Art Tech Alpha Jet

[cagey]

I hope Dave Ashby is reading this and can add a bit more in depth stuff to his review. Anyone elses 2p worth is welcome too. Have one of these and find it hard to criticise the quality of most of the kit  except I don't like the paper covers to the servo lead channels,nor do I appreciate that the tail cone is glued on at a two degree offset to the right , neither am I keen on the recommended lipo giving a c of g 20 mm forwards, needing an ounce of the heavy stuff at the tail end to get it just about on the forward limit. Phew, Have I done yet ? Well for the time being anyway. Does anyone have a clue as to how far fwds the c of g can go and still be flyable on one of these ? Be obliged thankyou

[David perry 1]

In fairness the paper covers are visible in David's review as dark blue patches. The fact that you don't like them is something you should have sorted at the shop, not moan about now. The tailcone is a jiggle i would agree, though whether of great import I dunno. You pays yer money etc As for the CoG... David's came out rather aft if I read his article correctly as he comments that it could be moved forward to good effect. This makes me me wonder whether you have either done something wrong or have picked up a Friday afternoon Alphajet ! The bottom line is, if you are unhappy take it back. Your consumer rights are very strong these days and you don't have to put up with poor product. D

[David Ashby - Moderator]

Of course I'm reading it cagey 

 

Ok, here goes...

 

1. I didn't find the paper cover an eyesore I'm afraid and didn't consider this important or worth comment. 

 

2. The tail cone is a continuation of the fuselage piece - I didn't notice any offset on my model. It'll make little difference in the air. 

 

3. Don't add weight at the tail, fly it first and then see. I fly using 2200mAh Li-Pos which weigh 180g. A little nose heavy should do any harm. Get someone to launch the model for you first flight.

 

I fly mine every week and it's clocked up 30 flights now, it's a wonderful thing.  

 

 

[cagey]

Thank you for your replies Dave and Dave. Honestly the paper comment wasn't a real moan, just an observation. I've cut out as much glue as poss and reset the tailcone to a more agreeable line up with the wings, no sweat. It is a thing of beauty in my eyes so it ain't going back to the shop. OK   Just call me Victor Meldrew if you like.. Now to my c of g problem, using a Maxpoly 2200 at 170 grams it sits nicely at 20mm forwards of the front limit, (450) at 430 mm from the pointy bit. With 20 g of weight right on the very tip of the back end it balances a gnats fwd @ 445 mm. Where exactly does yours balance Dave may I ask ? Never have been a chuck it and see person, usually means "Ouch!" in my experience, but will defer to the experts here and just ask if it's not a bit risky throwing such a nice machine into the air with the balance point nearly an inch too far to the sharp end ? Or perhaps use 1800 / 2000 instead ? Whatcha reckon learned people ?

[David Ashby - Moderator]

Ok just popped the pack in and the model balances 4" back from the leading edge at the root which I make a smidgeon under 450mm measured to the nose like in the instructions - not sure why they have to measure from there!

[David Ashby - Moderator]

I might do a little video showing how I balance it, would that be useful? I've got a new HD cam and need to play with it

 

I'd take that weight off the tail though if I were you. If anything mine feels slightly tail heavy in the air, you've got a slightly lighter batt than me so weight at the tail isn't needed.  

Edited By David Ashby - RCME Administrator on 19/08/2010 07:35:55

[cagey]

Thankyou for your rapid response Dave. Yes a vid would be very interesting,being as my one balances at 470 exactly without the lipo in !  Ar 500 exactly on the L/E cutout on top of fuselage, no mods,ESC as far back as poss-----spooky or what ? Going to get there somehow though. I think my avatar says it all. Ho Hum.

Edited By cagey on 19/08/2010 15:26:32

Edited By cagey on 19/08/2010 15:27:31

[cagey]

Just as a matter of interest, after trawling the net and seeing a lot of mentions of this problem on RCGroups, one of which did help somewhat. This is that the R/X is located in the elevator servo bay under the rear hatch. Aha  This explains the linked and extended Y leads for ailerons, plus the double ext. lead for the ESC that were stuffed in the rear end ( as a clue maybe ? ) Only a few grams but makes things about 6 or 7mm better. Bloody nice little looker though isn't it, paper covers are still poop though so there. . 

[David Ashby - Moderator]

LOL, I like the avatar. Right, here's a bit of vid, warts'n'all. Don't you just hate seeing yourself 

 

My Rx is under the wing, as I mentioned in the review, it's forward (just behind the l/e at the root) and I scalped a bit of foam from the wing underside away for a snug fit.

I think you can fly with your 170g batt or add a little weight (say 10-20g) to the nose.

 

 

[cagey]

Many thanks for your kind assistance to this old grumpy Dave. Damned good results from the HD Cam. you'll be pleased with that no doubt. If I see a camera pointing my way I put a bag over me head.  To the matter in hand,I relented and put the AR 500 in the elevator servo bay, perfect fit, bit of tape to hold it snuggly, long antenna out the back via small bore tube,easy.Now as your vid shows the magic spot is at 4" aft of the root L/E. Tempting to use the flap provisions with  5g servo, will just fit, hmmm, maybe. So with your good advice we are ready to rock and roll, nervesare still on edge from the last 5 flights of my FMS P 51d, your review says it all on that one too. 1/8 ply plate at the aft retract mount, lifts of smooth as you like , landings easy. Mk 2 retract screw jack--bang ! -snapped clean as a whistle, needs a mod methinks. Many thanks again sir.

 

                                                                                                         Regards Ken G.

[David Ashby - Moderator]

No problem Ken, good luck with the maiden 

[neil martin 1]

Hi..id be interested to know how your maiden went. Im due to maiden mine very soon. I am the person on rcgroups that posted my solution to the COG by relocating the servo and receiver into the rear of the model. Mine balances perfectly at 4" behind leading edge and is only slightly nose heavy with a 4S battery installed. I have not had a chance to maiden yet as we have just had a baby daughter so am up to my eyes in it (literally!). Thanks and totally agree it is a cracking looking jet!

[cagey]

Hello there Neil. Yep, that idea of R/x placement does help a tad don't it. Just a word of caution here buddy, I would have reservations about using a 4s with the stock fan and ESC. 14.8 volts would fry the motor I think. Congrats on the new sprat, now watch your wallet shrinking .

[neil martin 1]

Hi Cagey...I hear the voice of experience in your reply! Thank you for your kind words. The Alpha Jet is one of the last purchases for a while,hence the reason for wanting to clarify this COG issue before I lawn dart it. I think youre right with the 4S statement and the standard motor would fry. However im sort of thinking ahead and am curious as to what this model could take in the future. I have a nice Hoffman Mighty Mite sitting around but hey lets not get ahead of myself and concentrate on flyin it standard first!

[cagey]

The Alpha maidened this afternoon Dave and your review has encapsulted it's virtues admirably sir . Surprisingly little noticeable difference with the lighter Maxpolies to the Overlander heavier ones, just flew as if on rails, sounded lovely and turbineish, didn't need a Tessa Saunderson to get going, and once going kept doing so till a wee dot in the clouds, excellent. Faster than my 3S Squall by a margin and much nicer to look at, very good scale apppearance too. Like you said, "Sweet". 

 

 Probably what you want to read Neil ?  

 

                                                                                         Many  Regards, Ken  G .                                                                                             

[David Ashby - Moderator]

Nice one Ken, glad it went well 

[neil martin 1]

Exactly what i wanted to read. Thanks Ken.

[AK47]

Hi all

 

New here but i just wondered what size the magnets are on this model. I have ordered an alpha jet thats not going to be here until Monday but i was planning to use stronger magnets of the same size on the canopy. Has anyone successfully done this or is tape/screws the best option??

 

Cheers

 

Anthony

Edited By AK47 on 28/01/2011 16:19:17

[neil martin 1]

Hi...I fitted small strong magnets into the fuselage and kept the standard ones on the canopy. This has worked well for a 3S set up. Having since upgraded my motor and fan and running 4S...this has resulted in a canopy that stays on for all of 5 seconds! Have ordered some magnetic strip from ebay and will fit this week. I would recommend fitting aftermarket strong magnets or screw down tha canopy as the standard config is pretty unreliable.

[David Ashby - Moderator]

I just use a little bit of tape.

[Wingman]

[AK47]

Thanks for the comments re magnets. In the end i made a couple of catches from two small servo horns and screwed them just in front of the canopy. So for quick access to the battery i just swivel them ouit of the way. Hope it works!!

 

I appreciate there is a lot of talk about c of g but i just balanced mine and with battery c of g comes out at 430mm from the nose. This seems to be 100mm from the leading edge (at the fuz side). I was begining to think that some of these models must have longer noses than others as others have said that 100mm from l.e. is about 450mm from the nose! Think i will try her as is 430mm(100mm) but would appreciate some reassurance!!

Edited By AK47 on 08/02/2011 10:01:31

[YakMad]

David,

 

 

Just wondering have you tried a ground launch with yours, I mentioned this in another thread as my hand launches were not very good, can't believe how well it ROG's and looks scale as well, the wide fuz does help here I think.

 

I have to agree with you keep it simple use tape to keep the canopy on, I use two pieces of blue electrical tape which almost matches the colour of the fuz.

[Russ P]

David - Four flights today with my xmas present, fantastic sunny day no wind. Model climbed away supurbly from hand launch. I placed the rx behind the ESC and ran the aerial out through one of the vents under the wing/fus and taped it to the fus. Lipo weighs 180g, which balanced the model exactly where you show on the video. I also inceased the expo to 40% and the model handled beautifully.

 

One thing though, have you any suggestions as to improving the flight time. I'm using 3s 2200 and get a 5 minute flight, what can I do to get longer flight times. I sorry for my ignorence but this is my first electric model.

 

Thanks

 

Russ

[David Ashby - Moderator]

Yak - no haven't tried this I must admit but a hand launch certainly needs to be right - too steep and you'll get a stall that it's unlikely to recover from. I've found that tape too, as you say, perfectly matches the blue in the scheme.

 

Russ - the only answer is to try and increase the capacity of the pack or throttle back which isn't really on given the fun a full throttle pass will bring. The space is tight though so you'll be hard pressed to find a bigger capacity pack that'll fit in the space. It's worth looking around though I guess?

 

Great day for flying the Alpha today though, glad yours is going well.