New radio help

[Saito2]

I'll start out by saying I'm old-school to a fault. I live under a rock. Sad, but true (although I like my rock ). As such, ALL my radio gear is vintage or at the very least, basic AM stuff. I'm usually a Futaba guy simply because the vintage Futaba equipment has held up better than my old Airtronics and Aristo-Craft gear. My most advanced radio ever is the Magnum Jr in my Super Shot.

Now it seems Futaba is finally leaving AM behind, so I need to get with the program. I'm looking at two new-fangled radio choices for my Egress runner, the Tactic TTX300 or the Futaba 3PRKA.  I know nothing about this 2.4 GHz stuff. I don't know what binding is. I know what servo reversing, servo trim and end point adjustments are but don't know what "steering dual rate" is. I also don't know if either has BEC receivers as earlier Tamiya ESC's dont (101BK, etc.). 

The Tactic has steering and throttle EPA as well as steering rate adjustment, making it seem like the better deal. I just don't know Tactic as a brand. The Futaba only has throttle EPA but has "dual rates" for steering. I do trust Futaba as a brand.

So which is best for me and what means what? I would like EPA for the steering mainly so I don't strain the steering servo after the steering in the car has reached its mechanical limit (or to take full advantage of what's there). Any help greatly appreciated.

[Jonathon Gillham]

How many cars do you have? If you have a few what about the Futaba 3PV (or 4PV) which is more expensive than the 3PRKA but supports multiple models and has all the adjustment. Its about 50% more than the 3PRKA but provides much more flexibilty. I have about 4 sets with 1 being high end, and the rest cheap for bashers. Would you prefer to have a single good set to run multiple cars, or a set per car?

Binding is just a simple process to get the rx and tx talking, there will be about a 5 step guide in the manual. You can bind multiple rx to a tx but you need a better set to enable you to store the settings for each rx. So you choose the model on the tx, then turn the car on and it works. If you have the model wrong on the tx then it will still work but trim, epa etc will be wrong for that car. With the 3PRKA you would have to reset all the settings each time you use a different car, like if you swap crystals out on an am set.

I have the 3PRKA and find it great for a basher, overkill really as its usual Futaba quality, and the dual rate steering does work like EPA but I haven't really used it so don't know for sure. It definitely works well for a Tamiya with a basic servo, but I struggle when trying to set up a more complicated car with digital servo. I use a Sanwa MT4S for my racecars which has all the adjustment you could want and multiple model memory, like the 3PV.

Check the price of the rx, I recommend Futaba over Sanwa for that reason alone, Sanwa rx are expensive (I knew this when i got mine but got a great deal secondhand)

You can also go super cheap, the Flysky 2GT is about NZD $36 delivered from Banggood and works well, but doesn't have the epa.

[Prescient]

I have a few of the Tactics and the Futaba.

For the money you can't go wrong with the Tactic. They seem bigger as an OEM RTR supplier / USA prominent brand iirc. Really simple to use, great instructions and haven't had any issues. 

No external aerial on the reciever to worry about either.

The Futaba is also very very good.

Only one memory on either though so you need to swap the reciever to different cars. 

When I bought the Tactics, they were £29.99 from Modelsport. Half the price of the Futaba and the same price as many recievers alone. On that basis it was easy just to buy one per car. 

As for the functionality, both are pretty basic these days. 

Photos re Tactic TTX300 functions below.

[Only4Fun]

@Saito2   I don't know about the Futaba, but I have the Tactic TX300 which I use with my SCX10 and have had no problems at all with it. I have had it about a year and use it 3 or 4 times a month, for a couple of hours, and haven't had to change the

batteries yet, which are only cheap Ikea AA's. It also only uses 4 of these too, unlike most older transmitters which take 8.

I echo what Prescient said that they are really easy to use 

[Saito2]

Thanks guys. Yeah, I do admit cutting the amount of AA batteries in half is cool. I do get tired of feeding 8 of of those into my old AM gear. So I'm gathering steering dual rate and end point adjustment (EPA) are kind of the same thing?

[Juggular]

On 10/22/2017 at 2:53 PM, Saito2 said:

ALL my radio gear is vintage or at the very least, basic AM stuff

I feel you... Until this summer, this was how it was for me.  

Many still had batteries in them too. 

(The expiration date is March 2005.  I probably put them in in 2003 or 2004. 13 years ago!  How's that for leaving it under a rock?)

Since I kept the batteries from touching the contacts (with 3 pieces of papers), they were all alive after 13 years!  

 

Batteries in other transmitters that were partially blocked, did not survive.  All contacts had to be blocked.  

Anyway....

I settled on Flysky GT3B for about $30.  This one uses 8AA. From what I hear, it drains fast.  So I upgraded it with 11.1v lipo.  

I was suspicious of cheap Chinese stuff after using Futaba all my life.  For sure, it is cheaply made.  But it works.  

10 model memory, so I could get rid of 10 AM transmitters.  Each receiver costs just $5.  Under $100 USD, including the transmitter, you can control 10 cars.  Flysky GT3B comes with EPA, Dual Rate, Expo, and ABS brake.  (I guess EPA is an improvement over GT2)

 

To answer your question: End Point Adjustment and Dual Rates can have the same effect. 

EPA is a limiter.  DR is sensitivity adjustment for lack of better words.  

I think my FAV steering touches A-arm on one side.  Zahhak's steering link can stretch all the way, and kinda locks itself.  So, for these two cars, I'd set EPA to 95% to reduce the steering angle.  If you are on 3S and 5000KV motor.  You might want to limit throttle EPA to limit full throttle down to 73% or something. 

Dual Rate is a one-push limiter.  I always thought it was invented for airplanes.  The difference is pre-set (or quick access).  Dual rate often comes with a quick switch.  With a flip of a switch, an acrobatic plane becomes a docile plane by limiting the servo throw. Or visa versa.  My old FM Hitec has Dual Rate Release button on the left thumb.  Dual Rate is decided with a dial above the thumb.  I set the steering DR to about 70%, so my Wild Willy 2 would not flip in high speed turns.  But in slow turns, where I need more steering, I just push the DR Release button so the steering would be back to 100%.   Flysky also has D/R thumb-button at the grip.   

In my opinion, the difference is whether or not one is preset to for quick use (DR), or more permanent based (EPA).  

 

[Saito2]

Thanks Juggular. Now I get the difference between Dual Rate and EPA more clearly. I also kind of see the purpose for dual rate too.