View Full Version : Multiplex Twinjet
04-05-2004, 06:46 PM
I just flew my new Multiplex Twinjet for the first time yesterday. This is the 'blue shark' version, with twin Permax 480 motors.
They recommend an 8-cell pack, up to 10 cells max. I flew it on an old 7-cell-1800 NiCad pack because it was the best I had at the time. The speed controller is the Multiplex 30Amp / 40Peak recommended (but not included) with this kit. The kit included all the foam and internal hardware, decals, motor wiring harness, 2x480 motors, props, and control surface hardware. I had to purchase 2x24" servo extensions, the speed control, micro Futaba RX, and a pair of HS-81 servos. I also have a pair of APC props for it later on.
Flight performance was OK for the first few minutes, but not spectacular. No surprise there due to the battery I used. Once the pack got down a bit further the plane didn't quite power out of the corners as easily. I was impressed with how well it floated along at low power settings. I was also impressed with the range I got, expecting to need ferrite rings etc, but it worked great first shot at multiple power settings.
I'm going to make up a GP3300 Ni-MH, 10-cell pack. I'm new to electrics and that's what the guys are telling me to go with. Apparently it'll smoke along pretty good and handle aerobatics nicely on 10 cells.
Question, where's the best (cheapest) source for these cells?
04-05-2004, 11:37 PM
Well if you like to part with money like I seem to, you get yourself three Kokam 3 cell 1500 mah or Etec 1200 3cell packs and run them in parallel. I only have 3 Kokams at the moment but the Etec are lighter so they are on my want list. The props on it now are 5 x 5 carbon's I had to order two packs of two to get the two prop hub adapters you need to use with the twinjets two 480's. The three Kokams deliver 12 and a bit volts for quite a while since the total is now 4500 mah available, this then drops down to 9 before the Kokam ESC shuts the power down to the motors, as you know it floats in real nice so this is not an issue. The three Kokams weigh 340 grams in total this much less than the 500 grams you can expect the eight cell Sub C pack to weigh. This combination gives you speed, light weight, and duration.
04-06-2004, 01:28 AM
I recently bought this Jetset ViperTwin.. It was one pretty cool flying wing.. But I find the support for parts is really terrible here in CA. The people who sells it won't ship to Canada.
04-06-2004, 10:46 AM
I've gotten around that problem by getting a US PO Box just over the boarder. Its only 20min away. All they charge is $2 per package, way less than the brokerage fees I use to pay the carriers for bringing anything across... The vipertwin looks good! Too bad some companies don't realize that their sales would go up ~10% if they shipped above the 49th...
Anyhow back on batteries. Down at the Puyallup R/C show I was looking at a bunch of batteries like that, I think they were Kokams. The technology was interesting. I'm amazed how far batteries have come in recent years, but I hear they are a lot less tolerant to abuse. I'm not planning to go heavily into electrics, just wanted to try it out and I thought the twinjet looked pretty cool... For now it'll just be Ni-MH since I already have a charger for them. Good suggestion though! A friend of mine is experimenting with that side of things so I'll wait n' see.
04-07-2004, 06:57 PM
Went to my local flying field to try and get in flight pictures to post of my IFO in the Electric forum and brought my Twinjet out just because I like to fly it too. Well the LiPo's are too light when the wind is strong, non-directional and gusty. The extra mass of the NiMh's and NiCd's was required to ballast the plane out for these unsavoury conditions. It was the only plane flying steady enough to photgraph clearly..
04-07-2004, 07:06 PM
Looks pretty cool!.. Does the Hobby Wholesale still carries it?.. I see they have the microjet.. looks like only a single motor.. :?
04-07-2004, 07:47 PM
Well I don't know for sure about Hobby Wholesale, but since Hitec bought Multiplex any vendor who has access to Hitec product can order one. GH in Edmonton is where I got mine last summer. It was spur of the moment thing,I couldn't decide on the the single or the twin, when another customer pointed out that although they are both fast and aggressive flying planes the Twinjet being physically larger is a whole lot easier for older eyes to see. Since I had just got my first bifocals that week I bought the Twinjet. There's no one else in my local club interested in them or I'd have tried racing and/or combat with them. They are one tough bird, take a close look at the nose of mine, that was high speed impact with a stump which was a little taller than I thought. There was this nicely logged hill on the way to Kitimat (town 50 km south of Terrace, I work at the Aluminum smelter there) that looked just perfect to try some slope soaring, well the wind was great, I was having fun and wanted more. I had read about Dynamic Soaring on British web site, you loop around the back side of the hill then blast along rolling air that you find there. It sounded interesting so I tried it, worked real good too 'cept for the stump.
04-07-2004, 07:52 PM
My vipertwin is much larger.. it has a wingspan of 57inches.. I had to dial in some expo else it will be too darn sensitive to control. :lol:
04-07-2004, 08:10 PM
That a good bird too, whats it made of EPP ? I vaguely remember reading some adds for it, have to hunt up my back issues I guess. There is a slightly smaller couple of planes sorta like it. The FMA RAZOR and the Great Planes Slinger Electric Flying Wing. I have 2/3rds of a FMA RAZOR there is still 1/3 of the thing 80 or so feet up a spruce behind our local field. The battery got low on power at a most inopportune time, end of a fun partnership. The Viper Twin sounds like something I'd enjoy flying as well..
04-07-2004, 08:15 PM
check it out their video.. it's very cool.. it's a very fast flying wing..
Here is the link..
Hobby Wholesale used to carries it.. not anymore.. the guy in NJ won't ship to Canada citing the postal problem.. :(
04-07-2004, 08:46 PM
It's too bad, since its a really neat product that should go over well with us here in the promised land. Just imagine the Viper finished in the provincial colours of your choice, or even a federal Maple Leaf scheme! We'd buy em out of patriotism, well maybe not, but you get the idea.
05-17-2004, 03:15 PM
This week I finally got the right pack for my Twinjet. As I said earlier, I flew it on a 7-cell 1700 NiCad pack for a few flights and it was OK.
I bought 10 x GP 3300 cells from Norburn Model Aircraft Supply (www.norburnrc.com) for $7.95 each+tax. A friend at the field soldered the whole works together (thanks Dave). It made a HUGE difference. This is a great little sport jet now! Loops n' rolls are easy and the plane can get up some pretty good speed now. The increased weight did hurt the glide characteristics though.
As usual, even faster couldn't hurt so I might go for a brushless system after the stock motors are toasted... If not, the motors are pretty cheap from Tower Hobbies. Other changes I made were installing metal gears in the HS-81 servos (stripped 2 gear sets already) and I swapped out the 'zagi' plastic props for APC 5x5's and prop adaptors (also from Norburn). I got the kit from Helijet R/C (www.helijet.ca)
Overall its a great little jet, but I wouldn't necessarily call it a park flyer because it ate up a decent chunk of airspace. It would be fun for any new-intermediate flyer or an advanced pilot just looking for something fun to play around with...
I got to see this....Kelly flying something at less than 100 mph!!!!!!
I got to test fly a foamie ducted fan the other night (posted elsewhere)...It was a hoot!
06-23-2004, 01:01 AM
I know, I guess my age is starting to catch up eh? :roll:
Seriously though, having a foamies is a nice change of pace, and cleaning up the oil residue it infinitely easier!
See you in Red Deer Wayne, its been a while!!! I'm getting the Stingray ready to roll, just fixed the wingtip damage from Whidbey last year...
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