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Post by seabass001 on Feb 21, 2010 8:58:04 GMT 1
First I just wanted to say hello and say how cool this website is. I didn't realize how popular this plane is. I have had my SC for about 3 months and I love it. I would like to put a brushless set up in there and I was wondering what the recommended motor and esc from hobby city is. Any help and info on this would be greatly appreciated. Thanks
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Post by killioughtta on Feb 21, 2010 11:44:15 GMT 1
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Post by seabass001 on Feb 21, 2010 21:38:34 GMT 1
killioghtta, Thanks for the rapid response to my question. Have you had any problems with bending the shaft on that motor. Based on other reviews people say that it is a very soft shaft. I was also looking at this motor. www.hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=2111. I read some other post and see others have used this. Does anyone suggest a paticular ESC and motor mount for this as well. I'm swapping out the radio electronics and figured I would just do it all. I dont need my plane to go 100 mph. Just fly a little faster and more efficient. Thanks for your help guys. |
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Post by flydiver on Feb 21, 2010 21:57:28 GMT 1
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Post by Dillzio on Feb 22, 2010 5:33:09 GMT 1
I'd also recommend headsuprc, they sell high quality replacement parts for all their motors such as prop shafts and prop adapters, and he's done all the testing on the motors in terms of how much thrust you can get from different props and how much power they'll use. For the cub, I'd be looking at their 2410-08Y, 2409-18T, 2830, powerup 400 sport, 2409-12T, 2836, powerup 450 sport, 3530 or the 3536. I've put them in order from least to most powerful. Some motors come in different KVs, so you'll have to pick which one you want. A low KV motor (eg 800kv) spins at a lower speed, so you would use a larger prop like a 10x8. If you use a higher KV motor (eg 1400kv) the motor would spin faster, so you'd use a smaller prop like an 8x5. Higher KV motors are usually more a bit powerful than their lower kv counterparts, but when spinning at high RPM making sure your props are well-balanced becomes more important. If you wanted to keep using the same size propellers as the stock LP you probably want a motor of about 1000KV. www.headsuprc.comHeadsup also has decent 30A ESCs for $18, or you can look for an "eagle" or "hobbywing" 30A ESC on ebay, you can usually find them for a pretty good price. One cheap little motor i've had my eye on is the EMAX BL2215, it comes in 950 or 1200kv. It can always be found for a good price on ebay. You can get spare prop shafts from headsuprc too. |
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Post by seabass001 on Feb 22, 2010 6:23:36 GMT 1
I really appreciate all the input. I'm gonna research these tonight and then make a decision tomorrow and post what I'll be purchasing. I had no idea there were so many super cub flyers out there. Is mountig these engines to the plane an easy task? Thanks again!
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Post by Dillzio on Feb 22, 2010 7:59:22 GMT 1
Not an easy task, generally speaking. You want to make sure you know what ur doing before you do it. The one thing you can count on is that it won't be straightforward. The main complication is the "thrust angle". As the prop spins one way, the torque tries to spin the plane the other way. To counteract this, the motor is mounted on an angle to compensate for the torque. There are angles built into the firewall, and the gearbox so there's no easy way to keep them exactly the same, but you'll find many different ways of getting the job done on this forum. A couple of my personal favorites are supercubclub.proboards.com/index.cgi?action=display&board=sccgeneral&thread=2358&page=1 by duck and supercubclub.proboards.com/index.cgi?action=display&board=tt&thread=2527&page=1 by Killioughtta Erwin mounted his right on the firewall so lost the angle of the gearbox, so perhaps he can give us some feedback on whether he thinks it needs it or not? |
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foo
Flight lieutenant
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Post by foo on Feb 22, 2010 11:37:45 GMT 1
I can vouch for Duck's mount as Dillzio mentions, I just made a similar mount last week and its working well! Also got the same motor and battery. My mount is 14mm thick and is mounted right on the stock gearbox which I've sawn off to maintain the thrust angle.
What I did though was to mount a piece of foam (about 3 cm thick) on the inside of the plane (on the firewall side) and glued some velcro to it and the battery. This allows me to mount any battery vertically without affecting the CG (because the battery is mounted right on the CG).
Will post some pics sometime soon.
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Post by ginginho on Feb 22, 2010 15:52:57 GMT 1
[snipped] For the cub, I'd be looking at their 2410-08Y, 2409-18T, 2830, powerup 400 sport, 2409-12T, 2836, powerup 450 sport, 3530 or the 3536. I've put them in order from least to most powerful. Some motors come in different KVs, so you'll have to pick which one you want. A low KV motor (eg 800kv) spins at a lower speed, so you would use a larger prop like a 10x8. If you use a higher KV motor (eg 1400kv) the motor would spin faster, so you'd use a smaller prop like an 8x5. Higher KV motors are usually more a bit powerful than their lower kv counterparts, but when spinning at high RPM making sure your props are well-balanced becomes more important. If you wanted to keep using the same size propellers as the stock LP you probably want a motor of about 1000KV. www.headsuprc.com. IMO the 3536 is way too much power for a SC, you may get problems fitting it under the cowl and balancing the aircraft may be fun too. Something around 230-250w (into the system, assume 70% efficiency) will give you performance that will put a smile on your face (vertical clime for a couple of 100 feet) without it being stupid. I'm not sure Dillz has described the relationship between motor (Kv), prop and power. A motor will draw as much power as it needs to rotate the prop. One thing that is key is the max amps a motor can take. If the motor/prop combo is wrong it may run to destruction of either itself or another component (prop due to turning too fast, ESC due to overload, battery due to excess draw). An in-efficient set up will likely damage the motor as much of the power is only producing heat in the motor, which will effect the magnets. Too small prop on a low Kv motor will not provide sufficient thrust and hence is inefficient, whereas too large a prop on a high Kv motor will draw too much power and cause damage as outlined above. Therefore when selecting a setup you need to decide: 1) What size prop you want to turn; 2) How much power you want it to consume and produce; 3) What power source are you going to use. As Dillz pointed out, something around 1000-1050Kv is about right if you want to use similar sized props to those supplied by HZ. I'd disagree that higher Kv motors are more powerful. When like for like are compared (say 2830's) the higher Kv has more windings (11 over 9) and hence are capable of handing more current. They only are more powerful due to this. In fact, as motors get larger the tendancy is to have lower Kv's as the need in a larger aircraft is to spin bigger props, and use as least power as possible. Be aware that all the 2800 and 3500 motors have the shaft exiting the motor out of the rear (for behind firewall mounting or cage mounting), although they come with an adaptor that allows it to be used the other way round (check the pictures on the site). The battery size has quite a bearing on this, as this is what will power your beast. If you've only a 1500mAh pack capable of delivering at 10C (most manufacturer's ratings are very wrong) then this can deliver 15 amps constantly, with a flight time around 6 minutes. So a bigger motor and hence more power will require a bigger pack capable of delivering the required amps to spin the prop and give reasonable flight times. One cheap little motor i've had my eye on is the EMAX BL2215, it comes in 950 or 1200kv. It can always be found for a good price on ebay. You can get spare prop shafts from headsuprc too. That'll give reasonable performance (around the 180W mark), the 1300mAh 15C stock pack will just about cope with this, but I doubt it will last very long. |
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Post by killioughtta on Feb 22, 2010 16:05:15 GMT 1
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foo
Flight lieutenant
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Post by foo on Feb 22, 2010 16:26:28 GMT 1
Hmm, pop quiz: If you do get a separate BEC, do you have to use an ESC without a BEC?
I mean, what would happen if you have 2 BEC's plugged into a receiver?
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Post by flydiver on Feb 22, 2010 17:23:14 GMT 1
Yes, ESC is essentially the throttle.
You pull the red wire off the ESC to disable it.
You can use both BEC simultaneously but they have to have very close electrical properties or they 'fight'. Meaning, if you have to ask, you don't know how, so don't do it.
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foo
Flight lieutenant
Posts: 50
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Post by foo on Feb 22, 2010 17:31:40 GMT 1
Aah, thanks! So the signal will still control the throttle, but won't power the RX. I'm guessing the black (common) wire still needs to be connected? Hobby King has a Mystery ESC (40amp) ESC with a 4A SBEC which I'm considering for a 4 servo setup (that, or a separate 5A BEC) - future project, not for the cub  She's all upgraded now, so I'm looking for something else to spend money on ;D |
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Post by ginginho on Feb 22, 2010 18:03:19 GMT 1
Aah, thanks! So the signal will still control the throttle, but won't power the RX. I'm guessing the black (common) wire still needs to be connected? Hobby King has a Mystery ESC (40amp) ESC with a 4A SBEC which I'm considering for a 4 servo setup (that, or a separate 5A BEC) - future project, not for the cub She's all upgraded now, so I'm looking for something else to spend money on ;D Yes, the black is required. A 4A SBEC should be sufficient for a lot of installations, unless you are planning on running lots of big servos on many control surfaces. What sort of thing are you looking at? |
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Post by Dillzio on Feb 23, 2010 3:20:25 GMT 1
IMO the 3536 is way too much power for a SC, you may get problems fitting it under the cowl and balancing the aircraft may be fun too. Something around 230-250w (into the system, assume 70% efficienc >:(y) will give you performance that will put a smile on your face (vertical clime for a couple of 100 feet) without it being stupid. I agree that the 3536 is a stupid amount of power for the cub, but it's not really an uncommon motor for revheads to upgrade their cub with, the Turnigy 3536 is particularly popular. I've seen motor mounts to fit them to the cub on ebay, and here's one I just found on google: www.customrcparts.com/motorMountDetail.php?productID=100010&&bannerID=2That's a really nice looking mount by the way! I've heard of many people that have had to add a lot of weights to the front of their cubs after upgrading to 28-30 motors because they're just so light! The stock motor and gearbox weighs 145g, and the 35-36 motors weigh from 105-110g, so that still leaves you 40g for a speed controller and motor mount. I think I'd rather have a larger motor and just prop down as necessary than have to add weight to the nose of my plane, the only downside is that with a larger motor your battery life would be a bit less, cos you're using extra power to spin the heavier motor. It's much better to have your plane end up a bit nose heavy than tail heavy anyway, since a nose heavy plane is much easier to fix, and will require less weight to balance out. When I have my plane on it's CG rig, to get a 10 degree change in angle it takes about 1 ounce at the front of the cowl, or a 10c coin at the tip of the tail. This is because the tail is about five times further away from the plane's CG than the nose, you need about five times less weight to have the same effect on plane's balance. There sure is a whole lot to consider when upgrading to an outrunner huh? Another thing to be mindful of is what type of outrunner you get. With outrunner motors, the whole outside of the motor (the bell) spins, not just the shaft. The tricky thing is that some motors have the shaft sticking out the bell side of the motor (the side that spins), and some have the shaft sticking out the opposite side of the motor where the wires go in (which is stationary). You can get mounts for either type really, but generally speaking it's easier to get the type with the shaft sticking out the same side as the bell. These motors are from HeadsupRC: This is the powerup 450, which has the shaft sticking out the same side as the bell:  This is the 35-30, which has the shaft sticking out the opposite side to the bell, you can see it sticking out behind the top right motor mount, just in front of the red wire. In these motors, the prop adapter attaches to the bell, not the shaft like in the traditional type of electric motor:  You should have a read around here if you haven't done so already: www.headsuprc.com/servlet/the-template/faqindex/Page |
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She's all upgraded now, so I'm looking for something else to spend money on ;D