Official Black Horse L-39 Albatros 90mm EDF Jet Discussion Thread

[Aussie1]

I haven't started the conversion yet. Still under consideration.... Right now my biggest set back is because of the weight I wont be able to use this jet to do my AMA turbine waiver. It doesn't meet the requirements of 12lbs dry weight. yours turbine ready coming in at 10lbs gets real close. Using the Xicoy X90 would add a little bit but i'd still only be around 10.5lbs dry.

What a silly rule that is!! It must have been written before micro turbines were common. We had a similar rule here in Australia that said that all turbines were subject to a heavy model inspection, even though some of mine weight 3kgs. Now, it is just a one off turbine inspection. I reckon that with the X90 and heavier batteries for the inspection, you will easily make the 12lbs dry.

[406PIlot]

I haven't started the conversion yet. Still under consideration.... Right now my biggest set back is because of the weight I wont be able to use this jet to do my AMA turbine waiver. It doesn't meet the requirements of 12lbs dry weight. yours turbine ready coming in at 10lbs gets real close. Using the Xicoy X90 would add a little bit but i'd still only be around 10.5lbs dry.

[Aussie1]

Aussie1 Fantastic Job!!!!!!! Again I appreciate all the info. You and everyone else have been a big help. I can't wait to hear about the maiden. I think it's safe to say we are all rooting for a successful up and down. Good Luck!!! Maybe we'll get to see some video? Cheers again to the good work and support.

Thanks mate for the kind words! Due to interstate work commitments, it will be a few weeks before I can get out and fly it, but I'm expecting that it will go really well, big wing, thick aerofoil and not too heavy. How is your conversion going?

[406PIlot]

Aussie1 Fantastic Job!!!!!!! Again I appreciate all the info. You and everyone else have been a big help. I can't wait to hear about the maiden. I think it's safe to say we are all rooting for a successful up and down. Good Luck!!! Maybe we'll get to see some video? Cheers again to the good work and support.

[Aussie1]

My turbine conversion is complete and it came out at 4.8kgs RTF so with the X45 producing 4.7kgs, it should go OK. That incudes 3 batteries and a full Unilight kit installed, plus the CG came in perfect with two batteries up front and one over the one litre tank which is over the CG. Also, I used a AR Booma 20 amp dual voltage regulator to power everything and a JR 12 channel RX. Now just to get time to maiden it!! One crazy design flaw from the manufacturer was the routing of the nose wheel steering cables. They exited the thin plastic tube and went back 180 degrees to the steering arm. I used some Nyrod inner, heated with a heat gun and bent to 180 degrees and fixed with hot glue. Works perfectly and a lot easier than pulleys, hopefully the pics show how I did it. Also, I have used the flexible hinges supplied as they are stronger than the wood that they are fitted into, and have never had one of these hinges fail.

[406PIlot]

I have another kind of important question. What kind of hinges are used on this Black Horse L-39? Is it a ca glued cloth/fabric hinge?

[406PIlot]

Great !!! Thanks for the picture confirmation and all the help. Just fantastic support from everyone on this form.

[Aussie1]

Using those on all surfaces I assume then? Are you running them at 6v or 7.4v? Have you noticed any issues with fluttering or weakness? 60oz @ 7.4v to me seems a bit light for a jet, but this is why I am asking someone who has one =)

Thanks again Cheers!

I'll be running them on 7.4v with the gear through a small 6v regulator. It's not finished yet, but those servos are possibly the best that you can get for a jet of this size, and a perfect fit! I have six small turbine jets and generally you won't fly it any harder than if you had a hot 12s EDF in it.

[406PIlot]

Just checked, my jet has these servos. https://www.modelflight.com.au/hitec...cro-servo.html

Using those on all surfaces I assume then? Are you running them at 6v or 7.4v? Have you noticed any issues with fluttering or weakness? 60oz @ 7.4v to me seems a bit light for a jet, but this is why I am asking someone who has one =)

Thanks again Cheers!

[Aussie1]

I saw 8 standard size servos listed on the spec page / manual, but someone in the thread said standard size doesn't fit. They weren't clear on if it's all surfaces or just elevator or rudder or what exactly. If you can tell me what you are using so I have a good reference that would be awesome.

Just checked, my jet has these servos. https://www.modelflight.com.au/hitec...cro-servo.html

[406PIlot]

Their website states, Servo: 08 standard high torque servos, size: (29 x 13 x 30) mm, but I will check mine to confirm. I bought this jet with all electronics already installed, but I want to inspect the servos anyway. Regarding the turbine, I would consider the new X90 as it is flexi thrust and the same size as a Wren 44!! http://www.xicoyturbines.com/X90.html

I saw 8 standard size servos listed on the spec page / manual, but someone in the thread said standard size doesn't fit. They weren't clear on if it's all surfaces or just elevator or rudder or what exactly. If you can tell me what you are using so I have a good reference that would be awesome.

[Aussie1]

Hi there, have just started the build of the L39 and mine will be fitted with an Kollibri T35 Gas turbine. The L39 fits very well together and I think the power from the T35 will be enough for the plane. There is loads of space in the airframe so the turbine conversion is straight forward.

Hi, just wondering how you went with the Kollibri T35, as I'm putting a X45 in mine, and it is surprisingly large jet!

[Aussie1]

I am trying to figure out what turbine i'll be using. My original thought was a Kingtech K45. However with our altitude (about 35-3600ft above sea level) I'll probably see a 15-20% loss in thrust. So I'm thinking a K45 or X45 wont work as well as thought or would leave things under powered. I would rather have extra power and just use less throttle stick which would also get me better flight times most likely. I'm leaning towards a Swiwin 60 or perhaps Kingtech K70 now, but wasn't sure if it will fit without major modifications etc.

Also can anyone confirm if "standard" size servo's do fit in all the surfaces or if they don't what surfaces need a smaller or mini servo?

Thanks everyone here is such a big help and it's appreciated!

Their website states, Servo: 08 standard high torque servos, size: (29 x 13 x 30) mm, but I will check mine to confirm. I bought this jet with all electronics already installed, but I want to inspect the servos anyway. Regarding the turbine, I would consider the new X90 as it is flexi thrust and the same size as a Wren 44!! http://www.xicoyturbines.com/X90.html

[406PIlot]

I am trying to figure out what turbine i'll be using. My original thought was a Kingtech K45. However with our altitude (about 35-3600ft above sea level) I'll probably see a 15-20% loss in thrust. So I'm thinking a K45 or X45 wont work as well as thought or would leave things under powered. I would rather have extra power and just use less throttle stick which would also get me better flight times most likely. I'm leaning towards a Swiwin 60 or perhaps Kingtech K70 now, but wasn't sure if it will fit without major modifications etc.

Also can anyone confirm if "standard" size servo's do fit in all the surfaces or if they don't what surfaces need a smaller or mini servo?

Thanks everyone here is such a big help and it's appreciated!

[Aussie1]

Thanks a TON! This is a huge help!!! Can you tell me what altitude you are at?

Again this was a big help and it's really appreciated.

My flying field is about 200 feet ASL. I have made my own pipe using a eBay spot welder, about 60mm at the front and 55mm at the back. Also, what turbine will you be using?

[406PIlot]

I measured 10cms between the edges of the EDF Mount. I have already installed my radio gear, Unilights and landing gear and its showing about 3.6kgs. I'm installing a X45 turbine and a single walled pipe so about another 800 grams including pipe and tank to go in, plus 900 grams of fuel. The X45 is equal to a hot 12s setup, so I'm expecting reasonable performance, and this jet has flown with a Kolibri 35, and a 90mm EDF, so will be interesting to see how it goes with a 45!!

Thanks a TON! This is a huge help!!! Can you tell me what altitude you are at?

Again this was a big help and it's really appreciated.

[Aussie1]

Can anyone provide the dimensions for the edf mounting area? How wide is it between the mounts that are installed and how long is it from the intakes to the mounts? I'm really contemplating doing this plane with a turbine, but I need to get a rough idea of size for the mounting area and actual weight of the plane to help determine the turbine size that would be needed or could fit.

Thanks

I measured 10cms between the edges of the EDF Mount. I have already installed my radio gear, Unilights and landing gear and its showing about 3.6kgs. I'm installing a X45 turbine and a single walled pipe so about another 800 grams including pipe and tank to go in, plus 900 grams of fuel. The X45 is equal to a hot 12s setup, so I'm expecting reasonable performance, and this jet has flown with a Kolibri 35, and a 90mm EDF, so will be interesting to see how it goes with a 45!!

[406PIlot]

Can anyone provide the dimensions for the edf mounting area? How wide is it between the mounts that are installed and how long is it from the intakes to the mounts? I'm really contemplating doing this plane with a turbine, but I need to get a rough idea of size for the mounting area and actual weight of the plane to help determine the turbine size that would be needed or could fit.

Thanks

[406PIlot]

Can anyone tell me the weight of this model without any electronics or engine etc.. the spec page says 10.1lbs , but doesn't say if that's flying weight or just the weight of the model..

If anyone can help me.out here that would be fantastic. Thanks!

[BraPapaD]

Converted my BHM L39 from JP 90mm 12s to Swiwin SW60B turbine.
I have a 1.4 litre tank, I get 7min flight at 80% power