Tim Mackey Posted February 23, 2009 Share Posted February 23, 2009 Just finished fitting out the Jart LT - more pictures tomorrow wind permitting after her maiden ( well mine anyway ) as I purchased it from Mike Evans of LMSA - all I needed to do was fit the radio gear and battery etc. AUW came out at 40oz dead on. Anyone know the correct throws and COG spot for this bird? Previous owner suggests on the main spar, which is around 65mm back from LE - and at the moment this is pretty much where she is perched on the balancer machine. Currently throws are 7mm +/- ailerons and elevator - huge amounts of rudder which I expect to be pretty ineffective by all accounts, and I have set up spoilerons, but again, I believe not much effect. Quote Link to comment Share on other sites More sharing options...
Ultymate Posted February 23, 2009 Share Posted February 23, 2009 According to Reed and Andy Ellison it's 60mm I presume back from L/E here's a link to the thread C/G Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 23, 2009 Author Share Posted February 23, 2009 TY Brian.... have just spent the last half hour going through a lot of that thread Consensus seems to be that anything from 60 -68 mm back from root LE is OK...so should be fine. Just hope for some decent blowy stuff tomorrow now! Forecast is rubbish TBH - much better Wednesday for Jarty things.... Quote Link to comment Share on other sites More sharing options...
Alan Dunstan Posted February 24, 2009 Share Posted February 24, 2009 Have you touched up the paintwork Tim or just going with it as it is? Be interested to see how one of these lighter weight Jart's fly. Alan Quote Link to comment Share on other sites More sharing options...
Alan Dunstan Posted February 24, 2009 Share Posted February 24, 2009 Tim - With spoilerons be prepared for loads of down elevator needed. Also don't expect them to slow things down. Certainly on the two aeroplanes I have them on they don't. What they do do is dump lift and force the plane down which is quite useful at most slopes but you need to kill the speed in the turns. Play with them at height and if possible set the Tx so you can modify the elevator compensation while in flight until you get it right. Basically with full spoilerons on you need it just nose down, coming forward gently losing height like its going out of fashion. Alan Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 24, 2009 Author Share Posted February 24, 2009 Going as is for maiden and trimming....then my mate Steve ( car paint shop guru ) is gonna fix her scars up. I know the spoilerons are not too effective - and as for operation and elevator compo etc, I have them on my Schizo Quote Link to comment Share on other sites More sharing options...
Slopetrashuk Posted February 24, 2009 Share Posted February 24, 2009 You will NOT need loads of down under spoilerons on the Jart. Tim, if you've never landed like this before you need to pop spoilerons when you have rounded the final turn into wind and then find the balance with the elevator. You will be pulling lots of up in to slow the Jart LT to walking pace. You must land the model slowly with the nose high or risk damaging the gel coat if you don't get it flat. CG is fairly neutral at 68mm. The Sd6020 wing needs little if any differential. Elevator throw should be set to avoid any flick. Don;t bother with coupled flaps and elevator. Good luck. Andy Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 24, 2009 Author Share Posted February 24, 2009 Cheers Andy. I have spoilerons on my Schizo just to dump some lift and slow her down a bit for landing...so expect similar from the Jart - a lot depends of course, as you well know, on how the hill is working on the day....can get pretty disturbed air on the back of the Rock! Because of the crappy mixing arrangement I have to deploy to get the 2 x aileron servos working as spoilerons also, I am limited at present to around 7mm +- on the throws - I know this is low.... but dya reckon 'twill be OK for first few flights until I decide whether I need a different setup? PS you STILL have not read my PM to you a week or so ago?? Will be Thursday now for maiden flight - today was useless - 5 -8 mph if lucky....we stayed until 3.30 scratching around with lightweight stuff - but the food was good - thanks Kev and Polyphilla Quote Link to comment Share on other sites More sharing options...
Matthew Lloyd Posted February 24, 2009 Share Posted February 24, 2009 What radio are you trying to set up here Timbo? I'm on a DX6i and set the flaps to minus 50 or so to give me spoilerons - giving me about 20mm up throw. Quote Link to comment Share on other sites More sharing options...
Ultymate Posted February 24, 2009 Share Posted February 24, 2009 Mathew I'm sure Timbo will be on to explain but as he explained to me today I think his R/X is the limiting factor, I'm sure he'll be along to give you the gen Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 24, 2009 Author Share Posted February 24, 2009 Indeed.... I am using an AR500 on DX7 and as the Rx does not have aux and I cant therefore use dedicated Tx spoileron mix, and the "2" aileron channels are nothing more than "Y" leaded together, to correctly activate the two wing servos, I have used P5 free mix in Tx to mix ail>gear and set gear to 0/0. Works fine as ailerons, but spoilerons ( p6 mix aileron to flap and set flap in flap sys ) are low in the travel. If I forget spoilerons, then I can get all the travel I need in ailerons. Lesser of two evils me thinks to have a little spoiler...trouble is it might be so low, that it does little more than introduce reflex and speed things up instead I will keep playing with EPA TA and mixing...... Quote Link to comment Share on other sites More sharing options...
Matthew Lloyd Posted February 24, 2009 Share Posted February 24, 2009 ah - thank you! Quote Link to comment Share on other sites More sharing options...
Ultymate Posted February 25, 2009 Share Posted February 25, 2009 Timbo have checked the forecast this AM and it's looking even better for tomorrowlooks likely your Jart will get some air under it's wings Off to work the streets now Quote Link to comment Share on other sites More sharing options...
George 420 Posted March 1, 2009 Share Posted March 1, 2009 Timbo, your gonna love the JART dude. It rocks! I have spoilerons on mine and find that they make no difference except to make it gain lift... (Perhapse I have too little up 'ron?.... ) So I would not loose any sleep over them mate. She lands good without them in my experiance! Nice graphix there too. Enjoy. George. cg 67/68 mm cant remember which. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted March 1, 2009 Author Share Posted March 1, 2009 Hi George.... your too late mate - she flew ( and very nicely too ) 3 times last Thursday, I did deploy the spoilerons ( albeit with only around 12 mm of up ) and the 3 landings were all fine.....I cant take credit for the graphics - previous owners handywork Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted March 1, 2009 Author Share Posted March 1, 2009 Hi George.... your too late mate - she flew ( and very nicely too ) 3 times last Thursday, I did deploy the spoilerons ( albeit with only around 12 mm of up ) and the 3 landings were all fine..... Pictures here... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted March 15, 2009 Author Share Posted March 15, 2009 My Jart is dead Having just refitted her with a lipo power pack etc, I was enjoying some superb fast flying this afternoon, when a mate and I had a nasty mid air - his beech leading edge equippped home brew foamy came up from nowhereand smacked Jarty full on in the port wing taking it clean off in half...the rest just sycamored down to earth at high speed and that javelin like nose screwed itself right up to the canopy in the ground. It took two hands and a lot of grunt to unearth it. Lost the wing half ( with servo still in it ) and the canopy too.... search party found zero. The other model escaped with little damage and was landed back in the normal zone. Fuselage is cracked and broken in 2 or 3 places, wings of course are total write off, and tomorrows full post mortem will show any further losses suffered. She will live again somehow - probably with some new foam /veneered wings, and my mate who is a car body repair specialist by trade will repair and spary the fus. As most modellers know, ANYTHING is repairable if you have the time patience, skill, and above all enthusiasm to undertake whats required - and of course, the model must be worth the bother. Jarty is such a model If you are squeemish... look away now Quote Link to comment Share on other sites More sharing options...
Bruce Richards Posted March 15, 2009 Share Posted March 15, 2009 The tail looks OK Looking on the bright side. Hope it flys again. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted March 15, 2009 Share Posted March 15, 2009 hard line's timbo--i'll put a box of match's in the first post............. ken anderson............ Quote Link to comment Share on other sites More sharing options...
Alan Dunstan Posted March 15, 2009 Share Posted March 15, 2009 Oh Tim thats a real shame. That was a good looking aeroplane and I was looking forward to seeing it in the air sometime. Mid airs do happen though but a real shame with something so new. Commiserations. Lee will be mortified. Alan Quote Link to comment Share on other sites More sharing options...
David Ashby - Moderator Posted March 15, 2009 Share Posted March 15, 2009 Sorry to see that Tim Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted March 15, 2009 Author Share Posted March 15, 2009 Yeh I am pretty gutted TBH - but have decided to bite the bullet and just orderd online a set of replacement wings. Mulling it over, I decided that home brewing a foamy set just didnt seem right somehow for this animal. I shall strip the fus tomorrow, and whilst I await the new wings, I can sort out repairs. Hey these things happen, no-ones fault, its just one of the many risk we take every time we fly. Quote Link to comment Share on other sites More sharing options...
Ultymate Posted March 15, 2009 Share Posted March 15, 2009 Just got in from power flying Tim to find this bad news awaiting, sorry to see that mate. I think you made the right choice with the wings, all things considered the fus looks remarkably unscathed. Quote Link to comment Share on other sites More sharing options...
Slopetrashuk Posted March 15, 2009 Share Posted March 15, 2009 Tim, Tim, Tim...... You can't get emotionally attached to anything that you plan to throw off a big cliff.... S mashed L ost O r P ulverised E ventually Sorry to see it though. Andy Quote Link to comment Share on other sites More sharing options...
Ultymate Posted March 15, 2009 Share Posted March 15, 2009 I was emotionally attached to the missus but I'd gladly .............. no I'd better not commit that to print Quote Link to comment Share on other sites More sharing options...
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