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Red-Rx7

Power/Unpower a servo to stop it in mid travel?

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Howdy all...

I have a "problem" in which I need to resolve. I think I have the resolution, but need assistance in "building" it.

I am using a Spektrum DX6 transmitter / receiver to control a robot I am building. It is a 6 channel system, in which I am using 4 channels to control the robot already. Thus, the two gimbles are already being used.

This leaves me with two more channels (gear/aux); which on the transmitter is controlled by a two position switch (1/0) positioning.

I need to be able to control (left/right) direction of a servo, and have it stop at random spots. Without the need to have it stop, I could set the ATV points, and just use the gear switch to make the servo pan left and right accordingly. Yet, with the Aux channel, I am wondering if someone could help me / tell me how to build something that will kill the power to the servo; thus stopping it in place.

As expected, I am trying to control a camera pan movement with two, two positioned switches. I am thinking that I could flip the gear switch down, then hit the aux switch "aka the power switch" and have the servo arm rotate to the left. If I push the switch to the upward position, it would rotate the servo arm to the right. At any point in its travel, I could hit the aux switch to stop the movement.

I already have the means to provide power via the Aux switch remotely. Rather, I just need a means to make the servo stop/go accordingly. Would a relay or something work?

Any help would be great!

Thanks,

Mike

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I certainly could envision a microcontroller based solution that mixed the two toggle switched channels into a single servo control solution. But that would take some significant engineering effort. Beyond that, your relay trickery sounds like it would work. There are commercial R/C controlled relays on the market. Budget $20.

Or, you could put your DX's DSSS RF deck into a more advanced R/C Tx that provided six proportional channels. No doubt you've seen the rcgroups.com thread on that conversion.

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I just looked at the DX6 manual and I see it can support up to 3 mixes. Why not mix the two toggle channels together to achieve the results you need?

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I just looked at the DX6 manual and I see it can support up to 3 mixes. Why not mix the two toggle channels together to achieve the results you need?

In looking at the manual, I never really understood what mixing did. :ph34r:

So, if I understand this correctly, I would use the Rudder Dual Rate style of setup?

I would select the Aux channel (#6) and have it 6/6 on the mixing. I then would set the travel adjustment values with the switch flipped one way, and do the same for the opposite. Finally, I would set the On/Off switch to the F1 (Flap Switch)?

Thus, I would hit the Aux switch, and it would be set to rotate the camera to the left. I would then power the switch, by hitting the gear switch. I could flip the gear switch on/off to stop it in various points?

Is that correct?

Thanks again!

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It wouldn't be a dual rates solution. Instead, you would mix the Gear and Aux channels together. My hunch is that you could set up the two switches so that combinations would provide center, fixed left, and fixed right positions.

The mix would involve only channels 5 & 6. You'll have to experiment with mixing them, plus the T-ADJ, to see what you come up with. If you get this two work, then you could use the PanCam too.

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I had some free time so I worked out a DX6 Mix setup that might help you out. My solution would be best used with a Pancam interface, but it will work without it. You can now use the two switches to point forward (neutral), right, and left. Without PanCam, these are fixed positions.

1) First, open the DX6 manual and read about Mix A and Mix B. Get familiar with the menus and sub menus. If you don't do this, you might get lost with my instructions.

2) Start with a new model memory. Perform a model reset to clear any settings that might cause confusion with the setup.

3) Plug the pan servo into the Rx's Gear position. Verify it works. The Flap servo position will not be used.

4A) Go to the "Mix Ach" menu.

4B) Enter "56." This mixes Gear to Flap.

5A) Goto to Mix A56 sub-menu.

5B) With the Gear toggle switch in the forward position, enter 0% mix.

5C) With the Gear toggle switch in the back position, enter +125% mix. Note: This percentage determines the max servo position. If PanCam is used, it determines servo speed. So, keep that in mind if you need to change things later on.

6A) Go to "Mix Bch" menu.

6B) Enter "65." This mixes Flap to Gear.

7A) Go to to Mix B65 sub-menu.

7B) With the Flap toggle switch in the forward position, enter -125%. Note: This percentage determines the max servo position. If PanCam is used, it determines servo speed. So, keep that in mind if you need to change things later on.

7C) With the Flap toggle switch in the backward position, enter 0%.

8) Exit the menus. You are done.

Operation:

* With both switches forward, the servo will be at neutral. Let's call this the home position.

* With the Gear Switch backward, the servo will rotate to one end.

* Home the switches. Servo at neutral.

* With the Flap Switch backward, the servo will rotate to the other end.

* Home the switches. Servo at neutral.

If you wish to reverse the servo direction, use the Gear Rev mix menu.

For a really clever implementation, you could rewire the two switches into a single SP3T (center off) toggle switch. One with a spring return to center would be nice. That would give you intuitive left, center, and right positions. I'll leave such a task up to you or your bench tech.

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