Author Topic: Indoor Stunt (Read 2910 times)

TDM · « **on:** January 15, 2010, 01:16:11 PM »

Nobody says a word about indoor stunt and it looks like a lot of fun. I was just watching a video of a few gentleman having fun with a indoor stunt plane.

Alan Hahn · « **Reply #1 on:** January 15, 2010, 01:26:33 PM »

I think the biggest issue is having access to a building with a high enough ceiling.

Igor Burger · « **Reply #2 on:** January 15, 2010, 01:37:53 PM »

Any classic gym for basketball is OK. You have to check the height and subtract body height + arm + span and that is the line length. I use 15ft and so far looks enough in every high school gym.

And if it is still too low, you can fly at least low figures up to square eight ... still enough fun

TDM · « **Reply #3 on:** January 15, 2010, 03:24:39 PM »

What set up do people fly. Planes, motors timer etc.

Igor Burger · « **Reply #4 on:** January 15, 2010, 04:36:28 PM »

60W motor with 700-800mah 2s lipo battery, 30" span at ~6oz, prop GWS 10x4 at 4300 rpm (gowerned) on 15ft lines and lap time 4.9 - 5s. It does full pattern with one lap between fiures in 3 to 3:15 minutes. Modesl are converted from R/C F3AI kits or just done from scratch.

http://www.rcmodely.sk/CLClik/
http://www.rcmodely.sk/zobrazclanok.php?id=300
http://www.kdesombol.sk/Madar/GB/
http://www.kdesombol.sk/Madar/GB/gb2.jpg

Vincent Corwell · « **Reply #5 on:** January 16, 2010, 01:19:28 AM »

Very nice Igor

Can you list the full setup , that I can buy off the shelf please ?

Also where to get those airframes, I am converting my Baby

flite Streak for the same purpose, see above

Vincent

Igor Burger · « **Reply #6 on:** January 16, 2010, 03:01:25 AM »

Whole model must as light as possible, all of those models are very closo to those 6oz and all of them use the same setup, beside one which has power regulation (first video)

Motor is Cemech Python 60. I affraid it will be difficult to find on your side of globe. But maybe if you can find equivalent of 30g heavy (little over 1oz) motor with kv=1350rpm/V and internal resistance 150mohm or less, then you are on good way. Most important is that low resistance, because motor makes lot of torque at high current and most small motors having 200-250mohm will burn. I will eat 400mah in 3 minutes, so it gives AVERAGE current 8A, menas you must find motor rated at least 8A, better 10A.

ESC is Jeti Spin 11A in governor mode set to 4300rpm.

Battery is 2s Zippy 800mah (must be many many many C

). It needs only 400mAh for whole flight, so may be also 700mah will be enough, but 640 is for sure too small, it will be very hot after flight and wil last only short time, because Lipos gets high internal resistance discharged, so they start to heat lot on end of the flight, so it is not good idea to discharge it more than 2/3.

Prop is GWS 10x4.7. It is relatively large, but model is very light, and does not keep low speed very much, so it needs large prop for good speed stability.

Timer is my very light single chip type.

TDM · « **Reply #7 on:** January 18, 2010, 07:00:11 AM »

I those kits that you showed can you give some general parameters?
What is the thickness of the foam?
I understand the span is about 30in.
Does it have a spar in the wing?

Igor Burger · « **Reply #8 on:** January 18, 2010, 07:07:16 AM »

the foam is 3mm thick (0.12")

that "retro style" model has carbon LE and TE (3mm x 0.5mm) ... you can see it here: http://www.rcmodely.sk/obrazok.php?id=1893&text=

that model from R/C kit does not have anything, but the wing is really soft, it is better to use something on TE and LE

Vincent Corwell · « **Reply #9 on:** January 19, 2010, 07:34:17 AM »

All great info Igor

I would buy a complete package RTF, airplane with motor,ESC,timer
and battery ready to fly , tested and flown

If there was such a thing on offer

Vincent

Igor Burger · « **Reply #10 on:** January 19, 2010, 07:40:36 AM »

I do not think so

Igor Burger · « **Reply #11 on:** January 19, 2010, 07:43:22 AM »

That motor is from Czech, so it is close to me, may be I can help with them. Everything else is not big problem I think.

Vincent Corwell · « **Reply #12 on:** January 19, 2010, 08:10:39 AM »

Hi Igor

I am waiting from Hobby King

Turnigy 2211 1700Kv, 10a ESC, 2s 750 x 20c battery, GWS 8x4 E prop

and timer from Will Hubin, to fit to my Baby Flite Streak

I can get the airframe " The Clik " from England Hyperion motors etc

I was just dreaming of a box with a ready to fly CL indoor pland complete !

Vincent

Igor Burger · « **Reply #13 on:** January 19, 2010, 08:49:34 AM »

that prop is too small, you will need 10x4,7 and that kv=1700 is too much for such a prop

Alan Hahn · « **Reply #14 on:** January 19, 2010, 10:13:50 AM »

I think these indoor models would come under the "slow flyer" category (unless I am really mistaken

), so these are relatively big props (diameter and width) turning somewhat slowly.

I believe the 10-4.7 is a "Slow Flyer" prop. They are pretty wimpy compared even to the APC Electric props we use in normal electric CL PA. For an APC slow flyer prop, the manufacturer (APC) recommends that the max rpm=65000/diameter(inches). So a 10" "Slo Flyer" prop shouldn't be turning more than 6500 rpm.

And to turn slow, you need a lower kV motor--which is what Igor is saying I think.

Archie Adamisin · « **Reply #15 on:** January 19, 2010, 10:21:04 AM »

Vincent,

What is the target performance of the Baby flight streak indoors? I believe the system you have selected would make it a great indoor sport model, but will not do very good as an indoor CLPA unless it is very light and you add some width to the elevator.

My BFS outdoor model weighs 9 ozs RTF on 42' lines and it does around 3 sec/lap. I am turning a 4.7 x 4.2 @ over 19,000 rpm with this. It is quite fast and flies very well. Indoors, limits on line length require an extremely light model. If I were to build an indoor Baby flight streak, I would use the same system you have selected and try to build the model in the 5-6 once range. This would of course require some very good wood and lots of holes. Of course, the success of this model would depend greatly on the room you have. You won't be able to fly as slow as Igor's models and stunt very well if you have to fly on less than 25'.

I look forward to hearing how this goes for you.

Archie Adamisin
Muncie, Indiana

Vincent Corwell · « **Reply #16 on:** January 19, 2010, 11:24:42 AM »

thanks Archie

I am committed to the setup on order, will see how that goes
first
I can reuse the batteries and ESC and timer, in a EPP airframe
with a more suitable motor and prop later
At the moment I only have the bare airframe which weighs 4 ounces
First try does not have to be perfect

Vincent

Vincent Corwell · « **Reply #17 on:** January 19, 2010, 02:26:59 PM »

By the way Igor

can you specify an alternative motor, Axi, or Hyperion or Turnigy please ?

Greatly admire all your electric activity

Vincent

Igor Burger · « **Reply #18 on:** January 19, 2010, 02:57:05 PM »

I live in Slovakia what is very close to Czech and Czech is country with probably most producers of BLDC motors per a head. :- ))))) ... just to mention AXI, PJS, MPJ, MEGA, MVVS, Cemech, JETI and several more which I do not remember.

So I had a chance to choose from them (those Czech) that best and it is this one. FOR THIS KIND OF MODEL.

May be there are others (produced outside of Czech), I am not sure, because I do not know them but what I AM sure, noone of chip "equivalents" is usefull because of chip materials resulting in high internal resistance. Problem with them is burning and losing power at load overhead. That big prop loads them lot at climbing and high resistance does not allow making anough torque.

I think there are available Scorpions which are close, but similar motor will be heavier, for example this one will be usefull:
http://www.scorpionsystem.com/files/i393_data_chart.htm

I am no sure, it is necessaru to try, but if it is too slow, then its quicker version http://www.scorpionsystem.com/catalog/motors/s22/S-2208-30T/

may be we should wait until they do S22II :-)

but you can see that it is heavier, while python 60 weights 32grams, scorpion with similar parameters is at 40g ... but python is certaily more expensive, its price is ~40euro
... if you are 100% sure that you can do model very light, for expaple 150g then you can use one of those smaller scorpions, may it will be enough, but its efficiency is worse than python which has internal resistance only 150mohm at 1350 rpm/v http://www.scorpionsystem.com/catalog/motors/s22/S-2205-40T/

Rudy Taube · « **Reply #19 on:** January 19, 2010, 10:04:43 PM »

Hi Igor,

Thanks for all your help on this. My guess is that indoor CL would be perfect for the 50% of the USA that is frozen for 4 to 6 months of the year. As Peter mentioned on another thread, indoor CL combat should be a great event too!

INDOOR PLANES AND POWER SYSTEMS

I think this AXI motor might work, it is only .65 oz. (18.5 gm):

http://www.hobby-lobby.com/brushless_axi2203.htm?pSearchQueryId=412384

It is used for indoor 3D RC planes and it looks like it has the right #s for CL. It should turn the larger prop you use for slow CL. :-) ..... and I think AXI is made in your part of the world? My AXI motors have always performed very well.

Here is a link to some excellent indoor 3D RC models that might be perfect for indoor CL:

http://stores.homestead.com/fancyfoam/-strse-Indoor-Models-cln-Mono-dsh-Planes/Categories.bok

These models weigh only 5 oz RTF (this is with a radio on board with 3 servos, should be lighter as a CL? :-) This link also gives recommendations for motors, ESCs, etc. I fly one of their outdoor foamies, it is a great flyer and an extremely nice kit, so easy even I can build it! ;-) It comes complete with CF spars and everything is laser cut to perfection.

My guess is that any RC 3D setup that can stop in vertical flight then go straight up again should have enough power to weight ratio to fly a slow CL pattern. :-)

Regards,

Dennis Adamisin · « **Reply #20 on:** January 19, 2010, 11:24:10 PM »

Plan B on the indoor stunt. Up around here we have indoor golf facilities, so called "golf domes", many of which are big enough to fly a full size stunter in. Some of the places are routinely rented out by the RC crowd, seems like a critical mass of ECL'ers could do the same.

Of course the Pontiiac Silverdome is still vacant..!

Vincent Corwell · « **Reply #21 on:** January 20, 2010, 01:05:02 AM »

Hi Igor

I looked at Rudys Axi motor but the rpm/v=1720 and
the internal resistance is 285 mohm

I can buy Axi motors locally , perhaps we will find a
suitable Axi specification to match your Cemech motor ?

Vincent

Igor Burger · « **Reply #22 on:** January 20, 2010, 02:09:46 AM »

There is one big difference between R/C and C/L. R/C has controlled INPUT power by throttle, while C/L goes all the time constant rpm and controlled is OUTPUT power by efficiency of large prop. It means it works on constant rpm and output power is large if model slows down little to very good efficiency of prop, but in level flight it does not pull and the efficicency of large prop at its pitch speed is low and lot of input power is used to air mixing and not to thrust. But the motor is feeded all the time and it means that battery is far larger than or R/C.

For example while my r/c stunter of the same construction can fly 5 minutes on 250mAh battery, the same model for c/l needs 700-800mAh battery for 3-4 minutes. and it dictates difference in weight of the model, and also rating (and thus the weight) of the motor. It must be able absorb heat from 60W of input power in 3 minute long time, but producers say max current only for short time and at full throttle (not PWM), so we need to take in conservatively.

My motor with IR=150mohm is hot after the flight, but I can keep it in hand, while its equivalent differing only in IR=200mohm (MPJ) is so hot that it starts to smell (winding is covered by resin) and chinese "equivalen" with RI=260 burned during flight. So I do not think that the axi with higher kv (which automatically means higher current) and IR=280 can last in such a model. In that case it is better to use little heavier motor for example like that larger scorpion.

Vincent Corwell · « **Reply #23 on:** January 20, 2010, 03:12:56 AM »

this looks very close :
AXI 2208/26 SILVER LINE is suitable for all models of 300-400 size and microhelicopters.

Specification
No. Of cells 6 - 82 - 3x Li-Poly
RPM/V 1330 RMP/V
Max. efficiency 80%
Max. efficiency current 5 - 9 A (>72%)
No load current / 10 V 0,7 A
Current capacity 10 A/60 s
Internal Resistance 170 mohm
Dimensions 27,7x26 mm
Shaft diameter 3,17 mm
Weight with cables 46 g
Recomended model weight - 200 - 450 g
Recomended prop without gearbox -
2xLi 8"x4,5"
3xLi 7"x3,5"
8 cells 8,5"x5

Vincent

Igor Burger · « **Reply #24 on:** January 20, 2010, 03:17:26 AM »

looks good but 46g is far more than 32g of python

Vincent Corwell · « **Reply #25 on:** January 20, 2010, 03:23:50 AM »

Igor , I looked on Cemech web site, I can buy from them in €uros

but for Phthon I can only see Python 30 or Python 80 ?

would you be interested in selling a complete unit,

in kit form or even ready to fly please ? Shipping should not be

a major with such light weights ?

Vincent

Igor Burger · « **Reply #26 on:** January 20, 2010, 03:37:34 AM »

Yes, it is discontinued, it is problem, last time we got them on special request

Alan Hahn · « **Reply #27 on:** January 20, 2010, 07:44:22 AM »

Quote from: Igor Burger on January 20, 2010, 03:37:34 AM

Yes, it is discontinued, it is problem, last time we got them on special request

What details exist on this "Super Motor". My main curiosity what the Stator diameter, length and # teeth. My guess is that it is ~25mm x 5mm and is a 12 tooth design. On the other hand since the resistance is phenomenally low (almost unbelievable if I compare it to other motors with the same kV and weight

), maybe it is a 9 tooth setup.

Igor Burger · « **Reply #28 on:** January 20, 2010, 08:23:12 AM »

It is not any supr motor. It is even ugly if you look from back uncoveder side. It is just good match with our needs.

It has 22mm 12 pole 9 tooth setup. If I see it well, stator consists from only 5 layers of 0.8mm plates, so it is reason for relatively high no load current, but it does not nemm anything for us, because use it overpropped at low rpm.

KV=1390
IR=150mohm
I0=0.8A
Imax=10A (short time)

Warren Allred · « **Reply #29 on:** January 20, 2010, 09:12:27 AM »

These are a bunch of fun!

I started with a converted RC 3D model on 20' 1/2A lines back in 2004ish, and hung my transmitter from my belt for motor control.

This allowed touch and goes plus pattern work etc...

I did some demos at the 2008 AMA show in Ontario and people really seemed to like it.

Very fun and relaxing!

TDM · « **Reply #30 on:** January 23, 2010, 08:21:45 PM »

How about a geared motor? Does anyone have experience with them? I am thinking a hi KV inrunner geared

.
One more question? What kind of lines do you use?

Thanks Traian

Igor Burger · « **Reply #31 on:** January 24, 2010, 01:38:20 AM »

I use green Spiderwire fishing line. It has minimal elongation and strength of thinnest is far more than you need.

Warren Allred · « **Reply #32 on:** January 24, 2010, 10:15:11 AM »

Quote from: Dorin Morosanu on January 23, 2010, 08:21:45 PM

How about a geared motor? Does anyone have experience with them? I am thinking a hi KV inrunner geared .
One more question? What kind of lines do you use?

Thanks Traian

I haven't tried a geared motor - But I'd personally shy away due to the gearbox whine - Outunners sound so nice.

No reason it wouldn't work fine however.

I used the standard cox 1/2A dacron line because I had a bunch.

Rudy Taube · « **Reply #33 on:** January 24, 2010, 04:35:49 PM »

I agree with Warren. The annoying whine of a geared setup is reason enough not to use one. There are other reasons too.

Dorin, I can see why you would suggest a geared system. ..... Geared elec. systems are more efficient, they allow larger, slow turning props and fast turning motors (where both items are happy). They are tempting, but they have problems.

In the beginning (many yrs. ago) we all used geared setups in our RC fomies (1/2A size planes). We also tried geared setups in our 40 pound IMAC scale aerobatic planes, and all sizes in between. We loved the power that the very large props delivered! .... BUT:

PROBLEMS:

1. Like Warren said, annoying whine, NOT quiet. (defeating one of the important advantages of E power)
2. In the small indoor size, the gear system is very fragile. You would spend more time on maintenance than you would on flying.
3. Our large models needed constant lube for the gears but still had high wear. Belt systems have problems in models, but they are used in full scale electric planes with strong metal mounts.
4. One more item for "Murphy"

5. One more added expense
5. Motors got hot, needed cooling collar.
6. Not reliable enough for CL.

When outrunners became available, we all converted and are very happy campers!

If CL ever has an elec. "MAX LIFT" event, then a geared system would be perfect.

Here is what is now used in our IMAC planes today:

http://www.aero-model.com/Hacker-Brushless-A200-8.aspx

This would make one awesome indoor CL motor. Let's see, a 130" WS Nobler on 100' lines, AWESOME! ..... Dennis, do you have the Ph# for the Pontiac Dome?

Alan Hahn · « **Reply #34 on:** January 24, 2010, 05:10:46 PM »

Like I mentioned in my first reply, the main difficulty is getting access to a gym with "reasonably" high ceiling.

However I do have parts (Gobrushless GBx.1 ) that I I can rewire to get the kV that Igor has. Since my stator is identical to his, I should be able to achieve his power.

But I still don't have the gym!

But it does look like a lot of fun!

TDM · « **Reply #35 on:** January 26, 2010, 09:03:22 AM »

Alan where would you go get the motor from and how do you do the work necessary to make such a motor?

Alan Hahn · « **Reply #36 on:** January 26, 2010, 11:25:41 AM »

Quote from: Dorin Morosanu on January 26, 2010, 09:03:22 AM

Alan where would you go get the motor from and how do you do the work necessary to make such a motor?

http://www.gobrushless.com/shop/

There are two ways--one is to wind your own (click on brushless kits), and they have tutorials there. I think we are talking about the GBx Brushless Outrunner kit -GBx 1-single. You are winding to a kV between 1200-1400 rpm/V.
Another option would be to just buy the MicroDan 2505 3D ( 1200kV or 1490 kV versions) motor (click on Brushless Motors)--more expensive but weight is about right.

If you buy a kit, all you need to do is to wind the motor to the kV you want. Magnets are already glued in(wire is provided). Like I said, there are tutorials and a user database where you can see the kV of different wind counts. It looks like to me you would want ~22-25 turns of 26 gauge wire (the wire that comes in the kit) to get a kV in the 1200 to 1400 range. The wire would be terminated in the "Wye" configuration (explained in tutorials). The object is to stuff as wide a wire as possible to get the turns you want. This minimizes the coil resistance and maximizes torque. If you buy one, I'd recommend also buying some 24 gauge wire because that may fit in with 24 turns and will give you less resistance than the thinner 26 gauge wire that comes with the kit.

I will say that the kit is more expensive that buying motors direct from Hobby King, assuming you can find one at Hobby King in the right kV range.

edited to replace some part that I apparently sliced out of original reply (the brushless kit type and kV to wind to.

TDM · « **Reply #37 on:** January 26, 2010, 12:37:03 PM »

I looked in the Hobby King site but I did not find anything suitable yet maybe some of you gentleman can point in the right direction.

Traian

Alan Hahn · « **Reply #38 on:** January 26, 2010, 12:46:08 PM »

Quote from: Dorin Morosanu on January 26, 2010, 12:37:03 PM

I looked in the Hobby King site but I did not find anything suitable yet maybe some of you gentleman can point in the right direction.

Traian

There may not be for this particular kV range. I am not sure.

Warren Allred · « **Reply #39 on:** January 26, 2010, 12:49:47 PM »

General range:

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=5382

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=4918

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9378

Author Topic: Indoor Stunt (Read 2910 times)

Alan Hahn

Alan Hahn

Alan Hahn

Alan Hahn

Alan Hahn

Alan Hahn