Goldberg cub ARF electric conversion
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Goldberg cub ARF electric conversion
This is my first venture into electric power, I have been flying glow and gas for awhile watching the electric flyers in my club do thier thing quietly
I already have a new E-flite power 46 and a apc 13X8E, that I hope will be suitable for this plane. I do need help in choosing a flight battery pack and ESC more than anything though......The instructions included with the motor suggest several combinations with a 60 amp ESC and lipo 4 cell batt packs. I think I would prefer going the nimh route and they suggest one combo with two 7 cell 3000mah packs in series. Tower sells a 12 cell 3600mah pack, would this perform okay, or would I be better off using two 7 or 8 cell packs in series? as the 12 cell looks to be the largest pack they sell for planes. I think this plane would not suffer too much hauling the extra weight of the nimh pack over a lipo. I also have a hard time swallowing the expense of a $160-$200 single pack[:@]
Thanks in advance for your suggestions.
Mike
I already have a new E-flite power 46 and a apc 13X8E, that I hope will be suitable for this plane. I do need help in choosing a flight battery pack and ESC more than anything though......The instructions included with the motor suggest several combinations with a 60 amp ESC and lipo 4 cell batt packs. I think I would prefer going the nimh route and they suggest one combo with two 7 cell 3000mah packs in series. Tower sells a 12 cell 3600mah pack, would this perform okay, or would I be better off using two 7 or 8 cell packs in series? as the 12 cell looks to be the largest pack they sell for planes. I think this plane would not suffer too much hauling the extra weight of the nimh pack over a lipo. I also have a hard time swallowing the expense of a $160-$200 single pack[:@]
Thanks in advance for your suggestions.
Mike
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RE: Goldberg cub ARF electric conversion
Make sure that you program your ESC for the NIHH as they are normally set for Li-Pos and will not perform correctly with the NIHH. Also make sure that the cells are of good quality and have the ability to dump their charge as needed and not hold back the power. I tried the NIHH route and gave up, there is no comparison and the Li Pos are not that more expensive. Norm
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RE: Goldberg cub ARF electric conversion
Mike - 4 cells of lipo is about the same as 12 cells of NiMH. If you were to use a 12 cell pack it will be able to spin a bigger prop than the 7 cell in series (which is 14 cells). As for ESC get any that can handle up to 6 cells of lipo and rated for like 80A if possible, this will allow you to fly slightly larger planes later on, something in the 90 size category. You can go branded with Castle Creation/JETI etc or just shop from United Hobbies for the so called China branded ones, they work fine.
Its worth buying lipos, they are so much lighter but your plane is a Cub and it will not be that fussy about wing loading. Choice is yours, nowadays with the new 4,300 mAh NiMH packs the 3,000 cells are much cheaper.
Please do try to buy a watt meter, it helps when you are selecting props. A balancer for lipos are in order too.
Its worth buying lipos, they are so much lighter but your plane is a Cub and it will not be that fussy about wing loading. Choice is yours, nowadays with the new 4,300 mAh NiMH packs the 3,000 cells are much cheaper.
Please do try to buy a watt meter, it helps when you are selecting props. A balancer for lipos are in order too.
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RE: Goldberg cub ARF electric conversion
How is a watt meter used when selecting props? Is it something that is carried on board and then data is downloaded after a flight?
The inst sheet included with this motor suggests that a 4 cell 4200mah (2S2PPL X2 in series) lipo and a 13X8E apc prop will give 670 watts of motor output. Does that sound accurate? Would I be safe with that combo for starters in a 8lbs cub? Is there a better combo to start with?
Mike
The inst sheet included with this motor suggests that a 4 cell 4200mah (2S2PPL X2 in series) lipo and a 13X8E apc prop will give 670 watts of motor output. Does that sound accurate? Would I be safe with that combo for starters in a 8lbs cub? Is there a better combo to start with?
Mike
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RE: Goldberg cub ARF electric conversion
Mike,
The power system will fly the cub just fine. Horizon is recommending 2 2s 4200 packs in series because that what they sell. Thunder Power even makes a 4s2p. You can find these for sale on several web stores. Any 4s 3700+ capacity will work just fine. Just make sure that the pack can handle a current draw of at least 60 amps. Why 60? The setup listed will pull just shy of 50 amps and you want some overhead so the battery will last longer.
A wattmeter is to an electric guy as a tach is to a glow guy. Buy or borrow one. There are many to choose from. I use an Astroflight one.
To use a wattmeter, you hook it up between the battery and the esc using connectors. Run the motor up for about 30-60 secs and read the display to get the following info:
Amp draw..............Make sure that you are below the limits set by the motor, esc and battery manufactors.
Voltage..................Often overlooked, but you are checking to see how well your battery is holding voltage under load.
Your looking for about 3.5 or better per lipo cell under load. About 1 volt per cell for nimah.
Watts.....................Basically the unit is multipling volts times amps. The power output to the motor. There are many rules of thumb
about how much is enough. Some say that watts doesn't matter as much as people say. 75-100 watts per pound
for a cub is just fine.
Enjoy your plane.
John
The power system will fly the cub just fine. Horizon is recommending 2 2s 4200 packs in series because that what they sell. Thunder Power even makes a 4s2p. You can find these for sale on several web stores. Any 4s 3700+ capacity will work just fine. Just make sure that the pack can handle a current draw of at least 60 amps. Why 60? The setup listed will pull just shy of 50 amps and you want some overhead so the battery will last longer.
A wattmeter is to an electric guy as a tach is to a glow guy. Buy or borrow one. There are many to choose from. I use an Astroflight one.
To use a wattmeter, you hook it up between the battery and the esc using connectors. Run the motor up for about 30-60 secs and read the display to get the following info:
Amp draw..............Make sure that you are below the limits set by the motor, esc and battery manufactors.
Voltage..................Often overlooked, but you are checking to see how well your battery is holding voltage under load.
Your looking for about 3.5 or better per lipo cell under load. About 1 volt per cell for nimah.
Watts.....................Basically the unit is multipling volts times amps. The power output to the motor. There are many rules of thumb
about how much is enough. Some say that watts doesn't matter as much as people say. 75-100 watts per pound
for a cub is just fine.
Enjoy your plane.
John
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RE: Goldberg cub ARF electric conversion
Yeah, 75 to 100 watts/lb. is fine for a Cub--meaning it will fly. It will indeed *fly the wings off it* if you don't exercise some restraint with the left stick. 60-70 w/lb. for a big floater like the CG Cub is more than enough for scale like flight and some scale aerobatics.
Not everything with wings on it has to be able to take off vertically or hover.
Rick
Not everything with wings on it has to be able to take off vertically or hover.
Rick
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RE: Goldberg cub ARF electric conversion
Thanks for all the help, I guess I will spend the extra $ and get lipo packs as all of you suggest. One of the e-pilots at my field probably has a watt meter that I could borrow.
Mike
Mike
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RE: Goldberg cub ARF electric conversion
hey Mike
I just finished this plane. I used a E-Flite power 60 / Castle Creation 80 ESC./15x8apc prop. I use 2 Maxx Amp 4000mha 11.1 volt li-poly batterys in series. the plane flys great. it weights 8lb.
the power 46 should give you a ton of power. I like using 2 batterys in series. 2 S li-poly batterys are real cheap. and will give you the same performance as the 4s Li-Po's
the Batterys mount perfect in the fuel tank position. I left the front wind sheild removiable to accsess the batterys. it works great.
I can post some pictures if you would like to see the setup.
also anti slip cloth works great for battery trays and inbetween the batterys with a velcro strap to hold them down.
I just finished this plane. I used a E-Flite power 60 / Castle Creation 80 ESC./15x8apc prop. I use 2 Maxx Amp 4000mha 11.1 volt li-poly batterys in series. the plane flys great. it weights 8lb.
the power 46 should give you a ton of power. I like using 2 batterys in series. 2 S li-poly batterys are real cheap. and will give you the same performance as the 4s Li-Po's
the Batterys mount perfect in the fuel tank position. I left the front wind sheild removiable to accsess the batterys. it works great.
I can post some pictures if you would like to see the setup.
also anti slip cloth works great for battery trays and inbetween the batterys with a velcro strap to hold them down.
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RE: Goldberg cub ARF electric conversion
ORIGINAL: bsipro
hey Mike
I just finished this plane. I used a E-Flite power 60 / Castle Creation 80 ESC./15x8apc prop. I use 2 Maxx Amp 4000mha 11.1 volt li-poly batterys in series. the plane flys great. it weights 8lb.
the power 46 should give you a ton of power. I like using 2 batterys in series. 2 S li-poly batterys are real cheap. and will give you the same performance as the 4s Li-Po's
the Batterys mount perfect in the fuel tank position. I left the front wind sheild removiable to accsess the batterys. it works great.
I can post some pictures if you would like to see the setup.
also anti slip cloth works great for battery trays and inbetween the batterys with a velcro strap to hold them down.
hey Mike
I just finished this plane. I used a E-Flite power 60 / Castle Creation 80 ESC./15x8apc prop. I use 2 Maxx Amp 4000mha 11.1 volt li-poly batterys in series. the plane flys great. it weights 8lb.
the power 46 should give you a ton of power. I like using 2 batterys in series. 2 S li-poly batterys are real cheap. and will give you the same performance as the 4s Li-Po's
the Batterys mount perfect in the fuel tank position. I left the front wind sheild removiable to accsess the batterys. it works great.
I can post some pictures if you would like to see the setup.
also anti slip cloth works great for battery trays and inbetween the batterys with a velcro strap to hold them down.
I would like to see the pics of your plane, as this is my first electric I would like seeing how others have done this conversion. I will take some shot of my rig-in-progress to post.
I have been looking at the electrifly 5000mah 2S lipoly packs that tower sells for about $100 ea. I would use a pair in parallel, of course.
I have also been eyeing some electrifly 3600mah 12 cell nimh packs (80 amp disch capable) @ $55ea. They are heavy at 30oz compared to a lipo pack, but very economical $ when compared to lipos $$$.
I don't know where folks find inexpensive good quality packs. I have priced single flight batt setup at around $200 a pop. I'd like to have at least two.
Would I really pay a heavy penalty in flight performance, weight, and flight time with the above mentioned NIMH $ pack?
I would really like to know before I waste money on something unsuitable for this application.
Mike
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RE: Goldberg cub ARF electric conversion
Hey Mike
here are some pictures of the cub. I get about 15 min flite times, with 1volt drop. I used 1-3/4 x #8 nylon spacers for the motor mount. just center the e=flite motor mount on the x on the fire wall drill 4 holes I used blind nuts and 2-1/4x8 screws. I have used this mounting system on all of my planes and it holds up very good. I also used the Hangar 9 cub landing gear they are a little wider up at the fus. but they work better and look good. I think I paid $4.00 for them at the LHS.
here are the pictures. there are some showing the venting in the cowl and the fus. there is a perfect spot mid way back just cut out the covering.
here are some pictures of the cub. I get about 15 min flite times, with 1volt drop. I used 1-3/4 x #8 nylon spacers for the motor mount. just center the e=flite motor mount on the x on the fire wall drill 4 holes I used blind nuts and 2-1/4x8 screws. I have used this mounting system on all of my planes and it holds up very good. I also used the Hangar 9 cub landing gear they are a little wider up at the fus. but they work better and look good. I think I paid $4.00 for them at the LHS.
here are the pictures. there are some showing the venting in the cowl and the fus. there is a perfect spot mid way back just cut out the covering.
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RE: Goldberg cub ARF electric conversion
Here is a picture of the engine box I made from light ply, a little more work than making standoffs. I normally build these boxes for my gasser planes as a alternataive to the flexy standoffs, I know it's probably overkill for a small electric motor, but old habits die hard
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RE: Goldberg cub ARF electric conversion
hey mike
I like your motor mount. you are going to enjoy this plane it flys real nice. I added 3- 3/8 holes in the firewall to get some air flow over the ESC and the batterys. it keeps everything nice and cool.
I like your motor mount. you are going to enjoy this plane it flys real nice. I added 3- 3/8 holes in the firewall to get some air flow over the ESC and the batterys. it keeps everything nice and cool.