ameyam

Finished it, bar final engine install and cowl. Wont cut the cowl untill after the test flight but I am out of time as it will rain any time after this week, so most likely will fly it only in September- October[].

Meantime I am going to get some of the parts I couldn't install or am doubtful of. For e.g. 3.75" - 4 " foam wheels, replacement 1.5" horn (for the one I messed up on the elevator) and, most importantly, replacement landing gear. Just look at them- it weighs 3.6Kg and the gear shank is already bent out. Anyone can suggest which ones to get?

Ameyam

kochj

Flew my reactor/saito 1.25 last wk...
I had added a on-board glow and a 2000mah lipo battery undet the gas tank...
I had a double heavy washer ( the apc 16x4w prop was too thin and the spinner adapter bottomed out)

Anyhow.... the 16x4w is way too slow of a prop and it came out nose heavy.
Combined with the landing fear fix...I didn't like it with a nose heavy condition...

I have a smintor 16x6 wood and a 3blade 15x6 prop that I will try out...
One thing to note....weight adds on fast...
I didn't need the onboard ignition, it was added to wieght, and a little piece of mine....
If I dit it again, I would have purchase a ignition system, as this makes kick backs non, existant. and smoth running
engines...

I don't have a decent video recorder,,, it is a older digital, and a pain to convert from tape to cd...
It also helps to have a camera guy.....

I may pick up a onbard vid. camera and put it on my head, but then the issue is the size of the plane, gets small really quick

kochj

No activity for a while on this one....

I have a gallon on fuel through this plane with the saito 125.
This setup is the way to go if you want a 4-stroke on it...
PULLS FOR EVER..... Unlimited Vertical. into the stratosphere...
But not overly fast..... PERFECT....

My only issues with the plane is that I have a hard time getting pleasant rollers...
While in knife edge, it wants to Roll flat, and pulls to the canopy quite a bit....

I have it in a almost completely Neutral position...(c.g. wise) but still tail heavy.

I It seems to flop around when doing spins..... and when doing the 45deg inverted upline C.G. test, it doesn't change pitch, but seems to roll to one side....

Things I need to change:
1.The stock hardware just allows too much movement (or slop depending on how u look at things) in the Elevators and Ailerons....
This contributes to a already lacking 3d throw, and numbs up the controls... This equates to poor control in High power knife edge rolls ( it wants to sway off course) and seems to go a bit goofy....
2. C.G. It would be MUCH more stable if it went forward... It may help the above considerably...


One other thing to note.....
While out flying this wk=end.....I had noticed my engine pinging/leaning out, while on up lines when the tank was 1/2 empty or less, even when set 400-500 rpms richer..... and got worse throughout the day....

I ran out of gas on my last flight of the day ( because I richened the needle more, and then didn't account for the increased use of fuel)...
It was in a low altitude High/alpha manv.... didn't have any airspeed....So the plane landed hard.....
The result was that the top of the firewall ripped out....

I think that the firewall could have been loose prior to this, and caused excess engine vibrations which caused fuel foaming in the tank, which caused the LEAN running behavior....
A quick fix..... but ....

CHECK YOUR Firewalls... I had even placed thinned epoxy on the other side of it... and it still pulled out....
It may or may NOT have been the issue.. JIC...

kochj

I wanted to add that the firewall was well glued from factory...
THe firewall actually broke in half... could have been due to prior hard landings ( were a few, due to flying in tall grass)
and then the slightly weakened firewall broke...

THe bottom of the firewall remained intact... so again.... Great planes did there job well...
Perhaps a ticker firewall if using a larger engine... and you have hard landings...

Seems others didn't have issues with a gas 2stroke, but a 4stroke gives out a beating...more than a 2 stroke...

Other options would be to use a Alum. mount instead of the plastic stock one... this also caused shaking, due to mount flex...
I may use a dubro mount (alum. with ruber inserts to absorb some of the vibes)....
will see//

kochj

did some digging on options....and Here is what I found...

Some of the ill handling is do to BLOW Back on the controll surfaces...
Exple: I have s3001's on all the ailerons.... 33oz @4.6 and 40oz on 6 volts.... If you use the outer servo arm hole, it is about 20oz..... and that isn't going to cut it...
According to the manual, that isn't enough....

The other servos may not be enough either on the elevators....
In all thoughts, my plane is setup like a 1.20 size...and I wouldn't expect the Standard digital Karbonite Hitec servos to do the job....

ameyam

Hi kochj,

whats your all-up weight without fuel on the Bipe? Having set up the Bipe in the summer, I havent flown it yet due to health issues and the monsoon. Mine is around 3.65Kg with my reinforcement job and the FS110a. I get a better CG balance with the DLE 20 but running the ignition cable is a problem, it gets to around 3.8kg and I cant install the cowl without hacking it quite a bit.

I am concerned that its too heavy for the landing gear, so I am planning to get replacement Dubro heavy duty gear as a replacement.

Ameyam

kochj

Dry weight is 7.4 or 7.6 lbs (w/o fuel) Or @7.8lbs =3.53 kg
If you run the stock gear they will sage no matter what engine you have!
If you run on grass, you had better have a strong prop or it will break or be damaged just ruining it as the prop will hit the grass
or worse nose over and break it..

Saito 125 2~ 7.4 lipo bats. And on board glow power.

ameyam

So, what did you use?

Ameyam

kochj

I used the stock gear.
shaved off the paint and the white primer...
Wraped the landing gear w/fiberglass and epoxy and microballoons

I believe it was this size.....

http://www3.towerhobbies.com/cgi-bin...?&I=LXJDR0&P=7

If you paint it, it will not stick out.... but when you have a plane that can be flown all day w/o any issues....with landing gear.... I will give up the good looks...

Otherwise you could go with som other brand of gear...

Go with gear off a 1.20 - 20cc aerobatic plane that is 2-piece design...


I didn't wrap mine initially....
If you want to be quick about it...you can leave the paint and just wrap the carbon tube under it..and let it dry....
This may work out fine...as it doesn't allow the paint to separate from the gear....(loose adheasion and back to square one)

You coul also pick up a 3-blade prop and just FLY and forget about it.....
Th OS 110 will have plenty of power to pull it...
DO NOT use a low pitch wide blade prop w/this plane.... it doesn't fly fast enough...

kochj

winter is on the way.... get it up in the air...
and fix what ever doesn't work for you..

ameyam

Actually our side flying starts in winter (OCT-NOV). Antway, did a test assembly today, the airplane is 2.67kg (5.88lb) without engine and fuel. If I put in a DLE20 (w battery), the total would be 3.75kg (8.26lb) where as with the 110a it would be 3.5kg (7.71lb). The weight had me worried untill I did the wing loading calculations. With the DLE20 and a ignition battery, it comes to 16.63oz/sq.ft and with the 110 it comes to 15.5oz/sq.ft. These are really low numbers but then this is a bipe. Note that the airplane balances better with the DLE and I have built is so I can convert to gas (read as well reinforced). With the 110, I have to put the battery in the nose hatch (which I would do anyway) and its still balances at the very rear limit of CG

What engine would you guys suggest to use?

Ameyam

mkoe

Interesting thread, Irecently got one of these. Iam using an OS91FS surpass with an APC 15x6 prop, balance point at centermark for CG.

What I've been reading here is everyone seems to have KE problems. Mine tucks to the gear in KE. Isee where others that are running a more aft CG tend to tuck toward the canopy. So, other than that the plane is a great flyer.

Had some issues at first with, Rudder. In flight it always seemed to go right. Found that the balance tab was misaligned. Cut that off and true it up and that problem solved.

Another issue was flooding of the engine at idle. Engine mounted inverted. Cure was ,relocate the tank. The original mounting puts the tank centerline approx 1.25 inches above the NV with the engine mounted inverted. Pulled the tank out, filled the large bunghole in the firewall. I then used the battery tray that is made for the electric conversion and installed that. It is now the mounting plate for the tank. Some mods were done to the formers to accomodate the change in location but this put the tank centerline within 1/8" of the NV. Now idle is great and that problem solved.

Next will be to find that sweet spot to minimize the KE tuck and then add mix.
Nice thread here and some good info as well. It's good to read others real world experience with an airframe and use that knowledge for comparision. Thanks

MK

ameyam

Anyone know the screw size that screws in through the top wing into the brace? I have lost the screw and need a replacement. Couldnt find the reference in the manual

Ameyam

mkoe

1-1/2" 6-32 I just pulled mine out to check

ameyam

I have to choose between the 110A and DLE20 on this airplane. Given its already 2.67kg w/o engine and fuel, I am concerned of the weight with the DLE20. Inspite of that, the wing loading with the DLE20 and ignition battery is 16.6 oz/sq.ft (at 3.75kg or 8.26lb) and that with the 110a is 15.5oz/sq.ft (at 3.5kg or 7.71lb).

What would you guys suggest I do?

I have another question- I was about to refurbish a 75ax by ordering a piston-liner. What is the power comparison between the 75ax and the 110a in the mid throttle range where we usually 3D? If the 110a has similar power, I wont invest in the 75ax. The piston liner costs half the engine price.

Ameyam

kochj

USE the 110F ....
Place it on it's side and it will never fail you.... Inverted makes for a cleaner install, but I have only had headaches from inverted 4-stroke installs, as you end up leaning the bottom end so much that it doesn't give you
much safety margin.....

The Dle20 hacks the cowl up, is loud and annoying, and runs great.... with very little maintinence....

Stop overthinking this and just get it up.....
All this thinking and wondering, and you may dumb thumb it anyway....


I will try to put up some video of mine so you can get a idea of what mine looks like...

In my experience, the only time I crash my planes is when the engine quits.....I know why guys like the electric stuff.

ameyam

Hi Kochj,

right now thinking is just about all I can do. Due to health problems I havent been able to fly at all since April and monsoon, which is our off-season, is just coming to an end. Still, it will be atleast another month till they mow the grass down enough to let us fly these models. Till then its trainers only

I too dont usually crash unless the engine quits. Which is why I wanted to DLE. With glow, the engine could cut any time. The cowl hacking and weight was my only concern.

Anyway, I am going with the 110a for now. I will review a bit later in the season whether I want to gas it.

Wish GP would come out with a slightly different cowl design that will atleast let the compact wrap around mufflers fit into the cowl atleast. Wonder whether the head on the DLE20 can be rotated 90 deg so that the exhaust points to the rear. Then even the stock muffler can fit

Ameyam

kochj

no the dead can't be ratated on the dle 20 do to the intake ports located on the front and back.

I have my saito mounted on it's side and it has been completely reliable....
Only time it dead sticked was because it ran out of gas, and the other was when I adjusted the low end needle after flying a few times prior, and then went back out w/o
giveing it a good run up to see if problems prior to flight...

It seems the os 4-strokes do better when inverted than saito's....

kochj

Wow. Spell checked messed that uP
I meant to say. The DLE head can't be rotated

steinywi

I have 2 years of flying on the bipe and dle, over 10 gallons through it. I have flown this plane hard and so have others it is an unbeatable combination. Weight came in at 7 lbs. and 8 oz., which is awesome. Yes the muffler takes a lot of the cowl but the fun I have flying it makes up for that. Oh did I mention a 6 oz. tank for 10 minutes of flying. Oh, and no mess from glow fuel!!!

ameyam

Ok, I just finished putting together my Bipe. Mine comes to 3.65kg or 8lb without the cowl (that wont add too much) with a FS110A. Is it too over weight?

Ameyam

flazo

Hi,,

what is the size of the Motor Standoff for the Electric setup?

thank you.

ameyam

Hi,

flew the the Bipe a few weeks ago for the first time and got it a bit more settled now. Pic is updated. I am flying with a 110FS and found that it just crawls across the sky with a 15x6 and zips across with a 14x8. The 15x6 is so bad though that when the wind picked up to 10-15mph in the afternoon, I couldnt even do a loop. I put the 14x8 back though and it has much better penetration. I am using MAS though so I feel that the props must be flattening out with engine torque which the 110FS has a massive amount of- the JXF 15X7 wooden was thrown off. APC props are in the post and I will be testing soon

Ameyam

rowdyjoe

My Feedback: (9)

Great thread. Lots of great ideas about this great bird. Irecently traded for a used GPReactor Bipe but, have not flown it yet. I just finished a thorough inspection and installation of the receiver, 2 LIFPo batteries (6.6v), 1 voltage regulator for the ignition (limted to 5v max), a larger fuel tank, and shrinking our the wrinkles. It has a Zenoah 20cc CDIengine on it.
She was built by a fella from a local club who does very, very good work (Inow have 2 of his former planes). She's all dressed up now and ready to fly but, the weather won't be right for another couple of days. So, I'll have the time to fire up the engine and make sure it's tuend and ready.
I should be afraid of this beast as it has 4 full span ailerons that are 4" wide, a rudder like a barn door, and elevators that look a lot like giant fly swatters. However, Iplan to tame her down with mucho expo and limited throws. Once i get a feel for her I will likely change those settings. I'm not a 3D pilot but, am looking foward to flying this attractive and well built machine.

The builder of this plane added a very good modification to the landing gear for strength and flexibility. Look closely at the picture of the gear and you will see 2 rods extending from the axle area to the underside of the fuselage. What you can't see is the two short springs that attach the rods to a mounting fixture. This system appears to work quite well and not only adds strength but, provides a cushoning effect during landing. Hope this is valuable info for the folks on this thread.

I hope to fly her later this week when the weather clears and the winds calm down.

RJ

ameyam

Hi,

flew my Bipe for an extended period on Saturday and finally hovered it . My buddy who is a more accomplished 3D pilot hovered her 15 feet off the ground. He has to keep banging the sticks around to keep it stable. The 110FS doesnt seem to have sufficient power to pull out. I tried my hand too. With a 16x6 JXF wood it was much easier but I couldnt get it stable. I dont get it- whay do you need to keep gunning the throttle for hovering? Shouldnt a fairly fixed throttle with minor corrections be able to keep her stable?

Ameyam