Author Topic: First Electric combo (Read 2927 times)

WhittleN · « **on:** February 08, 2012, 10:37:14 AM »

One of my old pylon racing buddies e-mailed me asked me for some information on getting started in Electric Stunt. He mentioned he had read my Cookbook on stunt set-up. He had some further questions on what parts to buy to - he wanted to buy the right parts the first time and not get down the road and hit a dead end. He said he bought a Brodak Vector ARF. I think the Vector is a good starting point. So his questions got me to thinking. What would I tell a newcomer to get started with? Better yet how would I spend my own money with what I know today?
Ok we have a Vector we need to decide 4 cell or 5 cell battery system? The battery cell count will influence the motor Kv rating and the mAH capacity on the battery for a 4 cell (4S) system we want a Kv rating of around 900Kv for the 5 cell (5S) we would prefer a Kv rating of around 750Kv.

So if it was my money here is how I would spend it on a 4 cell battery
system for the Vector.

1. Starting at the very front a APC 12 x 6 E Pusher prop.
2. A Scorpion SII 3020-890 motor
3. ICE Lite 50 ESC with Castle Creations cable and interface to down/upload
information.
4. If you are just testing the water and don't expect to fly electric much
any cheap 4S3300mAH battery will get you started.
4a. If you are serious about flying and don't want to buy new batteries 50 or so
flights down the road get - ThunderPower 4S3300 G6 25C batteries.
5. Will Hubin FM-9 Timer and controller.

For a 5 cell system - now you are serious.
1. Same - prop as above APC 12 x 6 EP
2. A Scorpion SII 3020-780 motor - notice the Kv rating is lower!
3. Same - ICE Lite 50 ESC with Castle Creations cable and interface to
down/upload information.
4. ThunderPower 5S2700mAH G6 25C batteries. Notice higher cell count -
lower MAH required
5. Same Will Hubin FM-9 Timer and controller.

Source of supply for the items mentioned certainly not the only sources but reliable sources in my experience.
Motor =
http://www.gobrushless.com/shop/index.php?app=ccp0&ns=catshow&ref=scorpion
ESC = Tower
http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXXXT8&P=7
Batteries = Advantage Hobbies
http://www.advantagehobby.com/185520/THP27005SPL25/?cat=1069
Timer = E-mail Will, tell him Norm sent you
whubin@kent.edu

Now I didn't mention a charger but if you want to take care of the most
expensive part of your investment - the batteries - don't go cheap here.
I spend my money on an FMA 10XP ($159) plus Balancer boards and a power
supply http://www.progressiverc.com/fma-cellpro-10xp.html these guys are up
in Seattle: They also sell iChargers which are very good also.

There are hundreds of alternatives to the above, remember I said if it was "MY" money.
On my Sultan-e (a somewhat larger stunter at 700 sq in wing area) I run the Scorpion 3026-710 motor, the ICE Lite 75 ESC, ThunderPower 5S2700 G6 25C batteries and of course the Will Hubin FM-9 timer system.

Mike Haverly · « **Reply #1 on:** February 08, 2012, 12:53:47 PM »

Last weekend I tried a 4S 3000 Turnigy on my Plettenberg/Schulze set-up. I was really surprised at the difference. By the time I got to overheads the power was so low it didn't feel safe. No more cheepies for me! Your recommendations look right on to me.

William DeMauro · « **Reply #2 on:** February 08, 2012, 05:53:33 PM »

Norm,
I would have recommended exactly the same!!! I have the I-chargers 306b and 206b and love them.For the power supply I would use a converted server supply, you cant beat them,(I've written about them here and mentioned them in my column in Stunt News). I have a few extra that I'm considering offering for sale. As far as batteries I feel that the best budget batteries are the Gens Ace brand offered at Hobby Partz http://www.hobbypartz.com/98p-25c-3300-4s1p.html. They have a great reputation on the RC boards. I have 2 of the 3800's and wont hesitate to use them in competition.
William

WhittleN · « **Reply #3 on:** February 09, 2012, 07:35:05 AM »

Mike and William
Thanks for your endorsement.
So now we have an alternative battery that last and at about $32 dollars is half the money. Certainly worth ones consideration.
William
Good point on the server power supplies. Since I had two computer power supplies I am powering my FMA 10XP charger with them wired in series. To do that you have to isolate the second power supplies’ common. This could be somewhat complex for the non electronic guys but instructions can be found on the internet. I now have a 25.3VDC @ 25Amp supply for about $50. I know you have done something similar with the server supplies. This gives one the ability to charge two 5S batteries in series at about 3C. I’m really not fully convinced that parallel charging is for me and my batteries – but that is an entire new subject.
Norm Whittle

John Rist · « **Reply #4 on:** February 09, 2012, 08:08:29 AM »

Quote from: William DeMauro on February 08, 2012, 05:53:33 PM

Norm,
I would have recommended exactly the same!!! I have the I-chargers 306b and 206b and love them.For the power supply I would use a converted server supply, you cant beat them,(I've written about them here and mentioned them in my column in Stunt News). I have a few extra that I'm considering offering for sale. As far as batteries I feel that the best budget batteries are the Gens Ace brand offered at Hobby Partz http://www.hobbypartz.com/98p-25c-3300-4s1p.html. They have a great reputation on the RC boards. I have 2 of the 3800's and wont hesitate to use them in competition.
William

Looks like Hobby Partz is another good source of all kinds of budget priced electric stuff.

Dean Pappas · « **Reply #5 on:** February 09, 2012, 12:11:07 PM »

Hi All,
Hi Norm,
The Pattern guys are quickly migrating to 24V inputs to their chargers as you described.
The only trick is to put a protection diode across each supply's output to prevent it from becoming reverse-biased if one of the two series supplies should start more slowly than the other. Granted, this is belt and suspenders, but where I come from that's a good thing.

Regards,
Dean P.

WhittleN · « **Reply #6 on:** February 09, 2012, 12:45:03 PM »

Hi Dean
Did so, and it only drops .25VDC as a result of the IR of the diode at about 18amp draw.

Norm

William DeMauro · « **Reply #7 on:** February 09, 2012, 04:03:11 PM »

Norm,
I'm actually using 2 server supplies. I had 2 in series to give me 24v at 55 amps and 1600+ watts. I just swapped them out for 2 in series that give me about 25.3 v at 76 amps and 1820+ watts !!!
I also forgot to mention that I feel the Cobra line of motors should be seriously looked at as they have way oversized bearings and should work very well in our applications http://www.rcdude.com/servlet/the-Brushless-Motors/Categories. In this case the 2820/12 or 2820/14 would work fine.
William

WhittleN · « **Reply #8 on:** February 10, 2012, 12:47:17 PM »

William
Wow 76 amps @ 25+VDC do you charge your electric GM Volt with that. It must charge several batteries at a time. I suspected that you were using a couple of server supplies.
Fully concur on the Cobra motors but have not tried one yet.

Norm

Dean Pappas · « **Reply #9 on:** February 10, 2012, 02:58:45 PM »

Quote from: WhittleN on February 09, 2012, 12:45:03 PM

Hi Dean
Did so, and it only drops .25VDC as a result of the IR of the diode at about 18amp draw.

Norm

Hi Norm,
That's a series diode, yes? I was actually suggesting a diode across each supply:
under normal operation it will never conduct, but if one supply should fail to start immediately, then it prevents the reversed output.
That should give no voltage drop at all.

later,
Dean P.

WhittleN · « **Reply #10 on:** February 11, 2012, 04:15:26 PM »

Dean
Series yes, AkA isolation diode. Both supplies have loads in the 5VDC line; otherwise they sometines fail to start if they don't see a load.

Norm

William DeMauro · « **Reply #11 on:** February 11, 2012, 05:54:04 PM »

Norm,
The server supplies don't have to be loaded like the PC supplies. There is an abundance of low cost or no cost server and PC supplies out there. The instructions for the conversions are on RC Groups and other sites. If I ever get my act together I have some extra server supplies that I can set up and offer for sale if you guys out here think there would be a market for them.
William

Dennis Toth · « **Reply #12 on:** February 12, 2012, 07:21:19 AM »

Guys,
On the charger Thunder Power has a model TP610C AC/DC that is the complete package - has a built-in power supply and wall plug, DC power input (for charging from deep discharge battery or car), and balancer. This charger can handle up to 6 Lipo cells, also does A123 and Ni-cads. The cost is around $125 ish depending on the seller. I have used the TP610C standard unit for over two years and it is a very nice reliable unit. For Christmas my wife got me the TP610C AC/DC unit and I have used it since and it is great for contests (only need to pack the one unit no power supply) and takes up less room in the shop.

Best, DennisT

Andrew Borgogna · « **Reply #13 on:** February 12, 2012, 01:13:07 PM »

Norm with all due respect I would recommend the following:

KR timer with built in governor and programmer (less expensive than Hubin FM-9 and programmer)
Thunderbird ESC (less expensive than the ICE and no need for governor mode it's in the KR timer)
Turnigy motor again for first timers it keeps the cost down.
Turnigy battery same reason as motor.
I would also recommend a Hyperion EOS battery tester and a decent battery charger with balanced charge.

This system works, it's very easy to use, I have several planes flying with it, and the cost is reasonable.
Andy

Howard Rush · « **Reply #14 on:** February 12, 2012, 09:30:26 PM »

Quote from: Dean Pappas on February 10, 2012, 02:58:45 PM

Hi Norm,
I was actually suggesting a diode across each supply...

How hefty a diode?

I guess it would also let you know if you hook the battery up to the supply with the wrong polarity.

Dennis Toth · « **Reply #15 on:** February 13, 2012, 06:03:24 AM »

Andrew,
The information you posted sounds interesting, can you post some sources for purchase of these items. Does the Thunderbird ESC or the KR timer have a brake function to stop the prop rotation? I know some will say that isn't a big deal for a starter ship and in no wind or very light wind conditions it isn't but in wind above about 8 mph the spinning down prop once it hits into the wind cause the ship to drop out of the sky suddenly so I feel the brake is important even for a first timer.

Best, DennisT

John Rist · « **Reply #16 on:** February 13, 2012, 09:38:40 AM »

Quote from: Andrew Borgogna on February 12, 2012, 01:13:07 PM

Norm with all due respect I would recommend the following:

KR timer with built in governor and programmer (less expensive than Hubin FM-9 and programmer)

A source for the KR timer please.

Allan Perret · « **Reply #17 on:** February 13, 2012, 09:40:10 AM »

Quote from: William DeMauro on February 09, 2012, 04:03:11 PM

I also forgot to mention that I feel the Cobra line of motors should be seriously looked at as they have way oversized bearings and should work very well in our applications http://www.rcdude.com/servlet/the-Brushless-Motors/Categories. In this case the 2820/12 or 2820/14 would work fine.
William

I am looking at the Cobra 2820/14 as a sub for Scorpion 3020/890 that Norm recommends above. Does the Cobra 28xx have larger bearings than the Scorpion 30xx. I searched online but could not find any internal dwgs that would specify bearing sizes. But based on weights and external dimensions I dont see how it would be possible.

Andrew Borgogna · « **Reply #18 on:** February 13, 2012, 09:46:26 AM »

Hi Dennis
For my use I don't use a brake, but the technical information for the Thunderbird ESC says it has a break and how to set it. The default setting is brake off. It does require a radio control transmitter and receiver and uses some stick functions to turn the brake on. The KR timer along with the programming stick can be ordered from RSM Distributions. Any other questions you can contact me at abborgogna@hotmail.com I will be happy to work with you.
Andy Borgogna

WhittleN · « **Reply #19 on:** February 13, 2012, 10:57:10 AM »

Andrew
As I said - "if it is my money" you may feel free to recommend any system you so chose. Keith's timer with built in governor is very good so it is a very good recommendation. Not running a brake, for me would be a problem since I fly in competition and they do judge landings.
Allan
The Cobra looks good try it and give us a report. I does have larger bearings.

Norm

Keith Renecle · « **Reply #20 on:** February 13, 2012, 11:45:18 AM »

Hi Guys, I used most of the low cost ESC's with my governor timer and as far as I know, they all offer a brake function. As Norm says, the brake on the prop is essential for a nice landing. A spinning prop slows you right down too quickly. The FAI rules call for a stopped propeller, and for the one lap necessary before tuch down, you sure need the prop brake.

Always try and get a programming card for the esc, or have a buddy with one. I have used many of the Hobbywing and ZTW esc's and they work very well. The ZTW has the smoothest throttle resolution that I've tested. Some of the Turnigy esc's are also made by Hobbywing.

Keith R

Allan Perret · « **Reply #21 on:** February 13, 2012, 12:07:56 PM »

Quote from: WhittleN on February 13, 2012, 10:57:10 AM

The Cobra looks good try it and give us a report. I does have larger bearings.
Norm

When you say larger bearings, it must be the thickness and not diameter?
The 3020-890 Scorpion max. contin. watts is 780. The Cobra 2820-14 is only 530 watts. The Cobra 2826-10 is a closer match to the Scorpion at 660 watts. Do you think it would be a better choice for a 40 size plane in the 45-50 oz range.

jim welch · « **Reply #22 on:** February 13, 2012, 12:38:54 PM »

Allen...take a look at the Cobra 3525-10 ..KV780....bearings external 16mm x5mm x5mm....internal 11mm x 5mm x 5mm...3,4,5,6, cell lipo compatable...
Innov8tivedesigns.com Jimmy

Allan Perret · « **Reply #23 on:** February 13, 2012, 02:00:06 PM »

Quote from: jim welch on February 13, 2012, 12:38:54 PM

Allen...take a look at the Cobra 3525-10 ..KV780....bearings external 16mm x5mm x5mm....internal 11mm x 5mm x 5mm...3,4,5,6, cell lipo compatable...
Innov8tivedesigns.com Jimmy

920 watts on 4s & weight of 9oz seems like overkill for a 40 size plane. Thats more like a 60 size motor.

WhittleN · « **Reply #24 on:** February 13, 2012, 03:18:17 PM »

Allan
I would try the Cobra C-2826/10 with 4S or the Cobra C-2826/12 for a 5S. I have not tried these but with a 16mm OD bearing it should be very robust .

Regards
Norm