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Aerial Photography and Video > Converting Caliber ZG To Electric...Need Help Please.

Wayne Mann
Senior Heliman
Location: United States of America

Hi Guys,

I am also posting this in the electric conversion section as well as I am trying to get as much feed back as possible.

I am in the middle of converting my Kyosho Aerial Video machines from G26 power to electric power. I have had my belly full of vibrating, tail rotor kicking, inconsistent from day to day and just plain noisy engines.

The Caliber ZG mechanics drive train is very similar to the Maxi Joker’s drive train. The engine drives a secondary pulley via belt with a standard pinion gear/main gear for the second stage. So I am thinking the efficiency losses will be nearly the same between the two machines.

With virtually no experience with electric helicopters and less than none if you count interest, I need a little help. I have been reading for the past three days, day and night trying to rap my head around as much useful information as possible. I have formulated a basic plan of attack with regards to my basic needs and the type of equipment I want to use.

My all up weight is going to be in the 22 to 24 pound range…this is a guess, will probably be a lighter.

At that weight I will be using 810mm Rotor Tech blades which is just under a 72” disk.

I need 1550 to 1600 head speed for my set up for rotor head stability and faster forward speed stuff.

I think an Actro 24-5-32 engine from what I have read is what I need. I will spend the money on the Pleti 370-40-A2 if it is a much better choice for the power requirements that I have.

The Kontronics Jazz 55-10-32 ESC…may not handle the 12S2P A123 cells, not sure?

A123 cells in either a 10S2P, 11S2P or 12S2P

One of the threads I was reading was talking about the efficiency loss in the drive system and through the electronics. For normal Aerial Photography and Video work according to this thread a .85 loss was to be expected. If you Maxi Joker guys run the numbers how much head speed loss are you experiencing? If the numbers say you should have 1400 for a head speed, what is your real head speed.

These are my numbers:

Motor KV 435 x voltage 11S2P A123 at 39.6 volt = engine speed of 17226 divided by gear ratio of 9.23:1 = 1866 head speed x a .85 efficiency loss = 1586 rpm for head speed, which is right where I want it.

I have the option of going to 9.44:1 or 9.03:1 for gear ratios or I can make a pulley if necessary. I may have to have a pulley made any way if the machine shop can not adapt my clutch bell pulley so that it can be fastened to an 8mm motor shaft. I can obviously also change the cell count in the batteries to a 10S or to 12S for speed changes or efficiency requirements.

I would love to have a 9 to 10 minute run time out of this set up if possible. Does that seem reasonable?

Now does anyone have any great inspirational thoughts or words of wisdom that they would like to throw my way…please? Pretty please. I am mostly concerned about the ESC handling the 12S2P A123 cells if I need to run the 12S2P packs. The efficiency loss number seems also to be a big guess, at best, until you get something running so that you can determine the actual losses. I’m hoping that some of you with the Maxi Jokers can tell me what your actual losses were.

Thanks for the help in advance

Wayne Mann

05-11-2008 08:00 PM

tabbytabb
Elite Veteran
Location: seattle

Wayne,

Here is a quick rundown of my setups.

Ship 1 Maxi joker 2:
Actro 32-4 running on 12s 5000mah Lipos with a 14T pinion I am getting 1350 headspeed ( I will check the throttle percentage today for you). AUW is in the 20-22lb range depending on lens and I typically fly for 6 mins or so and put back somewhere in the neighborhood of 2200 to 2500 Mah. This is with NHP 800s which are quite a bit more efficient then the V blades I also run but dont lift quite as much.

Ship 2 Maxi joker 2:
Actro 24-5 running on 12s 5000mah lipos with 14T pinion getting 1400 HS (once again I will check the throttle percentage) Just a tad more efficient then the other setup but a little bit less power under load then the 32-4.

Some things to consider from my experience.

1. I would strongly advise you to use an overrated ESC like the powerjazz from kontronik so that you will never have to worry about an overamp or thermal shut down if you are flying in hot weather or really pushing the machine.

2, I would also advise you to use Lipos for their higher energy density and lower weight. Every ounce counts on electric and my ship at 19lbs flies alot better then the one at 23lbs. I also think this will help in getting your 9 minute run time as well. If you are worried about lipos being dangerous my experience with them has been nothing but great. Especially when using the thunderpower chargers and balancers to keep everything in check. I have never had a fire problem or other safety problem and I deem lipos to be safe if you remain careful and diligent in their care.

3. Do you really need 1500 to 1600 HS? This is going to eat up a lot of current to spin this fast. If you could get away with 1400 it would go along way towards the 9 minute flight time.

Gotta run to mothers day brunch, more when I get back.

Tabb

05-11-2008 08:23 PM

HOMEPAGE

Wayne Mann
Senior Heliman
Location: United States of America

Thanks Tabb,

I decided to weight everything to see what my all up weight was going to be. My Caliber ZG with everything ready to fly, camera included is just a tick over 20 pounds. The Caliber ZG by itself is right at 14 pounds. One of my 90 size Calibers (06) version which is what I will be converting is 10 pounds. After weighing everything it looks like I can figure on 12 pounds for the model, plus 6 pounds for the camera mount with camera. So I will be looking at 18 pounds all up ready to fly weight with an A123 11S2P pack. It is also quite possible for me to lighten up the model quite a bit as I have added some stiffening pieces to make the structure more ridgid.

I will consider the Lipos, but I am all but dead set against them.

The switch in ESC to the Power Jazz is not a problem.

Wayne

05-11-2008 09:49 PM

Wayne Mann
Senior Heliman
Location: United States of America

Hi Tabb,

I did some math on your number two ship and here is what I have; with a 14 tooth pinion you are running a gear ratio of 10.83:1 With the 12S2P Lipos at 44.4 volts your engine speed at 100% throttle should be 19314 rpm unloaded. 19314 rpm divided by the gear ratio = a head speed of 1783 at 100% throttle setting. You said that your head speed is 1400 on this ship which means that there is a 21.5% loss in head speed due to throttle position, load and electronic efficiencies. Does ship number two weigh pretty much the same as number one?

Now If you can tell me the throttle setting and the weight for ship number two it will give me a good idea how much loss there is due to load and electronic inefficiencies. Figuring out the load losses versus the electronic losses will be a challange. Flight testing is probably the only way.

I am going to assume that the efficiency loss between the Joker and the Caliber is about the same. The Caliber has a belt drive tail rotor, but the MBL belts that Kyosho uses are very flexible and are nearly as efficient as tube drives.

Edited, I just finished running some numbers and if I use a 12S2P A123 pack with my 9.23:1 ratio and figure in your same 21.5% loss I will be at 1598 rpm on the rotor head which is great. I am figuring on an all up weight of 18 to 19 pounds which with 810mm long Rotor Tech blades at 245 grams gives me plenty of auto safty.

I really appreciate the help

Wayne Mann

05-11-2008 11:59 PM

ErichF
Key Veteran
Location: Odessa, FL 33556 (Tampa Area)

Wayne,

We recently converted an Observer to electric. We used the Plettenburg 370 motor and a Castle Phoenix 110HV ESC. The 110HV shut down five minutes into the second flight. We are waiting for a new one, and in the meantime will be getting a Kontronic Power Jazz instead.

We are also using the TP 10S 5000 packs in parallel.

It's still in prototype phase, and may have to get Chris to send some different pulleys for a more optimized ratio. It sure sounds kool though

05-12-2008 02:44 AM

Wayne Mann
Senior Heliman
Location: United States of America

Hi Erich,

I took the little wifey out to see Iron Man tonight. It was a really good movie.

I heard you talking about it at the Lake City contest, but at the time I didn't think that I was going to have to go this route or I would have been paying more attention and asking questions, but I am way past being sick and tired of crappy weed wacker motors. If someone made a 30 or 35cc opposed twin I would have a lot of interest in that as long as it was made from all billet stock with a ONE PIECE CRANK SHAFT and balanced to the finest tolerances. Ok, it is time to stop smoking the crack now and dreaming as that will probably never happen.

I got so feed up with it the other day I de-fused one of my contest models and put a set of the AP landing gear on and set it up with a ZG tail boom so that I could run the 810 blades. Before putting the mount on I did a couple test flights to see just how bad the smoke was going to be and I even ran a carbon boom out as an exaush extension to get the smoke away fromt the mount, but if I just hovered the machine at 20 or 30 feet the smoke would just roll up all around the model. So I scraped the idea. Does anybody know or remember anything about the Dave's Diesel conversion. I wonder if a YS 91 would run good as a diesel engine. I'm just kidding about the diesel thing.

I am going to change to the Power Jazz myself, just for safety reasons. I assume the auto went ok after the ESC failed?

Are you guys converting in an effort to get away from the vibrations or is this just something to play with?

Wayne

05-12-2008 04:47 AM

ErichF
Key Veteran
Location: Odessa, FL 33556 (Tampa Area)

Yeah, never heard of too many guys successful with nitro because of the smoke. You need a pretty breezy day to get away with it.

We were still taking readings from the autopilot and batteries when the ESC failed, so I was only in a five foot hover.

We decided to try the E conversion because Chris gave us the parts to test it, we weren't having luck with the autopilot because of vibrations, and the noise issue. What little we got from the one and a half flights was good news. The absence of vibrations allowed the autopilot to maintain gyro and accelerometer happiness. We had a very steady attitude resolution and could have started tuning the autopilot to fly the machine on the third or fourth flight.

We opted for the 10S because we were using the same batteries for an electric converted Sig Rascal 110 airplane. Also, the chargers, TP1010Cs, only go to 10S. 12S gives more power, but less amps. We have 10S packs that we pair in parallel, giving a total of 10,000 mah to fly on. Besides, the torque in the Plettenburg is not to be underestimated. The "soft start" on that POS Castle caused the flybar to get bent, it came on so hard! The Pletty is an expensive motor, but well worth it, IMO. Peter Wales uses them to fly his huge 1/3 scale Bell and his nice Airwolf. He also uses an $800 ESC from Schulze.

I've attached a couple pics of the E-Observer conversion.

05-12-2008 05:14 AM

tabbytabb
Elite Veteran
Location: seattle

Wayne,

I just remembered to check my throttle percentage and I am at 1300 HS with 61% throttle on the powerjazz running 12s on the actro 24-5. This is at 20lbs AUW with the TP exteme V2 5000 mah packs

Hope this helps

Tabb

05-16-2008 09:02 PM

HOMEPAGE

Wayne Mann
Senior Heliman
Location: United States of America

Hi Tabb,

Thanks for the info. I plugged in your numbers into the Electric Calculator that they have over at Scale RC Helis dot com for your number two ship with the 24-5 motor and it gives me a head speed of 1588 rpm which seems right since you say you are running at 61% throttle setting. I had always heard that speed controlers didn't like to be run at low to mid settings and that they wanted to be at something like 80% or better? That helps a lot if I can just throttle back, so to speak, when I am just doing photos or sitting still.

Wayne

05-17-2008 03:37 AM

tabbytabb
Elite Veteran
Location: seattle

Wayne,

With the powerjazz is had so much current headroom that I have been getting away just fine with a 61% setting now for hundreds of flights. Everything comes down cool to the touch and HS is maintained to within +- 5rpm assuming that the motor/esc/lipo setup can handle the load.

I would say that if you use the powerjazz throttling back has proven to be no problem. Especially given that my average current draw is around 26 with spikes to around 39 or so.

I wish the joker had bigger grips so that I could give those 810s a try! They look like very nice blades.

Tabb

05-17-2008 09:03 AM

HOMEPAGE

xfc3dcd
Heliman
Location: West Carrollton, Ohio usa

Wayne,

I have also had good luck with the Lipo batteries. I have a Schulze charger and balance during every charge.

Wendell

05-17-2008 06:14 PM

xfc3dcd
Heliman
Location: West Carrollton, Ohio usa

Oh yea, me and the misses saw Ironman last weekend and we both thought it rocked!

05-17-2008 07:23 PM

ozace
Key Veteran
Location: melbourne, australia

This sounds fascinating. As one of the earliest A123 players i dont think they make a great choice on a big AP ship. The extra capacity or lighter weight of lipo sacks makes more sense for these heavy machines. The voltage sag of the A123's makes setting up more effort than just plugging in some lipo packs.

I would have thought 2 6s 4900 lipos packs in series would have been ideal.

The Powerjazz or poptart schulze are the only 2 options for these big things as well.

Please keep up informed with your progress.

we can never have too many, can we ?

05-19-2008 10:59 AM

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Aerial Photography and Video > Converting Caliber ZG To Electric...Need Help Please.

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