Radio for Mantis

[John Gallagher]

I'm building a Mantis this winter. I have a Flash5x radio. Is it even possible to use this radio with the Mantis? The flaps are one channel, ailerons - two channels, Rudder Elevator - two channels; for a total of five. I have an Electron receiver so I can plug the battery in channel 6.
I've used this radio for my XP-3 DLG with flaperons but don't like the fact then when you reduce the throw of the ailerons to the recommended amount you limit the throw when they are used as flaps.

John

[nuevo]

Depends on what mixes are available. IMO, you require the following mixes:

flap -> elevator for landing

The following mixes would be nice, but you can get by without them, at the cost of less efficiency for a given task, and increased pilot workload:

full span camber - good for thermalling and launching
launch mode - LOTS of full span camber
aileron -> rudder - coordinated turns

Added: I forgot, aileron differential is important to turning efficiency. This means being able to drive two aileron servos.

flight modes - launch, cruise, thermal, land and ability to redefine various mixes depending on flight mode.

Note: you can get by without any of these mixes. I know a guy who could land quite well with none of the above mixes. You have to remember to shove quite a bit of down elevator when pulling flaps. So that's potentially a safety issue, as well as pilot workload during a critical time.

[bjaffee]

I've actually thought about this, as a friend of mine was trying to figure out how to use a 5x with a full house plane. Unfortunately, the 5x has no capacity to do seperate ailerons and flaps...only flaperons. About the only way to do it would be to use a y-harness on the ailerons and put them on channel 1, and put the flaps on a y harness on channel 5...with one of them reversed (using a reversed servo or an onboard servo reverser). In the end, it isn't much better then using a non-computer radio, since you don't even get aileron differential.

Hopefuflly I'm wrong and there's some way to do it that I'm missing, but if you're serious about flying full house planes, I'd suggest getting a new radio.

[Ollie]

To get the full potential out of a full house sailplane like the Mantis you need to be able to put the flap servos on separate channels (for crow), the flap function on the throttle channel and you need trailing edge camber preset on a three position switch (launch, thermal and penetrate). I am not aware of any HiTech transmitter that meets every requirement. Multiplex, Airtronics, JR and Futaba have products that do everthing you might want.

[John Gallagher]

Originally posted by Ollie
I am not aware of any HiTech transmitter that meets every requirement. Multiplex, Airtronics, JR and Futaba have products that do everthing you might want.

My next question was going to be if the Hitec Eclipse would handle it.
The Mantis has only one flap servo (one piece flap on center section of three piece wing), so it's a little different than most full house sailplanes.
The flash5x does do elevator to flaperon mixing, so I was hoping that the Eclipse would do elevator to flap/camber mixing.
What mixing would I be giving up if I went with an Eclipse radio?
I guess I'm hoping that someone out there is using an Eclipse with a Mantis or full house sailplane and could tell me how difficult it is to fly with the Eclipse.

What's the lowest price alternative in the Multiplex, JR, Futaba, Airtronics lines?

John

[nuevo]

For all of the radios, there are many tradeoff's. A few I can think of:

price
compatibility with existing equipment (can this new TX talk to your existing receivers.
available mixes (most will cover the bases)
flight modes
my peave: landing mode not on a switch, but on the flap stick

I hope you take the time to assess your needs, and weigh those against your personal constraints like (cost/budget, brand bias). If all else fails, I recommend using what the guys in your local club use. That way, you can get instant help on the field for a programming issue you don't know how to solve. I am a programmer by trade, so don't have this issue. :D

The Multiplex cockpit might do it. Not sure. If not, the Royal Evo looks promising at ~400 for the TX (very limited availability until Feb). Lots of guys use the JR 8103, Futaba 9C, Airtronics Stylus for these types of sailplanes. Also, radios that are not made any more, but popular with glider pilots are: Airtronics Vision 8SP, JR 388, JR 387, Futaba 7UAF (might have sailplane version). These are the lowest end radios I know of that I see at glider fields a lot. There are higher end radios in each brand for more $$.

The Futaba 9C and 8UAF radios are priced attractive. I personally don't like them, but others are very happy.

Frankly, I don't see much in the way of Hitec radios being used for 5/6 servo sailplanes. I don't have enough experience to comment one way or the other on the Eclipse.

What is neat these days, is many manufacturers make their radio programming manuals available for free online. It takes a lot of time to read and understand. If you are willing to pay this price (time to read and comprehend), you will likely make an informed choice that you will be happy with for a long time.

A few notes:
Airtronics does not make it's manuals online
If you want a Stylus, I highly recommend the GLID card (another $100).
The Royal Evo (and Multiplex 3030/4000) has a completely different paradigm in programming than other Asian radios. I like it a lot, but it is different, and local help might be an issue.
Use the search engine here or RCU and look for questions about a radio you might be interested in. Lots of helpful info to be found.

Hope this helps.

[Ollie]

John,

I found prices for the JR378 ($339), Airtronics RD8000 ($299) and Futaba 9CAF ($359). I think JR will custom configure your system with JR servos and battery pack of your choice. The RD8000 can be set up to be modulation shift compatible with HiTech receivers. The 9CAF has sliders for trailing edge camber which is a very nice feature. Some serious shopping might turn up much better prices than I mentioned above. Also, if you already have a 7 channel receiver, you might be able to just buy a transmitter with more cost savings. It really pays to shop around. I wasn't able to get a handle on Multiplex but they are now owned by HiTech so in a sense HiTech offers full house sailplane radios through their new subsidiary.

[bjaffee]

The primary issue with the Eclipse is a software problem that prevents you from having full trailing edge mixing on a preset switch. You can still control the trailing edge with a knob, i think but there's not a preset you can use.

I know both the Futaba 8U and 9C will allow you to program for a single flap. I think you can get a 9C transmitter by itself for around $250.

[Fast-Forward]

A fellow CRRC'r flies his Mantis with the Flash 5x. He uses flap on ch3 (throttle) and it does NOT mix down elevator. I flew it at a contest once (due to me folding my wing on launch) and it flew very well. In fact, it flew so well that I had to have one.

I purchased a used Mantis with the MH-32 af. I love it!
I use a Futaba 9c and a 8 ch Futaba Recv (My previous radio was teh Flash 5x). for mine. I also have one flap.

I went from flying contests and placing 9th and 10 with my old sailplane (2.5M Searcher) to 5th and 2nd with my new/used Mantis (MH-32). Needless to say, I REALLY LOVE my MANTIS!

Here is how I exactly setup my Mantis:
(from http://home.att.net/~CASA/Mantis/Mantis_page_Constuction_tips.htm)

The recommended CG location is 4-1/4 inches aft of the wing leading edge. The recommended tow hook location is 1/8 forward of the CG. (Note: some folks are flying Mantis with towhook 1/8 behind CG. Quicker rotation but try at your own risk:) The following control throws are what I use. They are probably different from what Tom Kiesling uses and you will probably want to change them to suit your preferences. I only mention them as a starting point for the first flights. The ruddervators move up and down 3/8 inch with full elevator input. The ruddervators also move up and down 3/8 inch with full aileron input (aileron to rudder mixing). The ruddervators move a half inch up and down with full rudder input. The ailerons move 3/8 inch down and 3/4 inch up with aileron input. For launch, the entire trailing edge moves down about 20 or 30 degrees. With the above mentioned CG and tow hook locations the elevator requires a very slight (1/32 inch or so) up deflection for launch. For landing the flap should be able to drop a full 90 degrees with a fair amount of down elevator mix with flap deployment. If you wish to use reflex you will have to sand a slight bevel on the flap leading edge with a sanding block.

http://www.charlesriverrcpictures.org/09_06_03/128_2850.jpg

[nuevo]

Fast-Forward:

Nice looking bird.

What's the picture of in the middle of the wing? Do you have any close-ups?

Is there something on the nose of the plane, too?

[John Gallagher]

Thanks to all who responded, especially to Fast-Forward for all the Mantis setup info. I bought the Luckenbach fuse and the club member who bagged the wing used the Aegea airfoils. This is going to be a huge jump in performance over the old R/E Phrophet I've been flying. I can't wait.

John

[Fast-Forward]

My Mantis has two red eyes on the pod. It's supposed to be a Mantis - Mantis.
Fritz, our club guru, wanted the nose to be reminiscent of a Praying Mantis.

The sticker is of my last girlfriend.......Actually, it's a picture I found from searching for pictures on Google.com - images.
I found the picture and I added the text. It really came out great. I swear it flies better with Miss Mantis on the wing.

[Fast-Forward]

== I bought the Luckenbach fuse and the club member who bagged the wing used the Aegea airfoils. ==

That sounds great. Almost all of our 8-9 CRRC contest flyers have the Luckenbach fuse and Aegea foils. They really like it and it's a fairly inexpensive approach to TD flying. I'm not sure if the setup instructions I posted earlier will be spot on considering they are for the old Mantis (the one that I have). Make sure you use the larger v-tail. It's designed specifically for the Aegea wing. It has a much larger control surface compared to the old Mantis.

Additionally,
here (http://www.charlesriverrcpictures.org/09_14_03.html) are some more pictures you can use for reference. The pictures on the top of the page are from a fellow club member who recently completed his Pretty Aegea Mantis. (Pretty = Lukenbach call fuse Pretty Mantis, Aegea = Mark Drela's wing/tail, Mantis = this is where it all started, Apparently the idea was hatched many years ago on the drive back from the NATS. Thanks Tom Kiesling!)

[aeajr]

I am very close to buying the 9C for RES and full house planes. I will be flying sport, club contest and some Eastern Soaring league flying, but I don't expect to become a touring contest flyer.

The 9C was mentioned a couple of times here. The 9C looks like it can do just about anything. I did pick up this one negative post and was interested in your thoughts.

In looking around, I found this as one of the few negative reports on the 9C. Any opinions on this? Here is the thread for the broader comments:
http://www.copilotconsulting.com/ma....2003/7465.html

Here is what this pilot said. Is this correct? Is he being fussy or would this be a real concern? These are lifted from the pilots comments. He is a serious contest flyer.

"The Futaba 9CA has a butterfly (crow) mix hard-wired
to switch A and three flight mode mixes hard-wired to
switch G.

The 9C's butterfly function on switch A cannot be used
to define a landing mode because its effects are
additive to whatever may have been selected on switch
G flight mode. Anyone who has tried landing like this
will have found the results too unpredictable to be
safe under any pressure.

So try thinking out of the box: maybe I can manage
with 3 flight modes and Start mode could be adapted to
a landing mode? If you try to program a landing mode
into one of the three modes on switch G you find that
these are predefined mixes and will not accept input
from the Throttle/Airbrake stick or another mix which
could define the offset you need in order to be able
to start the butterfly/crow from zero on a slider.
It is therefore not possible to use the available
mixes to mimic butterfly/crow on one of the three
modes on switch G.

I would appreciate the thoughts of the 9C users.

I am trading up from a HItec Prism 7X. I have been flying 2 RES planes and just launched my first 6 servo 3M plane. The Prism has some limitations on what it can do in mixes so that is why I am looking at the 9C.

Appreciate any thoughts.

[Fast-Forward]

I'm really not sure what he means so; I'll give you my experience with the 9CA. I have Crow setup on switch A. Up is inactive and down is active. I could leave it active all the time but, I leave it off (prior to landing) so I can keep the stick centered for rudder usage. Also, I couple my ailerons with my v-tail. This was on the recommendation of the Mantis Page. (http://home.att.net/~CASA/Mantis/Mantis_page_Constuction_tips.htm#RADIO%20PROGRAMMI NG%20AND%20SETUP)

Prior to landing I push the throttle/flap stick down and flip switch A down. I the adjust crow as needed. It's worked for me and the only think others have said is that I reversed the throttle/flap engagement. I guess most people leave the stick up in the disengaged state. Anyways, it works just fine and I haven't had any problems with my 9c. It's really a sweet radio compared to my ol'Flash 5. I really like the ease of programming and existing mixes. I'm not one to flip switches and adjust as I fly. I find that I like to use a launch mix, dropping ailerons and flaps about 10 degrees or so, and the landing or Crow mix for landing. I haven't used the reflex as of yet and I'm not one to adjust camber as I fly. Luckily the Mantis flies great with someone who likes to tweak throughout the flight and those who don't.

Also, I put my flap trim on VR D. I can add a couple of clicks of reflex or add some camber with ease. VR D makes an audible tone when it's centered.

The biggest deciding factor to purchase the 9c was that about 8 guys in my club decided to buy 9c's last year and I was fed up having one channel on the Flash 5. It's fairly inexpensive and I had plenty of help setting it up. My only wish is that it came in a brushed aluminum case vs. the gold color.

[Fast-Forward]

I put my launch and reflex mode on switch G. Towards me is active, centered is inactive, and away from me is reflex. I haven't used the reflex but, as of recently I started to use the launch mode more often. Unfortunately, we typically launch downwind and I've learned to maximize the lift with the launch mode.

What other radios are you considering and how do you use your Prism to engage landing/Crow?

Do you plan on attending the LASS contest next week?

[aeajr]

9C is really the only one I am looking at. I had been leaning to the Eclipse 7, but the 9C reviews have been great. Most of the posts are great! The Eclipse is getting a little old and is limited in many ways.

Can't do crow on the Prism. Can't assign functions so I can't do elevator comp with spoilers on the throttle stick. Nor can I put compenstated flaps on thottle stick. Can't have separate servos for flaps either so I can trim and reverse them from the radio. Had to do all that mechanically.

Only 3 model memories. I have 10 planes.

I bought it used for $65 and it has served me very well as a first radio. Now it is time to move up. Would love to be able to use it as a buddy box if I can. Any thoughts on that with the 9C and the Prism?

[Fast-Forward]

I'd go with the 9CA. I'd be great to find a good deal on it. I bought mine on sale at servocity.com (http://www.servocity.com)

I'm not sure about - Assigning functions so you can add elevator comp with spoilers on the throttle stick. I'm sure you can but, I haven't done it yet. I will soon though. I have a RES plane, Kummerow Searcher, to setup for the CRRC RES contest in July.

It will allow compenstated flaps on thottle stick.

It will let you have separate servos for flaps.

I'm sure the 8 model memory will get you by but, you could get the 16k cam pack and get all 10 of your models in there.

It looks like you can pick up the Trasmitter from Servo City for 289.95.

It comes with:
#FUTJ74
(1) Transmitter
(1) Frequency Flag
(1) Channel Module
(1) 700mah Tx Battery
(1) Tx/Rx Charger
(1) 16K CamPac Module FREE
(1) Neck Strap
(1) Manual

[briandlg]

I wish I had known about that when I first bought my 9c. I bought the whole package from my LHS and paid for a bunch of servos and a receiver that I've never used. :(

[aeajr]

One of the things I like about Servo city is they have almost all their radios available as just the radio. Then they put together custom flight packs at a small discount if you buy them with the radio.

Nice arrangement.

[NickW]

I may have missed it by scanning through the above posts, but another factor to consider if you plan on purchasing a new radio is what do other members of your club own? Theres nothing quite like being able to yell out "Hey which mix is the landing mix" and get three answers to quickly solve your problem.

I flew both the Mantis two meter and three meter for a couple of years off of a JR783, and an 8103. I am a big JR fan. You cant go wrong with any of their trannys. But there are lots of other great choices out there too. I have to say I am not a big fan of the eclipse series of radios. They just arent quite up to the challenge of all the mixes and modes us sailplane folk need.

Anyway, enjoy your Mantis! Im currently selling both of mine, but they are both great airplanes! I know you mentioned you have the single flap version. Make sure it is the single flap, as many of the newer mantis's have dual flaps for more mixing options, and less servo strain. Do be sure and put a strong servo on the single flap! I had a few experiences with mine where I was flying a bit too fast and went to pull flap. And the strain was too much for the flap servo to quite get it down. Of course the down elevator compensation kicks in regardless! Makes for an exciting couple of seconds!

[Bernie Wolfard]

I have a flash 5 and a 9c. The flash 5 simple doesn’t do enough for a full house sailplane even with one flap servo. I did however use the flash five with a Spirit Elite. I put the flap servos on a y harness (same as one flap servo) and cobbled together a landing mode. The pilot workload was too high however to get reliable results from this pilot.

I bought the 9c after careful research and bought at is simple the most bang for the buck. I have however criticized it in prior post for forcing you to put crow on a switch. It is called the Oh Sh*t switch because if you stand around the landing area at any contest the 9c and JR pilots will sooner or latter say Oh Sh*t on landing meaning they forgot to throw the switch which of course blows their landing scores. Another thing about the crow preset setting is that when the switch is set to crow the elevator trim adjusts the amount of elevator compensation to flap throw instead of elevator trim. Figuring this out almost cost me sailplane. If you get a 9c be sure to get Don Edbergs book Getting The Most Out of Futaba’s 8-Channel Radio Control Systems. While writer for the 8u the 9c is just an 8u with dial programming and sliders. You can easily translate the book to the 9c and without it is hard to figure out all this “easy to program” radio can do.

That said, the 9c is still the biggest bang for the buck if you buy it Tx only for < $250.00. If money where no object I would have an Airtronics Stylus with a Glider and Memory card.

Bernie

[aeajr]

That said, the 9c is still the biggest bang for the buck if you buy it Tx only for < $250.00. If money where no object I would have an Airtronics Stylus with a Glider and Memory card.

Bernie

Bernie,

You pegged it perfectly. 9C for $290 Does almost anything I am likely to need. Not perfect but lots better than my Prism 7X.

Airtronics Stylis, glider card+ memory card $500+ Or Evo 8 for $500.

They seem like better dedicated sailplane radios from all reports, but they cost a lot more. Bang for he buck the Futaba 9C seems to be the king.

If I lean anything cool or come up with any neat tricks I will post them.

[aeajr]

Thanks for all you help. I ordered the 9CH from Servo City with my own custom package of receiver (electron 6) and servos (HS-81MGs). Got a good price.

In other threads the sailplane guys recommended the H version. Same SW, mixes and such but the switches are in different positions which they say work better for sailplanes. When a BUNCH of people tell you that, you listen.

Again, thanks for the help.

Clear skies and safe flying!

[bigjohn]

The 9C's butterfly function on switch A cannot be used
to define a landing mode because its effects are
additive to whatever may have been selected on switch
G flight mode. Anyone who has tried landing like this
will have found the results too unpredictable to be
safe under any pressure.


As far as I can tell, this guy was pointing out his own ability to become confused while flying.

It's true, the butterfly function will be added to whatever flight mode you have selected on switch G. So, if you are in normal flight when you go to land, you won't have any problems. I don't get how this results in "butterfly function on switch A cannot be used" unless you are too easily flustered to manage your switches. If you have both launch & landing mode selected at the same time, you will get more flap & less down elevator. So don't do that. What's so hard about remembering that? :rolleyes: :rolleyes:

I only use the G switch for launch mode anyway. I use the VRd slider to manage camber, both positive and negative.

PS- I wish I'd known NickW was selling his Mantis, for what ended up being a heck of a price. I bought Nick's old 2M Orion and was looking to upgrade to a 3M airplane. I believe I'll scratch build an Aegea Mantis unless another deal like Nick's comes along.