RFFS-100 Opinions

mlitke · Feb 15, 2002, 01:38 AM

I just got my RFFS-100 system in the mail today and my head is swirling with ideas. I got out my digital balance to check the weight, the Rx is 1.9 g with crystal and no antenna, the servos (coil and magnets) are 1g a piece and the system when weighed all together is 3.9g.

So, anyway on to my request for opinions. To start off I think I will go with something simple, similar to the Skeeter design, but at some point I think it would be pretty cool to do a 12" span IFO, do you think the actuators would be able to handle it? I was thinking of doing something like the original design with aero balancing on the control surfaces, but I am bit skeptical that the actuators would be able to handle such large surfaces.

My next question is what motor to use. I am planning on using only 2 cells to keep the weight down. I have KP00 motors, N20s and am going to order some M20s from Toytronix. Geared or direct drive, and what props? I have used the KP00 with a U-80 prop in the past on 40-45g planes and it seems to need about 4 cells to get decent power. I have also tried the KR-1 units with a free flight type prop and it has more power then the KP00, but I also ran it on 4 cells. I don't think either would do all that well on 2 cells, but maybe with a plane that is half the weight they would be okay.

I will try to get some photos up on my web site of the RFFS-100 when I get some time.

Thanks for your thoughts,

opualuan · Feb 15, 2002, 02:10 AM

balancing of control surfaces... how exactly is that accomplished? for the elevator, would I put extensions down the side of the tail on the left and a right with a counter-weight?

kp00 with 3-4 cells will probably be a decent match, most likely gearing is required to pull that plane around...

I have 3 airframes to try, a graupner micro taxi clone, a rubber-power look-alike scratch-built 18" span floater, and an 8" span scratch-built bipe... I'll be interested to see how fast you can fly without neutralizing the servos!

fill · Feb 15, 2002, 08:06 AM

What I have been playing around with, if I were wanting more power with the M-20 motor and increase the cell count to 3 or 4 cells, then I would go with the M-20 from Toy Tronics. According to my studies, the KP-00 works best on 2 cells, when increasing the cell count to 3 cells, your current goes way up, and if the Toy Tronic version is geared right with the right prop, then it will give the same power on less current.
Just my 2 cents worth.

Philip

Graham Stabler · 08:36 AM

I agree with Phil, on two cells the KPOO is the only option. On three the higher voltage version by toytronics seems like a really good bet. I think its the same size so a ready made gearbox is there if you want it. Having said that on three cells in a small model the KPOO should be pretty hot so it depends what you want to do. "Decent thrust" well thats comparative!

I have seen pictures on a Japanese sight of an IFO type model made from depron using the old DU system with a SHR receiver. The surfaces were mass and aerodynamically balanced but I suspect mass only would be fine. I tried to make a 10" pibros recently for IR and used 0.5mm carbon rod facing forward from the elevon's tip. I then wrapped some solder around this at the tip and just knipped a bit off the end until it balanced. This model didn't fly because it was overweight and I broke it but the elevons did work and those were 200 ohm actuators with far less umph then you'll have. Why not make the surfaces a bit smaller, you can always enlarge them later.

The little biplane you now see on the american funfly web site can do aerobatics so thats further proof there is enough power.

Graham

Graham Stabler · Feb 15, 2002, 08:31 AM

As if by magic the next post down had the link to the model I referd too.

http://www.oyajin.gr.jp/~toko/eplane...fan/index.html

Graham

CMT1961 · 12:58 PM

---

Kirk Krest · Feb 23, 2002, 10:54 PM

Hi,

I built a plane for Dynamics reciver and actuators and they do make noise when not centered. I got some actuators from Cloud (9 that have centering pots to solve this problem. Also my plane has a N20 motor with a 4:1 gear ratio and I use 4 120 NiMh cells. Ralph Bradly told be about this and it has worked very good since except my reciver died and I cant fly it any more. The actuator got board from Cloud 9 got really hot with my futuba transmitter but works ok with my Hitec radio. Go figure?
Hope this helps.

Feb 15, 2002, 01:38 AM	#1
mlitke Registered User Seattle Joined Feb 2002 37 Posts	RFFS-100 Opinions I just got my RFFS-100 system in the mail today and my head is swirling with ideas. I got out my digital balance to check the weight, the Rx is 1.9 g with crystal and no antenna, the servos (coil and magnets) are 1g a piece and the system when weighed all together is 3.9g. So, anyway on to my request for opinions. To start off I think I will go with something simple, similar to the Skeeter design, but at some point I think it would be pretty cool to do a 12" span IFO, do you think the actuators would be able to handle it? I was thinking of doing something like the original design with aero balancing on the control surfaces, but I am bit skeptical that the actuators would be able to handle such large surfaces. My next question is what motor to use. I am planning on using only 2 cells to keep the weight down. I have KP00 motors, N20s and am going to order some M20s from Toytronix. Geared or direct drive, and what props? I have used the KP00 with a U-80 prop in the past on 40-45g planes and it seems to need about 4 cells to get decent power. I have also tried the KR-1 units with a free flight type prop and it has more power then the KP00, but I also ran it on 4 cells. I don't think either would do all that well on 2 cells, but maybe with a plane that is half the weight they would be okay. I will try to get some photos up on my web site of the RFFS-100 when I get some time. Thanks for your thoughts,

Feb 15, 2002, 08:27 AM	#4
Graham Stabler Sticky Shepherd Oxford/England Joined May 2001 3,998 Posts	I agree with Phil, on two cells the KPOO is the only option. On three the higher voltage version by toytronics seems like a really good bet. I think its the same size so a ready made gearbox is there if you want it. Having said that on three cells in a small model the KPOO should be pretty hot so it depends what you want to do. "Decent thrust" well thats comparative! I have seen pictures on a Japanese sight of an IFO type model made from depron using the old DU system with a SHR receiver. The surfaces were mass and aerodynamically balanced but I suspect mass only would be fine. I tried to make a 10" pibros recently for IR and used 0.5mm carbon rod facing forward from the elevon's tip. I then wrapped some solder around this at the tip and just knipped a bit off the end until it balanced. This model didn't fly because it was overweight and I broke it but the elevons did work and those were 200 ohm actuators with far less umph then you'll have. Why not make the surfaces a bit smaller, you can always enlarge them later. The little biplane you now see on the american funfly web site can do aerobatics so thats further proof there is enough power. Graham
	Last edited by Graham Stabler; Feb 15, 2002 at 08:36 AM.

Feb 23, 2002, 09:36 PM	#6
CMT1961 Registered User Joined May 2001 79 Posts	--- ---
	Last edited by CMT1961; Oct 05, 2006 at 12:58 PM.

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Feb 15, 2002, 02:10 AM	#2
opualuan high-speed freak San Jose, CA Joined Sep 2001 3,861 Posts	balancing of control surfaces... how exactly is that accomplished? for the elevator, would I put extensions down the side of the tail on the left and a right with a counter-weight? kp00 with 3-4 cells will probably be a decent match, most likely gearing is required to pull that plane around... I have 3 airframes to try, a graupner micro taxi clone, a rubber-power look-alike scratch-built 18" span floater, and an 8" span scratch-built bipe... I'll be interested to see how fast you can fly without neutralizing the servos!

Feb 15, 2002, 08:06 AM	#3
fill Registered User Houston Texas Joined Mar 2001 745 Posts	What I have been playing around with, if I were wanting more power with the M-20 motor and increase the cell count to 3 or 4 cells, then I would go with the M-20 from Toy Tronics. According to my studies, the KP-00 works best on 2 cells, when increasing the cell count to 3 cells, your current goes way up, and if the Toy Tronic version is geared right with the right prop, then it will give the same power on less current. Just my 2 cents worth. Philip

Feb 15, 2002, 08:31 AM	#5
Graham Stabler Sticky Shepherd Oxford/England Joined May 2001 3,998 Posts	As if by magic the next post down had the link to the model I referd too. http://www.oyajin.gr.jp/~toko/eplane...fan/index.html Graham

Feb 23, 2002, 10:54 PM	#7
Kirk Krest Registered User Spring, Texas, USA Joined Nov 2001 48 Posts	Hi, I built a plane for Dynamics reciver and actuators and they do make noise when not centered. I got some actuators from Cloud (9 that have centering pots to solve this problem. Also my plane has a N20 motor with a 4:1 gear ratio and I use 4 120 NiMh cells. Ralph Bradly told be about this and it has worked very good since except my reciver died and I cant fly it any more. The actuator got board from Cloud 9 got really hot with my futuba transmitter but works ok with my Hitec radio. Go figure? Hope this helps.