Mikael-OEMF

Monday 16th of April was the day when my new Ripmax Harmony had its maiden flight. Having less than one years experience as a modelaviator. This was huge for me.
It is my first model with twin engines and the retracts are also new to me. The difficulties that I have had were mostly about the retracts and the choise of servos for these.

RETRACTS:
1: The instruction book pictures ordinary servos for both nose and main retracts. I had to buy a special retract servo for the mains and the a heavy duty servo for the nose gear.
2: The links are plastic. One broke during the initial taxi test on the ground. All are now changed to metal links.
3: There is more plastic in the retract linkage. A horn on the starboard main came of during the maiden flight. Result was the wheel just hung loose under the plane. Unlocked and not retractable. Thus my first landing was on 2 wheels. Luckily no damage was done during the landing.
4: The retracts are factory mounted. There is a pin in the retract unit that is neither locked or secured with any form of adhesive. As the plane vibrates a lot due to poor enginemounts. It will come loose. And it did. I had to use force to get the retract unit out to refit the horn mentioned in 3. Result splintered wood in starboard gear mounting plate.

ENGINE MOUNTS:
1: They are predrilled. But for what engines I do not know. OS46AX´s are recommended in the instruction book. I do not have one. But my guess would be that they have almost the same distance between the holes. I had to blind of the holes with 3 mm round wood and epoxy glue. Furthermore I had glue in 2 pieces of 1mm plywood due to the large space in the precut engine mount. It would have been nicer if they had just made a firewall and then had supplied a standard nylon or alloy engine mount.
2: It is a very tight fit to get the tanks in. I thought I was being carefull to wipe of excessive epoxy when I glued it together. But there was a bit left making it even harder to get one tank in, than during the prefit. I punctured a tank.
3: Vibrations! There are a lot of those. Before I close the cowls. I will have to dismount the engines and resecure all screws as they are coming loose. Currently I am thinking of a trip to town. I want to try to mount one of those alloy rails for drapes to see if I can reinforce the engine mount and reduce those vibrations.

Here is a link to a picture of the Harmony on display at the opening day of this season in our club.
http://www.oemf.dk/070407%20Standerhejsning%20(5).JPG

It flies well. And it is such a thrill to hear those 2 engines. All of a sudden my 2-stroke trainer engines are huge. I am waiting for better weather. My second flight was perfect. Perhaps I can enjoy the third. 2nd had the heart rate of first flight.
If You have 2 0.46 engines from Your trainers. Then buy one. I will continue to write of what I learn from mine here.

Anyone else out there who has got a Harmony?
Best regards
Mikael

DelRay

Mikael,Nice looking plane,and congrats with the maiden flight, it's a rush ,for sure. I hope you get the vibration problem sorted out, thanks for the link to the pic. I'm not at all familiar with this plane, but like you mentioned, it sounds like all of your problems are with the less than adequate motor mounts. I would use a piece of aluminum .125 flat stock stock, drilled and tapped for the bottom side of the motor mounts if you don't modify the firewall to use the standard mounts available.
Jim

orygg

Hello i have one me to,gone use to irvin 40 2stroke think it gone fly fast, verry ise to bulld to[sm=bananahead.gif][sm=49_49.gif]

Ed_Moorman

My Feedback: (1)

Very nice looking twin. Wish they were available in the states.

orygg

Hello i dont like the gear on my plane,plastic

orygg

Hello proplem getting retraks working,do you have som pics off it,only 1gear inn nr2 geting inn then coming oute help

orygg

Hello do you have pics off the retraks main,nede help on maine gear,watt retraks servo do you use,i have retraks servo butt gear gett inn then aute,have don everiting [] nede help best regards orygg

orygg

Hello and ready to fly my harmony,pics is coming[sm=lol.gif]

Mikael-OEMF

Hi there orygg
Sorry for the long responce time. I am a marine engineer and have been at sea for the past three months.
But I use a Hitec Optic 6 transmitter. I started out with standard servos for the retracts. The one for the main gear was too high and ruined some of the wood and covering. And it just didn´t move far enough for the wheels to come in and out properly. So I had to buy me a special retract servo for the main gear. For the nose gear a standard servo proved to be too weak. So I had to buy a larger and stronger servo for that too.
Hitec Servos
Standard: HS 325 HB
Nose gear: HS 475 HB
Main gear: HS 75 BB
I have tried to adjust the servos so they do not humm. That is they keep pulling and thus using power. But then they don´t lock properly. I will ask for a solution I saw on another model. When I meet that guy again. He had a back-up power unit. 2 batteries and an alarm for change over to back-up battery. If the alarm was audiable or visual I do not remember. But I want something like this for my Harmony.
I had my Harmony out for a presentation in the club before I left for sea. It was utter failure. Nose retract. First a broken plastic linkage. Then a brass rod broke. It is the one for turning the nose gear. The one that goes in the slide. I´ll try seing if a bolt will do the trick.
3 months off the sticks. I am back to flying my trainers untill I feel confident enough to have another go with the Harmony.
But I´ll be back with an update. Hopefully within the next 2 weeks.
Got me a digital camera now. Pictures coming when I´ve finished reading the manual.
Best of flying weather for You all
Mikael

orygg

Hello hade my 1 flight withe harmony on sunday, flying par off irvin 40 2t lots off power
4 point, knif edge no problem att all, plane is flying beutefull,this is a god plane 1 twinn best regards olav [sm=49_49.gif][sm=thumbs_up.gif]

orygg

hallo here is mine harmony,a god first twinn it is fast,stable as a rock , i have 2 40 irvin 2stroke on it lots off power,her is som pics best regards orygg

Mikael-OEMF

Looks too good Orygg. Makes me want to repair mine.
Had an engine failure last year. Made a turn the right way and of reasons unknown I did one the wrong way causing a spin and what can only be descriped as an uncontrolled landing. Outfield behind bushes and a slope. Minor damages only.
Made me stop that project. Have bought better engines. I am changing the OS46LA´s to OS46AX´s. Will make some reinforcements on motormounts. The wooden boxes are coming apart.
My largest problem is the statistics though. 3 take-offs and 2 landings. [)]
This can only be improved with a good summer. And first a little work.
May You have nice and calm wheather and lets have a Harmony-summer.

Mikael

orygg

Hi i Had an engine failure me to butt no problems, plane turn smod no rudder at all,landing no problems,i have stop bothe enging my selfe and one engin plane still flying god no bad habit at all,best regards olav

ps only ting i want to do is to install air retraks and modifie nacells.i flying knife edge only one meters from the ground,i trust my plane and engin and have done all you can do to test engine from left to right [sm=thumbup.gif][sm=biggrin.gif]

exocet-RCU

My Feedback: (1)

Who makes this kit? I notice the Japanese characters for "Harmony" on the wing. Is this a Japanese kit? If so, I will have to have my friend there find one for me...... Very cool plane. Looks fast!

Tim

orygg

Hi Ripmax Harmony you can by it from uk mabe in usa? and yes the plane is fast and stable. thanks olav


Http://www.ripmax.com

Mikael-OEMF

Here are 2 pic´s of my Harmony

JL1

My Feedback: (93)

If anyone wants one, pm me.

orygg

Hi gone by one more what is the prise on the plane

Mikael-OEMF

The cheapest I have seen is by Al´s Hobbies in England.
http://www.alshobbies.com/
£129.99 inc. VAT
£110.63 ex. VAT
I have used that shop several times. They are good.

Orygg No flying below the grass [)]

orygg

Hi Orygg No flying below the grass [)] OK over the grass

ian51291

hi guys,i use 2 sc46 in mine with genesis mini pipes it sounds awsome,i had the vibration problem one engine mount started to come apart i reinforced the mont with some ply and now its fine.the retracts are not the best in the world lots of play in them but they seem to be holding up,i use hitec retract servos on the main and nose gear,ive had about 30 flights now and i love it such an easy model to fly,recomended.

Mikael-OEMF

30 flights... I´ve had 3 flights. But I am just about ready to get it airborne again. Did an hours work this evening. Got the new engines installed. This time it has to be fully finished before next flight. No hoses hanging around and no cable ties visible. I.e. exept for the one holding the receiver battery. I can´t find another place for it except for just behind the nose gear well. Got to fit the cowls. Orryg´s Harmony looks so fine all finished.
My engine boxes were also coming apart. So this week has been used to reinforce them. First I cleaned them with rubbing alcohol. Flushed and brushed the dirt and oil away. Then I used 3 hour epoxy glue. Every right angle is now reinforced. The glue was laid on with a stick and then the wing was left wedged in between the walls in the narrow corridor down in my basement. Quite amasing that they planned those walls to be just far enough apart to hold a Harmony wing in 45 degrees over 50 years ago ) Well slow curing glue flows out and forms like a welding seem. So that should hold. I have been thinking about putting some silicone tubing over the push rod for the gas... But if the rattling dosn´t stop. Then I can take it apart again.

SC engines? They look just like the OS engines. I am shopping for a .70 four stroke. Are they copy cats? Are they just as good? Where do You buy Yours? Half price or so?

Weather forecast for Denmark. Tooooooo goooood to be true for the season. And I am home. Got 2 flyable models and 2 undergoing minor modifications. A few new ones in and out of their boxes. But engines... I do not need stereo. A few dancing girls could be nice though. But listen to the sound of my favourite engine. It is on YouTube. Search for Saito FG-36 OEMF.

Stay above the grass guys
Best regards
Mikael

ian51291

Ive had no problems with the sc engines they are copies of OS same size same engine and silencer mountings.the cost of them in the uk are around £40 try galaxy models or steve webb models they seem to be the cheapest here is a pic of it

orygg

Hi tinking ho fast is this plane 150mph?

ian51291

hi guys had 8 flights yesterday weather in england really good the harmony flying really well but on the last flight i brought it around put the gear down and as they came down one fell off so gear up and belly land luckely there was no damage thenks to the mini pipes acting like skids.took the retracts out and found the pivot pins missing on both so i replaced them with bolts and lock nuts now all is well so it is worth checking them
cheers.