Tim Mackey Posted February 20, 2008 Share Posted February 20, 2008 Nice article there Nasa, I like the IC mount idea ! I think I would have probably tried ( albeit regretfully) the retracts, and just ensured that the "groundsman " did a good job on the strip. I just hate so much to see those legs dangling on a fly past - not to mention those on the model ! Quote Link to comment Share on other sites More sharing options...
nasa_steve Posted February 20, 2008 Share Posted February 20, 2008 cheers timbo this model is a little cracker i'm dead pleased with it. its a shame my strips are so rough otherwise i would definately have had the retracts. hence why i normally fly aerobatic scale as they normally have fixed undercarriage anywayregardssteve Quote Link to comment Share on other sites More sharing options...
Phils Posted February 21, 2008 Share Posted February 21, 2008 Steve, Great article and it certainly gives food for thought on using electric in a jet instead of a glow. I would imagine, although not a turbine, the sound is quite acceptable on a pass and certainly an improvement on a glow. Sorry I just cannot imagine hearing this jet with the sound of a 4 stroke!Have to agree with Timbo on the retracts although I can imagine your dilema, and full marks on the engine mount. So what are the electric options? Is your power train likely to be a good datum to start . . . . guess you can already hear the cogs in motion and those model shows are not far away. M m m m its an old trick but it might just work! Regards,Phil. Quote Link to comment Share on other sites More sharing options...
nasa_steve Posted February 21, 2008 Share Posted February 21, 2008 i've heard one with a 4st believe me the sound does'nt fit the shape if you know what i mean, as i've already written 5s is a good starting point you need 700watts plus to fly this beastie so start from there obviously the more power you can stick up the back the better. if you've not already got cells or motor go for 6s as the watts will be higher for less amps or try a fan if money is'nt an object a good 90mm fan with 1200watts plus should give it a good turn of speedregardssteve Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 21, 2008 Author Share Posted February 21, 2008 Just remember to ensure the chosen ESC, motor and prop / fan will be OK on 6s and the resultant RPM and wattage For 1200 watts - you would pretty well have to be on a 6s Lipo pack otherwise the resulting Amps will be very high. Even on a 6s that comes out at 57A, on 5s it would be nearer 70A !! Quote Link to comment Share on other sites More sharing options...
Phils Posted February 22, 2008 Share Posted February 22, 2008 Thanks Guys,As an original oily head now embracing the electric side of the hobby as well, I am finding it really enjoyable AND educational. I almost understood every word you guys said . . . Seriously, it must be rubbing of on me! Thanks everso, Phil. Quote Link to comment Share on other sites More sharing options...
nasa_steve Posted February 22, 2008 Share Posted February 22, 2008 thanks for that timbo i'm a sparky by trade and its not that dificult to forget that to some people i might just as well be speaking afgan regardssteve Quote Link to comment Share on other sites More sharing options...
Reno Racer Posted November 13, 2008 Share Posted November 13, 2008 Just converting a KeeCat 65 now, once I've recovered the model with Mick Reeves aluminium sheet foil. I have both an used (yet!) 90mm AP900 fan and HET 600-33 for EDF power and a 1450watt outrunner, should i decide to just convert to electric pusher prop power - still undecided, i think the duration and ROG distance will decide - I feel a few test ground runs coming on!! AUP should be about 2.5 - 3Kg (5.5 Lbs - 6.6Lbs), so requiring between 1000 and 1400 Watts, both power plants should be OK, although run on 6S Lipos I expect the Amps will be in the region of 45-60 Amps (depending upon power option), which should give about 7-9 mins duration, based on at least some 1/2 throttle usage!! . I will start with a 100A OPTO ESC, although I might reduce this down to an 80 Amp.Of course changing to 8S Lipo would reduce this to between 33 and 47 Amps, atlhough I'm not sure the HET motor would take more than 6 S. So go on, what do you all reckon, EDF or pusher power????. I bought this as in 'intro' to jet flying, before I move onto the Tamjets 1:12 EDF F-16, which is sat in my garage 1/2 built and looking very fast and twitchy!!! Quote Link to comment Share on other sites More sharing options...
Reno Racer Posted November 13, 2008 Share Posted November 13, 2008 Sorry, big fingers, small keyboard (retched laptops!!). AUP should obviously read AUW! Quote Link to comment Share on other sites More sharing options...
david coward Posted November 13, 2008 Share Posted November 13, 2008 Hi, what is the length of your strip? my "gas bobcat" is a pig to get to rotate, but if I can just hit the "bump"! at the right time everything is OK and she flys well once she has left the ground. A good model to fly without the expense of turbines.Regardsdavid Quote Link to comment Share on other sites More sharing options...
Reno Racer Posted November 13, 2008 Share Posted November 13, 2008 Oh, good question - must be about 80m, although I do have access to a tarmac airfield (Boscombe Down)I think that the pusher prop will have much higher initial thrust, rather than the EDF and turbine 'thrust lag' - so I may start with pusher and maybe convert to EDF later? Quote Link to comment Share on other sites More sharing options...
Former Member Posted November 13, 2008 Share Posted November 13, 2008 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Reno Racer Posted November 13, 2008 Share Posted November 13, 2008 Very fair point; 3 degrees above hoziontal worked a treat on the ROG distance on my EDF F-20. I will see how she fairs once completed, the Keecat 65 has a very thick wing section, although it clearly reduces towards the tips, I am assured she glides like a big trainer - so I presume lift shouldn't be a problem. Everything can be solved with additional thrust!!! Quote Link to comment Share on other sites More sharing options...
nasa_steve Posted November 13, 2008 Share Posted November 13, 2008 to be honest if i had access to tarmac i would go straight to edf if you want to keep cell count down fit a wemotec midi rotor to the ap900 shroud and enjoynasa Quote Link to comment Share on other sites More sharing options...
Alan Dunstan Posted November 13, 2008 Share Posted November 13, 2008 Steve - I have a Bobcat powered by a Jen57 which flies beautifully but is very noisy, mainly because of prop noise. With glow motors the pusher range available is very limited but with electric and being able to make the motor turn either way I guess you can use std tractor props. If so what size do you use and how noisy is it? Subjective impressions will do. Someone else was talking about the Bobcat being difficult to get in the air, and Eric did recommend making sure you have a reasonable amount of positive while it is on its wheels. He is dead right. You need at least a degree or two or it just will not lift off, and the main wheels are so far behind the CofG that no matter what you do with the elevator it will not rotate. I eventually wound my own nose leg that is about 1/4" longer than standard and made out of much better wire just so it would always lift off by itself. The downside of that of course is that you really have to get the nose up on landing otherwise you bounce your way down the runway. Some people advocate having switchable up on the ailerons (about 1/8") just to help get the attitude right. And I must agree about the u/c. When I get my next one (for electrics) it definitely will have retracts. It always looks wrong going by with the wheels hanging down.Alan Quote Link to comment Share on other sites More sharing options...
nasa_steve Posted November 14, 2008 Share Posted November 14, 2008 i use standard tracter props yes 12x8 or 12x10 but a pusher will always be noisy there is no real way round that .it is something to do with the props proximity to the rear of the wing. you could go edf that would probably be quieter my elevator set -up is as is but they do need near on full flying speed to rotate i've not put extra hieght on the front leg at all. as i said i'm not keen on fixed undercarriage but with both my flying fields i have no choice they eat retracts on models i can slow down the cat comes in very quick so retracts would not last one flight.nasa Quote Link to comment Share on other sites More sharing options...
Modellbauuk Posted April 25, 2011 Share Posted April 25, 2011 Anyone know where I can get hold of a keecat 65/bobcat 52 or 46 or a goldcat 44 in the Uk? Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted April 25, 2011 Share Posted April 25, 2011 Ian i have a Bob Cat for sale, PM me if interested . TW2. Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted April 26, 2011 Share Posted April 26, 2011 Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted April 27, 2011 Share Posted April 27, 2011 Posted by Ian Budgen on 25/04/2011 00:28:26:Anyone know where I can get hold of a keecat 65/bobcat 52 or 46 or a goldcat 44 in the Uk?I was looking for a .50/.60 size cat last weekend after planting my Lightning Dart wing, but couldn't see any in the UK. Ashford Models seem to have stopped importing them. Are there any more hidden away in need of a new home, or am do I need to resurrect the LD in order to utilise my pusher pipe & props? Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted April 27, 2011 Share Posted April 27, 2011 While we are on the subject of things that go fast i have this as new Kyosho Pitts S2 for sale ,PM if interested ,sorry if its off thread. Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted April 27, 2011 Share Posted April 27, 2011 Bob i PM ed you on the Bobcat and Sniper. Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted April 27, 2011 Share Posted April 27, 2011 Thanks Tom, I've just replied. Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted April 27, 2011 Share Posted April 27, 2011 Bob Cat sold thanks every one. Quote Link to comment Share on other sites More sharing options...
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