Robby

My Feedback: (18)

****
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**
When looking into the fuse the battery tray has a notch in the front of it and on the rear..
This is where the hook and loop material is to go once everything is ready to be secured
into plane... Of course, make sure battery and receiver are well wrapped in foam to
protect them from vibration.. [sm=thumbup.gif] [sm=thumbup.gif]
The rudder and elevator servos are pluged directly into RX.. The aileron and throttle
servos have a short extension each.. I do this so not to have to keep plugging into the
RX each time wing is removed... If the extension ever gets messed up easier and less costly
to replace than the RX ... The blue tape on the one is to mark it for the aileron servo
and the servo itself also has a piece of blue tape on it... Kind of an insurance type of
thing when putting on wing to go fly..... No fun making a mistake plugging the wrong
wire in and having to remove wing to correct it... [][][]
****
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***

Robby

My Feedback: (18)

***
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Now that the radio is all in and everything is set and adjusted time to do THE
two most important parts of this build.. Balance the props and balance the plane... [>:]

The props will have an effect on the balance of the plane.. So if the plane can
use additional nose weight put on a heavier prop,, and if too nose heavy use
a lighter prop..
In the first pic there are several props laid out.. The first one is a 9x6 Zinger
which weighs about 12 grams(0.4 oz), the second one is a 9x6 Master Airscrew
which weighs 16 grams (0.6 oz) and the third is a 9x6 APC which weighs 22
grams (o.8 oz).. To give an idea how many grams are in an ounce,,
1 ounce = 28.3495231 gram... The Tiger Shark motors say to use a 10x5 to
start and then switch to 9x6 or 9x7.. I went with a 10x5 master Airscrew to
do the first couple starts and maiden... After a while I want to try out the three
different 9x6 props and see if much difference can be noticed...
The next thing that is very important is to balance the props...
Both of the 10x5 Master Airscrews for this plane were heavy out of balance..
There are a few ways to balance props... I choose material removal on backside
of the heavy blade... Once both props are balanced,, balance the plane...
The Tiger Sharks .36 weigh about four ounces more than a .40 LA which is largest
engine recommended for this plane... So that puts this plane at about 8 ounces
towards the nose to start with... With the recommended balance point of 3¼" from
the leading edge and plane upside down,, this plane came out slightly nose heavy...
Before the maiden I will look to see if I can move the RX and battery back some to
better balance the plane.... Still, acceptable given using the heavier motors...

At this time I also did a AUW (all up weight) on this plane.... On the front cover of
the manual it states the Twinstar should weigh 5 to 5½ pounds... This plane, built
by the book, comes in at 6pounds, 6 oz (just under 6½#) .. The only additional
weight would be adding antenna tube, and using heavier engines,, but thats only
about half a pound..... (1 pound = 16 ounce).....

Soooo, looks like we are about done with this plane...

Robby

My Feedback: (18)

***
***


Sooooo, you have been wondering.....
" Is this guy ever going to get this plane done and flying.."

Welll, folks,,** we** are** almost** there.... Plane is balanced, radio all checks
out,, and today, Sunday, 03/13/05 at 5PM the motors were first started and run
for one tank which lasted 8 minutes.... RPMs were at about 13,000 running
slightly rich... Today the air was dense and it was 34 degrees when run.........
Minor adjustment on throttle linkage required and then we are set to go......
******************** **** ********


Here are a few pics of the plane finished and ready to hit the skyways... ***
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***
****

William Robison

My Feedback: (3)

Robby:

So now the rest of the world sees what happens when Robby squeezes a tube of glue in the box and shakes it. A glorified plastic scale model, so fas as its assembly is concerned.

If you believe that you probably would be interested in some prime swamp land in Fla ...

Robby, you've done a fine job of assembly, and anticipated questions, answering them before they were asked.

Now we only have to hope it lasts more than one flight, and makes it to McDonough Ga.

Bill.

2slow2matter

My Feedback: (1)

As a matter of fact, I do like my VMAR arf. It served it's purpose very well. Don't you have anything better to do than dig up old posts and try and stir the pot? If it's an argument you want, we can surely start one of those, but you might get your feelings hurt. I believe the words in red above all posts talk about flaming, degrading, insulting....other posters, so I'll leave it at that. Perhaps you should read those rules yourself...........

Robby

My Feedback: (18)

Alrighty....
I wanted to go do the maiden today but with it being rather windy
and temps in the mid 30's I chickened out... Sadly, I will be away
for a while so the maiden will have to wait till I return....
But not to fear.... A full report will be done once I return and put
the Twinstar up where it belongs... In the AIR ..

Let do a basic cost of the Twinstar....

****Hobbico Twinstar ARF LXJPH0 ------------------ $119.99 Tower Hobbies
****2 Tiger Shark .36 engines -------------------------- $ 91.54 Kangke Industrial USA, Inc
****Futaba R127DF Receiver-------------------------- $ 53.95 Servocity
****Futaba Crystal ------------------------------------- $ 10.99 Servocity
****5 Futaba 3004 Servos ----------------------------- $ 69.95 Servocity
****1650 NMH Battery ------------------------------- $ 16.00 RC Accessory
****MPI Charge Switch 3170 ------------------------- $ 14.99 LHS
****2 MPI 6" Extensions 3130 -------------------------- $ 7.00 LHS
****2 OS A-3 Glow Plugs ------------------------------ $ 7.98 LHS
****Package Buttonhead screws ------------------------ $ 1.49 LHS
****Fuel Tubing ----------------------------------------- $ 2.00 LHS
****2 Master Airscrew Props 10x5 --------------------- $ 3.78 LHS
****Antenna Tube -------------------------------------- $ 1.49 LHS
****TOTAL ================================ $ 401.15 TOTAL

The above does not include any shipping or tax as it varies per local..
And this does not show building materials as epoxy, CA, and etc .......

But this will give you an idea what it took to put this plane together....

I hope this build has been a help and you have enjoyed it so far.....
I know I have in doing it...

Any comments or questions are welcomed..

Robby

My Feedback: (18)

I am currently out of town and will do maiden and flight
reports upon my return...

Stayed tuned for more to come...

bjar

My Feedback: (1)

You won't find Nirvanna without any nerve.... My son and I are newbies to R/C. He as soloed a few times our Mach 1 trainer and at 15 is doing great and his father(me) is getting closer? Anyway bought a Twinstar because I like Twin engine planes and hope to experience more in the future. Honestly, we were going to assist(stand back and watch/gopher) with our local "Pro" in building this plane . But finding this Twinstar build coupled with the signature "You won't find Nirvanna .... just keeps eating at me! Hence going to take the plunge and see what happens with our first arf build. Have 2 well-broke in LA 40s for it from local flyer who had mid air with his. He loved his by the way. Robby, Thanks for taking the time to do the build write up. PS Can some one tell me what twin engine/twin tail plane is used on the Western Union TV commercial with the elephants?

William Robison

My Feedback: (3)

bjar:

You should have no trouble at all assembling the Twinstar, or flying it. Both are easy, that's the way it's designed.

I have not had a TV set turned on since June of 1971 so I've not seen the WU ad, but the plane most probably is a Beech D-18. Pictures attached. Please note these pictures are all tri-gear conversions, the plane was originally a tail dragger with only the last production offereing tricycle gear from the factory as an option.

Bill.

PS: An ARF is built when it's put in the box, before shipping from the factory. wr.

Robby

My Feedback: (18)

bjar,
You are welcome.. And you do not need a "pro" to build the twinstar for you... It really is a simple
build and should only take about ten to twelve hours in your leasure to do..

The two main areas you should deviate from in the manual is the install of the throttle servo tray..
Where I did do it by the manual I would not do it again that way as creates problems hooking up
the throttle linkage...
Cut them and epoxy UNDER the wing skin.. This will provide for proper alingment of throttle linkage..

The other concern is the nose gear.. The 'flat' is incorrect for proper steering arm action.. This I did
address within this thread... Simple and easy cure ...

Done as a stock build the twinstar is easy to build and easy to fly, just as Bill said..

Robby

William Robison

My Feedback: (3)

Oops.

The TV cut-off date should have been June of 2001, not 1971. Checked broadcast reception when I moved here, lousyand not worth the effort. I have always refused to allow the cable companies to screw me, so no TV.

Bill.

2slow2matter

My Feedback: (1)

WR....
I'm impressed.

glennd

My Feedback: (1)

Quit messing around and put it up... Don't forget the pics too. Nice assembly report!

NIpilot

My Feedback: (6)

I've been flying my twinstar now for two months and have put 32 flights on the bird. I have nothing but fun so far with this plane. I'm using 2 OS LA 40's and normal 10% fuel. Using a jumble of old servos and all are performing fine. Easier then I expected to sync the engines. Even though the tanks are small you spend so much time throttled back in the 1/3 range its common to get 9 min flights without any flameouts. I'm using APC 10X7 props in an effort to reduce noise impact on my flying field. Runs strong and vertical is as far as you can see to control it. Mostly its just a kick in the butt to see a twin doing slow rolls on takeoff and slow rolls across the sky as far as you can see. The sound makes the hair stand up on you neck on a good flyby.
My only failure and it occured early on was the demise of those cheapo spinners. Both came apart and cracked the back plates in short order. I balanced my props well on a Dubro balancer and still they came apart. In fairness and a big Atta boy to Hobbico, I pointed out this matter and they replaced the spinners. Who knows how long the new ones will last? I can tell anyone who would like to try one of these things that you can't have any more fun on $119. You get alot for your money. Not to say it couldn't be better in some regards. But how much are you willing to pay for a sport trainer twin? I think Hobbico has done a great job. In reality with all the good engines and radios at most guys fingertips these days, I hope the offerings of better, and more detailed twins continues. A nice sport model of a Cessna 310 or Beechcraft Baron would be pretty cool.
Almost forgot to mention something. Yes, I have had engine out situations. Three to be precise. First one with one of the engines being brand new. I break my engines in, in the air with no more then one tank on the ground. I build to fly! LOL I quickly learned to use my dual rates and on downwind or when doing lots of touch and goes, its just better to leave the rudder on high rates. Gives a guy that extra needed travel to fight off the spin, crash and burn syndrome. With the OS 40 its not overly hard to fly the pattern on one engine but raise the nose too high or too fast at low airspeed and I can assure you its going to be a rekit. Sometimes lowering the nose and bringing in the power slowly is the only option you have. If your climbing out steep and slow, right after departure and loose one. Well kiss it goodbye. The same techniques that apply to full scale apply to flying technique here. In all honesty, I can't help but sometimes blast straight up on departure. The critical time is so short, I feel its worth the chance taken. Unlike full scale, If I mess up here its just a few garbage sacks and you get to fly another day. LOL Try it, you'll like it!

Robby

My Feedback: (18)

Alllrightyyy....

Good to see another happy Twinstar flyer....

I have put this project up in the air... Yes,, pics were taken...
Even a vid...

On first flight zero trim was required on any of the controls..

Engines were not totally in sync on first couple lfights but still
did not create any problem....

On the day I maidened the Twinstar there was about a 20 MPH
slightly crosswind.. NO problem... On the first landing, because
of wind I brought it in a little fast and it didn't want to land right
away... Positive spins were almost non-existant.. Inverted spins
were great.. Rolls well in either direction...
In my opinion the low rates as given in the manual are a little too
low... However, all flights have been kept at stated rates...

Flight times are about eight minutes currently with a heavy throttle...

The engine manufactor suggested using a 10x5 prop for breakin..
This was done.. Next time out I will be switiching to the recommended
9x6 props for after breakin...

So far have had the plane at four different fields and at least ten
different people have flown it... All have been happy with how the
plane handles... Three have bought a Hobbico Twinstar as a result..
So it goes to show,, it you can see it, play with it, you WILL get it...

Have *you* gotten it yet...?

Robby

Robby

My Feedback: (18)

Allrightyyy...
Lets do an update on our Twinstar project...

As noted, recommended motors are .25 to .40LA...
Where most people seem to go with .32 / .36 size and are
extremely happy I have received questions about use of
larger and smaller motors on this plane...
This past week end, July 16/17, in McDonough Ga I had the
chance to fly both a .46LA and a .25LA Twinstar..
I'm apologize as I was not able to get pics to put with this
portion of the thread..
First off, lets look at the .46LA.. It is one of the original versions..
Was basically stock and used the standard five servo set-up..
Cost of using .46LA for power as per the Tower Hobbies site
( http://www2.towerhobbies.com/cgi-bin...?&I=LXBY20&P=0 )
is $69.99 ...
Ok,, start it up,, tune them in, and let it rip... Even tho the LA
series are not considered to be a performance type of motor it
still was more than enough for this plane... Ten feet, force it off,,
and still climb up uneventfully.. The down side.. On a short take off,
high rate of climb, should a motor die, major problem.. The plane will,
and does, quickly rotate and is not controllable... During flight and encounter
a loss of a motor it does require more rudder to maintain straight flight..
I found it was easier to fly plane around, line up to runway, and kill other motor
to land... The .46LA it does spool up rather quickly and should you add too much
throttle when plane is going slow does want to yaw...
As there is a good amount of out thrust is does keep it from happening too
quickly as long as you don't jam the throttle...
Landing.. Very little difference with the .46LA as the weight is not that
great to be of concern.. However, it seemed to respond better to slight
throttle on landing to maintain good control ..
Flight times were in the 6 to 9 minute range depending on throttle
management...
End result.. Excellent flying plane with this combo for someone who
wants their Twinstar to perform slightly better.. Downside, it does require
better than average flying skills especially in an engine out situation and
slightly less flying time...

For those who may be wondering... Yes, plane is still intact and suffered
no injuries during the making of this segment... However, I can not attest
to the same of the owner, Mike Sigler of McDonough...


.

Robby

My Feedback: (18)

There have been several comments about how the Twinstar would be
with .25 size engines which is minimum recommended engine size for the
Twinstar.. And of course there have been many comments that the plane
would suffer if made using the smaller motors..
Mike Sigler of McDonough Ga. who wanted a Twinstar but wanted to use
the smaller motors.. He asked to to put it together as such and then maiden it...
So,,, who am I to refuse .. Sooo, with several RCU members present,,
off we go to fly some Twinstars...
The plane was assembled as per manufactures instructions with only
a couple of minor changes... The throttle servo mounts were installed
INSIDE the wing to lower the servo for better alignment to throttle
linkage.. The other being that the battery was mounted in the far front of fuse,
under windshield area mostly to balance the plane...
All control surface throws were set to manufactors specs for maiden..
Engines are .25LA
( http://www2.towerhobbies.com/cgi-bin...?&I=LXBY16&P=0 )
which sell on Tower Hobbies site for $62.99 each...

The use of the .25 size motors reduces the overall weight by almost
½ pound by time you are done with mufflers and proper props.. This
weight difference is definitely seen... The .25LAs gain RPMs
well with the 9x5 props and pull this plane with ease...
Plane balanced very well with putting the 1450 nickle metal battery in fuse,
in front of wing mount.. Everything else is in stock location...
Take off does like a little more of a run down the runway before liftoff..
If you try to force it off it pretty much doesn't respond.. Even on a forced
takeoff the Twinstar was controllable.. On grass,, it does require a longer
roll to get liftoff..
The day these flights were done the grass was about the height of the wheels
so it did cause it to take a while to get off... But again,, it did have ample power
to obtain liftoff and at a flyable speed...
Climb-out is more than adequate.. No, it does not have unlimited vertical...
It seem that much more than a 45 degree angle it starts to falter on climb-out...
Most maneuvers that the plane is capable of are easily done with exception to
doing a large loop.. It does loose out on the upper end... bring the plane on
full power, point nose down, gain tons of speed, and a full loop can be attained..
A few take offs on a paved runway were done at about ¾ throttle.. The Twinstar
used about 30 feet and was up for a gentle climb-out... Add full and now plane
goes up well...
Most flying can be done at ½ throttle with ease.. At about ¼ throttle is starts
to become unflyable... At full throttle the plane is a blast to fly... As is normal
with the Twinstar, a positive spin doesn't happen.. But put it into a negative spin
and it performs quite nicely... The plane will fly at ½ throttle, inverted, very well..
And yes,, even at 4' above the pavement.... Rolls are very easy to do of course
and if you can fly a single, and do these things, you should be able to fly a Twinstar
in the same manner...
Soo, now it is time for the treaded engine out situation... With the use of the
smallest recommended motor on the Twinstar it is again, a non-eventfull
occurrence.. As long as there is speed there is more than ample control...
With engine out making a couple patterns on a 600' runway was not a problem...
The use of rudder was helpful of course and with more speed less rudder was
required.. Flying on one motor the plane did not like to climb,, but it was possible
to increase altitude somewhat... Doing a touch an go on one engine was not easy...
Skill came into play on that one... Now here is where everyone thought this plane
was a goner.. Coming in on approach I decide to go around... Oh heck,,
lets do a roll while we are at it,, and then fly the pattern and make another
approach... Nooo, I do not recommend trying this.. But it can be done... Upon
landing the plane does not like to taxi on one motor,, especially on grass...
Now we try a total engine out.. Both motors are dead.. This is where this plane
really shined... Keep it level and point it where you want to go and it will
go there... Where it is not a 'floater' the Twinstar with the .25's does glide just
about as good as most trainers..
This is Mike Siglers 'second' plane.. He has flown the heck out of his trainer
and has gotten proficient with that and his Kadet.. After four or five months of
flying and a few gallons of fuel in his other planes,, time to see how he handles
flying his Twinstar..
Nervous as heck he took over the controls on the Twinstar while it was in
the air... After a few passes he got very comfortable flying it... His first take
off with it was a little 'nervy' but he was able to maintain control and get the
plane up... Every take off after that one was done with ease... As for landing
it, Mike was not comfortable at this point in his flying 'career' to do it.. However,
being persistent, I talked him into landing it.. A little bouncy , but landing was
success..

Flying times were slightly longer...
About 7 to 10 minutes depending on throttle management..

So to answer the question on how will the Twinstar fly with smallest recommended
motor.. Very well... Have to say was a lot of fun and was a pleasure to fly.. Nooo,
not a rocketship, but an enjoyable flying TWIN plane that should be within reach of
just about anyone who can fly R/C ...
Engine outs are not so drastic with the smaller motors and the plane will
maintain flight on one engine... A word of caution at this time.. Make darn sure
that you balance the props as the smaller motors are very susceptible to vibrations
if props are out of balance.. With the design of the nacelles the vibrations will be
amplified causing the fuel to foam which will make air bubble in fuel line causing
motor to die..

Would like to thank Mike Sigler of McDonough Ga. for the use of his planes to do
this portion of this thread and Henry County RC club for the use of their very
nice facilities ...

JAkridge

Hey Robby, I havn't forgot about a T.S. for my little 25 LA's. Just working on other projects, and those are for Water
Kind of fell in Love with these float planes. I've been throwing all those round black things in the trash.

Seen a TwinStar on floats?????????? And will the little LA's break water with the added float weight ?


Well I found a picture of 1 on floats with a search. Yep....thats the next plane.

jrf

My Feedback: (551)

Juz:

I have a Twinstar I on floats with two OS 40FPs. (25LAs would be a disaster on floats.) With the 40s it is fast and does very nice pattern style aerobatics. The wing loading is a little high, but with flapperons to slow the landing speed down it is an easy flyer. I've been flying it for 4 or 5 years and never dunked it.

But, it's time to move on. I'd be willing to sell it, with the wheels and floats, with or without the servos and engines. PM me if you are interested.

Jim

Robby

My Feedback: (18)

HAve to agree with the above,, JuzPlaneKrazy1...
Using .25s and floats won't make it...

jrf, did you list it in the marketplace..?

jrf

My Feedback: (551)

No, not that ready to sell it, but Juz is local and if it fits his need...

Jim

JAkridge

jrf, Sure I'm willing to take a look at it. I did'nt think the 25's would make it (wishful thinking). There's not a whole lot of planes I would like that they will fit on. Maybe time to sell them, they are great little engines, just limited in plane size.

Ok jrf please if you could a few pic's emailed to me would be great and $$$.

F.Ciccarello

My Feedback: (60)

Maiden flight on my twinstar. I have 2 blue o.s. .25 LA engines on the plane and it fly's great. The twinstar fly's like a trainer and it's very predictiable, so far no bad habit's.

Both engine's rpm: idle 2800- 3200 half throttle 8500-8400 top end 12000
11800.

maiden flight was uneventful. 3 flights today and more tomorrow.

over and out.

TheParrot

Hey everyone... has anyone tried flying a Twinstar with a pair of OS 26 Four strokes, or similar engines? Would this be enough power for it? Thanks.

Shadow-RCU

My Feedback: (3)

I fly mine with the 26 four strokes with 10-6 two bladed props. I fly off a paved runway and it has more than enough power. If you fly off grass the take off may be marginal. The 10-6 props are close enough to the ground that in the grass it kills the engines. I will probably try shorter three bladed props at some point. In the air it is plenty fast. It will do fairly large loops, rolls and fly inverted without a problem. Nice thing about the 26's is I can get about ten minute flights with the stock tanks. I usually start looking to land after seven to give myself some room.

The major problem I had on my first flight was I had read it was sluggish on the ailerons so I put in all the aileron travel I could get. It was anything but sluggish. Luckily I had duel rates and managed to slow down the roll rate and get it back on the ground. Made my low rates the high rates and reduced the low rates even further.

Its a great flyer and I've had a ball with it. Twins definitely fly and sound different. Those two 26's sound great when they are in synch.

Hope this helps.

Randy