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Post by Dillzio on Mar 17, 2011 3:46:36 GMT 1
Ging, Fly, thanks for all the info. I'm not sure a Stryker really would be any cheaper than the funjet. At my local hobby shop (model flight) they sell the stryker fuselage only for $70 but they sell the funjet kit for $99 or $120 for the ultra. www.modelflight.com.au/products/Parkzone_F27C_Stryker_Bare_Fuselage-5873-163.htmlwww.modelflight.com.au/products/Multiplex_Funjet_ARF-4609-10.htmlAccording to the FJ build thread here www.rcgroups.com/forums/showthread.php?t=621504 the kit comes with motor mount, pushrods, horns, decals, all that cool stuff that you wouldn't get in an "airframe only" kit. Seems like it would be worth paying the extra $30 to get a complete kit that just needed a motor, ESC, servos and receiver. Given your experience fly, of butchering your stryker on its maiden, perhaps it would be better for me to warm up on a HK parkjet before I invest in a decent airframe? It doesn't look like it's all that hard to control from the video, but there again, without actually flying a jet myself I can't talk from experience: |
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Post by flydiver on Mar 17, 2011 4:53:58 GMT 1
That's an option. In that case I'd think I'd leave it stock unless there are some glaring issues you can't live with. Didn't look too bad in that Flite Test. Small little beggar but you would probably get a feel for a jet, just in a smaller space.
Note-just got done watching the 3rd review. Not nearly as bad as I thought it might be, maybe not too bad at all. Sounds plenty to start stock and if you want it nasty fast go to the 2730. Nice that it can run fine on light 2S-those are cheap. I run my 3D and combat planes on those.
Whatever jet you get, put a couple of BIG BOLD DARK lines on the bottom and maybe make the fins fluorescent pink or other topside differentiation. It makes a big difference. White and a couple decals doesn't cut it. You'll see.
$70 for a Stryker bare frame? Jeez - $20 in the states.
I bought the entire Stryker (use and 'defective') for $30. The guy had crashed it, routed the antenna along the long servo wire and it had no range at all. Once I figured that out it was fine. I became the problem.
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Post by toff on Mar 17, 2011 8:52:46 GMT 1
Just as a thought - why not get some 6mm depron and build your own? It's real easy, and as I keep pointing out, Blackrats eurofighter on rcgroups is a quick and easy build, fast flier, and is stupidly manuveurable............... Save you tons of money, and teach you quite a bit about parkjets.
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Post by Dillzio on Mar 17, 2011 13:32:33 GMT 1
2S? The thought never crossed my mind, but I don't see why not. Power goes down, but so does weight. I just looked up the price comparisons on HK and there's only like $1 difference between 2S and 3S for 1300mah 20C Zippys. Is going 2S really going to be worth it?
If Strykers are so cheap over there it might be worth my buying one from O/S and getting it sent over... after I learn how to fly the baby jet anyway.
Making my own huh? I'll have to check out that thread, although I'm not entirely sure I have that much faith in my abilities.
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Post by ginginho on Mar 17, 2011 14:38:42 GMT 1
2S? The thought never crossed my mind, but I don't see why not. Power goes down, but so does weight. I just looked up the price comparisons on HK and there's only like $1 difference between 2S and 3S for 1300mah 20C Zippys. Is going 2S really going to be worth it? It saves a fair amount of weight. I ran the Fox on 500mAh 2S, getting its AUW to around 100g. I just checked a bare styker in the UK can be had for less than £25. I don't know how that exchanges to AUS$. Making your own takes this hobby to the next level. Make it out of whatever you can get, depron, correx, bluecore, EPO, supermarket pizza bases etc etc. All good fun and you can make what you want and it doesn't matter if you stack it. It costs next to nothing and another can be made if necessary, normally with some improvements. |
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Post by flydiver on Mar 17, 2011 15:53:02 GMT 1
You know that KV thing?
1500kv motor on 2S will spin the same prop at the same speed as a 1000kv at 3S. The amps will be higher though. That's the idea behind the 3000kv 2730. That's a pretty high kv. Parkjets generally run in the low 2000kv with medium-small props (6x4). If you run that 3000kv on 3S and try to push the larger prop you fry things. You can up the kv and drop the voltage and achieve a similar effect. You can run it on 3S but just like the Cub, you have to prop down > 4x4? (guessing here). It'll go like stink but it won't have much thrust and will take awhile to get up on the prop.
Small differences in prop size at those RPM's make a HUGE difference in amp draw. The same equation that you start learning on the Cub when you upgrade takes a big step up. It's just one of the things you learn when you move to jets. Like old fly keeps saying; "flying is easy, the electrics are hard".
Simple profile planes are not hard and some of them can go pretty d**n fast on cheap equipment. You already have the skills, you just don't have the experience yet and it's a whole new road to go down. So far my profiles have been 3D or combat, not jets. One of my combat deltas with a 3000kv GWS 2205 goes like stink on 2S though. It's too fast for fun combat it turned out. It's a fun 'failure'.
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Post by toff on Mar 17, 2011 22:39:53 GMT 1
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Post by Dillzio on Mar 19, 2011 3:04:59 GMT 1
Thanks heaps for all the input guys! It seems like the parkjet will also be an nice enexpencive platform for me to experiment on to get a handle on the differences between how 2S and 3S goes, and using high KV motors.
Geeze Toff, that eurofighter goes like a greased Scottsman! Something I don't get though, if it's made out of flat material, how does it get it's lift?
Or does it just use thrust to keep itself in the air?
Oh, and how many KV is ur motor?
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Post by flydiver on Mar 19, 2011 6:06:30 GMT 1
My eurofighter runs on a towerpro 2812 motor To my knowledge there is no TP 2812. New motor? There old web address crapped out so I couldn't check. There is a 2408-21 with a relatively high KV, 1400-1700 depending on how it's wound and who you believe. There's also a 2700KV 2415-9T heli motor that could work for jets. |
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Post by Dillzio on Mar 20, 2011 9:15:13 GMT 1
Got a jet motor selection question here.
When choosing a motor for a 4-5 inch prop, you want a motor of about 2300-3000kv. In this range, you can easily choose an inrunner OR an outrunner.
What's the difference? Is one preferable over the other?
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Post by toff on Mar 20, 2011 10:30:28 GMT 1
Is it for a pusher? If so, an outrunner is whats needed. Not that it's any better, but it's far easier to mount than an inrunner.
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Post by ginginho on Mar 20, 2011 10:58:15 GMT 1
Is it for a pusher? If so, an outrunner is whats needed. Not that it's any better, but it's far easier to mount than an inrunner. Generally cheaper too. |
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Post by Dillzio on Mar 20, 2011 13:34:59 GMT 1
isn't an inrunner easier to mount, because with an inrunner only the shaft spins?
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Post by flydiver on Mar 20, 2011 16:10:24 GMT 1
It really depends on the application. Inrunners generally are more expensive and for some mounts ( stock Funjet, Stryker for example ) are easier to mount. Since they ARE more expensive some planes have been designed for outrunners.
I really good inrunner is a pretty nice motor; Megas, HET, ARC, Medusa-but $$
Some just aren't so good; most of the HK - they are heavy, inefficient and get hot easy-but they are WAY cheap so quite popular.
A good inrunner is harder to make than a good outrunner, thus cost more. At the top both are equally expensive.
since an outrunner has a (much) larger outer diameter for a given performance envelope they develop more torque so they are generally more useful on planes. Like the Cub an inrunner (the brushed motor is an inrunner) has to be geared down. When you get to the jet stage level RPM's that equation starts to break down. When you get to the EDF stage (super high RPM) the inrunners generally shine. Until recently the outrunners couldn't even compete in the EDF category but they have improved.
Many folks don't realize it but you can get low KV inrunners. I have a 1300KV Mega in my Minimag and a 1200KV in a Sig Rascal. Those applications were designed for direct drive brushed motors so an inrunner is a direct drop in, no hassle, no mods necessary.
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Post by killioughtta on Mar 20, 2011 17:31:45 GMT 1
I know I've been absent here a while but I couldn't help pitching in on this debate. I've skimmed the surface of most replies. I too love this jet. At least what I've seen of it. I've wanted one for a while now and am waiting for the right moment (my 27th is coming up on April 1st) to buy one. I've trained in jets in the last year or so (latest video at my site www.maydayrc.com/h29) with ones I have built from scratch. One was slow; with a big wing and medium control surfaces. The latest is a bis smaller (about the size of the HK pak jet) with proportionally bigger control surfaces and a bit faster. I don't know if I can recommend this jet for Dillz but I say give it a shot. Just be cautious of your past with loosing planes and all. lol I CAN say take it slow at first and ALWAYS check control surface movement right before flights on elevon-configured jets. It'll be something new to you so making sure it's right will pay off. A couple of weeks ago I met with a kid from RCgroups at a local park to fly his small F35 and he launched it without checking it first. It flew 10 feet up and forward and nose-dived. After I checked, the surfaces were moving the opposite direction and he had no chance of controlling it. Also, once you master this plane, it will be a f*cking blast! ;D |
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