Official Freewing Twin 80mm F-14D Tomcat Thread

[dk91105]

Since you have the stock BEC, why don't you measure its actual output voltage yourself?

Sold it, the fans, and the esc as soon as I pulled them all.

[Evan D]

First, when you say "Looking at the specs of the replacement servos I see they are capable of running at 3 different voltage ranges." that is not true. They spec the output torque and speed at those three voltages. That does not mean they won't or can't (or can and will) work outside of those specific voltages. Most of these items have a specific voltage they work best at. Too low and they have to work hard to move what you want to move, too high and they may burn up with the load you are applying. Always a trade off.


The wing sweep servos are not really servos, they are repurposed retract units. They run on a max 5.5V spec. That said a few have run them at 6V and they have reported to survive.

There is a way to have separate voltages for groups of electronics. A picture is worth a thousand words on this one and, I'm sorry to say I don't have one.

"I can find no voltage input info on the wing sweep servos and someone who has one of these planes stated to me that 6v will burn them out. They didn't offer any more info than that. Can anyone provide some additional insight to this?

Second, I want to run any and all of my replacement servos at a higher voltage for the performance increase. How can I seperate those servos from the rest. I do not want to burn out the stocks that remain."

[dk91105]

First, when you say "Looking at the specs of the replacement servos I see they are capable of running at 3 different voltage ranges." that is not true. They spec the output torque and speed at those three voltages. That does not mean they won't or can't (or can and will) work outside of those specific voltages. Most of these items have a specific voltage they work best at. Too low and they have to work hard to move what you want to move, too high and they may burn up with the load you are applying. Always a trade off.


The wing sweep servos are not really servos, they are repurposed retract units. They run on a max 5.5V spec. That said a few have run them at 6V and they have reported to survive.

There is a way to have separate voltages for groups of electronics. A picture is worth a thousand words on this one and, I'm sorry to say I don't have one.

"I can find no voltage input info on the wing sweep servos and someone who has one of these planes stated to me that 6v will burn them out. They didn't offer any more info than that. Can anyone provide some additional insight to this?

Second, I want to run any and all of my replacement servos at a higher voltage for the performance increase. How can I seperate those servos from the rest. I do not want to burn out the stocks that remain."

Thanks, I'll do some more poking around on that.

[nuts-n-volts]

Note the disconnected positive wire going from the BEC to the RX. This will let you run 8.4V (2sLiPo) servos to all controls and 5.0-5.5V (whatever you want to program) from the BEC. The reason for the double connectors coming from the Battery is because the ports in the Rx can only handle 5A each. Like Evan and Kallend have said, the wing servos are basically converted retracts and Freewing has them maxed at 5.5V. You must run them at no more than 5.5V.

[dk91105]

Note the disconnected positive wire going from the BEC to the RX. This will let you run 8.4V (2sLiPo) servos to all controls and 5.0-5.5V (whatever you want to program) from the BEC. The reason for the double connectors coming from the Battery is because the ports in the Rx can only handle 5A each. Like Evan and Kallend have said, the wing servos are basically converted retracts and Freewing has them maxed at 5.5V. You must run them at no more than 5.5V.

Thank you for this explanation and diagram. This will solve the part of my quest for sure. The other part, I am not necessarily wanting to replace ALL the servos. The flap, steering, even aileron servos I believe will be left stock. Is there a way to feed 8.4v to the replacement servos and keep 5.5 - 6v volts to the remaining stock servos? Is it basically the same principle as outlined above? Just feed the positive wire from the BEC that is outputting 5.5v to the servo extension leads that are going to stock servos and pulling the + lead before it gets to the RX?

[Evan D]

Yes exactly. BUT... you may want to swap it around and have the receiver at 5V if you only have a couple at HV.

[kallend]

Thank you for this explanation and diagram. This will solve the part of my quest for sure. The other part, I am not necessarily wanting to replace ALL the servos. The flap, steering, even aileron servos I believe will be left stock. Is there a way to feed 8.4v to the replacement servos and keep 5.5 - 6v volts to the remaining stock servos? Is it basically the same principle as outlined above? Just feed the positive wire from the BEC that is outputting 5.5v to the servo extension leads that are going to stock servos and pulling the + lead before it gets to the RX?

Why are you doing this? I am not aware of others finding a need to run servos at higher voltage in this model. Seems to me that you are just creating problems for yourself for no particularly good reason.

Anyhow, be careful. Running two different voltage power sources can lead to safety issues if not done right.

[BigNug]

Aros...you might have had it nose heavy. Im definately behind the recomended cg mark. I dont think ive ever had this one bounce on me. But...i shortened the nose and main gear springs on mine to make them softer and the model sits lower. It does take a number of flights to really dial in the mixes..but once you do your rewarded woth a awesome flying model. I always felt my f14s were exteemely easy to land all things consodered. I hope you decide to get another!

Been reading through this thread as I need to make multiple mods after some landing gear mishaps, and one bucking bronco landing.

Corsair Nut: How much did you shorten the springs?

Everyone else: has anyone else done this as well?

Thanks in advance!

[rifleman_btx]

Here's another flight in fpv half wings forward half wings swept. Was having issue with my head tracker.

[BigNug]

Here is my nose gear mount reinforcement plate I used. Carbon fiber as well

@rifleman_btx What did you use to connect from the retracts to the top CF plate? I saw a video where someone used 4-40 threaded rod. Curious what you used.

[BigNug]

I did some double plate cf to reinforce the mains, I'm doing grass ops, so figured this would be a must. The first plate sits on top of the plastic gear mount and is glued in place, the second was just to flush everything up even.

@rifleman_btx what type of glue did you use?

Thanks in advance!

[rifleman_btx]

I used jb weld plastiweld, got it from the autoparts store

[rifleman_btx]

For the screws what I did was find some screws that would reach through, and they were 4-40, and secured them in with a washer and a split washer over the flat washer, secured with a nut.

[BigNug]

Thanks Rifleman!

[rifleman_btx]

He was so excited to catch the wing transition Lol all I heard was "oh now thats bad *ss"

[Gravythe clown]

Yep he’s correct, that’s bad ass.

im still waiting on this weather to settle down so I can actually fly something. In the past 7 months I’ve only be able to fly maybe 5 times. I need to get some flights in to get back in the groove before I maiden my rebuild F-14.

Gravy

[rifleman_btx]

Definitely, get as comfortable as you can before taking this thing up if you added alot of weight, mine flys different when I run the fpv system it adds a decent amount of weight up front

[rcSpanky]

Does anyone know for sure if I can use the power system from a Freewing Twin 80mm A-10 in the Tomcat? They are 9 blade fans vs the 12. Will I have more power? Less Power? Are they compatible with the air frame etc.etc..

Help appreciated.

[xviper]

Blade count isn't everything. You need to look at KV and whether they are inrunners or outrunners.
Actually, this information is quite easy to research and confirm. MotionRC does not list static thrust for the stock F-14 fan, so go to RC Castle and look up the stock fans for the A-10 and the ones for the F-14. You can't even buy a stock replacement fan at RCC for the F-14, only an upgrade. They also list the static thrust of all their fans. You can also see the dimensions of their fans. The stock fan for the A-10 - static thrust of 2.9kg. They no longer sell the stock fan for the F-14, so no numbers for it, but they are lower kv 12-blade outrunners and I'm guessing they don't produce as much static thrust as their equivalent higher KV 12-blade inrunners or even the 9-bl inrunners.
The stock A-10 outrunner fans - static thrust 2.9kg, so yes, they will likely be more powerful than the stock F-14 12-blade outrunners. (Much different KVs.)

The upgrade fans for both the A-10 and the F-14 are the same: (9-blade inrunners)
https://www.rc-castle.com/index.php?...roduct_id=8801
Static thrust - 3.0 - 3.1kg each. These will be your biggest bang for the buck.

However, for a few bucks more, since you want 12-bladers, consider a pair of these:
https://www.rc-castle.com/index.php?...roduct_id=7861
12-blade fans, 3.1 - 3.2kg static thrust.

Now, if you really want even more thrust and if you trust the numbers, look at the FMS 80mm fans. Their most powerful boasts static thrust of 3.4kg but you'll have to do some foam cutting as they are slightly bigger diameter cans than Freewing.

You can go to RC Castle and run the numbers for yourself.

[dk91105]

Now, if you really want even more thrust and if you trust the numbers, look at the FMS 80mm fans. Their most powerful boasts static thrust of 3.4kg but you'll have to do some foam cutting as they are slightly bigger diameter cans than Freewing.

You can go to RC Castle and run the numbers for yourself.

The 80mm fans from the FMS v3 futura is what I'm putting in mine. Interestingly the fuselage only required very minor trimming but the covers required quite a bit.