Official Freewing 90mm F-104 Starfighter Thread

[Alpha]

Question for you experienced F-104 owners. I keep seeing pictures of the F-104 flying with the speed brakes sucked in. Is this to get more air to the fan, or just poor fitting doors/sloppy linkage? Quick look over the instruction book doesn't address this specifically.

John Bergsmith Hi John, the 90mm F-104's airbrakes were designed to have a dual function. With a unique sprung mechanism, the brakes function as variable volume cheater inlets when the suction requires it so, and only to the extent to which the fan requires additional air. On the ground, full throttle sucks the inlets inward to their full degree. In the air, full throttle sucks the inlets inward to a lesser extent (because in flight at speed the aircraft's scale located intakes are actually contributing to the total requirement).

Whenever the throttle is backed off, the sprung mechanism returns the brakes to flush with the fuselage.

When the speed brakes are deployed outward, a servo drives them outward and keeps them in the position set by the user. In this deployed position, the sprung mechanism is disengaged.

It's one of the simplest yet most sophisticated mechanisms we've deployed to address a model-specific need (additional air at slower airspeed) within the confines of that model's scale outline.

[John Bergsmith]

Thanks Alpha!

[Hardway]

The speed brakes open in to give the fan more airflow. Also, they can open outward to act as speed brakes. You are on the right track!!!

[gooniac33]

I'm thinking about upgrading my f-15 to 8's.. and putting the f-15 inrunner fan in the f-104. It is a heavier EDF... does anyone have any thoughts on that. Would it CG properly? Would it be a good upgrade? I do feel that a lot of the scale EDF Jets or somewhat underpowered. I do like speed😊

You don't have much room for battery and then the motor is at the very rear of the plane which makes it near impossible to add a heavier motor. I tried when I first got mine and there was no way. However now with the new EDF units that come from Freewing the 1650kv outrunner will give it a really good boost. I added the FMS unit to mine which was significantly lighter than stock which helped with balance and its a unit that is happiest at half throttle settings. The plane flies much better with this set up and is able to fly more effortless. I added about 1 min flying time to the plane and its for sure faster than it was stock.

[gooniac33]

Question for you experienced F-104 owners. I keep seeing pictures of the F-104 flying with the speed brakes sucked in. Is this to get more air to the fan, or just poor fitting doors/sloppy linkage? Quick look over the instruction book doesn't address this specifically.

It's pretty cool how they work. The are cheaters for intake when not being used as brakes. Then when you need them they work as airbrakes. Now that I have used a new power system my plane can actually use the airbrakes effectively. With the rearward CG of the stock configuration they make the plane pitch up when deployed....

[gooniac33]

Take a look at my playlist to see how much I have done with this thing over the years...

https://www.youtube.com/playlist?list=PLsFORvKk7TcEPoYCBu0Bpz_8E4SZGZiNR

[flyinhigh042]

I’m becoming more interested in the F-104 ARF PLUS. I have a few questions for you 104 drivers...

1) Would it possible to remove the factory gyro and replace it with my Aura-8? And potential issues there?
2) I already have the Freewing 12-Blade 4068-1835kv fan unit, 130a ESC and 8a BEC. Would this be a good power system for the 104?
3) I have a couple Admiral Carbon 6s 5100’s that work great in my F-15. Are these too big and/or heavy for the 104?

Thanks!

[Beeg]

Any gyro will do. The stock one works great. The biggie is roll. This model has a dutch roll tendency especially when slow on approach.
I've always stuck with the stock powerplant but anything comparable would work.
Battery placement and weight are more sensitive in this model. The 5100 carbons are a lot heavier than a "standard" 5000mAh pack. With a standard 5000mAh most guys do the EvanD mod so they can slide the battery as far aft as possible.

Batteries

https://www.rcgroups.com/forums/showpost.php?p=35754694&postcount=1340

EvanD mod

https://www.rcgroups.com/forums/showpost.php?p=35759649&postcount=1365

[flyinhigh042]

Any gyro will do. The stock one works great. The biggie is roll. This model has a dutch roll tendency especially when slow on approach.
I've always stuck with the stock powerplant but anything comparable would work.
Battery placement and weight are more sensitive in this model. The 5100 carbons are a lot heavier than a "standard" 5000mAh pack. With a standard 5000mAh most guys do the EvanD mod so they can slide the battery as far aft as possible.

Batteries

https://www.rcgroups.com/forums/showpost.php?p=35754694&postcount=1340

EvanD mod
https://www.rcgroups.com/forums/show...postcount=1365

Thanks for the info. I appreciate it. If the factory gyro works well, maybe I should just stick with it. I had a hunch the Carbon 5100’s might be too heavy for CG reasons. I also have four Admiral 6s 5000’s. I imagine they would come back good and hot with the fan unit I would be using...

[DCORSAIR]

Thanks for the info. I appreciate it. If the factory gyro works well, maybe I should just stick with it. I had a hunch the Carbon 5100’s might be too heavy for CG reasons. I also have four Admiral 6s 5000’s. I imagine they would come back good and hot with the fan unit I would be using...

I've had two of the F-104 and they flew great with the stock power plant, little slow getting going but once the gear is up and all that they actually flew really good, you will need a lot of nose weight if you go with the 1835kv, I never did try the 1835kv in mine but I had to add a little lead in the nose as is was with the stock power plant, you can cut into the canopy area and move the battery forward to help but I didn't want to do that, it's a fun one to master and takes time, I think it's the hardest one to land, flying is no problem, it's getting the flaps right and AOA, very little aileron is needed as well, or you will have a drill bit on your hands but once dialed in, it's actually easy to land but can be a handful when your learning its flight envelope. I did get the stock gyro working really good as long as there is only a gentle breeze, to windy and the jet will rock back and forth and I spent many many flights making adjustments and never got it perfect, but it was close to perfect.

[Beeg]

I'll second what DCCORSAIR says about landing. In my opinion, this is definitely a plane you want to try and fly when it's not windy and definitely not gusty as nailing the speed on approach is critical to pulling off a decent landing. Approach and Landing this one takes all your concentration if you want it to end well. I've wrecked two sets of landing gear (not cheap) trying to land in gusty conditions on our (short) 400ft geotex runway. I only take this model out when conditions are almost perfect unless you have a lot of very nice runway to work with. Some guys with LOTS of pavement are OK with windy conditions. This model is not forgiving on landing so screw up more than one or two approachs going around and before you know it you're out of battery.
With this model, on your maiden, get it trimmed as quickly as possible after getting up then start an approach to get the feel incase you need a couple go arounds.

With that said, it's definitely the coolest profile in the sky doing fly-bys and my favorite EDF for looks. It's an adrenaline rush and never look away. It will disappear in the sky with that short wing if you get too far out in the wrong kind of sky!

[flyinhigh042]

Thanks guys! I have always loved the F-104. And have always wanted a decent looking F-104 model. I’m looking for that challenge and adrenaline rush. The main issue I’m seeing now is the weather in my area. We have a 500’ paved runway that is sufficient for my current EDF fleet. But, it’s almost always breezy at the very least here. The “perfect” calm day almost doesn’t seem to exist here. So I’m not sure the 104 will be a good fit. I’ll have to give it more thought. It wouldn’t get flown much if I have to wait for calm conditions to exist.
Thanks again!

[gooniac33]

I’m becoming more interested in the F-104 ARF PLUS. I have a few questions for you 104 drivers...

1) Would it possible to remove the factory gyro and replace it with my Aura-8? And potential issues there?
2) I already have the Freewing 12-Blade 4068-1835kv fan unit, 130a ESC and 8a BEC. Would this be a good power system for the 104?
3) I have a couple Admiral Carbon 6s 5100’s that work great in my F-15. Are these too big and/or heavy for the 104?

Thanks!

I have had the plane for a while and flew it stock for over a year with decent results. It was fast but very unforgiving. The cg with stock units is just a hair before being tail heavy and if you pull too much up elevator at low speeds the plane will most times not recover. Once I switched the fan unit to an FMS 90mm 12 blade which is considerably lighter bit has just a tad more thrust (which actually comes out to a really good increase in over all thrust since its so much lighter) and it shifts the cg further forward! I gained a minute in flight time, gained a lot more performance at cruise settings and am no longer on pins and needles when its time to land. The edf unit is really far aft. Having a lighter unit is a good thing! If you get the kit plus I would for sure recommend getting the FMS unit over the stock. Add in an HRB 6s 50c 6000 pack and you will have a great combo! Its not for the faint of heart though. It is not as easy or relaxing plane to fly!!

[flyinhigh042]

I have had the plane for a while and flew it stock for over a year with decent results. It was fast but very unforgiving. The cg with stock units is just a hair before being tail heavy and if you pull too much up elevator at low speeds the plane will most times not recover. Once I switched the fan unit to an FMS 90mm 12 blade which is considerably lighter bit has just a tad more thrust (which actually comes out to a really good increase in over all thrust since its so much lighter) and it shifts the cg further forward! I gained a minute in flight time, gained a lot more performance at cruise settings and am no longer on pins and needles when its time to land. The edf unit is really far aft. Having a lighter unit is a good thing! If you get the kit plus I would for sure recommend getting the FMS unit over the stock. Add in an HRB 6s 50c 6000 pack and you will have a great combo! Its not for the faint of heart though. It is not as easy or relaxing plane to fly!!

Thanks! Looks like you found a good power system combo for the 104. I’ll look into it.

[Evan D]

The bigger motor will offset the heavier battery, if they fit... the extra power will be nice but the extra weight won’t be. The gyro really is good. As noted the proper flaps on approach is important. More important is careful use of the speed brakes, they are super effective.

[gooniac33]

The bigger motor will offset the heavier battery, if they fit... the extra power will be nice but the extra weight won’t be. The gyro really is good. As noted the proper flaps on approach is important. More important is careful use of the speed brakes, they are super effective.

Yeah with the stock set up the airbrakes can be really scary. Once I got the cg shifted and the weight went down the brakes dont cause any change in attitue but will reallt slow the plane...

[full-send-nation SRQ RC squad]

I just purchased the starfighter and it should be at my front door in two days or so, i'm excited for the challenge. I have a question about electric wheel brakes should I consider putting jp hobby electronic wheel brakes on the 104? My field in Sarasota Florida is 500ft long. What are the main wheels diameter and as well as axle? Thanks guys.

[DCORSAIR]

I just purchased the starfighter and it should be at my front door in two days or so, i'm excited for the challenge. I have a question about electric wheel brakes should I consider putting jp hobby electronic wheel brakes on the 104? My field in Sarasota Florida is 500ft long. What are the main wheels diameter and as well as axle? Thanks guys.

I used 80mm of flaps on mine and it would come in nice and slow, just have to stay in the power a little more, very little flare needed with that much flap....

[Beeg]

I just purchased the starfighter and it should be at my front door in two days or so, i'm excited for the challenge. I have a question about electric wheel brakes should I consider putting jp hobby electronic wheel brakes on the 104? My field in Sarasota Florida is 500ft long. What are the main wheels diameter and as well as axle? Thanks guys.

500ft should be fine without brakes but it'll use most of it. Most times I could get mine stopped in about 300ft without wheel brakes if everything worked out just right.

Go to Motionrc F-104, "Support" tab, and download the manual for parts descriptions..

https://www.motionrc.com/collections/rc-jets/products/freewing-f-104-silver-90mm-edf-jet-pnp#support-tab

Here's the page you want..

[John Bergsmith]

Has anyone installed the 90mm 12-Blade EDF 6S Power System w/ 4068-1835kV in the F-104?