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I'm intending to build my dynahead with 4WS but only using 2 channels. I am hoping that a y lead will provide the answer. My concern is that looking at the manual the servos are in the same orientation so if they turn in the same direction the vehicle will ūü¶Ä steer. This might be fun but not what was planned. Do I have to reverse one of the servos wiring to get it turning in the opposite direction? Or am I missing something completely. I have a 5 channel radio that I could use but would have to purchase some form of external mixer as radio has no mixing facility. Y lead on 2 ch seems easiest and cheapest!!

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you need one of these - it worked really well with my 3ch radio and a CR-01 - the third channel on the radio was a 2 position switch - which enabled me to cycle through: front steer, rear steer, four steer and crab.

https://bastens.com/products/bastens-quadsteer

 

I know have a six channel radio so I can have lights as well but still use the above as I could never get the mixing to work in the same way as above.

 

 

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Different model servos can rotate different directions. The choice of clockwise or anti-clockwise operation by the servo manufacturer seems completely arbitrary. If you have a few servos lying around you might be able to find two different servos that rotate opposite directions, then you can just use them with a Y cable. Reversing the external wiring of the servo will just cause it to stop working. It is possible to reverse the wiring of the internal potentiometer and motor which has the effect of reversing the direction of the servo:

 

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Did they change the servo position on the Dynahead? On the Konghead the servos are on the same side of the chassis, but they are mounted in opposite directions so they turn correctly. A Y lead worked perfectly.

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Hi Bus' - you can buy Servo Y cables that reverse from left to right (typically used for planes for the wing flaps for example), have a look on ebay - it's what I used on my 4WS conversion to Desmond which still uses a convention 2-channel radio.

Jx

 

edit. Here's one - this is exactly what I bought: https://www.ebay.com/itm/Logic-Rc-Y-Lead-Servo-Reverser-Ideal-For-Flaps-P-FS-SRY-Reversing-Y-Lead/360588433328

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Definately on the same side with spindle to the front. I used y leads on planes for ailerons but they were attached to opposite ends of the servo horn in each wing so the worked as opposites. I'll have a look at all the alternative once everything is here. I've ordered 2 new waterproof servos the same so presume they will rotate in same direction. Might of rewired plug if it worked but not dismantling it to rewire. Just realised how dumb I'm being. The front track rods are on the rear of the knuckle whereas the ones on the rear are on the front of the knuckle so the same movement will cause opposite steering.!!!!!!! ( as above with ailerons) Having said that will still look at @gizard idea

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Just looked at the bastens quad steer and it looks awesome. I have switchable channel on my planet t5 which would be perfect. Might be doing an order later. Just need to be careful of nasty import duty as it comes from US.hey it's only more money!!!!!!!

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It does require a 5 second don't touch anything (calibrates itself) at start-up otherwise it will not work. Works really well and it now seems cheaper - I am in the UK and had 2 of them - any questions ask the chap - he answered mine. I guess crab steer might not work too well with the middle wheel dragging around?

 

 

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How complicated is the soldering, it's not my greatest skill:wacko: although I do have a friend who is Ito electronics so maybe he can help?

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Soldering isn't difficult if you have the right gear and patience. That circuit board looks like you would need a pretty fine tip to do the job right. Like most things, the amount of prep work has an impact in the outcome. A quality iron makes the job so much easier. Need to be in a reasonably ventilated space too due to the fumes the solder gives off.

Youtube will have plenty of videos to show you how to do it. The main thing is making sure you get heat into the pieces you are soldering to ensure good contact once the solder has set.

Soldering is a handy skill to have in RC land. From fixing gear to being able to have custom wiring is very rewarding. 

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That circuit board is just an Arduino Pro Mini development board that they have loaded their custom 4WS software on - the holes are 0.1" / 2.54mm apart so not too difficult to solder. Shouldn't need a special tip on your soldering iron but having a vice or 'helping hands' to hold the circuit board and wires still while you solder will be invaluable. It looks like they get you to cut the two 3-pin cables in half, strip and solder the bare ends to the Arduino board. The hardest part will be stripping the 3 wire ends to the correct lengths without breaking off too many strands of copper which will cause the wire end to be weak. The insulation on those 3-pin cables usually is PVC instead of silicone like is used for RC power cables, so you have to work quickly with the solder iron to prevent melting the PVC insulation too much. Some glue (epoxy glue, hot glue) for strain relief is usually a good idea where you terminate bare wire to circuit boards too.

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Posted (edited)
15 hours ago, Biz73 said:

Did they change the servo position on the Dynahead? On the Konghead the servos are on the same side of the chassis, but they are mounted in opposite directions so they turn correctly. A Y lead worked perfectly.

On my Dynahead it all works fine for 4ws using £1 Chinese servo y lead so the above is correct, remember Tamiya generally make things simple!

Edited by taffer

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Should work fine with a Y lead, but Preferably you'd want proper mixing,

If you intend to crawl or drive the G6-01 slowly or as a crawler, it's not as much of a issue, if you want to put a brushless in it and drive fast, I suggest forgetting about the 4WS altogether, unless you like being upside down most of the time. 

A Digital radio with Mixing will allow you to tune in exactly how much steering you want each servo to do, my spektrum radio also has a rate option switch where I can flick a button and turn off the 4WS then Flick again for full 4WS, I can also program in anything in between. 

Juls

 

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I have a Konghead and bought a Y servo lead and it worked fine. Remember the wheels at the rear need to turn opposite to the ones at the front anyways. This was with a simple 2 channel transmitter

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I think Ive realised that a y lead will work to give me permanent 4WS but if I want to cut in and out the quad steer is a good option as it will work in 2 ch and 3 ch mode

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my 2 boards came complete - but they were more expensive back when I got the them ;) 

 

 

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