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Converting a Spektrum DX7 from Mode 2 to 1

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  • Converting a Spektrum DX7 from Mode 2 to 1

    I found this and thought it could be usefull for anyone, please delete if its been posted or irrelevant etc.
    (its not my post so I take no credit)


    Oh no! I've bought a DX7 on the wrong mode

    You are not alone! I bought mine on Mode 2 and then realised that there's no easy way to get it to function on Mode 1 (see diagram above for the differences in the modes). Apparently it requires a return to base firmware modification, at some cost.
    After removing the back of the set and moving the ratchet from the left stick to the right, and vice versa with the return spring I found the only way I could implement 'delta' mixing was to create two custom mixers one mixing 'AIL to THR' and the other mixing 'THR to AIL'. Bear in mind that 'THR' in my case is actually my elevator servo.
    The problems with this solution were that I lost Dual Rates on elevator - instead the elevator DR switch gave me throttle dual rate! Furthermore, I had some issues with the failsafe not doing what I wanted. Not good eh?

    So what next?
    All my web searches amounted to nothing so I decided to grab my soldering iron and see what I could do. Fortunately, it turns out that I could put the soldering iron away and just grab a crosspoint screwdriver instead! This is a non-destructive and completely reversible mod!
    Disclaimer: I modded my Tx as I cannot be without it while it's sent away for official remoding. For 'proper' modding, why not send your set back to the source. If you wish to (probably) invalidate your warranty and be frustrated by losing tiny invisible screws then read on! Any damage caused to your Tx following these instructions is your doing.
    Note: any screws you take out, please put them somewhere safe - and preferably in separate piles with a note to say where they're from.

    Let's get started - remove the backplate
    OK, flip the Tx over take out the battery and unplug it, remove all the case screws and then remove the back of the Tx.
    You'll find that a single circuit board containing the battery socket is attached to the backplate. It's easier if this is removed so you can get the backplate completely clear. Notice that the orange/grey wire attach to the circuit board where it says 'red/black' - irrelevant but made me chuckle. The single crosspoint screw detaches this PCB.
    NOTE - from now on, the pictures will show the sticks labeled as they appear from the front of the set! Also note that, as mentioned, I've already changed the ratchet and spring to my mode.

    The mission objective
    Our mission is to somehow get the output from the right stick (six white wires with a brown one) over to the opposite side of the board where the left stick (six white wires with an orange one) are plugged in. However, they're not plugged in. The white connector is a soldered joint despite appearances and even if we could successfully unsolder all six at once, would it work? Who knows?
    An easier solution would be to swap the Y axis potentiometers, i.e. to make the left stick turn the right potentiometer and vice versa. These are fortunately mounted on symmetrical PCBs and so can be directly swapped.
    See diagram below - incidentally, in this diagram I've carefully removed the RF board from the Tx by removing the four black screws holding it in place. Handle this with care and, if you unplug the antenna lead please remember to replace it later!


    THE TWO PCBs WE NEED TO EXCHANGE


    However - the astute reader will notice that the digital trim switches will be reversed, but you can't have everything right?

    Set the wiring free
    With a small flat bladed screwdriver you can release the small plastic cable ties that hold the wiring loom together. These ties can be replaced and reused later in the spirit of recycling.

    Remove the power switch and fuse PCB
    Right in the centre of the Tx is a PCB containing a fuse, and on the reverse side, the power switch. This is held in place by two small black screws and a large shiny one in the middle. Things are easier if you remove this board - shown still in place below.

    Now remove the stick gimbals
    Each gimbal is held in place by four crosspoint screws. Referring to the photograph below, undo these screws and then gently lift out each stick gimbal. This makes access to the potentiometer boards very easy. The screws holding the gimbals are different from most of those removed so far so please store them separately.

    LOCATION OF THE GIMBAL SCREWS


    Removing the potentiometer PCB
    The potentiometer PCB is held in place by a small metal bar which keeps the pot in contact with the stick mechanism and then directly to the gimbal via a black plastic subframe, attached with two black screws. See photograph below.
    Remove the metal plate and then undo the two subframe screws. This allows the PCB to be lifted free of the gimbal. With both sticks removed, simply exchange the PCBs and reattach them on the opposite side, making sure everything moves freely as it should and the microswitches click when you apply the trims, as they should.
    Note: Make sure each stick is centred and that the potentiometer is in the 'twelve o'clock' position. This is the pot centralised and can be confirmed by running it through it's travel in both directions to get an idea of the centre.



    REMOVE THE METAL BAR AND THEN LIFT OUT THE PCB


    Routing the wires
    With the potentiometers now successfully relocated, the wiring loom - those orange or brown groups of cables - can be rerouted. Cross them over below the power switch PCB as shown below.



    REROUTE THE Y AXIS WIRING



    Putting it all back together
    The question is can you get the thing back together without having screws left over? If so then a job well done. If not then join the club!
    Replace all the PCBs and bits you've removed, retie the cable ties and make sure that little antenna lead goes back securely into place on the RF board. Replace the back of the Tx, plug in the battery and then see what happens...

    The good news
    Your Mode 2 Tx is now Mode 1 - you can use all the pre-programmed mixers, the dual rate switches will now affect the correct functions and the failsafe will throttle back rather than apply up elevator which is what mine used to do. If you have any problems with the failsafe, hold the sticks where you would like them to be should you lose signal and then rebind the receiver (may be specific to the AR6100 and 7000).

    The bad news
    You will find that the digital trim display on one side seems back to front - it stands to reason since we've inverted the potentiometer PCBs. However, on my Tx this is on the throttle function - where I never ever touch the trims. The elevator trims on mine (left stick) are fine and work in the correct sense.

    Finally
    I hope this has worked for you and unlocked the features of the DX7 that were previously unavailable. My Tx is now operating as it should have right out of the box. Also, no wires have been cut and nothing resoldered so, should Spektrum ever release details of how the end user can change the firmware to another mode, simply put everything back as was!

    Source: Mugi - Tutorials - Changing Spektrum DX7 from Mode 2 to Mode 1

  • #2
    Aww!
    Before you spilled the beans we could get realy cheap second hand mode2 dx7 txs!

    surely you can swap the wires on the switches and trims too!
    www.heli-extreme.co.uk a good club in south Sheffield
    600n pro BeastX Align DFC head bls251, 3xbls451, align gov, 600d, 2in1
    trex500, BeastX DS510 swash, Beast X cutr and carve head DS520 HK3026-1900, Align 425D blades, 5S4200 rev'trix, K&BDD dampers, AR6200
    "450" superframeSTK, align DFC head v2tail, hk22281-8 on 3S 9650w9257gear commander 55A align 325D hitec digitals Tarot ZYX, AR6100e
    MCPX kbdd tail and blades, miniaviation bats

    Dont spend more flying models than it costs to fly for real

    Comment


    • #3
      All the switches are on the opposite sides as well (opposite to Mode 2, I recently found out while visiting Tim )

      i.e. IdleUp is on the right and Throttle hold is on the left (Mode 1).

      But hey, it's a start!
      Cheers,
      Rob
      Team Align, Midland Helicopters, Optifuel, Cyclone Blades, Scorpion Motors, Thunder Power, Savox Servos, JR Propo

      | 3D Championship

      Comment


      • #4
        i.e. IdleUp is on the right and Throttle hold is on the left (Mode 1).
        Could never get on with that, I bet its like trying to write your name with the wrong hand and up-side down :/.
        But yep its a start if ever someone pressed the wrong 'buy' button and didnt relized .

        Comment


        • #5
          As I said at the time Rob.

          Which side is the throttle on your car.??

          Which side is the throttle on your motorbike.??

          Why the hell do you choose to go all foreign when flying your helis..

          Comment


          • #6
            Here we go!! Dont start him on this one
            Henseleit TDR V-Bar x2
            SAB Goblin 700 V-Bar
            SAB Black Nitro V-Bar YS91 Tareq SRX
            T-Rex 700e DFC V-Bar
            T-Rex 700N MAJ DFC V-Bar YS91 Tareq SRX
            Synergy N7 V-Bar OS105 HZ-R
            Synergy E7se V-Bar
            Synergy N5c FBL V-Bar
            Gaui NX7 V-Bar YS91 Tareq SRX
            T-Rex 550 E FBL V-Bar
            Gaui NX4 V-Bar
            V-Control

            Proud owner of TWO!! Platinum Stars!

            Comment


            • #7
              Very true Tim

              Comment


              • #8
                Can you not just set it in the service menu?

                Ensure the Aileron D/R switch is in the UP position.
                Press and hold the DOWN and SELECT buttons and turn on radio. Now you're in the setup menu.
                Scroll up/down until you get to the screen that says [Model Reset]
                Press the Adjust Decrease button (r/h side of LCD)
                Flip the Aileron D/R switch down
                Press the Adjust Increase button
                Flip the Aileron D/R switch up
                Press the Adjust Decrease button
                Keep alternating this Aileron D/R up/down and Adjust Increase/Decrease sequence (about 5 cycles)
                The radio will 'beep' and the LCD will go dark. This is the LCD test.
                Scroll Up/Down (left side of LCD screen) through the Service Menu (at your own risk)

                I have not got one here to test. But in the service menu on my DSX9 you can set the default mode. I must admit you can also change the mode in the setup menu, but the hidden menu changes its default setting.
                Cheers Adam
                Volatilis vacuus alai
                Owner of an "Evil Gold Star"



                Comment


                • #9
                  DSX9 is a different radio to the DX7. Very easy in the DSX9.

                  Here is the link with all the details contained it the original post.

                  Comment


                  • #10
                    how long are the wires on the switches? can you unscrew them and swap them side to side?
                    mo fooled me with his tx. He fitted bling gold switch surrounds, but at the time also turned on eof the switches 180 degrees. Had me really confused as to why one channel had to be reversed compared to my tx.
                    www.heli-extreme.co.uk a good club in south Sheffield
                    600n pro BeastX Align DFC head bls251, 3xbls451, align gov, 600d, 2in1
                    trex500, BeastX DS510 swash, Beast X cutr and carve head DS520 HK3026-1900, Align 425D blades, 5S4200 rev'trix, K&BDD dampers, AR6200
                    "450" superframeSTK, align DFC head v2tail, hk22281-8 on 3S 9650w9257gear commander 55A align 325D hitec digitals Tarot ZYX, AR6100e
                    MCPX kbdd tail and blades, miniaviation bats

                    Dont spend more flying models than it costs to fly for real

                    Comment


                    • #11
                      how long are the wires on the switches? can you unscrew them and swap them side to side?
                      Mo fooled me with his tx. He fitted bling gold switch surrounds, but at the time also turned on eof the switches 180 degrees. Had me really confused as to why one channel had to be reversed compared to my tx.
                      www.heli-extreme.co.uk a good club in south Sheffield
                      600n pro BeastX Align DFC head bls251, 3xbls451, align gov, 600d, 2in1
                      trex500, BeastX DS510 swash, Beast X cutr and carve head DS520 HK3026-1900, Align 425D blades, 5S4200 rev'trix, K&BDD dampers, AR6200
                      "450" superframeSTK, align DFC head v2tail, hk22281-8 on 3S 9650w9257gear commander 55A align 325D hitec digitals Tarot ZYX, AR6100e
                      MCPX kbdd tail and blades, miniaviation bats

                      Dont spend more flying models than it costs to fly for real

                      Comment


                      • #12
                        Now here is something completely different - can you turn either DX7 or 9 to mode 3?

                        In mode 3, elevator and ailerons on left stick and throttle and rudder on right stick. I am thinking of getting a DX7 or 9 but only if either of them allow me to get mode3.
                        My DX6i has been changed to mode 3 ...but by an electronic wizkid.
                        Last edited by Hangar-7; 05-01-2010, 12:52 AM.

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                        • #13
                          DSX9 will program to all 4 modes in the software.

                          DX7 is hardware conversion.

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                          • #14
                            Things would be a lot easier if everyone flew the right mode which is mode 1
                            Shaun Senior

                            Spectrum Promotions (embroidery and printing)
                            www.spectrumpromotions.co.uk
                            E-mail: Shaun@spectrumpromotions.co.uk

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