pnuts

Hi,
I just ordered a Dandy Sport and an EPS300C-C motor/gearbox from Mountain Models. I have a few gas planes under my belt, however this will be my first electric. I have an 8 cell NiMh battery (800mah i think) that i plan to use. While waiting for the kit to arrive i've been shopping around for the electronics to put inside the plane, and would like some help from the more experienced folks. I plan on using a Hitec Prism Tx. Here is a list of things i am considering

Plantraco DSP4-SC Rx/ESC
Hitec Electron 6 Rx
FMA M5 Rx

Hitec HS-55
GWS Pico BB

Right now i am leaning towards the Plantraco Rx and the Hitec servos, thus eliminating the need for an ESC.

1. If I use the Pico servos i can save about 5g, but at the expense of less torque. Would this be worth it?

2. The ESC in the Plantraco Rx is rated for 10A continuous, will this be enough for this particular motor? Does anyone have experience with this Rx?

3. Eventually i'd like to use Li-Poly batteries, will this ESC work with 2 cells of this type?

4. I would also like to be able to put a brushless motor into this plane at some point. As i understand this requires a different speed controller. Can i plug in an external speed controller into this receiver and simply not use the ESC that is built in?

5. It would be nice to be able to use the same Rx in another airplane in the future. If i were to go with either the Hitec Electron 6 or the FMA M5 could someone recommend a good speed controller for this model? and would the flexibility of having a separate Rx and ESC outweigh (pardon the pun) the ~12g weight savings that i accomplish by using the hybrid receiver.

Thanks for taking the time to read this, and i welcome any suggestions that anyone might have.

shams42

My Feedback: (1)

I can answer some of these questions.

First, I'm using the GWS Pico BB servos. I really like them. They are reliable and light.

The 10-amp ESC should be fine with that setup. Keep in mind that if you get a 350C instead of a 300C, you'll need to use a smaller prop than the recommended 10x8 to keep from burning up the motor. The 10x8 with an 8-cell pack can pull about 10.5 amps, so be careful. I'm using a 15 amp ESC but I'm sure the 10 amp will suit you well. On the website, it says that this can support up to 12A momentary draws.

You can use LiPoly batteries if you limit yourself to 2s1p or 2s2p packs. 3 cells in series are too much juice for this motor. The ESC will work fine, however, there is one concern: the cutoff voltage is too low. This means that if you run your motor until the motor cuts out, you've discharged your pack too much and have possibly ruined it. In practice, this isn't a big deal. I rountinely get 20 min on a 2s 1500 mah pack. Until I got used to it, I landed every few minutes and checked the voltage with my multimeter to make sure that it wasn't discharging too much. When I pull the pack out after 20 min of flying, it shows about 7.4-7.5 volts. In hindsight, I wish I would have gotten an ESC for LiPoly batteries.

As far as using a brushless ESC with that receiver, I don't know, but I don't think it can be done. If you are going to go brushless at some point, you might as well go ahead and get a seperate receiver and ESC. I'm using a Berg 4*DSP and love it. It's one of the lightest I've ever seen (7 grams).

http://www.aeromicro.com/berg4.htm.

The castle creations Pixie 20 would be a great ESC to use with LiPoly cells. It's $39 at www.allerc.com. (they are a forum advertiser, BTW.) It is light and rated at 20 amps.

Matt

pnuts

Thanks for your suggestions shams, but i have another question. The model is almost built, and its time to think about covering it. It came with the Doculam clear film, and the instructions suggest that i paint the balsa surfaces ie fuselage and tail. What paint would work well without adding too much weight? Would i be better off getting a roll of monokote and foregoing the paint? Or perhaps i should get Solite instead of Monokote?

thanks for any help

shams42

My Feedback: (1)

I covered mine in Solite. It was pretty easy to work with, even for a newbie, though I've seen many that look better. The best thing about solite is that it is very, very light. On a light model like the dandy, every ounce counts.

Matt