Super-sensitive DCT buttons

[SteveThackery 3,090]

Colleagues,

 

About the buttons we use for controlling the DCT........  I'm talking about the two on the left handlebar and the A/M on the right bar (not the big thumb-operated one).

 

Well, on my bike they are super-sensitive and even a very light brush with finger or thumb will actuate them.

 

You will know that they have an over-centre, or "collapse", action to them.  This is usual with switches and gives tactile feedback that you have operated the switch.  Most switches actually switch just after the collapse action, so the user has to press the switch until it "clicks" in order to operate the contacts.

 

But on mine, the contacts operate well before the switch clicks.  Even a very light pressure is sufficient, and it's actually quite a nuisance when I'm wearing thick gloves because I do occasionally actuate the switches by accident, most commonly the A/M one on the right if I shift my grip on the handlebar.

 

Is it just my bike that's like this, or is it usual?  (Mine's a 2016 model.)

[outrunner 4,457]

I think they all must be the same, on my 2016 750X a feather-light touch is all you need to shift up or down. I also find that when wearing my thicker Goretex gloves you need to think more about finger position to avoid any Oops moments.

 

 

Andy.

[SteveThackery 3,090]

Ah, that's interesting.  Thanks, outrunner.  At least I know it's not just mine.

 

I'm still tempted to take a look inside the switches to see if anything can be adjusted.

[Mikdent 4,070]

21 minutes ago, SteveThackery said:

 

 

I'm still tempted to take a look inside the switches to see if anything can be adjusted.

 

May I refer you to your very own signature.  

[SteveThackery 3,090]

9 minutes ago, Mikdent said:

 

May I refer you to your very own signature.  

 

LOL!!  Briliant!  Hoist by my own petard.

 

Jerry, you realise, don't you, that that was a challenge which I simply cannot ignore.  Those switches are coming to bits today!

 

(I wonder how much a new switch cluster costs.....)

[Rocker66 34,375]

40 minutes ago, SteveThackery said:

 

 

(I wonder how much a new switch cluster costs.....)

You may soon find out😀😀 I hope not though.

[fred_jb 10,264]

I found the optional foot lever to be excellent - not sure if it is still offered for the 2016 model, but I found it made manually controlling the DCT a pleasure, and particularly handy for knocking it down a gear when needed.  Although it only operates electrical switches it has a nice mechanical feel so makes it feel that you are operating a particularly nice conventional gearbox. Gives your left foot something to do, so is much more instinctive for a motorcyclist and saves scrabbling around trying to locate the teeny paddle switches in clumsy gloves. I found that particularly difficult as my left hand has a tendency to go numb which has me struggling to find the indicator switch, let alone anything else, so taking some work away from the left hand was ideal for me.

[Mike5100 2,061]

coincidentally someone has just produced a diagnosis of the known issue with the selector buttons on the Africa Twin.  He's not talking about the same switches but has produced a diagram showing how the detente works.  Steve - if the 3 switches that concern you use the same kind of ball and spring mechanism maybe you could get stronger springs.  Here's the thread.

http://www.africatwinforum.com/forum/201-electronics/11930-set-button-fail-2.html#post171026

Mike

[Derek_Mac 1,404]

17 hours ago, SteveThackery said:

 

LOL!!  Briliant!  Hoist by my own petard.

 

Jerry, you realise, don't you, that that was a challenge which I simply cannot ignore.  Those switches are coming to bits today!

 

(I wonder how much a new switch cluster costs.....)

 

 Steve,

            hopefully you don't break it because, according to Lings, they're unavailable at the moment.

[SteveThackery 3,090]

1 hour ago, Mike5100 said:

coincidentally someone has just produced a diagnosis of the known issue with the selector buttons on the Africa Twin.  He's not talking about the same switches but has produced a diagram showing how the detente works.  Steve - if the 3 switches that concern you use the same kind of ball and spring mechanism maybe you could get stronger springs.  Here's the thread.

http://www.africatwinforum.com/forum/201-electronics/11930-set-button-fail-2.html#post171026

Mike

 

Hey, thanks for finding that, Mike.

 

I've dismantled the "up" switch on the left bar.  Unfortunately it uses a much cruder (and presumably cheaper) method than the ball-and-spring, which I will try to draw later on.  I would imagine the same system is used for the "down" switch and the "A/M" switch, although I don't know for sure.

 

I don't think I would recommend trying to fix or modify our switches.  The "up" switch, at least, is sealed up with some incredibly tenacious stuff that looks like bathroom sealant but is much tougher and stickier.  It's a real faff removing it to dismantle the switch.

 

Nevertheless, I was able to confirm that the microswitch operates before the collapse action (on mine at least), which is why they feel over-sensitive.  It is quite straightforward to alter this by Dremelling away some plastic, and in hindsight I wish I'd just done that.  However, I decided to try and "improve" the collapse action as well, to make it more positive, and in the true spirit of my sig, I managed to stop it working altogether.

 

I think I can fix this by making a new nylon part, but for now I'm going to fit a reasonably strong return spring to reduce accidental operations of the switch.  The microswitch now operates right near the end of the button travel, so even though there is no collapse action I think it will be an improvement.  And as I say, if I can find some nylon rod I'll make a new part on my lathe to restore the collapse action.

 

As for the other two switches, I think I'll go ahead and see if I can remove the right amount of material so the microswitches operate after the collapse action.  But I won't mess with the actual collapse mechanism itself.

 

Diagram to follow later.....

[SteveThackery 3,090]

So it's a bit of a rubbish system, I think:

 

 

The blue part is pushed to the right by the switch button.  The ramp on the blue part pushes the piston upwards and to the right.  The step in the piston is pushed against the rim of the cylinder, making it harder for the piston to be pushed upwards.  With enough force on the blue part pushing the piston upwards, the step is eventually forced past the rim (this is the "collapse" part of the action).  The piston then moves freely upwards into the cylinder, resisted only by the return spring.

 

My immediate reaction was that the rim of the cylinder and the step on the piston, being forced past each other, will wear (or suffer plastic deformation), although I expect the manufacturer has made sure that won't happen.

 

On the whole, though, it looks like a pretty crude system to me, which is borne out by the rather unsatisfactory operation of the switches.

Edited May 2, 2017 by SteveThackery

[Slowboy 20,357]

Very entertaining, at least your living up to your signature line. It won't be long now😀

[SteveThackery 3,090]

OK, final report!

 

I succeeded in making the switch actuate when the button is much closer to the end of its travel, which I think will reduce the unintended gear changes.

 

In my attempt to make the "collapse" action better I made it worse, so in the end I gave up on it because I wanted it all back together for tomorrow.  So right now the switch feels great, with a good weight to it and less tendency to actuate on feather-light touches, but without the "over-centre" snap action.

 

Although it's no big deal, I think I will have another attempt at restoring the collapse action in due course, when I've had time to mull it over and think up how best to do it.

 

Obviously I will keep you informed of developments in this gripping saga!  

[Slowboy 20,357]

Said it wouldnt take long😁