without any issues. Other brands may work too.
While this may be true, one of the Castle Creations Phoenix 25 ESCs on my Flying Styro P-38 overheated simply because the BECs were connected in parallel... I started a thread about the issue in the Castle Creations forum -- the answer was that one BEC must dissipate the extra (unused by a servo) voltage as heat. I disconnected the second BEC, and it never overheated again.

So, it sounds like you can connect two CC Phoenix xx BECs in parallel, as long as you are actually USING enough (more than 4) servos. Otherwise, you are better off clipping the pin.

One final note -- I'm interested in the BEC because of a P-51 I am putting together... It will be "full house", with retracts (4 servos), and the Phoenix 25 is only rated for 3 servos on a 3s LiPo... (This is also why I'm interested in the servo rate reducer).
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