Go Back  R/C Tech Forums > General Forums > Radio and Electronics
FLYSKY GT3b Transmitter >

FLYSKY GT3b Transmitter

Like Tree1Likes

FLYSKY GT3b Transmitter

Old 05-26-2011, 12:09 PM
  #1531  
Tech Master
iTrader: (138)
 
reptile's Avatar
 
Join Date: Dec 2010
Posts: 1,492
Trader Rating: 138 (100%+)
Default

Originally Posted by J.Pietsch
I'm not talking the response rate from the radio to the rx, I'm talking how fast the servo moves. My servo is more than plenty fast, one of the fastest on the market, I'd like to slow it down. I believe on Spektrums they call this a "frame rate" which can say slow it from .06 to say .09 or something along those lines, know what I mean?
I know what you are speaking of as my KO PROPO radios have this option it's called steering speed you can make the speed of the servo slower in both directions or slower one way out and faster to come back in or oposit if you chose so.
That what you mean?
reptile is offline  
Old 05-26-2011, 12:26 PM
  #1532  
Tech Adept
iTrader: (50)
 
Mundy1's Avatar
 
Join Date: Mar 2011
Location: Mid-Michigan
Posts: 245
Trader Rating: 50 (100%+)
Default

A little more food for thought on speed.
My Tekin rs speed controls, all 3 of them flash the lights that mean loss of radio signal when used with this radio.
I spoke with Tekin and they said this radio has a slow freq hop and the speed control is catching the slow hop and registering it as lost signal.
Everything works just fine and uniterupted .
Mundy1 is offline  
Old 05-26-2011, 12:31 PM
  #1533  
Tech Regular
 
losikid67's Avatar
 
Join Date: Apr 2010
Posts: 368
Default

So its not in a million different places, heres the functions of a rock crawler that we use aux channels for

Dig-Locking on axle or the other to achieve tighter turning, and sucks down the suspension

4WS- 4 wheel steering, to be able to make the front and rear tires turn.

Lighting-turn lights on and off

Multi speed trannies-Change gears to get different ratios

winch-to use a winch, in, lock, out

And more- There really is a ton of stuff out there.

Now for how each one of these works.

Dig-So there are 5 ways to obtain dig on a crawler. The oldest one in the book is a mechanical dig. Which is simple disconnecting the outputs in a tranny and sometimes into a slot to lock them. This is done with a servo. trim, EPA's and 3 positions is required on the aux channel. The next way is more/less a homebrew way for a MOA (motor on axle) crawler. This uses two lever switches and a servo. What the lever switches do is short out a motor so it'll lock up. 3 positions are required and epa's would be nice. The next way which is just a modern version of the lever switches is a Punkdig (mentioned a few posts aboved) the punk dig does the same thing as the two lever switches, except it uses relays controlled by a rx to do the switching. 3 postions are required for this. Now there are two more ways which envolves two esc's. The first way uses a wantAmix which i build and sell (www.overkillrc.com). The wantAmix requires a 3 position switch for dig functions, and linear control for bias mixing. The wAm is an adapter that plugs into and rx for the throttle and aux channel. It will then mix thos two channels for dual esc's how ever the aux channel tells it too. The last method uses radio mixing...please see below for mixing

4WS-4ws is popular with super crawlers and just bashers. Some people like Front only, crab, mix, rear only. Crab is where the wheels turn the same way, it so the crawlers tracks diagonally while still facing forward, and mix is like what monster trucks do, so the can turn sharper (wheels turn opposition directions). This requires mixing or a 4ws computer, see below for mxing. Now the other method which pro drivers use is just to have full independent control of each, so the aux channel would have to be linear.

Everything else uses a 3 position switch and usually needs trim and epa's.

Ok so basic aux channel functions should be
3 postion switch
EPA's
Trim

Now for more advance stuff, linear and mixing.

Mixing- There are two things we use mixing for. Dual ESC's and 4ws.

Dual ESC's. So for dual esc's the ideal setup would be to have a 3 position switch for basic dig functions. This switch will need to act like this

Pos 1-Ch2 controlled by trigger, Ch3 is at neutral
Pos 2-Ch2 and Ch3 are both evenly controlled by the trigger
Pos 3-Ch3 is controlled by the trigger, Ch2 is at neutral

Now there needs to be something to bias that mix, or adjust the mix rate. This can be achieved with a momentary 3 pos switch, two momentary butons, or a rotary switch/encoder, a pot could be used as well. Now what needs to happen is each click of some sort will adjust the mix rate, by a pre set step rate. So one click up will decrease ch3 by 10 percent of where the trigger is. Another click up will decrease the rear again by 10 percent, for a total of 20%. and visa versa a click down will decrease ch 2 once ch 3 has obtained 100% mix. A nice option to have is so if you change directions or push a different button it will even out the mix. This is just a preference though.


Now for 4ws, i explained kind how it'll be mixed above (front, crab, mix, rear) This could be achieved a number of ways, one button to cycle through would work. Some people may like bias steering as well, but they could just use the dual esc features.

Linear-Now linear control can be done a number of ways, easiest would just be installing a pot to the ch 3 A/D encoder. How ever the best way to implement this is again with a 3 pos switch and a step rate. So each click will increase or decrease the ch 10%


This is all i have time for now, if something doesn't make sense lmk and i'll fix it. i'll also revise and edit when i get back home, i'll let ya'll know if i change anything
losikid67 is offline  
Old 05-26-2011, 01:15 PM
  #1534  
psx
Tech Adept
 
Join Date: Mar 2011
Posts: 204
Default

Originally Posted by bugman72
In essence, what we crawlers are looking for with regards to channel 3 is a left-center-right output to control a servo, basically like either of the other two channels, just not necessarily proportional. Proportional would be the best-case scenario, but I'm not sure if it would be possible.
I am working on something as this (3 or more steps). Proportional can be done with some mixing or modifying radio (potentiometer instead of CH3 button).

I also wanted to mention that I flashed my radio with PSX's new setup. WOW, there are a LOT of added features with this new flash. I'm not sure if anyone else had this occur, but I DID have to go in and calibrate the battery even though the manual file stated that it shouldn't be needed. When I turned on the radio after flashing, the battery voltage was showing .3V.
I don't know why this wasn't set to defaults, but You can use global-reset to set it to defaults. But if it was after first flashing, it can be because of radio started after flashing, but was very soon stopped by flash-verify process and this gets it to inconsistent state. I will try to change some order of writing to EEPROM and we will see if it will help.
psx is offline  
Old 05-26-2011, 01:19 PM
  #1535  
psx
Tech Adept
 
Join Date: Mar 2011
Posts: 204
Default

Originally Posted by J.Pietsch
I'm not talking the response rate from the radio to the rx, I'm talking how fast the servo moves. My servo is more than plenty fast, one of the fastest on the market, I'd like to slow it down. I believe on Spektrums they call this a "frame rate" which can say slow it from .06 to say .09 or something along those lines, know what I mean?
I already wrote this to TODO list before. What I found in other manuals I putted to TODO list as possible functions
psx is offline  
Old 05-26-2011, 01:30 PM
  #1536  
Tech Adept
 
Join Date: Feb 2011
Posts: 147
Default



thats all that needs be said...
FireFrenzy is offline  
Old 05-26-2011, 02:04 PM
  #1537  
psx
Tech Adept
 
Join Date: Mar 2011
Posts: 204
Default

Originally Posted by losikid67
So its not in a million different places, heres the functions of a rock crawler that we use aux channels for
It was a long post, I think I understand it and put it whole to TODO file

What will be done first are those 3 (or more) position switches, which will be operated with 2 buttons of one trim.
And it is also possible to use those buttons long-press (when not using autrepeat) to some special functions (reset value to center, or set it to side, ...).
psx is offline  
Old 05-26-2011, 02:47 PM
  #1538  
305
Tech Adept
 
305's Avatar
 
Join Date: Apr 2011
Location: Czech Republic
Posts: 109
Default

Originally Posted by reptile
Just a quick heads up on the flysky 2.4 technoligy. It's much slower response than spektrum and ko propo 2.4 Read how i found out. I have the flysky 2.4 ...
My head sometimes don't take it. Kopropo Ex-1UR = 220,- USD, GT3B = 28,- USD. What do ya expect? Do you really think that putting any 2,4G module to Kopropo makes a miracle and let it act like the original?
To make faster "response" times - in fact, we are talking about frame rate - possible you need the tx module and rx "paired". To make GT3B working with faster frame rate times you must also reconstruct the firmware of the receiver - and this could be much more tricky than with the tx.
Please, the GT3B WILL NEWER be like the much expensive radios. It is ideal for bashers, start or occasional racers and everywhere, where the "response" is no mantra ... in fact, I know a number of onroad racers, who can beat the shit out of you on track with a standard radio - it's not in the "response", it's in their hands.

Last edited by 305; 05-26-2011 at 03:44 PM.
305 is offline  
Old 05-26-2011, 03:03 PM
  #1539  
305
Tech Adept
 
305's Avatar
 
Join Date: Apr 2011
Location: Czech Republic
Posts: 109
Default

Originally Posted by beeferman
I read what I could find about this and it seems the 2.4 GHz of these radios uses something called GFSK technology. Not DSM or FHSS. GFSK is the same technology used in Blue Tooth applications. I think it is easy to implement, therefore making things cheaper, but has some limitations.
You are mixing terms. GFSK is a type of signal modulation (quite advanced), FHSS is a spread spectrum technology used to distribute the modulated signal. The Flysky tx and rx both use the same transciever chip called A7105. Yes, it's cheap, if you buy 5000pcs, you'll get it for 1,- USD/pc. . If looking at it's datasheet and having on mind the high frame rates, I think there are no limitations to build a "fast response" system with it. It's capable of 500kbps data speed.

Last edited by 305; 05-26-2011 at 03:46 PM.
305 is offline  
Old 05-26-2011, 03:03 PM
  #1540  
305
Tech Adept
 
305's Avatar
 
Join Date: Apr 2011
Location: Czech Republic
Posts: 109
Default

Originally Posted by Mundy1
A little more food for thought on speed.
My Tekin rs speed controls, all 3 of them flash the lights that mean loss of radio signal when used with this radio. I spoke with Tekin and they said this radio has a slow freq hop and the speed control is catching the slow hop and registering it as lost signal. Everything works just fine and uniterupted .
Quite interesting. Suppose you talked to some salesman, but not a technician. Really do not understand, what does the freq hop has to do with a "loss of signal" in the ESC connected to a rx. I've tried the GT3B with four brands of ESC (Tamiya, DSYS, Graupner, Robitronic) and all worked well.
305 is offline  
Old 05-26-2011, 03:04 PM
  #1541  
305
Tech Adept
 
305's Avatar
 
Join Date: Apr 2011
Location: Czech Republic
Posts: 109
Default

Originally Posted by psx
I already wrote this to TODO list before. What I found in other manuals I putted to TODO list as possible functions
WOW! That must be a LOOOONG TODO list! Seems like you're gonna be quite busy for next couple of years!

Last edited by 305; 05-26-2011 at 03:43 PM.
305 is offline  
Old 05-26-2011, 03:47 PM
  #1542  
Tech Elite
iTrader: (61)
 
Join Date: Dec 2009
Location: Warsaw Indiana
Posts: 2,454
Trader Rating: 61 (94%+)
Default

Guys i got a few qustions. First how hard is this raido to upgrade? im good with soldering and so on. 2nd. will the raido handel lipo right out of the box? i know i will have to put a plug on it. thats no issue. I have been wanting one of these raidos for awile. the price of the recevers are a huge plus for me.

thanks for your time
tcb22185 is offline  
Old 05-26-2011, 03:55 PM
  #1543  
Tech Master
iTrader: (138)
 
reptile's Avatar
 
Join Date: Dec 2010
Posts: 1,492
Trader Rating: 138 (100%+)
Default

Originally Posted by 305
My head sometimes don't take it. Kopropo Ex-1UR = 220,- USD, GT3B = 28,- USD. What do ya expect? Do you really think that putting any 2,4G module to Kopropo makes a miracle and let it act like the original?
To make faster "response" times - in fact, we are talking about frame rate - possible you need the tx module and rx "paired". To make GT3B working with faster frame rate times you must also reconstruct the firmware of the receiver - and this could be much more tricky than with the tx.
Please, the GT3B WILL NEWER be like the much expensive radios. It is ideal for bashers, start or occasional racers and everywhere, where the "response" is no mantra ... in fact, I know a number of onroad racers, who can beat the shit out of you on track with a standard radio - it's not in the "response", it's in their hands.
I am not saying it will be as fast as a better radio I am just stating here because i seen alot of guy's asking about the flyskys 2.4 speed and i just now found out it is a slower response speed than the big name radios for sure.

Theres nothing wrong with the flysky it is what it is... if you want all out response speed go with the big names.

Flysky it's a great radio for the $$ and even better with PSX working it up to perfection!!

I don't mine it's slower than what i used to have because i don't race and for all the $$ saved it's worth it for sure especially if you have alot of RC's like i have.
reptile is offline  
Old 05-26-2011, 04:00 PM
  #1544  
Tech Addict
iTrader: (11)
 
TIZAO's Avatar
 
Join Date: May 2011
Location: Tacoma WA
Posts: 744
Trader Rating: 11 (100%+)
Default

Well just ordered mine!.... lets see how long it takes to get here! LOL!
TIZAO is offline  
Old 05-26-2011, 06:22 PM
  #1545  
Tech Master
iTrader: (34)
 
j_blaze14's Avatar
 
Join Date: Feb 2008
Location: Tampa, Fl
Posts: 1,692
Trader Rating: 34 (100%+)
Default

slow? compared to my helios i sold a few months back i can't tell response time at all even with slow or fast servos. if anyone can tell the difference from using it they really are a pro. i think tebo said he could not tell the difference between the new and old helios and its supposedly a lot faster. if i can't tell i'm not spending any more money on a radio.
j_blaze14 is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.