Jump to content
Losi XXT-CR

Any 4ws experts? Konghead

Recommended Posts

Can anyone help. I'd like to be able to turn the rear steering on and off via the transmitter for my Konghead while driving.

I'm using a Flysky FS-i6 Transmitter and 6 channel Rx.

I can get the 4ws to work by plugging the rear servo into Ch5 and then setting a mix with Ch1 and assigning Ch5 to the 3 way switch. 'Up' on the switch results in the rear servo going 100% left, 'Down' results in 100% right and the 'Middle' position results in neutral but then working with the front servo. So getting the 4ws working is fine. But what I can't figure out is how I can turn it off while driving. I tried using one of the two way switches, but this results in the servo being either 100% left or right, unless I add an offset, but it didn't really work right and I still couldn't switch it off.

Anyone know how I can turn the Mix on and off while driving? I couldn't see a way of assigning this to a separate switch. I also looked at the Dual Rate setting, but these are not available for Ch5.

Share this post


Link to post
Share on other sites

Dual rates are what you need, I used it on my konghead, as the things useless in 4ws if you want to drive slightly fast on grippy surfaces I set mine up for 10% rear steer and 60% rear steer on a dual rate switch on my DX4c. 
 

in the end since I wasn’t wanting to use the konghead as a crawler I removed the rear steer altogether. 

Share this post


Link to post
Share on other sites

There should be a way of doing this.  I have an FS-i6 and it's this kind of setting that I will need to look into to make it work with my Tamiya MFU-01 whenever my new receivers deem it a suitable time to arrive.  That said I've just looked at my FlySky tx and I can't work out how to do it.  By default (if you are in Aeroplane / Glider) mode the DR switch is SWA and can be used to change DR on channels 1, 2 and 4 (assuming Mode 2 setup).  As far as I can see there's no way to set up DR on a mix channel.  Which I have to say is a little bit annoying and not the first time I've found a relatively simple thing that the FlySky just can't do.

There is a firmware update for the FS-i6 but I haven't tried it on mine yet.

This has intrigued me so much that I want to experiment and find out but unfortunately all my receivers are locked away in models that I can't currently get to due to stuff being stored in the way thanks to an ongoing house renovation that has been held up by not being able to get a carpet fitter in for 3 weeks, and my new receivers that I ordered and wanted for this weekend haven't arrived.  Gah.

If I have an update to this I'll post it.

Share this post


Link to post
Share on other sites

So I've had a bit more of a play around with this.

I plugged the rear servo into Ch4, this allows me to control the front steering with the left stick and the rear steering with the right stick. Only trouble is, as you accelerate and brake, it is all too easy to wobble the left stick, so not much use unless only crawling. Now I have the rear servo on Ch4 I use use the Dual Rate function which allows me to set channel 4 to 0%, thus it no longer activates the servo with the left stick. Setting up a Mix between Ch3 (front servo) and Ch4 allows 4ws from the right stick, but I'm back at the same issue of then not being able to toggle the 4ws on and off easily. The Dual Rate settings on Ch4 seem are not utilised via the Mix.

So sadly I'm no further ahead really. Getting the 4ws working on separate channels seem easy enough (but so is using a Y cable and a single channel). I can also get the rear steer to work independently of the right stick (front steering), either by use of the 3 way toggle switch or the left stick. Which might have some uses but isn't what I'm wanting to achieve.

 

Share this post


Link to post
Share on other sites

I would have thought it’s possible with any digital radio? My dx4c is a el cheap o radio, took a matter of seconds to set up the dual rate steering. However it is a pistol radio, sounds like your trying to use a aircraft radio so maybe that’s the issue. 

Share this post


Link to post
Share on other sites

I can set up dual rates, that isn't the issue. What I can't do is essentially turn one of the Servo's on and off ;) So as to be able to switch between 2 wheel steering and 4 wheel steering.

Share this post


Link to post
Share on other sites

Sadly I'm not familiar with your radio's operating system, but on the Spektrum and JR radios that I am familiar with, mixes have several parameters that can be defined when setting them up. These include the master and slave channels, the mix percentage, the relative direction of travel and most importantly for your purposes, whether the mix is always active or whether it can be switched on and off, and if the latter, which switch activates/deactivates it.

Do these parameters match what you have available on your radio? (They might be called something different.) If so, I'd set the mix with your front steering on your preferred stick as the master, the rear steering on an auxiliary channel as the slave and the mix activation/deactivation on a 2-position switch. Id leave the mix at 100%, same direction. The geometry of the steering links will see to it that the rear wheels move less than the front ones, in the opposite direction. 

If this isn't possible, you might go analogue and modify a Y-lead to include a receiver-controlled switch on an auxiliary channel to physically cut power to the rear servo. One of the little switch units sold for turning lights on and off ought to do the trick.

Share this post


Link to post
Share on other sites

In my radio I set position 1 to 0% and position 2 to 50% to have off or on steering, I have also played with position 1 at 10%. Position 2 is obviously what ever the max servo throw is required for maximum steering. Obviously I have channel mixing on as well so only ch2 is steering both servos, but ch 3 has dual rates configured. 

Share this post


Link to post
Share on other sites

I still need to look into this (my Rxs have still not arrived) but I was thinking about it at the weekend.  When I first set up my Yota Class 1 on this radio, I was using the right-hand vertical axis to control the winch.  However (as OP mentions with left-stick steering) it's easy to trigger it accidentally when driving.  So I somehow managed to hook it up to SWD (top-right 2-way switch) so that when the switch was down, the right vertical axis was disabled, and when the switch was up, the right vertical axis would operate the winch.

So it is definitely possible to have an aux switch (not DR) enable / disable a channel.  I think I did it by going into the aux switch / aux channel settings and setting SWD to operate the right vertical axis channel, but I can't recall exactly as it was a while ago, and unfortunately that setting has been changed in favour of something else.  I will be spending time in my workshop tonight and GOOD NEWS my Yota Class 1 is not stuffed away in storage but easily accessible on the floor.  I didn't want to play around with this last week because the receiver itself is buried under waterproofing and I really didn't have time to get to it, but I want to know the answer to this now as it will help my big rig builds.

I'll check my settings and (all being well) update tonight.

Share this post


Link to post
Share on other sites

So I spent a good 40 minutes playing with my FS-i6 and couldn't get this to work.  Simply I don't think it's possible.

I did have my Tx set up to operate Ch2 (right vertical axis) either On or Off using SWD, however after quite a lot of fiddling I realised I'd done this by assigning the Flight Mode switch (D/R, usually on SWA) to SWD and setting up a 0 / 100 DR on Ch2.

I figured it might work if I set up a mix from Ch1 to Ch2 and also had the DR on Ch2, but that didn't work.  The DR switch made Ch2 turn off if using the Ch2 axis, but it had no effect on the operation of Ch1 (the mix still worked with the DR in either position).

I wondered if I could be clever and do it backwards - put a mix on Ch1 to Ch2, but then set Ch1 with a DR of 0 / 100 and no DR on Ch2, but alas, in this configuration, the DR switch affects both Ch1 and Ch2 when using the Ch1 axis.

So it looks like you have some options.

1) Continue to use the left horizontal axis for steering.  Set up a DR on that channel so you can turn it off when you don't want to accidentally steer.  (Incidentally this is how I run my Mod Clod, so I can crab, rear steer or not steer at all depending on my requirements.  It's up to me to steer properly.  Obviously you can't crab a G6-01 because of the central axle.)

2) Try downloading the firmware update for the FS-i6 to see if it adds more functions.  ISTR there is an update that takes it up to 8-10 channels (I forget exactly).  I haven't installed it on mine as I don't have the cable and right now I don't need all those extra channels anyway.

3) Investigate some kind of on-board controller that lets you run the rear servo from a Y-lead but allows you to turn that on or off with an aux channel (e..g SWD operating Ch6).  Not really sure what's out there in that respect.  Could probably knock something up with an Arduino taking inputs from Ch1 and SWD on Ch6, but if you're not into electronics then that's probably a no-go.

4) Get a different radio...

Share this post


Link to post
Share on other sites
11 hours ago, Mad Ax said:

So I spent a good 40 minutes playing with my FS-i6 and couldn't get this to work.  Simply I don't think it's possible.

I did have my Tx set up to operate Ch2 (right vertical axis) either On or Off using SWD, however after quite a lot of fiddling I realised I'd done this by assigning the Flight Mode switch (D/R, usually on SWA) to SWD and setting up a 0 / 100 DR on Ch2.

I figured it might work if I set up a mix from Ch1 to Ch2 and also had the DR on Ch2, but that didn't work.  The DR switch made Ch2 turn off if using the Ch2 axis, but it had no effect on the operation of Ch1 (the mix still worked with the DR in either position).

I wondered if I could be clever and do it backwards - put a mix on Ch1 to Ch2, but then set Ch1 with a DR of 0 / 100 and no DR on Ch2, but alas, in this configuration, the DR switch affects both Ch1 and Ch2 when using the Ch1 axis.

So it looks like you have some options.

1) Continue to use the left horizontal axis for steering.  Set up a DR on that channel so you can turn it off when you don't want to accidentally steer.  (Incidentally this is how I run my Mod Clod, so I can crab, rear steer or not steer at all depending on my requirements.  It's up to me to steer properly.  Obviously you can't crab a G6-01 because of the central axle.)

2) Try downloading the firmware update for the FS-i6 to see if it adds more functions.  ISTR there is an update that takes it up to 8-10 channels (I forget exactly).  I haven't installed it on mine as I don't have the cable and right now I don't need all those extra channels anyway.

3) Investigate some kind of on-board controller that lets you run the rear servo from a Y-lead but allows you to turn that on or off with an aux channel (e..g SWD operating Ch6).  Not really sure what's out there in that respect.  Could probably knock something up with an Arduino taking inputs from Ch1 and SWD on Ch6, but if you're not into electronics then that's probably a no-go.

4) Get a different radio...

Thanks for the detailed reply. While it is a shame you couldn't get it to work, it does reassure me, that I wasn't going mad!!! :D

Think for now I'll just set it to rear steer on the left stick and do it manually when at low speed and see how it goes. It is easy to change it back over if I want permanent 4ws. I'll also see if I can investigate option 3 a little further.

I do have a 3ch Core RC radio, will have to see if that has any different capability, but haven't looked at the option yet.

Share this post


Link to post
Share on other sites
On 12/6/2019 at 8:18 PM, Busdriver said:

https://bastens.com/products/bastens-quadsteer . Dont know if this is still available but you could contact the supplier

Just had e mail from Pat of Bastens to say that he has quadsteer in stock if you are interested. He had forgotten to change stock level on website. I am going to get one for my Dynamog. Hope this is of interest.

  • Thanks 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...