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-   -   Hobbyking SU 47 (http://www.Wattflyer.com/forums/showthread.php?t=73166)

pattern14 02-09-2014 10:39 PM

Hobbyking SU 47
 
I've had this one in the box for a while, after getting the airframe very inexpensively. I looked at the RCG site but not much there. Does anyone have any tips /advice warnings on this model. No idea who it is made by ( could be a clone of sorts), but it appears to be of average quality, similar to Starmax, durafly etc. Any leads or pointers appreciated:)

thepiper92 02-10-2014 01:18 AM

I have this model, still hanging up. I have no clue what to do with it. It is a dual 55mm edf, and I bought two fans for it, hooked them up to one car esc actually. It seems hard to fit the electronics in, and once they are in, they are in as you glue the halves together. With a dual edf, you'll need a high c rating batt, and with the battery slot, max of 1000-1300mah will fit...around 2-3 minute run time. I too would like to get it working. I have the controls working and everything, just a matter of installing two esc's, how to connect the battery to two esc's, and so on.

pattern14 02-10-2014 10:15 PM

Quote:

Originally Posted by thepiper92 (Post 939578)
I have this model, still hanging up. I have no clue what to do with it. It is a dual 55mm edf, and I bought two fans for it, hooked them up to one car esc actually. It seems hard to fit the electronics in, and once they are in, they are in as you glue the halves together. With a dual edf, you'll need a high c rating batt, and with the battery slot, max of 1000-1300mah will fit...around 2-3 minute run time. I too would like to get it working. I have the controls working and everything, just a matter of installing two esc's, how to connect the battery to two esc's, and so on.

Thanks for the reply:). It seems that this one is not all that popular, but its unusual configuration has always intrigued me. Since posting yesterday, I have managed to get a lot done already. With my GWS Me 262 down for a major overhaul, I pulled the electrics out and they fitted almost perfectly into the airframe. The twin esc/single battery set up and motors will handle the smaller 55mm fans no problems. The battery compartment just holds the 2200mah lipo, and the servo's and linkages seem very simple to set up. It appears to be an elevon arrangement, as both ailerons and elevators are connected to the same servo. With no instructions or even pictures, it is a bit of a mystery bird. I don't even have a COG point to work with:rolleyes:.

Still, I'll use silk and WBPU to add strength, as well as bi directional tape, and it should be a bit more robust. Hoping to get it to test flight stage by the end of the week. My 18 year old son is off to Uni to do engineering, and wants to test fly this thing before he leaves. Here's hoping the weather co-operates as well....cheers:)

thepiper92 02-10-2014 10:19 PM

A 2200 mah does fit, but you have to jam it in there, was worried about damaging battery or plane. The setup is two servos, one for each side, causing the plane to have two sets of ailerons and two elevators. How did you set up the twin esc, where did you install them in the airframe? You have to glue the airframe, so isn't it hard to install, or did you install on the outside and use the supplied plastic strips to cover the bottom? Also which fans did you use?

pattern14 02-11-2014 07:48 AM

Quote:

Originally Posted by thepiper92 (Post 939640)
A 2200 mah does fit, but you have to jam it in there, was worried about damaging battery or plane. The setup is two servos, one for each side, causing the plane to have two sets of ailerons and two elevators. How did you set up the twin esc, where did you install them in the airframe? You have to glue the airframe, so isn't it hard to install, or did you install on the outside and use the supplied plastic strips to cover the bottom? Also which fans did you use?

You're right about the battery; it was a bit of a squeeze. I'm considering dropping the whole plastic cage thing and just making my own battery box up, like I did with my Starmax F 22 Raptor. As far as the fuse goes, I have taped the two halves together with clear packing tape, as well as fixing all the wings, tail section etc. the same way. Over the last five years or so, I have experimented with making these cheap Chinese foamies more durable and repairable, and packing tape really adds strength. It does take some practice to get get a good finish, but it is worth the hassle. My mate from the UK, Barry ( Bazex49) uses lightweight habotai silk and water based varnish/laquer on his foam planes with great success as well. The problem with gluing them is they tend to rip chunks out when a wing or such impacts on the gound, where as with tape, you just remove the damaged section, repair it, and then tape it back in again.

I am considering covering the various sectioins with silk and WBPU, and then taping them together, for the best of both worlds, but for now, it just taped together while I sort it. I'm using 3800kv turnigy outrunners with the stock 3 bladed fans, and twin 40 amp ESC's. These are held in place with bi-directional tape, just ahead of the fans, so are always in a cooling airflow. I had to make a channel in the foam under the fans with a soldering iron to allow the 3 wires to pass through with interfering with the fan seating. Bi-directional tape was used to attach the fans to the fuse, and the lower half of the fuse then taped to the top section. I did exactly the same thing with the Raptor, and it still works perfectly to this day. I'll try and get my son to post some pics of this set up with his phone, as my camera died some time back, and I have yet to replace it. The photo's should really help explain what i've done. Here's hoping i get some more progress tonight ( I'm a shift worker, and usually build at 0200:D while the world sleeps) Cheers:)

thepiper92 02-11-2014 02:31 PM

Quote:

Originally Posted by pattern14 (Post 939698)
You're right about the battery; it was a bit of a squeeze. I'm considering dropping the whole plastic cage thing and just making my own battery box up, like I did with my Starmax F 22 Raptor. As far as the fuse goes, I have taped the two halves together with clear packing tape, as well as fixing all the wings, tail section etc. the same way. Over the last five years or so, I have experimented with making these cheap Chinese foamies more durable and repairable, and packing tape really adds strength. It does take some practice to get get a good finish, but it is worth the hassle. My mate from the UK, Barry ( Bazex49) uses lightweight habotai silk and water based varnish/laquer on his foam planes with great success as well. The problem with gluing them is they tend to rip chunks out when a wing or such impacts on the gound, where as with tape, you just remove the damaged section, repair it, and then tape it back in again.

I am considering covering the various sectioins with silk and WBPU, and then taping them together, for the best of both worlds, but for now, it just taped together while I sort it. I'm using 3800kv turnigy outrunners with the stock 3 bladed fans, and twin 40 amp ESC's. These are held in place with bi-directional tape, just ahead of the fans, so are always in a cooling airflow. I had to make a channel in the foam under the fans with a soldering iron to allow the 3 wires to pass through with interfering with the fan seating. Bi-directional tape was used to attach the fans to the fuse, and the lower half of the fuse then taped to the top section. I did exactly the same thing with the Raptor, and it still works perfectly to this day. I'll try and get my son to post some pics of this set up with his phone, as my camera died some time back, and I have yet to replace it. The photo's should really help explain what i've done. Here's hoping i get some more progress tonight ( I'm a shift worker, and usually build at 0200:D while the world sleeps) Cheers:)


Thanks lots of good ideas. Looking forward to edfs. Which escs and battery you using. I have these units I think http://www.hobbypartz.com/88e-adf55-c20-kv4100.html with the 25c 2200 3s, the battery is hot in 5 seconds. Need a higher c rating.

pattern14 02-11-2014 10:14 PM

Quote:

Originally Posted by thepiper92 (Post 939708)
Thanks lots of good ideas. Looking forward to edfs. Which escs and battery you using. I have these units I think http://www.hobbypartz.com/88e-adf55-c20-kv4100.html with the 25c 2200 3s, the battery is hot in 5 seconds. Need a higher c rating.

I use a 40 amp ESC and minimum 40 "C" rating with all my EDF's because of the high workload. ESC Brands vary, but I tend to stick to the better quality ones ( about $20-30.00 range) as the few extra dollars are worth it. Batteries tend to not last as long either, compared to my prop planes, although I'm sure that some out there will disagree;-) Good airflow around both is essential for EDF.

Anything from 3500 to 4100KV seems OK for these size fans, although I have got the best run from the HET in runners so far. They are expensive, but have outlasted all my others. Likewise the HET fans seem better quality as well. I use them in all my 70mm jets.

I've not had much to do with the 55mm fans up till now, so it is a bit of a learning thing for me as well. Here's hoping I'll get some pics up by tonight, cheers:)

thepiper92 02-11-2014 11:09 PM

So naturally this would need two 40 amp escs. Would a 40c 2200 even fit. A 20c just fits and isn't a higher c rating slightly larger, or am I wrong about that? Also, how about one esc. Currently there is a car esc in the plane and it seems to run both motors fine, no cutting out, though I heard it is a bad idea. Is there a benefit to inrunner driven fans?

pattern14 02-15-2014 05:33 AM

Quote:

Originally Posted by thepiper92 (Post 939763)
So naturally this would need two 40 amp escs. Would a 40c 2200 even fit. A 20c just fits and isn't a higher c rating slightly larger, or am I wrong about that? Also, how about one esc. Currently there is a car esc in the plane and it seems to run both motors fine, no cutting out, though I heard it is a bad idea. Is there a benefit to inrunner driven fans?

Sorry I took so long in getting back:). Being a shift worker means that days and nights blur a bit, especially when they change my hours at short notice. You can use one ESC for Brushed motors, but with brushless, you really need one ESC per motor. The control wire needs to be cut or removed for one of the ESC's, so the inputs don't fight each other. I've built numerous twins and once you get the basics right, it is very straight forward. Using a single car ESC would not normally be the go, so I'm interested to hear that it actually works. I've only ever used seperate ESC's, so I really can't comment on the pitfalls. As for innrunner and outrunner pro's and con's, I guess it depends on application. I use both, but it is primarily for compatability with the EDF unit, more so than than any other reason. Outrunners have more torque, and inrunners are more streamlined, although i'm sure there is more to it. I'm just about to go out and test fly this thing, so hopefully, I'll be back with the maiden report in the next few hours. Still no photo's yet, but I WILL post them soon:rolleyes:

thepiper92 02-15-2014 05:46 AM

I've researched on using one esc some time ago. There can be an issue if the motors are running the opposite directions, or if the motors are different/if the props are different.

pattern14 02-15-2014 07:54 AM

A promising start
 
Quote:

Originally Posted by thepiper92 (Post 940045)
I've researched on using one esc some time ago. There can be an issue if the motors are running the opposite directions, or if the motors are different/if the props are different.

Well there you go; I usually run my twins counter rotating anyway, so I may experiment with some spare motors and ESC's that are lying around.

The maiden went better than expected:D. I did not use the standard battery case, but left it out and made a hatch for the compartment. I was able to slide an 1800 mah nanotech 50c 3s battery right up into the nose compartment and got the COG right on 160mm from the intake edge. Slightly nose heavy, but not a bad idea for a first flight. I had grave concerns about the dubious servo linkages, and this was confirmed on the first flight. Lots of slop and flex, with poor elevator response. On the positive side, brilliant roll rate, good glide, and adequate power, as well as cutting an unusual profile in the sky.

She hand launched very easily, and landed just as well, so the whole thing looks very promising indeed. I have already decided to junk the standard servo set up, and have seperate servo's for all four surfaces, identical to the Raptor. I'm not sure if the company just cheaped out on the servo set up, but it is definitely not up to it. No doubt she will fly much better with conventional linkages and adjustments. It will not take much work to change it over either, plus I'll scrape out all that dead weight in the nose cone so I can use a bigger battery for more duration. I'll get back with more a bit later, cheers:)

thepiper92 02-15-2014 05:50 PM

Did you leave out the landing gear and just belly land?

pattern14 02-16-2014 10:44 PM

Quote:

Originally Posted by thepiper92 (Post 940078)
Did you leave out the landing gear and just belly land?

I don't use landing gear on any of my planes, as I fly from home, and the surrounding paddocks are way too rough. These ARF foamies are pretty fragile at best, so I usually reinforce the underside with gorilla tape and thin strips of coreflute. If I can't hand launch, I don't fly, although I am building a bungee setup to see if that would work on some of my more difficult planes. The nearest club, with a sealed strip, is miles away, but I'm not prepared to pay their ridiculous fees ( after a 3 hour return trip plus petrol cost), "earn" my wings, and then wait in line to fly for 15 minutes, at the same time as being told that "electrics are not real planes anyway":rolleyes:. Plus they don't do combat:(. I know it sounds bitter, but I really dislike formal clubs.

back to the SU47 though.....my son left for University yesterday, and being his plane, I'll wait until he come back during his break to fly it again. In the mean time, I'll strip it down, fit proper controls, and do some mods here and there. We'll fly both it and the F22 together to see how they compare, and I'll get back in about 4-6 weeks with an update. All the best, cheers:)

thepiper92 02-16-2014 11:28 PM

I land and take off from the street, while looking out for some cars, and making sure I don't hit street poles. I also am not too fond of the clubs. Club in Ontario wants 100 for membership. I'll see if they will let me fly, I'm only there for maybe a week. They were quite negative towards me. I hadn't flown yet when I last saw them, but I mentioned how I also was into rc cars. They guy started saying how the rc crowd is completely different. I disagree, especially with some of the people on here who enjoy pushing their planes to the limit and doing crazy things. I suppose the age of the members was a factor, guys who use the fm radios, gas only, and so on. There is on guy in his 40s in the club who flew drones in the military. He told me he wanted to get a car track set up, but the club president said cars are noisy...last time I checked electric cars are silent.

pattern14 02-17-2014 12:19 AM

Quote:

Originally Posted by thepiper92 (Post 940163)
I land and take off from the street, while looking out for some cars, and making sure I don't hit street poles. I also am not too fond of the clubs. Club in Ontario wants 100 for membership. I'll see if they will let me fly, I'm only there for maybe a week. They were quite negative towards me. I hadn't flown yet when I last saw them, but I mentioned how I also was into rc cars. They guy started saying how the rc crowd is completely different. I disagree, especially with some of the people on here who enjoy pushing their planes to the limit and doing crazy things. I suppose the age of the members was a factor, guys who use the fm radios, gas only, and so on. There is on guy in his 40s in the club who flew drones in the military. He told me he wanted to get a car track set up, but the club president said cars are noisy...last time I checked electric cars are silent.

yeah, it's a real shame that there is so much "us and them' with R/C, and the scene here is particularly limited due to the weather conditions and isolation. The clubs literally seem to discourage new fliers who don't fit the parameters. At least flying on private land means I can do as I please, and Wattflyer is here to share ideas and experiences:D

thepiper92 02-17-2014 12:38 AM

I really don't understand it. The club definitely turned me away from them in a way. I, more or less, want to fly there to show the guy I can fly, without the help from an instructor, or starting off with a massive trainer so I can see it easier. He told me there was no way to learn with a small plane, but that is exactly what I did, and I didn't start with an instructor, which he also said was required. He seemed to not understand that my involvement in rc cars gave me the basic tools I needed to learn planes, and rather saw those who play with rc cars as riff raff of a sort...planes, cars, they are all toys meant to be enjoyed. Planes are harder, I admit, but still are just fun.

pattern14 02-17-2014 10:36 PM

It is supposed to be fun, but too many out there take it seriously. Some of the threads on these forums can get real nasty as well, but the moderators usually sort it out.

Looks like I've only got about 10 days to re-do the servo controls on this, as my son is coming back for a visit weekend after next. Here's hoping the weather plays along:rolleyes: Better get to it.......


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