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New to Electrics

Old 04-01-2007, 10:17 AM
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Default New to Electrics

I have been out of RC for almost 10yrs(but have been flying Microsoft FlightSims for 7yrs) and am going to purchase a Sig Rascal electric ARF. It is powered by a MAXX Speed400 and has a 20amp Speed Control.

My RC experience is fairly extensive but, as the post says...New to Electrics.

Any advice is appreciated getting me going towards the best batteries, chargers, etc. The Rascal calls for a 7 cell pack that SIG sells for about $22(and yes, I want 2!)

If I can get a bit more flight time with a bigger pack(will the plane hold it?) I'd be interested in hearing that, too!

Just looking to get a plane thats fun and easy and I don't have to buy as much degreaser as glowfuel! Sure am tired of oily planes.

Flown a lot of SIG models and even though the Rascal has no ailerons, I learned to fly on a rudder only MkI Kadet! SIG planes really fly great.

If you're a cyber flier on FlightSim2004 and like airracing, come see PROPS Racing!

Gary Osif
PROPS Race Director
www.propsracing.com
Old 04-01-2007, 11:20 AM
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Default RE: New to Electrics

If you are an experienced flyer buying all new stuff for electric flying then I would suggest you go straight to lithium packs.

I find it is helpful to post a link to the plane being discussed so we can all be sure we are talking about the same model. Is this your plane?
http://www.sigmfg.com/cgi-bin/dpsmar...FV4.html?E+Sig

For your rascal, you say the recommended pack is a 7 cell NiMh pack and it has a speed 400 motor. The pack on that site is a 600 mah pack.

I would suggest you go 2 cell lithium which are about 8.4V when fully charged, so about the same as a 7 cell pack. You will save weight and add duration. This pack would be good. Not sure of hte dimmensions of the battery compartment.

750 mah 2 cell pack, 25% more capacity and probably 1/3 the weight
http://www.fmadirect.com/detail.htm?...205&section=69

950 mah 2 cell pack - 50% more capacity and probably 40% less weight.
http://www.fmadirect.com/detail.htm?...207&section=69

If you don't mind having a shorter life span on the motor ( Speed 400 costs about $9 ) you could go to 3 cell. Just make sure your speed control is lithium ready so it has the right Low Voltage Cutoff. Lithium packs should hit low voltage cut off at around 2.75 to 3V per cell under load. If you get them to the point where they drop below 2.5V at rest you can ruin the pack.

I would recommend this charger - Cellpro 4S
http://www.fmadirect.com/detail.htm?...193&section=45

If you want to jump into the current sweet spot of electrics, don't buy that brushed speed control, replace the speed 400 motor and go to a brushless motor/ESC. 50% more efficent giving you more power and longer duration. I believe you could go 2 cell or 3 cell lipo on these.

I have had good experience with these combos:
http://www.maxxprod.com/mpi/mpi-264.html


This would be a nice fit
http://www.maxxprod.com/mpi/pdf/combo-061-10-15.pdf

or this one
http://www.maxxprod.com/mpi/pdf/combo-049-070.pdf

How's that?
Old 04-01-2007, 12:34 PM
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Default RE: New to Electrics

I agree with Ed. A brushless combination is a much better way to go and going with Li-Poly batteries will make a world of difference. I would go with one of the lower Kv Speed 400 brushless motors and a 3-cell 2070-2200 mah Li-Poly battery. Would you like some recommendations? Perhaps a Mega 1615/7 or a Medusa 028-032-1500 would work fine. I am looking at a 9 x 5 prop which should work well and give you plenty of ground clearance and tons of power.
Old 04-01-2007, 06:37 PM
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Default RE: New to Electrics

Sure appreciate the quick replies!

Looks like I have a lot to consider(and save up for!) to really get this set up proper.

Thanks for the info and I'll be doing my homework.

Gary
Old 04-04-2007, 10:11 PM
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Default RE: New to Electrics

SO, just to get her in the air with LiPos(say, 950mah 2cell) and the ESC you recommend, with the stock Speed400 motor would get me flying?

The charger you(Ed) recommends looks like a good one with the balancing needed for the LiPos(been doing my homework) Thanks!

I may just bite the bullet and save the extra coin to convert it over to brushless...........

Thanks in advance for the tips!
Gary


Old 04-05-2007, 11:51 AM
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Default RE: New to Electrics

No Problem. keep us posted on how it turns out.
Old 05-11-2007, 07:25 PM
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Default RE: New to Electrics

OK, I'm finally ready to piece this together and have a question or two before spending the coin......

The SmartBEC listed has an input voltage of 9v. Is that correct for the batteries recommended("8.4v when fully charged"?)

Once I determine the size of the compartment, I can get a better idea which packs I'll buy. Probably the 2 cell 950mah ones you mention.

Will I need more prop than the factory recommended 8-5?

Thanks again for the great advice!

Gary
Old 05-15-2007, 10:24 PM
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Default RE: New to Electrics

If you are using only 2 cell your esc should have a built in BEC and should work fine in this situation. The Smart BEC is made for 3 cells and up so will not work well with a 2-cell system
Old 05-15-2007, 10:37 PM
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Default RE: New to Electrics

Yeah, it appears the included ESC will do the job on the lower voltage pack.

I was looking at going brushless and 3cell but, it's gonna have to wait!

Thanks again and I'll post a pic once she's airworthy.

Gary
Old 05-16-2007, 07:37 AM
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Default RE: New to Electrics

I got back into R/C same way that you're doing. Started with Sig Rascal ARF for electric. I used stock motor and gearbox with 8/6 prop and 1000 ma 7 cell nickel battery packs. Plane barely flew with stock speed 400 and standard speed control. 20 degree climb - outs only. Next went with brushed speed 480 and 9/6e prop. Flew much better - 45 degree climb - outs and 15 minute flights. Plane liked the extra weight. Next was e-flite 400 brushless inrunner on 1500 mil 3 cell lipo's with cc 25 speed control. THIS IS IT! Climb out is 55 degrees plus. Plenty of power to get out of trouble. flights last 20 minutes plus. With 2100/3 cell pack flight times are over 35 minutes of cruising and floating. No matter what equipment you use, remember that this plane likes to fly at a specific speed. Too slow and it will snap, too fast and it is very hard to control. It likes to cruise at low throttle. It is very difficult to ROG from a slippery surface like blacktop - you must be sharp on the rudder and add power very slowly. Hand launches with the brushless setup are very easy and controlled with a shallow climb - angle. REMEMBER that with brushed speed 400 or 480 this plane is a handfull at times. Climb shallow and keep your speed in the range that the plane likes. My rascal has over 400 flights on it and is like new. Currently when I go to the field I usually take 6 or more planes with me. Remember that a good flying airplane is all in the setup and center of gravity. Keep working until you get it the way you want it to fly.
Old 05-20-2007, 11:49 AM
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Default RE: New to Electrics

Thanks for the great tips!

Sounds like she has a narrow flight regime to be sure. Too bad about the sensitive tail....I was hoping for ROG without too much sweating!

I'm going to put the 2cell LiPos in there to get her going and hope she has enough power. I just want her for a cruiser and possible thermal hunter.

Might(probably) step her up to brushless and 3cell eventually, though.

Gary

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