Utah Unicorn Flyers (Part III) - Page 5 - RC Groups
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Nov 08, 2004, 09:48 PM
Crash happens! :)
Last edited by Arrow; Feb 18, 2007 at 11:52 PM.
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Nov 08, 2004, 10:09 PM
Tight is Right
Darren Hintze's Avatar
do you require a standerd power system for combat.

We don't require anything. We're a pretty casual group focused on fun. However most have "Standardized" on a Mega 16/15/4 with 3s lipos and a 6x4 or 6x5.5 prop.

But there are many variations on this theme.

I, for example, fly with the /5 on 4s lipos with the same prop selections. Many of us are augmenting our lipo packs with low-cost NiMH packs. Right now, maxamps.com is running a great deal through RC Groups on NiMH cells for those with soldering capability.

I just picked up about 60 cells for various applications -- spent under $40 for all of them and shipping.

I've also found a cheap Mega-like motor on E-bay for ~$40 shipped my dad and I will be testing. Since my Mega seems to be lost in the Ether, I may replace my wing motor with one of these also (I've still got a loaner from my Bro-in-law).

Who is planning on coming Tuesday? Weather looks like it may cooperate, may not. If the "scattered showers" miss us, we'll have a great afternoon.

I have to deal with a virus that found its way through a soft spot in our network (read: silly employee who opened an infected spam after refusing to update virus detection for about 3 months) but assuming I get that done early enough, I plan to bring the F-18 down and fly it just prior to combat.

If I get pressed, the A-10 is now painted and will act as my alternate.

Last edited by Darren Hintze; Nov 08, 2004 at 10:18 PM.
Nov 08, 2004, 10:49 PM
More Combat Please!
Wind_of_Change's Avatar
I should be there. Tony possibly. My corn motor is acting pretty weird. I'm not sure if it's gonna live much longer. I may have to order a replacement and have it on hand for what I'm pretty sure is the very probable death of my current 4 turn. Somehow the casing got mashed in, and I think it's pushing my brushes in on the magnets, which are being slowly worn down. It sounds bad. One of our recent hits must have been worse than I thought.

I just wish brushless components weren't so dang expensive.
Nov 08, 2004, 10:55 PM
Tight is Right
Darren Hintze's Avatar
It sounds like you may be interested in the $40 brushless experiment too.

Yeah, Magnet wires rubbing the rotor is definately in the "not good" category. Mega fixes their motors for $50, but if an equivallent replacement is closer to $40, it doesn't make much sense.

If it is just a dent though, you may be able to remove the rotor and straighten the casing with some needle nosers. Just put some cloth over the end inside the motor to keep the pliers from rubbing the coating off the magnet wire. I had to do something similar with a Himax after I over-tighted a mounting screw and pushed the windings into the rotor. It worked fine afterward (in fact, I think that's the same motor that's inside my F-16 -- now pushing 500 flights on the motor.)

Nov 08, 2004, 11:13 PM
Flying Free
erashby's Avatar

Battery recommendations

I swear I'm going to finish my Unicorn one of these days.
But I need to replace the batteries first. I was using them for my daughters sailplane, and they are "peetering out". The battery packs were 9 cell Kan 950 NiMH, but I have been abusing them, running a Mega 5T with a 7x4 and a static amp draw of about 20 amps.

My unicorn will run either the 5T or a 4T Mega. I haven't covered my Unicorn yet, so I can enlarge the battery bay if needed. I was thinking of a 3S or 4S Lipo in the 2000MaH range, but the Kokam 3100 is tempting. My Lipo charger (BPP SC-2) will only handle up to 3S, so I will need to connect 2 packs of 2s in series. I also want to be able to use the packs in my daughter's sailplane and the Park Zone Stryker (a parts "kit" that I still haven't built), and also my Kontronic BL twinjet when I rebuild it (draws 35-40 amps).

So, I need suggestions:
1) Lipo vs GP 1100 packs? (I'm leaning towards lipo because I don't have good throttle management, and I hate to land. I only land when forced to by the LVC-- when I actually have time to fly, that is...)
2) If lipo, then 3S or 2S packs(2S so I can connect together for a 4s pack and still use my charger.)?
(Cost is not a big factor, because I work too dang much and fly too darn little.)
3) Which Lipos? Kokam? Thunder Power? Irate? Others?
I want a pack that can give 35-40 amps without too much ventilation.
4) What have you guys found?
Thanks for the input.
Last edited by erashby; Nov 08, 2004 at 11:19 PM.
Nov 08, 2004, 11:18 PM
Jared_Zygote's Avatar
I will be there too if the weather holds up.

Todd could you bring a sheet of thin black coroplast for me?

It sure is a thrill to watch your a-10 and f-18 Darren. Both Very cool planes!!
I ordered a GWS 109 for Christmas. I plan to glass and airbrish it.....then maybe fly it.
I was going to do the Alfa plane but one of my favorate things to do is build these things! I think I have spent the same amount as the Alfa with all the extra crap I ordered to make it the best 109 EVER! :-)

Im making a medium sized wing now that Lee cut for me. It is about 36 inches, EPP, with a very steep sweep to the wing. Should be interesting.
Nov 08, 2004, 11:26 PM
Flying Free
erashby's Avatar
Originally Posted by Jared_Zygote
ITodd could you bring a sheet of thin black coroplast for me?
So, if I actually show up, I could buy a sheet of 2mm black (or white) coroplast?
Nov 08, 2004, 11:26 PM
More Combat Please!
Wind_of_Change's Avatar

I've been looking into this myself for some lipo upgrades in my second Unicorn. I've got my eyes on the Kokam 2100 3S, or the Tanic 2500 4S.

Kokam Super High Discharge LiPo Electric Pack
2100 mAh, 3 cell series (11.1V), heatshrunk with DNS connector, super high discharge (20C / 90%)
Size: 108mmH x 63mmW x 23mmT
Weight: 254 grams
Ratings: 20C / 90%
Outputs: 11.1V Nominal, 2100 mAh
Applications: Supports up to 42A continuous discharge

Tanic 4S1P Lipo pack, 12C Discharge
30amp (nominal) li-poly 2500mah 14.8 volt pack
91mm x 56mm x 25mm - 230 grams

I'll try and remember to bring some choroplast tomorrow. Every time I bring it, I forgot to get it out, and nobody asks. So ask me tomorrow so I don't forget to get it out of the truck. I've got 2mm black, 2mm white, 4mm white. They're 1'x2' for $2 each. Big enough for a bunch of winglets.
Last edited by Wind_of_Change; Nov 08, 2004 at 11:29 PM.
Nov 08, 2004, 11:35 PM
More Combat Please!
Wind_of_Change's Avatar
Jared, didn't know you were ordering a war plane! I would have tried to talk you out of GWS. My Alfa was so superior to my GWS that it was like comparing apples and . . . . . poo.

I'd put brushless in my GWS if I were you, something strong enough to get you out of bad situations. Then figure out ways to really toughen up your control surface linkages, because their designs aren't meant for high power flight. You need to make sure that when you're flying hard and fast that if you pull up, your elevator actually moves and your ailerons don't whimp out, like mine did repeatedly.

The great thing about GWS planes is they're super cheap, especially if you get the slope-glider versions unpainted. $30 for a plane kit is amazing. For that price, I'd almost consider rebuilding a P-51 to fly against your 109. Almost.
Nov 08, 2004, 11:45 PM
Jared_Zygote's Avatar
Yea I plan to reinforce the control surfaces and the fuse itself with carbon fiber. I will be putting in my himax 2025-5300 and some new lipos in it. I really struggled with which plane to buy. I ended up with the gws 109 because I like the look of the 109 and I want to paint it and customize it myself. Im sure Ill try an alfa someday.

I also thought I needed a tougher plane for now. A glassed GWS will take a lot more damage then an Alfa.....You have seen me flying and crashing my formosa havent you? :-)
Last edited by Jared_Zygote; Nov 08, 2004 at 11:55 PM.
Nov 08, 2004, 11:45 PM
Tight is Right
Darren Hintze's Avatar
With performance Lipos, you really want to look at power density. Vintage1 has done a lot of work on the subject. Often, the 20C cells are not the way to go.

Look at Todd's example. The uber Kokams are LESS capacity and 24g heavier than the Tanics. Gram for gram, the 12C Tanics are actually more powerful cells.

However, in our wings, 6C average is usually plenty. 6C continuous is only 10 minutes. Most of us want to go almost twice that long before swapping packs -- so we average more like 3-4C. True, a higher "C" rated cell will hold voltage better for those WOT bursts, but how much $ is that really worth? Personal choice.

With the new 10+C cells out, 6-8C cells are pretty dang cheap and, usually, more than plenty for our applications.

If you like to assemble, it's pretty hard to beat the IRATE cells (most still 10C) from cheapbatterypacks.com. Just be sure to get the Zinc solder for use with the Al tabs.

I think the jury is still out on the GP1100's. Jared has had good luck with them. Todd hasn't. I'll be assembling some 10 and 12 cell CBP1400 AA packs soon. These are ~25A max cells. Hopefully the 10cell pack will have enough zip or the 12 cell packs won't be too heavy.

BTW, the 10 cell packs will double in the A-10 and the 12 cells will also fly the F-18.


Edit: Todd, I need some of that thin Cloroplast too. Lee's "miniwing" is officially front burner now -- assuming I don't have to rebuild my Unicorn after combat tomorrow
Last edited by Darren Hintze; Nov 08, 2004 at 11:49 PM.
Nov 08, 2004, 11:58 PM
Tight is Right
Darren Hintze's Avatar
Heh, we are really active tonight.

On the GWS stuff Jared, after building a dozen of these now, I'm never going to have foam ailerons on my planes ever again. They just don't cut it. Particularly if you're going to glass and paint it on your own, I'd use balsa for the control surfaces. All of them.

I've really liked my GWS planes. Todd's right, they never were as solid as his P-47, but my Himax-powered Corsair made my top-5 ALL TIME list. It was that fun to fly. The 109 is not as quirky as the GWS Mustang (I liked my mustang too, but no question, it was a handful to fly with wicked tip-stall tendancies) so I think you'll be fine.

Just remember, tiny elevator throws. No more than the instructions dictate.

Nov 09, 2004, 12:04 AM
Jared_Zygote's Avatar
Yea reading the threads and watching the simpsons....what could be better?

Balsa huh? how thick? Are there different kinds?

I also bought cool hindges to use
Nov 09, 2004, 12:09 AM
Tight is Right
Darren Hintze's Avatar
I just use the 1 or 2" wide aileron standard stock for the ailerons. I'll show you what I did on the A-10 tomorrow. All my GWS ailerons will be done like them in the future.

I think I used 3/32" thick contest Balsa for an elevator replacement on my Mustang. The GWS foam is thick, so lightweight balsa is critical there.

I'm just reading posts, studying up on a few items, and waiting for Midnight to roll around. HALO2 is coming out tonight!

There are other things than flying after all. We love Halo over here.

Nov 09, 2004, 12:16 AM
Jared_Zygote's Avatar
Yea Ill be picking my copy up tomorrow morning!!!! Ive seen it at E-3 for the past 2 years and cant wait to play it!! That and Halflife 2!!!

Oh and to keep on the subject of the thread....Unicorns rule!

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