Springbok Flyer

Hi guys,

Yes, it will be good if we can get an understanding of minimum required thrust - both on bitumen and on grass. Of course together with weight, flap settings and CG.

I also think SkyMaster needs to get the engine mounting standardised - it is no good having the intake duct not line up with the engine and then not being able to use the full bypass.

Thanks for all the information, Ali, Roland and Geoff - keep it coming. As usual, I will wait for all the R&D (by customers) to be done, before I plunge in and get one.

Cheers,

Jan

DAN AVILLA

My Feedback: (12)

Ali I was wondering how short the plane would be with rear section removed and the nose cone holding area modified as short as possable. You did not seem to have much on it. I have limited space in my trailer being a full time RVer. Thanks Dan Avilla

Alex48

Hi Jan

I think a 180 is plenty, certainly in the UK where we are flying at sea level in ISA conditions. Perhaps if your flying at altitude or very hot conditions or worse both more power would be good but then your putting more weight in it. BVM have flown theirs with the standard set up and love it. Ali, Roland and Geoff have flown with the mod and love it, I think its testament to the model that it can fly well with such varying setups. Either appears to be stable and safe. I'd buy one without hesitation and I'm not a dealer, distributer or have any or commercial interest in Skymaster. The model is not perfect but I've not yet built a model that is.

Springbok Flyer

Alex,

This is an interesting thought - which leads to the obvious; if you did not use the nose cone for anything, and mounted all you currently have in there, under the cockpit/engine hatch - will it help with the CG?

Jan

JackD

My Feedback: (4)

Hey Dan,

Dustin did a build thread in his site (rcjetaddiction). he posted this information there.
I gets smaller, but not a lot smaller. Like in your F100, it is pretty close to the tail

sooo... is it a F86 or a f104...

Later
Jack

DAN AVILLA

My Feedback: (12)

Ya Jack I have had my same 3 for many years and kind of getting tired of them . Looking for something new. Take care Dan

Alex48

Hi Jan

Yes if I'm honest it was probably a mistake putting the PB in the nose however I think Geoff did put his two batteries in there so the weight was probably the same. The FEJ lighting box is large and relatively heavy this is mounted just forward of the cockpit. I have two more booked into build and these will have all the equipment under the cockpit hatch. You could probably get away with having nothing in the nose. This would make the aircraft shorter, with no nose and no woodwork in the nose with the tail off I could stand it upright without it hitting the ceiling. The odd thing is our CG was forward of Rolands suggestion but it did appear to be well balanced in flight, again it seems to be very tolerant of vastly different set ups. Our forward CG may also have helped how the model presented in the air, I have the feeling the further back we put it the more we'll need the gyro.

Geoff White

Alex is right, I have the two 3900 Lipos in the nose. The only other components in the nose are the three servos and valves to operate the UC/Doors. I originally also had a 4000 Lipo for the ecu as well but this was moved because of CG issues. All the other equipment(RX's, PB Competition, Igyro) are on a board which is just behind the cockpit. During the install I paid attention to the comment in the manual regarding making sure everything is forward so the CG isn't rearward, hence everything being at the front. Turns out this may have been a mistake.

When I checked the CG, originally I was 20mm in front of Rolands recommendation and I was getting close to 20Kg(A uk limit) rather than add weight to the rear, I moved the ECU Lipo from the front to just behind the Turbine. This moved the CG back 15mm so I was only 5mm in front of Rolands position. I flew it in this position and it felt about right for me but I am going to experiment moving it to see if there is any improvement.

The slight problem I have is that I am using Lipos that are twice the size of Alex's so they are heavier and to get the CG in the right place I haven't installed the ejector seat and a pilot. Once I am happy with the CG I am going to swap the 3900 Lipos for smaller ones as per Alex and I think that will free up some weight to put the pilot in. I am also happy to use smaller Lipos on the Rx's as I have recharged the batteries and can see that each flight is taking approx 300Mah out of each battery so 2100/2500's should be plenty.

I am really looking forward to trying it again this weekend but looking at the forecast its not looking promising.

EDIT: Pics of the install are on post 245 on this page - http://www.rcuniverse.com/forum/m_90...page_10/tm.htm

Alex48

I forgot to mention that when I weighed Al's it hovered just under 19kg I wouldn't be worried about going over 20kg with yours.

F104Germany

Hello Alicongratulation for the first flightI hope you're excited about this F-104Please test my flaps and slats positions and you'll be amazed (slats 11 and 18 mm / flaps 45 and 90mm / 6 mm Elevator+ (back)with the k 180 turbine go 11.5 cm or 12 cm CG with empty fuel tankI've tested in the first F 104 5 thrustline Position I found the 2 degree position (the same as original) the best Less is not good (0 or 1 degree + F104 flys not good , fuselage have no boat effekt)you must found for your turbine the right CG it was little diverent (thrust 16 to 25 kg)It was a dream Plane with excelente flying datesI hope you understand meContinued good flights and hope we can fly on Jetpower togetherrgRoland

F104Germany

Sorry my Computer works not better

F104Germany

Hi,on Elevator i have no much Expo max. 15-20 %

Springbok Flyer

Roland,

Do you think 17kgs thrust is enough for this jet?

Thank you,

Jan

Alex48

In the UK I'd say yes, but if your flying at hot and high airfields I'd use something bigger, at least a 180.

F104Germany

Hi Jan as Alex wrote a turbine would be better than 18 kg+. Please take the measurements for Slats and flaps on the fuselage.That is what i wanted to say. rg Roland

jetpilot

My Feedback: (48)

[/quote]

Hey Dan,

Dustin did a build thread in his site

Later
Jack
[/quote]

Build thread? I think it was a Mention thread!
Scott

snobird

My Feedback: (36)

You got that right Scott

Ali

My Feedback: (5)

Two more flights today, this time powered by a Kingtech 180, and this time with quite a strong wind. Still no I gyro gained dialled in. I cant believe how well this plane copes. Out of the 4 planes that took off the 104 was by far the most solid and easiest to land today. ( The others were a Der jet Cougar, a Carf Hawk and Jet Legend F-16 ) go figure! The King tech behaved itself and worked like all my other Kingtechs ( Flawless ) I cant see me changing turbines anytime soon.... well thats is of course unless a Kintech 200 were to come along
I am sure I will get some photos of todays fun soon... Who knows< I might even get round to dialling in the I gyro next time.
Regards Al

Dave Wilshere

Ali


104 looked locked and groovy today, any landing would be better than the Cougar slam dunk, but it did seem to land sweet in rough conditions

Dave

Springbok Flyer

Ali,

What did you do with the CG, do you still have the 300g in the tail one?

Cheers,

Jan

Ali

My Feedback: (5)

Yes I do and now the ecu pack is back on the turbine rails

Springbok Flyer

Ali,

Any idea where the CG is now - measured at wing root from leading edge?

Are you starting to form any opinion about the thrust line debate - moving the turbine up 40mm or leaving it std on the rails? I see Justin, over on his site, seems happy with the standard position. Roland seem to think that when you go to the bigger engines, that the 40 mm modification is required. Of course then a bypass will not line up with the inlet ducting (should you want to fit one).

Finally, what are your thoughts using a 17 kg turbine - (I am very close to Gratton where you recently flew at the invitational)?

Thanks,

Jan

Ali

My Feedback: (5)

sorry, no measurements on the centre of gravity.
No idea on the trust line debate as I have only ever flown with the raised position. I just cant see how the standard factory position will work as well as the angle is so extreme. Right now all I know is that I have a plane that is locked in on the pitch aspect no matter what the throttle.
Regards turbine. There was a noticeable change in performance when I took the 190 Kaiman out and pit the 10 Kingtech. Not that the KT is underpowered, but personally a 180 is the least I would want to be flying this model on, especially if altitude/ heat are factors.
Regards Al

F104Germany

Hi Jan,I flew at the beginning with a 17kg turbine that goes. (JetPower Video17 kg thrust - 15-20 degree)But it's nice when you have more powerThe std thrust line we flew (user construktion-the SM 1:5 the same) in the F 104 -1:6,5 small but there was thewing load higher. I fly now 15 years, many F 104s over 500 flights . I think so I can say that the 2 degree thrust line better. rg Roland

F104Germany

Hi ,here Pictures from my first F 104 (17 Years back) and avonds with mod. wing Profil, 1 Krumpp F 104 with user new wing Profil, and the 1:6,5 with slats and mod wing Profil (same as 1:5 SM) rg Roland