CS 10 Blade / HK Aluminium 10 Blade

[Roger Cox 1]

Want to try my hand at a Ducted Fan Jet from the Hobbyking selection and from what I've 'heard' from the 10 blade fan units either the Changesun or one of the HK units, I would love to have one !

I may well choose to buy one of the models already fitted with the standard EDF unit and remove it for the 10 blade.

Has anybody info about retrofitting any of these models ?

I would be concerned about the amount of work involved with a particular model. I've heard that to retrofit the Durafly Vampire involves almost slicing the fuselage in half !

thanks

[Bill_B]

Posted by Roger Cox 1 on 16/10/2013 22:05:39:

Has anybody info about retrofitting any of these models ?

I would be concerned about the amount of work involved with a particular model. I've heard that to retrofit the Durafly Vampire involves almost slicing the fuselage in half !

thanks

Don't know where you've heard that about "almost slicing the fuselage in half!", but in my experience all it needed was a very small amount of fettling and then the CS unit (10 or 12 blade) dropped right in. The sound improvement is well worth the effort, but be aware that the 10 and 12 blade units will consume a lot more Amps than a standard 5 blade unit on the same motor. In my Vampire I ended up with the CS 10 blade fan on 3s 2650mAh using an Eflite BL15 3600Kv inrunner. This drew 56.4A (625W in) which made a very subdued 'whoosh' sound and propelled the plane in a very scale like manner. BTW, my vampire didn't have the added weight of retracts, so if you have those I would suggest going the 4s route on a slightly lower Kv motor with a larger capacity battery.

[Roger Cox 1]

Thanks Bill

I read about the 'slicing' from another forum, he was obviously one of the 'experts' that our hobby has an abundance of !

I don't have the kit yet but from the HK site pictures, did you 'open up' from the top side and roughly how large was the opening ? Was the 12 blade 70mm ?

Only an ic man would not understand your comments regarding:- heavier aircraft, bigger battery hence lower kv. Would you mind telling what that all means ?

Thanks again

[Bill_B]

Posted by Roger Cox 1 on 17/10/2013 17:44:13:

Thanks Bill

I read about the 'slicing' from another forum, he was obviously one of the 'experts' that our hobby has an abundance of !

I don't have the kit yet but from the HK site pictures, did you 'open up' from the top side and roughly how large was the opening ? Was the 12 blade 70mm ?

Only an ic man would not understand your comments regarding:- heavier aircraft, bigger battery hence lower kv. Would you mind telling what that all means ?

Thanks again

Firstly, the DuraflyVampire has a bottom hatch that enables access to the complete fan unit, so just undo the two screws underneath and gently ease the hatch off. All should be fairly obvious then.

My 10 blade CS EDF is 70mm, as is what's supplied in the Vampire

Where to start with your other questions! Here goes: If Vampire 'A' is significantly heavier than Vampire 'B', then more power will usually be required to fly Vampire 'A'. As your Vampire has the added weight of retracts and an extra servo, my 10 blade, 3s (11.1V) set up would hardly be able to sustain level flight if installed into your aircraft. Therefore to gain more power using my set up a 4s battery (14.8V) would be required to rotate the fan at a much faster speed thus giving more thrust. The problem then is because the motor is now revving higher due to the increased Volts, it is drawing more current so the flight time will be less if using the same capacity (mAh rating) battery as the 3s set up. The way to overcome this is to use a higher capacity battery (mAh rating), but this will of course be heavier and larger in dimensions. Also, the motor used in my 3s set up would now possibly be drawing more current than its maximum limit so to get around this a similar motor with a slightly less Kv rating could be used to keep the Amps drawn at a sensible level whilst still proving more revs and thrust than the original set up. Kv (Kilovolt) is the RPM of a motor per volt across it, so as an example a 3000Kv motor turns 3000 RPM per volt. If using a 3s battery (11V) the motor will be spinning at roughly 33,000 RPM assuming no frictional losses or loading (no prop or fan fitted). Put 14.8V (4s) across it and it'll be revving at 44,400 RPM, a significant increase. Just to confuse the issue further there are motors that can have the same Kv rating and physical size as each other, but have completely different Amp ratings. In my experience, it's usually the superior quality (dearer!) motors that can stand the higher currents due to the better materials used and tighter dimensional limits etc. Finally, always use a high 'C' rated battery in EDF models as they don't half get a caning.

I hope there's some sense in my ramblings, but it's late and I've just got back from work so please ask further questions if it's still not clear to you.

[Bill_B]

**Here** is a video of the Vampire with the new 70mm Wemotec minifan Evo. I think it's going about twice scale speed, but it does sound nice.

[Roger Cox 1]

that looks and sounds incredible - is that 'new' Wemotec a 9 blade version and if so, where can get one ?

cheers

[Bill_B]

Posted by Roger Cox 1 on 22/10/2013 14:35:45:

that looks and sounds incredible - is that 'new' Wemotec a 9 blade version and if so, where can get one ?

cheers

Yes, it's the new 9 blade Minifan Evo from WeMoTec, but unfortunately every model shop in Europe seems to be sold out of the combo unit (fan, duct and HET 2W-20 all assembled and dynamically balanced). Puffin Models are the main agents in the UK, but the last time I checked they didn't have any MinFan Evos in stock. You can buy direct from WeMoTec and just the fan is available if you already have the original Minifan Pro duct, or you can purchase the fan, intake lip, duct and prop adaptor as a complete package. Coincidentally I have a combo unit in transit from a model shop in Paris, but it took over 2 hours of searching on the internet to find it, but unfortunately they don't have any more in stock as I had the last one! I did find another available in Switzerland, but the unit price was too high as was the postage.

Incidentally, there are two versions of the 70mm MiniFan Evo available, the HET 2W-20 powered version (3-4s battery), or the HET 2W-23 powered (4-5s battery).

Good luck with your search If you're after one.

[Roger Cox 1]

Thanks Bill for all your help and information - can't believe that these 9 / 10 blade units are not stocked in the uk, it's not as if they're too expensive to hold a stock of and hurt the pockets of our poor supporting traders !

Have been flying ic for many years and haven't come across such poor product support - We've seen one new member at our club who turned up with the Vampire complete with the CS 10 blade and now there's at least 6 or 7 of us who want to have one now and not in a months time.

Have emailed BRC Hobbies about the (expensive) Lander units, I've simply asked them to respond with details of the edf airframe and 10 blade unit that I can buy 'off the shelf' - be interesting to see what they say.

Favourite at the moment is either the Vampire or Sea Vixen

**LINK**

roger

[Roger Cox 1]

Hello Bill,

Well I've ordered the Durafly Sea Vixen (ARF) from our HK friends, it's shown as an 'in stock' item at the UK warehouse so I'm expecting delivery next week.

I've also ordered the CS 10 blade from rock models hk so I'm not expecting to see that until....

I'm a little concerned about the 'balance' situation with this unit, but let's wait and see what the info says. Will start my homework about the recommended motor / battery / servo and speed controller setup

Sure to ask you for more information

cheers roger

[Bill_B]

Hi Roger, I think the reason for the world wide shortage of the Wemotec Evo is that, (a). it's only been available from about August this year, and (b). I think Wemotec under estimated just how popular the new Evo would turn out to be.

I too have ordered from Rock Models (eBay) earlier this year and my goods came within 14 days, with no payable tax. I think that's a fair time considering how far it has to travel and besides, it'll give you time to assemble that lovey Sea Vixen. The beauty of most EDFs is that they can easily be retro fitted with the model fully built as they need to be serviceable items. FOD can just as easily ruin a good day's EDF flying as it can a gas turbine!

You shouldn't have any balance issues, especially if you're sourcing your own motor etc. and I can recommend a good set up for you now. A HET 2W-20 (28mm inrunner), 80A ESC and a 3300 or 3600mAh 4s LiPo .This combo should produce just over 1Kg of thrust. If you want silly performance, then change the motor for a HET 2W-23 on a 5s battery. Oh, and if you do use a HET motor, please be sure to use the supplied heat sink, it'll give the motor a fighting chance of living to old age!

[John Dean]

I'll be watching this with interest as I've just bought the HK Sea Vixen as a kit so will be installing my own servos. CS 10/70 is on order from China, should be a couple of weeks yet, and also ordered Turnigy L2855 2800kv. Lot of info on the fan in RC Groups ducted fan threads. Just need HK to supply the missing nose leg retract and servo extensions to arrive and I can crack on.

John

[Bill_B]

Roger and John, when you get your Vixens built can you please post some pictures, if possible? Also, I'd be interested in the specifications of your setups.

[Roger Cox 1]

Sea Vixen arrived yesterday and she looks good - as for the CS10 blade which I ordered on the 23rd, it arrived today - 7 days from HKong !

HELP - Now it's time for a bit of homework to help with the motor choice, learn about speed controllers or esc's and ubec / sbec etc...the ic world is much easier to understand.

For information, the man in HKong is Rocky Law, Rocky's RC Models and his email address is [email protected] - received this email response to my question about balancing:-

"Hi my friend, thanks for your order. Please don't worry about the balance. A multi-blades fan unit is very easy to do the balance. You just need to find out where is the heavier point, and then add some epoxy to anothers side to balance it."

Just put the fan in my prop balancer it it doesn't appear to have a 'heavy point'

[Bill_B]

Likewise, my fan unit was perfectly balanced when I checked it so the next stage is try it out, either on the bench (please don't be tempted to hold it on your hand!), or in the plane. Hopefully it'll be vibration free. If it does seem to have a point where the fan resonates, it is possible to add a small amount of weight inside the spinner, or even just try rotating the spinner a small amount just in case it's not manufactured 100% true.

With regard to UBEC/SBEC and general ESC issues there is some good info within this site and I would perhaps recommend a look at the Electric Flight section as there is a specific ESC thread (and EDF, batteries etc.), that is full of great advice and info.

 

Edited By Bill_B on 31/10/2013 04:20:22

[Tim A]

I have actually got two HK vmapires the first one I got is the arf with retracts, have flown it with three batteries all 4s.

A 2200Mah, 3800Mah & 4000Mah and as Bill B say's there's actually very little if any gain using the larger batteries, the added weight overcomes any real benefit in speed or flight times, plus take off from grass is marginal and you use up any gain in getting off. All three batteries have a flight time of only 6 mins. That's being conservative on the throttle - it does glide well!

The second one was the basic kit. I added a CS 10 blade fan, 2300kv motor and 60 amp plush ESC. Easy to fit a fan in as the fuse comes in 2 halves split horizontally. No retracts, easy hand launch, (As long as the throwee doesn't chuck into the ground - Chris K). I only got the second because our club's El Presidente and I got into a competition over who could make theirs sound the best. Although a bit faster and better sound again it flew best on the 2200Mah battery. Flight times only slightly longer than the retract model.

It tends to prove the theory that airframes have a max speed that to overcome would require a condsiderable increase in thrust.

We have four HK vampres in the club and those with retracts we belly land to save the retracts. As for fan balance both mine are fine, they do seem to have a resonance about 1/3 throttle.

[John Dean]

CS 10 and Turnigy L2855 2800 kv arrived today so put it all together with no problems. Also routed out a slot for the ESC to motor cables. I'll put 3.5mm connectors on the extension cables so I can remove the fan if needed without any more soldering. Pics attached.

[Roger Cox 1]

Helpful pictures John,

What motor is that and what esc / battery setup are you going for ?

Did you try to balance the fan ?

cheers

roger

[Roger Cox 1]

Kiwicanfli !

"I added a CS 10 blade fan, 2300kv motor and 60 amp plush ESC."

Can you tell me something about the motor and esc - type, price and where from and what battery you're going to use ?

Thanks

roger

[Roger Cox 1]

also...which servo's are you fitting ?

were you able to buy all the servo / control surface linkages ?

thanks

roger

[Tim A]

Hi Roger, Motor used Turnigy L2855 2300kv 450watt, ESC Turnigy Plush 60amp, Servos Turnigy XDG-9 micro. All from HK.

Linkages as supplied in in kit. Servos are cheap and work well HXT-900's would fit but have had problems with them in other A/c - jittering & uncommanded movement.

[John Dean]

My set up is Turnigy L2855 2800kv, Hobby wing 80Amp ESC , as I already had it, Turnigy 4S 3300 30-50C LiPol, metal gear servos from Giant Shark.

[Jeff-C]

I find it amazing that a few years ago, very few people knew about HobbyKing.
Now pretty much every plane and every forum has something about their products.
It was strange to start seeing reference to all the Turnigy this and that in RCM&E magazines, but I suppose it just shows that when you start something in a small gap in the market, you can make that gap a cavern and basically start to monopolise and industry.

With regards to the CS and HK edfs. I am very tempted to fit either of these to my Sabre as the power is marginal, and everyone knows what a disaster it is when one of these gets slow on speed!

[Roger Cox 1]

Should I be looking at a ubec speed controller ?

I understand that in the event of a motor failure then I would still have control of the flight surfaces ?

Thanks for all the help with this one guys

roger

[Tim A]

Unless you had a catastrophic airframe failure due to motor/fan failure you would still have control of flight surfaces from power supllied by the ESC's UBEC. i would only bother fitting a seperate UBEC if you fitted retracts.

[John Dean]

A bit more progress today. Fan installed (after testing) with motor leads held with a few spots of hot glue and the two fuselage halves glued together. Excuse the stripey background, its the towel I rest it on to stop scratching the finish.