Steering Dual Rates

[Gareth Jones]

Hi,

Does anyone have instructions to show me how to put dual rates on an old stick transmitter?

Thanks
Gareth

[Dazzler]

Check your PM's

[Gareth Jones]

Thanks for the quick response.

The issue I now have is the transmitter I have got only has 3 wires to the steering potentiometer - it does not have seperate wiring for the trims, therefore the diagram you linked me to does not work....

So I have 3 wires and manual trims that move the steering potentiometer, can i still add in the dual rate potentiometer?

Bet this is an amazingly simple job for someone who knows what they are doing!

Gareth

[jaxx]

I'm not sure if itwill help, But this is what i put in an old Acoms.

http://i863.photobucket.com/albums/ab192/jaxx9000/pot.jpg

[Gareth Jones]

That is the diagram I have been sent the link to which seems nice and simple, easy to follow job done....

However, i do not have the "Trim Pot" therefore I am now back to the start and wondering how to wire in this dual rate potentiometer.

Hmmm

I have just tried to have a go but nothing I do seems to work :(

Gareth

[sparrow.2]

Have you thought of adding the trim pot as well maybe to get it to work?

Sorry if this is rubbish :thumbsup:

[jaxx]

Sorry that did not help, What is the transmitter you are trying to mod?

[Gareth Jones]

Any help is appreciated!

Its a Core RC Code Sport - I basically want a 2.4 system with no bells and whistles, however need dual rates....

Though I found a nice cheap solution!

Gareth

[jaxx]

just had a look mine. The trim pot is from maplins and is very small. The rate pot is also from maplins and is outside. So you do add your own trim pot! So the diagram i put up will be correct.

[jaxx]

Just had a look at maplins
fw22y External £1.59 You also need a knob for this
jm70m internal £0.99

Hope that helped

[RudolfXC]

The 'Trim Pot' on the diagram is not what is in the transmitter when new - it is added to correct the neutral position after adding the 'Rate Pot'.

[Gareth Jones]

Looks like another trip to Maplins tomorrow!

Thanks for your help.

Gareth

[terry.sc]

As I'm the person who drew that diagram 6 years ago (http://www.tamiyaclub.com/forum/index.php?showtopic=12992&st=0&p=100838&#entry100838), it's a lot easier to understand with the instructions that went with it.:D


Full instructions to fit it.
The Rate Pot wants to be a potentiometer with a 1/4" shaft that can be screwed through the case so you can adjust it.
The trim pot can be any small potentiometer, size doesn't matter although I use a subminiature one designed for circuit board mounting with the centre pin at the opposite side of the pot, such as Maplins part number UH16S, so it can be soldered directly to the pin on the rate pot.

1. Remove back of transmitter and drill a suitable hole for the rate pot, making sure the back of the transmitter still fits okay. Attach the steering rate pot to the case.
2. Rewire the transmitter following the diagram above, the green lead in the diagram was the wire that comes from the PCB to the middle pin on the steering pot, move it to the rate pot and add all the other wires.

3. Set the steering trim below the stick to the centre, switch on the transmitter and the car. With the stick at centre, turn the Rate Pot fully clockwise and anti-clockwise. The steering should not move, if it does readjust the Trim Pot until no movement is seen.

4. With the Rate Pot fully anti-clockwise, full movement of the stick should produce little movement. With the Rate Pot turned fully clockwise full movement of the stick should produce maximum steering. If the reverse happens swap wire on 1 & 2 on Rate Pot.

5. Tidy up all the wires in the transmitter ensuring none foul the stick mechanism and there are no possibility of short circuits.
Now replace back of transmitter.

[Gareth Jones]

Terry thank you so much for clearing this up!

I will be of to Maplins first thing in the morning. Just a quick last question, does the main potentiometer need to be a certain size? the one I have installed says 10k on it.....

I really should have fully read up on this before I started :)

Cheers
Gareth

[terry.sc]

The trim pot needs to be 5K Ohm, to match the steering pot. Maplins don't sell 5K pots, so you want the nearest which is 4K7 linear.

If you are buying from Maplins the parts you need are
FW21X 4K7 linear potentiometer
UH03D 10K horizontal enclosed preset

[Gareth Jones]

Sorted!

I wont lie and say it took me 10mins this morning to solve, but after a trip to Maplins and lots of soldering I am finally there!

It may have been more cost / time effective to buy the higher spec transmitter in the end, but least its now sorted :)

Cheers for all your help.

Gareth

[Steven Forster]

just out of interest how does the dual rate work, what is it used for ???

cheers :thumbsup:

[Dazzler]

It's End Point Adjustment. Restricts the angular travel of the servo, but still proportions the travel across the full throw of the stick.