Downwind3Zero

My Feedback: (10)

I ordered the Lado e-door actuators for my gear doors to make setup easier and to prevent them from not opening should the negative pressure be to grat. We'll see how that works.
Chris

artchristic1

Hi Malcomn;

What plane are you flying?

I will post a pic of my L-39 Bypass set up later.

Hop this helps.

Anyway try it with one half first but be ware that you will send all your
forward air pressure upward when it enters the fuse intake ware the hatch is,
if you are building the L-39.

I am not telling you what to do but just giving you ideas and help info.
I guess everyone has there own input for these issues and problems.

Hope it works out for you.

artchristic1

Hi Downwind;

I will post my NLG door set up for you today.

Hope it helps.

Downwind3Zero

My Feedback: (10)

That would be great! I received the Lado e-door actuators and will be fiddling with it soon.
Thanks a bunch, Chris

skywarrior

Hi,
Just received my new L 39 kit. I have the previous version which flies great but as you know is heavier. I have tried to solve the main gear door problem as follows. Removed hinges and rams from original and replaced with Robart ali vesrions which are realy strong and run true. Spent shall we say hours dangling the robart 165 cylinder in various mid air positions and had to leave the workshop. Finally figured out a place where the open /close geometry seems to work and have fixed as shown. Its not perfect when closed as the piston is inline with the hinge but its very firmly closed. For those interested I filled in the cutouts of the main formers to allow me to slided the wooden mounting strip of ply across from either side. When all is settled and permanently glued up I will mill out holes where I can to replace the airflow trough the frames.
Regards
David

artchristic1

Hi David;

It`s hard to come by good info for the gear doors but it is realy a trial and error type of thing.
My set up is on page 66 and I used the X style method to get as much horizontal pull as possible.
Your method seems to work well to.
My installation seems to have a very good door close pull even while
using the JL cylinders. I had to modify my factory hinges to get the right angle but they work real well.
I still didn`t post my build yet but everyone in this site will give you a good feedback for your issues.
Nice to see another JL L-39.
If you need help let me know I will do my best.
I have losts of pics of my build.
My plane is finished now and it is ready for first flight. Canadien winter is here so it will wait till next season.

skywarrior

Hi Artchristic,
I saw your hinge post originally but could not find it recently and it looks as if it works well. I chose the larger cylinders because I used them on the original version I have but its a bit of a lash up. I put a carbon rod thru the hole in the ram casing as a pivot and moved it around to fit rather like I have done here.
I have never used 2 mm air tube but of course the pressure is the same. I have a couple of questions which relate to it which I would appreciate your feed back.

Do you use 3mm with festo fittings as much as possible and then reduce to 2mm just before the ram or retract.

Does the smaller tube effect speed. The reason I ask is that I have large rams on main doors and standard as provided on the nose door. Does this effect sequencing of gear and doors.

I saw a post re the use of Robart low profile retracts as the guy had damaged the originals in a prang. I aske if they were more powerful than the originals but got no answer. How does your retract system work with the smaller tubing.

Thanks

David

artchristic1

Hi David:

I used the air throttle from JL to slow down my retract and extension time.
they work very well. They don’t drop out with lightening speed even if one is hung up a bit.
They drop down very slow and smooth. I used the jet tonic gear sequencer for my timing
so that if in the air the gears are too slow or too fast, I can adjust the timing.
The 2mm does affect the timing by being smaller due to the exiting air has to work harder to escape the cylinders but they do not affect the performance
of the retracts.
They are just easier to hide.
I did not use festo fitting to convert from 3mm to 2mm, I slid the 2mm into the 3mm and glued it in place with loctite 422 to save weight and problems. Very strong bond.
I used this same method in me SM F-4 at the IJMC in Ohio 2012
If you are wondering if they blow up at 100psi, well so far NO. In fact I always pressure up my line at 120psi
with one gear swing before each flight.
Remember to keep the retracts with a separate tank from the doors due to they require a large volume of air
and also they will give you one or two more cycles.
I hooked up the brakes and doors with the same tank.

Steve N.

Hi Artchristic,

I've been looking forward to your build thread as I have a G2 on order. If you start a new thread for your build, maybe you could post the link here so we're sure not to miss it.

Thanks in advance,
Steve

artchristic1

Hi Steve;

Yes, I will post my build here for everyone.
I look forward to it.
I have lots of good pics and they are well explained.
I have the G2 also and I can’t wait to fly it next season.
My Holidays start this Monday so I will have time to post
the build thread.
I built my plane with a split apart fuse just in case I have
to go some ware real far.
I will explain what I did. Very easy and low cost.
Hope to help you in any way.

skywarrior

Hi,
I have also beefed up the sloppy airbrake mounting with two triangle of epoxy plate drilled 8mm to fit the central tube. I then made a U shoe in e/plate and dropped it over the top of the tube and glued everthing up solid. Ligth modification and no slop at all.
All I have to do now is fumble with getting the two cap heads tight to fix the control arm in position. Patience is the virue sometimes but it will be done.

artchristic1

JUst for safety I heat shielded my aft fuse wires due to the exhaust heat from the turbine.
The normal wire shielding tends to get hard and brittle after a while.

Steve N.

Thanks a bunch Eugene,,, I appreciate it. Your clear suggestions and great pics with captions are a great help.

Steve

artchristic1

Hi Steve;

If by any chance your gears do not go up far enough into the wheel well when retracted,
just add one 1/16'' thick washers under the out board retract mounting screws.
This will make the gear sit higher into the wheel well.
I had to do this to give the door better clearance with the tires and struts.

skywarrior

Hi
i decided to make the fin and tail plane removable for transit. I used a three servo plug with heat shield too from Emotec which does the job brilliantly. Assembly time about four mins max. In addition I wrapped some thin ceramic blanket around the tailpipe under the servo lead to the tail plane. This also has worked well.

Downwind3Zero

My Feedback: (10)

Hi Artchristic,
Do you have any pics of how you set up the Nose gear door? Your pictures are great and I have use then all for reference, thanks!
Chris

artchristic1

Sorry
I forgot to take the pics.
I will do so tomorrow afternoon and post them.

Steve N.

Sounds good. It seems to me that the first version came with shims for the retracts. I understand that it helped with the clearance as well as helped them to stand at 90 degrees. Did you also have to add a bolt/block to the gear to maintain clearance for the wheel/trailing links? See posts 234, 235 and 238 on page 10.

artchristic1

I have some pics for you stand by.
Later

artchristic1

I have some new pics for you.
You have to modify the JL hinges like I explined
once in this site to get a good pull but you can try other methods
too but remember to stop the cylinder at the door closing point or
els the pull will deform the door when closed.

Hope this helps.

And for Steve,
I did not have to add the stops lik you mentioned, maybe I got lucky.
I removed some of the door flange to get my doors to sit flush
with the fuse frame.
I am not finished the set up yet but here is a pic. I have to make new flanges
and clean up the edges.
I like my plane with low clearance and very flush on all moving part.

Downwind3Zero

My Feedback: (10)

That's a great help -thank you!
Chris

artchristic1

Here are some pics of my bypass installation.

EDFCrazy

Is your turbine's nozzle not to far inside the thrust tube? i thought it had be be around 20mm away from the bell-mouth of the thrust tube. or can it be done like that because your using a full bypass

artchristic1

Hi:

Some people say it is an issue with the loss of power due to it being close to the bellmouth and may cause a collapsing of the tube.
That is true in some cases but only if the duct has no air to replace the exiting air.
My bell mouth sits just over the edge of the engine exhaust mouth.
The bypass air is enough to furnish the tube even at full static throttle.
This is my set up.
I used this setup on my F-4 and F-15.
In any case, the air comes from the intake (which goes around the turbine) if you use the bypass installation.
There is a 1/4 inch clearance around the turbine.
The engine is enclosed.
I will use HIGH TEMP WIRE SHIELDING AROUND THE EXPOSED WIRES AND FUEL LINES.
You can change it or do what you feel is best.
I am only showing you what I did.
Everyone uses their own set up and ideas.
There are still some changes to be made but the engine set up remains as is.
A friend of mine did not use the bypass on his large Yellow F-18 with a P200
and yet the tube still collapsed in flight. You can say either the tube was not strong enough
for the power out put of the turbine or it was not far away enough from the engine exhaust mouth.
In any case you choose your own conclusion.
Collapsing of any tube will only occur if the outside air pressure is higher than the inside air pressure of the tube.

skywarrior

I realised I did not have the Emotec plug unit so I improvised with a Multiplex plug with an Emotec circuitboard soldered to the pins for strength. The cable was covered in heat resistant covering.
I also covered one side of the pipe in ceramic balnket just for insurance.
The fin is shown with all parts setting having drilled the ali peg 4mm and inserted carbon guide tube for cap head screw. A 4mm blind nut was bonded under the top of the fus. beneath the guide original guide tube. Insert screw / glue and pull up tight to set. Trim and make good. Removable in two mins max at the field.