Park Hawk Hop-ups

[eflyer12345]

Jerry, ifxmnfly, had asked me the other day about the optimum motor upgrade for the Park Hawk. This led me to believe that others may be interested in the same type of information plus other things being done.

As far as the motor is concerned, the Speed 300 is the best bang for the buck in this bird, it is a good match. There are other motors that may give more performance, mostly in duration, but at higher costs. The key elements to look for here would be the weight, the ability to run on 8 cells, and having a kv of at least 4800. I have not seen a brushless that meets the weight requirement. The other motors that fit the needs are in the Speed 300 class and are the Jomar Pro 280 or the Simprop power speed 300. If others know a motor that would work, please feel free to let me know. Also keep in mind that some motors may require you to re-engineer the frame to fit them and must be able to hold the pinion gear in the correct location. Fit is important. :-)

Other things that are going on in different areas of testing that might be of some interest. I have been playing with the following. An EPP head that slides onto the frame of the bird. This is ridgid enough to maintain form, and adds "crash" protection if you come in at the wrong attitude.

Claws, I have been working with two sets of claws, one stationary, and one with wheels to see about rog performance. There is potential here.

Guano drop, if your neighbor annoys you, fly overhead, a quick blip of full down and you drop a combination of flour and water. This still has some bugs in it, but shows lots of promise.

-Jeffrey

[KeithK]

Jeffrey,

I have timed my airplane speed 300's (GWS 370's) and noticed a bit of improvement, With the high gearing of the P.H. advanced timing may have efficiency benefits as well as power. it is easy enough to do and worth a try. I found about 3/16th's inch advance to work good. Followed by a quick underwater break-in.


Wasn't there an article a while back about a small cartridge of shaving cream or tube holding shaving cream used as "guano"?

[eflyer12345]

Timing changes always make a difference. I would time for efficiency over power. The motor makes enough power to fly at half throttle. I only use full throttle for launch or when the battery is almost used up.

The only other time you may need full throttle is high winds, but the bird is not designed for that.

The shaving cream was listed in a quick review that was posted. That was not the setup that I thought up but would work well in theory. Weight is the only concern there.

-Jeffrey

[ifxmnfly]

Originally posted by eflyer12345
Guano drop, if your neighbor annoys you, fly overhead, a quick blip of full down and you drop a combination of flour and water. This still has some bugs in it, but shows lots of promise.

-Jeffrey

This has potential! I can foresee flyins with a contest for the greatest accuracy and another for the biggest mess. We could have annual ParkHawk Reunions in Florida. (You know ... a return to the Nest.)

:eek:

[eflyer12345]

How many does it take to make a club? Around here we have a few of the Park Hawks and there was talk of a club, perhaps the Flapping Flyers?

I would seriously consider the idea of events for a fly in. Adds some fun to it all. Anyone can fly any plane they want in the event, just bias the events towards the ornithopters.

-Jeffrey

Please keep in mind, half of this is tounge in cheek! :-)

[ifxmnfly]

I'd like to sign up for the Ornithopter Combat event. With a set of your claws, I could rule the skys!

[Reformed Slimer]

"How many does it take to make a club? Around here we have a few of the Park Hawks and there was talk of a club, perhaps the Flapping Flyers?"

....or Flying Flappers? :p

[bobandris]

Jeffrey,

Since you are a focal point for "Orni" developments, I have an off-topic question. What are the prefered mounting methods for the standard 8x720 NiMH battery pack? I have seen some complaints about rubber bands getting cut & failing. Is velcro an option. I will be running HS-81MGs in the tail, so balance is also a consideration.

Many Thanks,
Bob

[eflyer1234]

I did not see myself as the focal point, just an involved dealer. :-)

Anyways. The prefered method is still to use the rubber bands. There are some steps one can take to prevent a premature failure of the bands. Those steps are sanding. It is best to take an emery board or some sandpaper and round off the edges of the fuse where the rubber band touches. From manufacturing these edges are sharp and lead to the cutting of bands.

Velcro could be an option if you have the type that wraps around and sticks to itself.

I have seen one bird where a tray was made and then the battery velcroed to the tray. Tie wraps are also an option is you charge the batteries in the bird.

-Jeffrey

JGRC
www.jgrc.biz

[Sean Kinkade]

Hi ya'll, perhaps I can shed a little light.......

Motors: Jeff is correct about weight versus Kv versus cost.

The three motors I have used so far in my products are the stock Graupner Speed 300, the Simprop 300 ( identical to the Graupner), and the GWS 370. The GWS 370 is wound cooler and seems to give more duration when allowed in a set up. The 370 will not always fly the Park Hawk.
Here is a brief rundown on these particular motors and their applications.

Park Hawk: Speed 300 required on 8 cell 720 mah NIMH packs ( stock setup), GWS 370 motor can be used with a minimum of 9 cells NIMH, and best with 3 cell lithium set up. I don't know of any advantage of running the 370 on 9 cells. The speed 300 on 8 cells is better.

Slow Hawk: Speed 300 motor with 7 cell NIMH 720 pack ( stock setup), or can be flown on 8 or 9 cells with either speed 300 motor or GWS 370. Since the 3 cell lithium pack has such high voltage, the GWS 370 is recommended for lithium but I have flown my Slow Hawk on lithium with the Graupner speed 300 as well. The difference is rpm and power which you already have plenty of due to the high voltage, so instead of working the speed 300 to death, the GWS 370 runs a little cooler ( like a 6 volt motor vs. a 7.2 volt motor) and will give even longer duration.

I will be selling lithium packages soon and kits shipped with the package will come with GWS type 370 motors, however, retrofitted birds with lithium packs can still be flown with the speed 300.
(Incidentally,I've flown my Park Hawk on the lithium with pheasant like accelerations with no mechanical failures.)

As for other more expensive motors, I haven't tried them, and I haven't heard of any customers success stories yet. However I am still curious and from what little research I have done, the Hacker 20 series brushless and perhaps the AXI or (AC?) brushless motor from Hobby Lobby look like the best candidates. I have designed in a new motor mount in the Slow Hawk and upcoming Park Hawks to accomodate the Hacker in addition to the stock 300's. A small amount of dremeling the mounting holes will still be required to mount the Hacker but not a difficult task. The new motor mount configuration will allow for several different sized motor pinions to hopefully achieve an acceptable ratio with whatever the motors Kv is. So, there's a little factory designed-in room for experimentation for those who have a hankering to try and have the cash to dole out on those priicey motors. But for all of you customers on a budget I have to ask WHY FOOL WITH BRUSHLESS when you can get over 25 minutes with a can ferrite 300 motor on lithium? I think the money for a brushless motor/controller would best be spent on a lithium battery and charger.


Claws: You can make legs and claws out of pipe cleaners!
I don't know what Jeff has up his sleeve but I think good ol pipe cleaners will work. Whatever you make them out of they have to give on landing.

Beak, Head, Body, etc.: The new Slow Hawk fuselage has mounting holes for the attachment of an upcoming upgrade part which is a deep drawn seamless vacuum formed plastic head canopy and plastic side shells ( much like the SkyBird) There will be a body and head for the Park Hawk forthcoming too. I had some initial concerns about weight with the Park Hawk but lithium power has dispelled all of my fears. Body shells should be available by the first of the year.

And since this thread is about hop-ups, I don't mean to harp but lithum 3 cell is a quantum leap in performance folks! With the higher voltage, very little undercarriage is needed to get the Park Hawk to ROG. We've heard of rise off ice, but the Park Hawk on lithium could possibly rise off grass.

Sean

[Ben Diss]

I have a Hacker B20S with a KV of 4400. I'm flying it with 10 cells. Mucho power!

[bobandris]

Sean,

With regard to the GWS 370/3-Lithium performance upgrade. As best as I can check, you normally get the GWS 370 motor with a pre-installed pinion, I think it's brass. The smallest pinion they seem to ship it with is a 10 tooth one. My Park Hawk appears to have a 9 tooth steel pinion. When you installed the GWS 370, what did you do re pinions?

Also, what size & make Lithiums did you use?

Many Thanks,
Bob

[Sean Kinkade]

Bob,

I am able to obtain the motors without the GWS pinions ( which are metric). I can't really call the 370 motors "GWS" motors because I do not actually get them from GWS but I think they are the same as GWS. The rpms are identical but mine do not come with the capacitors soldered on.
I actually have some brass pinions as well as the steel.
Upcoming Park Hawks will have a slightly different gear ratio and the 9 tooth motor pinion will change to 10 teeth.

I am not certain of the brand of the lithium cells in my pack.
I do know that they are 2000Mah. The three cell pack weighs 5 ounces and the cells are cylindrical.
I will be selling Sanyo most likely.

Sean

[Jerry Rose]

Originally posted by Sean Kinkade
I will be selling lithium packages soon - and kits shipped with the package will come with GWS type 370 motors, however, retrofitted birds with lithium packs can still be flown with the speed 300. Sean

I want those Lithium packs now! And I want that 370 motor too. (I might as well go for the gusto!) This is better than Christmas.

What is the best Lithium charger for these packs?

[Jerry Rose]

I've been catching up on the Li-Poly posts and a lot has happened since NEAT! The following link has more information than you can absorb in one sitting, but well worth reading if you are considering the Li-Poly option! It will let you know what is going on with chargers and the Kokam batteries. Great reading.

http://www.rcgroups.com/forums/showthread.php?s=&threadid=56590&perpage=15&pagenumber=1

[Sean Kinkade]

Jerry and others,

I am now taking orders on a lithium battery/charger combo.

Battery:

3 cell 2000mah Li-Ion with Deans connector: $59.00

A/C quick charger with Deans connector:

110/220v input, 12v 2000mah regulated output $60.00

Motor: Mabuchi 370 with 9 tooth pinion: $16.00.

Limited combo special...you get the battery, charger, and motor for $99.00 plus $5.00 for domestic shipping.

E-mail me at thopter@earthlink.net

Sean

[BillB]

Great news.
How heavy is that Li-Ion 2000 mAh battery ?

[Sean Kinkade]

The 2000 Mah lithium pack weighs 5 ounces.

[Jerry Rose]

Originally posted by Sean Kinkade
3 cell 2000mah Li-Ion with Deans connector: $59.00
Motor: Mabuchi 370 with 9 tooth pinion: $16.00.
Sean

1) Is that battery pack made of three cells in series? If so, that would be 12.6 volts (unloaded).

2) If the first assumption is true, then how long would we expect the 370 brushes to last?

The motor is so inexpensive that if it only lasted 1/2 of it's design life it would be worth the power/duration of flight trade!

[kasra]

Speaking of hop ups, I have ordered some of those new Razor Brushless motors that are made by M. Orme. The first one is going in the Park Hawk. This motor has similar KV and mounting dimension to Speed 300. I will report back with the results.

Kasra

http://www.razormotors.com/

[Azarr]

Sean,

The new Mini AC 1215/12 has a Kv of 4700 and the version sold as the "Extreme" has a Kv of 6370. The "Extreme" is normally sold only with the gearbox, but I can special order them without the box. I just had Model Motors do some mods on the Extreme for a project I'm working on. The Hacker B20-22 and the new Razor motors might also be great replacements. Not really practical for a commercial project, but while expensive, once you get used to the reliability and effeciency of brushless, the the cost quickly is forgotten. The only problem I've ever had with a brushless is that when the "latest and greatest" comes out it's hard to justify it since you can't wear out the "old" stuff you're flying.

:D :D

Azarr
www.ecubedrc.com

[Sean Kinkade]

Hi Azarr,

What is the shaft diameter on the mini AC extreme motor?



Sean

[matthew.orme]

RZ300 data

5.8V power supply
APC 4.75 x 4.75 prop
18A
15,000 rpm

7 x N500AR (old red zapped cells)
APC 4.75 x 4.75 prop
23A
16,500 rpm

7 x N500AR (old red zapped cells)
APC 4.7 x 4.2 prop
21.4A
17,700 rpm



Geared with Maxon 4.4:1 Planetary
APC SloFlyer E-Props
7 x N500AR (old red zapped cells, not peaked)

8x6
10.9A
6250 RPM

9x3.8
10.1A
6600 RPM

Geared with Maxon 4.4:1 Planetary
APC SloFlyer E-Props
6V Power Supply

9x4.7
7.5A
5750 RPM

8x6
8.5A
5525 RPM

9x6
10.4A
5065 RPM

11x7
16A
3925 RPM

[eflyer1234]

If anyone is interested in the RZ300, we are setup as a dealer and expect our first shipment soon.

-Jeffrey

JGRC
www.jgrc.biz

[kasra]

I got a chance to fly the ParkHawk with the RZ-300 today. It has power to spare now. I flew with both 8-cell and 10-cell 720 NiMH pack's. In the excitement I forgot to set my timer but it seem's I am getting both more power and more duation out of the same pack than the Speed 300. I will try to have better data later.

Kasra