SkyMaster MB339 Build Thread
09-21-2019, 07:09 PM
#401
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Landing gear help
So I have I guess made it worse.. from the last time I tried it.. lol
if I dont fix this issue then there wont be flying it tomorrow....
I have maybe takin a risk but I pressurized that small tank past 150 psi
and it still does not seem to matter I dont hear it leaking air I even
loosed the brass fitting slightly to try to force more air in.. and still didnt
help. I was able to charge the nose gear with out any issues..
works great... I am just wondering if there is enough Oil in the gear
I understand that the oil if for the bottom end of the strut working dampining
but the way I read it the air is what suppose to hold the plane up....
any ideas ???
09-22-2019, 06:53 AM
#405
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I guess I over looked the video that you speak of....
I was up late last night looking and I didnt find
a thing to help me. according to a friend of mine
I am doing it right ... what I need is an explanation
of what could be the cause or problem as to why
its not working ?
if it was a seal...at a 150psi you should hear that leak
is it possible I dont have enough OIL in the units ?
I was up late last night looking and I didnt find
a thing to help me. according to a friend of mine
I am doing it right ... what I need is an explanation
of what could be the cause or problem as to why
its not working ?
if it was a seal...at a 150psi you should hear that leak
is it possible I dont have enough OIL in the units ?
09-22-2019, 07:02 AM
#406
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I found the video.... it was actually in the part for the MB-339...
I actually learned a little something.. so I am going to go
put it into action.. and get back and tell what my results are.
I actually learned a little something.. so I am going to go
put it into action.. and get back and tell what my results are.
09-22-2019, 08:59 AM
#407
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Sky Master Retract Service
I found the videos... and watched them twice.... and of course I was omitting a step.
so after watching the video and followed what was done mine is now fixed.
I always say.. ( knowing is half the battle )
Last edited by TeamMuir1; 09-22-2019 at 09:01 AM.
09-22-2019, 01:56 PM
#409
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Thanks for the compliment...
I have yet another question...check out the difference the air intakes are different
than mine.. I have noticed on this thread there are 2 different ones.. or maybe there
is the issue were mine just wasnt made that way or takin off. I will show the difference
Should I worry about not having it extended to the front of the motor?
should I make something? or just leave it alone ?
Last edited by TeamMuir1; 09-22-2019 at 02:02 PM.
09-22-2019, 04:46 PM
#410
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MB 339 Cockpits
I mentioned earlier that I bought my 339 second hand... the cockpits that came with the 339 are junk....
I am not too sure if they are worth fixing.... but I guess I am going to try and come up with something
that resembles a cockpit... I do like that pilot that I noticed earlier in the thread with the blue flight uniform
and the painted helmet that matches the frt insignia on the plane... thats cool detail.... I will have to go
back and reread that info on that pilot.
but if someone has more detailed pictures on their cockpits I would appreciate the help....
I have read some glue them to the canopy... and some didnt...not too sure what would be best...
but my cockpits are in terrible shape... wonder were that pilot was purchased at...with the blue
flight suit.
09-22-2019, 09:27 PM
#411
Yes the cockpits are of poor quality and the pilots are too small "scale". possibly to keep the weight down. I had to modify the tubs quite a bit to fit it all inside.
The nose gear is extended too high, look at pictures of the original, it is more "kneeling" as the supplied one does, thereby lowering the nose as You can see in ramp pictures.
The result is You need to flare the beast well, when still in the beginning I did not, and it started to bounce resulting in some damage. (Concrete RWY). Part of the problem was I had the CG too far in front, since is corrected, in stages, and now it flares like a *****.
Keep the intake tubes as is, they function well, don't need to reach the front of the engine.
However make a test you have the engine at the right place in FRONT of the thrust tube, the difference in thrust can be enormous. You need to measure the thrust with the engine in a few spots.
Which JetCat engine You have, P160, 180?
Richard
The nose gear is extended too high, look at pictures of the original, it is more "kneeling" as the supplied one does, thereby lowering the nose as You can see in ramp pictures.
The result is You need to flare the beast well, when still in the beginning I did not, and it started to bounce resulting in some damage. (Concrete RWY). Part of the problem was I had the CG too far in front, since is corrected, in stages, and now it flares like a *****.
Keep the intake tubes as is, they function well, don't need to reach the front of the engine.
However make a test you have the engine at the right place in FRONT of the thrust tube, the difference in thrust can be enormous. You need to measure the thrust with the engine in a few spots.
Which JetCat engine You have, P160, 180?
Richard
09-23-2019, 03:22 AM
#412
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Thanks for your inputs... I have the P180 in it ....
I was told from the previous owner that he flew it with the same
motor.. from looking at the pics I see what your talking about
looks like I may have to much air in the nose gear,.... and from my
understanding your saying that because it does It could make it bounce ?
I have rearranged the engine mounting straps were I could get the engine
as far forward as I possibly could to help in the C.G. issue.
I really would like to compare someone elses Xicoy numbers to my own
if someone has that info and wouldnt mind sharing pics of their MB-339 on the
scales... it would help not only me but I am sure alot of others out there for
future builds and maidens....
I was told from the previous owner that he flew it with the same
motor.. from looking at the pics I see what your talking about
looks like I may have to much air in the nose gear,.... and from my
understanding your saying that because it does It could make it bounce ?
I have rearranged the engine mounting straps were I could get the engine
as far forward as I possibly could to help in the C.G. issue.
I really would like to compare someone elses Xicoy numbers to my own
if someone has that info and wouldnt mind sharing pics of their MB-339 on the
scales... it would help not only me but I am sure alot of others out there for
future builds and maidens....
09-23-2019, 07:52 PM
#413
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I worked more on my 339 today after work....
it took many times trial and error to get the front gear at the correct pressure to keep it up
and to be able to rebound with out it being to hard,,, it was worth it cause I dont think I could get
it any better.... Started the P-180 after that... fired up and ran what seemed to good to be true..
sure is very strong for this plane ( so it seems ) ...
I set up the Cortex Demon Pro....that seems to be working great too... so with just a little more
beautifying it will be ready to maiden ( soon )..... I however would like to maiden it with cockpits
finished.. and pilots in... but that might not happen.. I am very anxious to get this bird in the air.
I have a light kit I thought about installing.. that may come later ... If I do that light kit the top of
the rudder has what seems to be a huge red light... would I have to install one that big ?
has any one installed a light kit and would post pictures.. I would like to get an idea what
I should do....
09-23-2019, 09:47 PM
#414
The nose gear isn't Your problem, it is designed wrong, the full unloaded position is much too far straight. I tried it also but one would probably have to figure out some kind of maximum extended stop in order to attain something scale like ground position and I wonder it then You have any upward/backward swinging left.
The P180 is just perfect for the job, if I could I would swap my P160 for a P180 anytime. The 160 is OK, but off wet grass I could do with a little more ummmpfff.
You have probably bought the P180 used, as normally they come with an original JetCat ECU. I don't know if JetCat has a good service center in the US, You might ask what a service costs, including an ECU. In all it is an expensive bird, You have to be sure about the reliability of the engine. It is also a heavy model, so possibly dangerous, I take no shortcuts in safety.
As I live close to Germany, it is less cumbersome to send it in to the factory if I run into some problems.
The demon...I fly it w/o any stabilization, absolutely not necessary, it is a stable bird. But the Demon is a good unit, I use them in two choppers.
The red light on top of the rudder is in full size a rotating beacon (or flashing nowadays), You can buy those in several sizes, as with MANY other modellers in Europe, we install the products of Unilight.at I have chosen my own separate units, however they sell also as sets. But a full blown system would set You off a few hundred euros...Service from them is outstanding, in the past I even got answers to mails during weekends... A good 2S Lipo with minimum 2500 MaH will do..
A few contributions back at number 396's pictures one can see them in bright daylight. I have found that with less than optimum visibility they really enhance one's view on pitch and bank angle. Especially when You can only see a silhouette, not being able to recognize top from under side. A real killer flying jet models. But In good light the difference in discriminating top from under side is tremendous well because of the complete different color scheme.
But I would test fly it w/o too much work, nice to do things, can be done later.
If the CG is about right (too many modellers talk about THE CG, which is not correct, all planes have a CG RANGE), For this jet it can be easily 5-6 cm. You can adjust to Your liking as a result of test flights. As long as You will not be too far aft, nothing serious will happen.
At the backside of the range it will become more sensitive on elevator, too far in front the Elev will become "Heavy" and You will need more Elev in roundout and flare during landing. As I fly many times with my son, he prefers a slightly more aft CG position in our models, I opt mostly for a more conservative front position.
Remember the original can be flown with different tanks, fuel capacity (not all exactly in the CG), and with 1 or 2 pilots. There is not one full size airplane I know of that has ONE CG position, all have a RANGE, to be precise an "envelope".
I note You have only one air bottle installed, I use three, as I always separate the brake system from the gear. Air tubing running to the brake pads is vulnerable to get damaged, depleting the system after T/O as a worst case, right after retracting the gear. For the gear itself I use two bottles coupled together, as it uses quite a bit of air during one full cycle. I would recommend to aim for 5 cycles before the systems starts to gets too slow for comfort. I start at 8 BAR. Mine looses a bit of air during flight, cannot find the leak.
Plus I operate the ventral air brake with an air cylinder as well, which gets air pressure from the brake air system. See it extended upon landing in my 396 contrib. It extends via a mixer when I select full flap, but would I have to make a gear UP landing, I can switch the mixer off and hope for less damage. Great to extend it, the model starts to whistle!
Good luck with the first flight.
Richard
The P180 is just perfect for the job, if I could I would swap my P160 for a P180 anytime. The 160 is OK, but off wet grass I could do with a little more ummmpfff.
You have probably bought the P180 used, as normally they come with an original JetCat ECU. I don't know if JetCat has a good service center in the US, You might ask what a service costs, including an ECU. In all it is an expensive bird, You have to be sure about the reliability of the engine. It is also a heavy model, so possibly dangerous, I take no shortcuts in safety.
As I live close to Germany, it is less cumbersome to send it in to the factory if I run into some problems.
The demon...I fly it w/o any stabilization, absolutely not necessary, it is a stable bird. But the Demon is a good unit, I use them in two choppers.
The red light on top of the rudder is in full size a rotating beacon (or flashing nowadays), You can buy those in several sizes, as with MANY other modellers in Europe, we install the products of Unilight.at I have chosen my own separate units, however they sell also as sets. But a full blown system would set You off a few hundred euros...Service from them is outstanding, in the past I even got answers to mails during weekends... A good 2S Lipo with minimum 2500 MaH will do..
A few contributions back at number 396's pictures one can see them in bright daylight. I have found that with less than optimum visibility they really enhance one's view on pitch and bank angle. Especially when You can only see a silhouette, not being able to recognize top from under side. A real killer flying jet models. But In good light the difference in discriminating top from under side is tremendous well because of the complete different color scheme.
But I would test fly it w/o too much work, nice to do things, can be done later.
If the CG is about right (too many modellers talk about THE CG, which is not correct, all planes have a CG RANGE), For this jet it can be easily 5-6 cm. You can adjust to Your liking as a result of test flights. As long as You will not be too far aft, nothing serious will happen.
At the backside of the range it will become more sensitive on elevator, too far in front the Elev will become "Heavy" and You will need more Elev in roundout and flare during landing. As I fly many times with my son, he prefers a slightly more aft CG position in our models, I opt mostly for a more conservative front position.
Remember the original can be flown with different tanks, fuel capacity (not all exactly in the CG), and with 1 or 2 pilots. There is not one full size airplane I know of that has ONE CG position, all have a RANGE, to be precise an "envelope".
I note You have only one air bottle installed, I use three, as I always separate the brake system from the gear. Air tubing running to the brake pads is vulnerable to get damaged, depleting the system after T/O as a worst case, right after retracting the gear. For the gear itself I use two bottles coupled together, as it uses quite a bit of air during one full cycle. I would recommend to aim for 5 cycles before the systems starts to gets too slow for comfort. I start at 8 BAR. Mine looses a bit of air during flight, cannot find the leak.
Plus I operate the ventral air brake with an air cylinder as well, which gets air pressure from the brake air system. See it extended upon landing in my 396 contrib. It extends via a mixer when I select full flap, but would I have to make a gear UP landing, I can switch the mixer off and hope for less damage. Great to extend it, the model starts to whistle!
Good luck with the first flight.
Richard
09-24-2019, 02:55 PM
#415
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NOSE GEAR
A good buddy of mine came by last night as I was working on the nose gear setup...He's a long time JET Pilot...
and after he looked at the nose gear assembly he made the comment that it could be fixed with a set screw
on the top side were the arm pendelem's you can adjust how the arm travels and were it stops. hhhhhmm
made some since... but I guess it wasnt in the design at the time they made the gear lol.
It took a good while to get the gear sitting were I was happy with it... its not a certain amount of PSI... its the
technique you use to get the Air in the retract... its a hit or miss thing... every ones plane weighs different.
the biggest problem I had was you have to cycle the retracts each time to get to the charge valve
so the plane has to be put together for 2 reasons.. keep the air in the system and to test your work ....
AIR TANK
I used the big Robart tank and your right I only have one.... and it will be used for retracts and brakes,
I didnt hesitate to only use one tank I can get 5 cycles with 125psi and still be able to use my brakes ...I
have the EVO JET PRO Proportional Brake Valve I dont think you can get any better than that for Air...I do
however see your point of the brake line if I were flying from a grass field. I however only fly off Pavement.
CORTEX DEMON PRO
I dont know how many people use the Cortex in the way I use it.... I put it on a 3 way switch 1 position
OFF... 2 position LOW and the 3rd Position MED. Used in different ways depending on what flight mode and
or wind condition's I really like to see a JET track in a straight line on the tarmac and come in without any issues
on a windy day especially a cross wind windy day... you spoke of how expensive these planes are why would
any one not have a Cortex to help in the unknown... the 339 isnt the most expensive JET I own.
I also have a Skymaster 1.3:65 HAWK 100.... so I know expensive lol
P-180
I am the 3rd owner of this motor... the 1st owner only had 2.36 min on it the 2nd owner a Good friend of mine
took it in and the plane on trade he sent the motor in for update and inspection and to change from Propane start
to Kero start... so once I installed it in the 339 and fired it up yesturday it was the first start after the update.
To me it seems as though I have a brand new motor...so I sure am hoping its reliable and I hear ( hope ) is
good.. lol
LIGHTING SYSTEM
If there is a product out there that will give the scale appearance of the lights on the plane I am all for that if someone
knows were these parts are I sure would like to get them.
I have the controllers and lights just need the lenses.
C.G
I went back to the start of this thread and reread every stitch about C.G. for this plane from what I am understanding
everyone says to start on the center of the wing tube....and then others that have flown the plane say go back something
like 2cm from the back of the wing tube.... I am all good with that information I set my 339 up on the Xicoy scales and
worked the measurments and plugged in the numbers and it appears that I am 2 tenths of an oz nose heavy.
I was hoping that some others would have Xicoy numbers and wouldnt mind sharring I take pictures of my Xicoy with
my planes on them and take pictures of the Xicoy screen so that I can retain that info and share at a later date.
I have a file folder on my laptop for each plane I own along with pictures of the build and any updates and ideas.
BEST UP GRADE
I am going to upgrade the front of each wing and add another anti rotation spot that will be a must I think.
A good buddy of mine came by last night as I was working on the nose gear setup...He's a long time JET Pilot...
and after he looked at the nose gear assembly he made the comment that it could be fixed with a set screw
on the top side were the arm pendelem's you can adjust how the arm travels and were it stops. hhhhhmm
made some since... but I guess it wasnt in the design at the time they made the gear lol.
It took a good while to get the gear sitting were I was happy with it... its not a certain amount of PSI... its the
technique you use to get the Air in the retract... its a hit or miss thing... every ones plane weighs different.
the biggest problem I had was you have to cycle the retracts each time to get to the charge valve
so the plane has to be put together for 2 reasons.. keep the air in the system and to test your work ....
AIR TANK
I used the big Robart tank and your right I only have one.... and it will be used for retracts and brakes,
I didnt hesitate to only use one tank I can get 5 cycles with 125psi and still be able to use my brakes ...I
have the EVO JET PRO Proportional Brake Valve I dont think you can get any better than that for Air...I do
however see your point of the brake line if I were flying from a grass field. I however only fly off Pavement.
CORTEX DEMON PRO
I dont know how many people use the Cortex in the way I use it.... I put it on a 3 way switch 1 position
OFF... 2 position LOW and the 3rd Position MED. Used in different ways depending on what flight mode and
or wind condition's I really like to see a JET track in a straight line on the tarmac and come in without any issues
on a windy day especially a cross wind windy day... you spoke of how expensive these planes are why would
any one not have a Cortex to help in the unknown... the 339 isnt the most expensive JET I own.
I also have a Skymaster 1.3:65 HAWK 100.... so I know expensive lol
P-180
I am the 3rd owner of this motor... the 1st owner only had 2.36 min on it the 2nd owner a Good friend of mine
took it in and the plane on trade he sent the motor in for update and inspection and to change from Propane start
to Kero start... so once I installed it in the 339 and fired it up yesturday it was the first start after the update.
To me it seems as though I have a brand new motor...so I sure am hoping its reliable and I hear ( hope ) is
good.. lol
LIGHTING SYSTEM
If there is a product out there that will give the scale appearance of the lights on the plane I am all for that if someone
knows were these parts are I sure would like to get them.
I have the controllers and lights just need the lenses.
C.G
I went back to the start of this thread and reread every stitch about C.G. for this plane from what I am understanding
everyone says to start on the center of the wing tube....and then others that have flown the plane say go back something
like 2cm from the back of the wing tube.... I am all good with that information I set my 339 up on the Xicoy scales and
worked the measurments and plugged in the numbers and it appears that I am 2 tenths of an oz nose heavy.
I was hoping that some others would have Xicoy numbers and wouldnt mind sharring I take pictures of my Xicoy with
my planes on them and take pictures of the Xicoy screen so that I can retain that info and share at a later date.
I have a file folder on my laptop for each plane I own along with pictures of the build and any updates and ideas.
BEST UP GRADE
I am going to upgrade the front of each wing and add another anti rotation spot that will be a must I think.
Last edited by TeamMuir1; 09-24-2019 at 06:34 PM.
09-25-2019, 01:38 AM
#416
Yes I looked at the nose gear a while ago indeed with a set screw in mind, but I still have to figure it out.
I think the design is already too old for Anton (Skymaster) to put any time in a redesign.
I once had a jet where I elected to simplify the air systems and use only one air tank, it was within 5 flights I was rewarded with a belly landing. It was a Pirotti Tuono with wing tanks, Landed on our concrete RWY, with just some scratches on the underside of the tanks.
The Cortex: If You have one around on the shelf already, OK, but really the plane does not need it, flies on rails. Maybe during turbulent conditions on final the effect of the Cortex can be seen, dampening the movements out.
However I always advise to fly a new model w/o any electronic help, then You really know what the basic behavior of the plane is, Anyhow, You can switch it ON during flight which is OK.
I am always careful with those units, I've seen too many wrongly programmed stabilizing ones(like with reversed ailerons).
In order to press the wing against the fuse I installed a screw which exactly does that and thereby presses the air system quick disconnect couplers firmly into each other. So that gives me an extra rotational stop. You are right, when the aft stop will fail, there is no backup and the result would be a dreadful crash.
If You read my previous posting, I did write where You can buy the best lighting system I know of at www.unilight.at
I can PM You the separate part numbers of the individual lights I used.
There is no need to be tenths of an inch to a certain CG, as I stated before, it is not critical at all, after a few flights You might end up 2-3 cms more aft of Your first flight by removing lead from the nose. I did start with a way too much forward position and once I landed hard because of this in one of the first flights. After moving it well backwards it now lands very easy. The only thing I note it still flies with an elevator setting which is well off "0". So in fact the incidence of the stabilizer is wrong, but adjusting that would mean a lot of work. At the moment It is stored for wintertime, so I cannot check whether the ELEV is offset to a down or up position.
Yes, I also document EVERYTHING from any model, keep track of all the bills for that plane, where I flew it, weights, any work I did on them. Keep all the manuals etc together. When I decide to sell a plane, I can discuss the price by showing all bills of all the components that are in. After a few Years one tends to forget how much money sits in a model. Plus the new owner will have all manuals etc all together and he knows all history about the plane and engine.
I think the design is already too old for Anton (Skymaster) to put any time in a redesign.
I once had a jet where I elected to simplify the air systems and use only one air tank, it was within 5 flights I was rewarded with a belly landing. It was a Pirotti Tuono with wing tanks, Landed on our concrete RWY, with just some scratches on the underside of the tanks.
The Cortex: If You have one around on the shelf already, OK, but really the plane does not need it, flies on rails. Maybe during turbulent conditions on final the effect of the Cortex can be seen, dampening the movements out.
However I always advise to fly a new model w/o any electronic help, then You really know what the basic behavior of the plane is, Anyhow, You can switch it ON during flight which is OK.
I am always careful with those units, I've seen too many wrongly programmed stabilizing ones(like with reversed ailerons).
In order to press the wing against the fuse I installed a screw which exactly does that and thereby presses the air system quick disconnect couplers firmly into each other. So that gives me an extra rotational stop. You are right, when the aft stop will fail, there is no backup and the result would be a dreadful crash.
If You read my previous posting, I did write where You can buy the best lighting system I know of at www.unilight.at
I can PM You the separate part numbers of the individual lights I used.
There is no need to be tenths of an inch to a certain CG, as I stated before, it is not critical at all, after a few flights You might end up 2-3 cms more aft of Your first flight by removing lead from the nose. I did start with a way too much forward position and once I landed hard because of this in one of the first flights. After moving it well backwards it now lands very easy. The only thing I note it still flies with an elevator setting which is well off "0". So in fact the incidence of the stabilizer is wrong, but adjusting that would mean a lot of work. At the moment It is stored for wintertime, so I cannot check whether the ELEV is offset to a down or up position.
Yes, I also document EVERYTHING from any model, keep track of all the bills for that plane, where I flew it, weights, any work I did on them. Keep all the manuals etc together. When I decide to sell a plane, I can discuss the price by showing all bills of all the components that are in. After a few Years one tends to forget how much money sits in a model. Plus the new owner will have all manuals etc all together and he knows all history about the plane and engine.
Last edited by richbran; 09-25-2019 at 01:41 AM.
09-25-2019, 04:03 PM
#417
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Richard .
You are so very right on all counts.... its been great having an you as an asset to this thread.....
I have never flown any plane with a gyro were I could NOT turn it off... ( Plain Smart )
I am going to work on the Front Rotation Pin upgrade .... and only thing left would be the
cockpits and Lighting... YES.. please PM me.... I would like to have that info on the lights you
used...
Thanks again
Ron
You are so very right on all counts.... its been great having an you as an asset to this thread.....
I have never flown any plane with a gyro were I could NOT turn it off... ( Plain Smart )
I am going to work on the Front Rotation Pin upgrade .... and only thing left would be the
cockpits and Lighting... YES.. please PM me.... I would like to have that info on the lights you
used...
Thanks again
Ron
09-30-2019, 07:20 PM
#418
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Flew the 339 Sunday.... three flights.... the plane seems nose heavy.... as its turning the plane is falling much
faster than expected.. I didnt do that much with it trimming... and fuel consumption tests.. as well as retracts...
all in all it went well.. the plane does have a hard time slowing down... so I will incorporate some crow...
and take out some nose weight.. and see how that goes....
faster than expected.. I didnt do that much with it trimming... and fuel consumption tests.. as well as retracts...
all in all it went well.. the plane does have a hard time slowing down... so I will incorporate some crow...
and take out some nose weight.. and see how that goes....
10-02-2019, 03:25 AM
#419
Ron, do You have the speed brake activated? It sure helps. Yes I also have some crow programmed in full flaps. Half flaps nothing, only full flaps they pop up about 5 mm. Nothing more as it will get a bit unstable in final in roll. There is an explanation for that behavior.
The nose dropping is nothing more than any other plane will do, in my opinion. But we might have different CG's.
Tailless deltas drop a lot more I have noticed...
The nose dropping is nothing more than any other plane will do, in my opinion. But we might have different CG's.
Tailless deltas drop a lot more I have noticed...
10-06-2019, 07:25 PM
#420
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Rich....Sorry for the long delay in my reply.. I have not been on here .....
I do not have the speed brake cut out to use.
if You think its a must I will work on it... I have had no time to
program Crow Thanks for the info on the amount to use.
We flew it Saturday... and it was not the flight I had hoped for
we had a flame out at throttle excelleration on fly by....
NO DAMAGE at all we were flying at an airport made it back
to land.... but the speed was very fast... she just didn't want to
slow down.
The flame out hasn't been diagnosed yet we left the power
on and connected the GSU .... it told us Power Failure.
The plane had 3 previous flights like I described before with
NO problems. We have an idea as to what it could have been...
before I go into that I will say we tried to start the turbine
again and it would not start... ( any idea's ) ???
I do not have the speed brake cut out to use.
if You think its a must I will work on it... I have had no time to
program Crow Thanks for the info on the amount to use.
We flew it Saturday... and it was not the flight I had hoped for
we had a flame out at throttle excelleration on fly by....
NO DAMAGE at all we were flying at an airport made it back
to land.... but the speed was very fast... she just didn't want to
slow down.
The flame out hasn't been diagnosed yet we left the power
on and connected the GSU .... it told us Power Failure.
The plane had 3 previous flights like I described before with
NO problems. We have an idea as to what it could have been...
before I go into that I will say we tried to start the turbine
again and it would not start... ( any idea's ) ???
Last edited by TeamMuir1; 10-06-2019 at 07:29 PM.
10-07-2019, 04:23 AM
#421
Ron I have a WREN (in another jet) and it exactly did the same, failed a few times during spinup after a prolonged time in idle. I hate that because I need to be sure it will spinup under any condition. It is currently in the UK for an inspection and service. I too fly at an airfield with 2800m at hand, so no need to worry about running out of landing surface... more like running out of eye sight
Maybe better to cut out the speed brake, if I remember correctly, the kit included some hardware, like the speed brake. One would have to make the hinges Yrself, I activate it by air pressure and a "cockpit" air valve, which has a large travel range. Supplied by https://www.modelaviationproducts.co...ion-products/7
They are from Canada, so not too difficult to get for You.
The effect of the speed brake is very well noticeable, it really works.
I noticed the engine You have is quite dirty, maybe send it in and have it serviced. That is the price if You buy 2nd hand... They might ask You to send it in including pump, wiring and valves. Better invest some money or risk the whole plane. Maybe switch to an original JetCat ECU... (not cheap though)
If it doesn't start it won't be too difficult to find the root cause.
Richard
Maybe better to cut out the speed brake, if I remember correctly, the kit included some hardware, like the speed brake. One would have to make the hinges Yrself, I activate it by air pressure and a "cockpit" air valve, which has a large travel range. Supplied by https://www.modelaviationproducts.co...ion-products/7
They are from Canada, so not too difficult to get for You.
The effect of the speed brake is very well noticeable, it really works.
I noticed the engine You have is quite dirty, maybe send it in and have it serviced. That is the price if You buy 2nd hand... They might ask You to send it in including pump, wiring and valves. Better invest some money or risk the whole plane. Maybe switch to an original JetCat ECU... (not cheap though)
If it doesn't start it won't be too difficult to find the root cause.
Richard
10-07-2019, 02:36 PM
#422
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Richard...... The motor came back from service and update... I bought it from a great Jet buddy...
so I know its a good motor... and it was updated for kero start as well.. now remember
I have 3 perfect flights on it... before this flame out.
I will consider cutting out the speed brake... sounds like it would help slowing it down.
OK.. so I will offer up some more news ... I am not too sure if it matters or not but the battery I
used on the ECU was Venom 5400 mah 7.4 volt 2 cell Lipo 20c
We are thinking maybe the battery had something to do with the flame out ???
YES.. I charged it 11:00 pm the night before ... so Im sure it was charged .
or was it ? lol
any ways.. I am curious to know what others use for battery on their JET CAT P-180
so I know its a good motor... and it was updated for kero start as well.. now remember
I have 3 perfect flights on it... before this flame out.
I will consider cutting out the speed brake... sounds like it would help slowing it down.
OK.. so I will offer up some more news ... I am not too sure if it matters or not but the battery I
used on the ECU was Venom 5400 mah 7.4 volt 2 cell Lipo 20c
We are thinking maybe the battery had something to do with the flame out ???
YES.. I charged it 11:00 pm the night before ... so Im sure it was charged .
or was it ? lol
any ways.. I am curious to know what others use for battery on their JET CAT P-180
10-08-2019, 05:49 AM
#423
Ron, The Lipo would be more than enough for the engine, I have a 2S/30C/3600 on my JetCat P160 but that is with the original ECU, so maybe not a good comparison.
Make a test start when it gets a bit darker outside (and If You have forgiving neighbors ) and see if You witness any fire inside the engine, looking from the backside. You should also be able to see an increase of the EGT while monitoring the terminal display.
If it does not light up, it can be the startup fuel is just a little low, or the Kero plug does not heat up enough. Anyway, the reason for not starting should have something to do with the flame out when the engine is already hot.
Also check the fuel pump, there should be a test menu, to see if it runs, but disconnect the fuel line from the engine if You don't want to flood Yr engine and maybe have a hot start next time.
Basically jet engines are simple devices, fire and fuel and they will run.
Be sure to have an extinguisher at hand when starting unwilling engines. But of course You always have. !!
Richard
Make a test start when it gets a bit darker outside (and If You have forgiving neighbors
) and see if You witness any fire inside the engine, looking from the backside. You should also be able to see an increase of the EGT while monitoring the terminal display.If it does not light up, it can be the startup fuel is just a little low, or the Kero plug does not heat up enough. Anyway, the reason for not starting should have something to do with the flame out when the engine is already hot.
Also check the fuel pump, there should be a test menu, to see if it runs, but disconnect the fuel line from the engine if You don't want to flood Yr engine and maybe have a hot start next time.
Basically jet engines are simple devices, fire and fuel and they will run.
Be sure to have an extinguisher at hand when starting unwilling engines. But of course You always have. !!
Richard
10-09-2019, 03:27 AM
#424
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Richard.. I have not had time to work on my 339 I will try later this evening...
We have the last of the year big Jet rally this weekend and from what I have
been told there are already people there ( lol ) its going to be a big one this
year I would assume since there are people already there camping and flying.
The name of our club is Rosewood RC Flyers.
face book is the only location I believe ...
https://www.facebook.com/search/top/...epa=SEARCH_BOX
Take a look around I think you would be surprised ....
I worked on removing some weight before last weekend's flight....I took out
5oz.. of lead and told myself that was too much so I put back in a 6 cell NIMI battery
that weighs in at 6.5 oz
just didnt feel confadent enough to take that much out ... lol I was really
hoping that someone Xicoyed their 339 and we could share some #'s I have my info
were I scaled out mine and am curious if its close to another 339 that is a known good
flying plane.
any way I will keep in touch.. and give some updated.. I am really looking forward to
getting my cockpits installed... did you glue the back cock pit to the canopy ?
We have the last of the year big Jet rally this weekend and from what I have
been told there are already people there ( lol ) its going to be a big one this
year I would assume since there are people already there camping and flying.
The name of our club is Rosewood RC Flyers.
face book is the only location I believe ...
https://www.facebook.com/search/top/...epa=SEARCH_BOX
Take a look around I think you would be surprised ....
I worked on removing some weight before last weekend's flight....I took out
5oz.. of lead and told myself that was too much so I put back in a 6 cell NIMI battery
that weighs in at 6.5 oz
just didnt feel confadent enough to take that much out ... lol I was really
hoping that someone Xicoyed their 339 and we could share some #'s I have my info
were I scaled out mine and am curious if its close to another 339 that is a known good
flying plane.
any way I will keep in touch.. and give some updated.. I am really looking forward to
getting my cockpits installed... did you glue the back cock pit to the canopy ?
10-09-2019, 05:20 AM
#425
I hope Yr cockpit tubs will fit, I see the components on the radio tray sticking up quite high.
When I did a complete reinstall a few Years ago I moved all the "service" points to the engine bay. That is, refueling, radio switch and air pressure.
Just for charging I need to remove the cockpit hood and the tubs.
I did not like to glue the back tub to the cockpit hood. I left the flanges on the tubs, and when installing them they slip UNDER the cockpit flanges of the fuse. I also glued a balsa block on the underside of the back tub so that the tub is pressed upwards against the fuse's cockpit flanges.
Then I tape them fixed with a few strips of black duct tape, hardly noticeable.
But again, I rate the cockpit design as awful. Fitting the front instrument panel was a disaster, as it needs to be removable to be able to work in the front of the fuse. I had to use Velcro to get it done and even removed some parts of the front tub so I could slide it under the instrument panel..
When I did a complete reinstall a few Years ago I moved all the "service" points to the engine bay. That is, refueling, radio switch and air pressure.
Just for charging I need to remove the cockpit hood and the tubs.
I did not like to glue the back tub to the cockpit hood. I left the flanges on the tubs, and when installing them they slip UNDER the cockpit flanges of the fuse. I also glued a balsa block on the underside of the back tub so that the tub is pressed upwards against the fuse's cockpit flanges.
Then I tape them fixed with a few strips of black duct tape, hardly noticeable.
But again, I rate the cockpit design as awful. Fitting the front instrument panel was a disaster, as it needs to be removable to be able to work in the front of the fuse. I had to use Velcro to get it done and even removed some parts of the front tub so I could slide it under the instrument panel..
