Substituting Analog Stick in Vectrex Controller

[gliptitude]

I have an already dissected Vectrex control panel in poor condition.

I have a neat little analog stick from an arcade game, with 5K pots.

Is it possible this arcade stick would work as a replacement, eventhough it has incorrect pot values? .. Maybe work with the non-analog Vectrex games?

I have read that small value pots like this are sort of interchangeable in some devices.

.. On a side note I have removed the springs from this arcade stick because it was set up to spring in one extreme direction, rather than the center, (for a football kicking game). So now it is loose and completely non-centering.

[kokovec]

It might work but you may have to change the resistors surrounding the 5K pots in order for the outputs to swing between +-2.5V

[Computer Nerd Kev]

It should work. My experience is that the standard Vectrex controller potentiometers don't move very far during use. This means that you won't have trouble registering fully on one way or the other, but it might be extremely sensitive with games that use the analogue functionality.

I don't think you should have to change any of the other resistor values, but you might have to adjust the trimpot that connects each of the joystick potentiometers to the +5V line.

There is a table at the bottom of this page on my website showing the voltage values of the X and Y controller outputs, while the controller is connected between +5VDC and GND (whereas it is +5VDC and -5VDC on the Vectrex). That shows how little the potentiometer actually moves during use.
www.computernerdkev.heliohost.org/vec2600/vec2600.htm

[kokovec]

I've designed and built a couple of PS2 Vectrex controllers and generally the Vectrex ADC wants to see +-2.5V.
You may not need to change the resistor values but bear in mind that the joystick will have 1/2 the travel and resolution than a normal 10K pot.

[vtk]

i used the analog pot from a playstation dualshock gamepad to repair a vectrex controller i had here, i had to remove the surrounding resistors as kokovec mentioned, using jumper wire instead of the resistors

it ended up with the joystick not having as much travel as the original vectrex pots, but it does work fine still (once calibrated), and is very smooth in motion compared to the original vectrex pots which feel more 'clunky' compared to the more modern ps2 design

[gliptitude]

Well my first attempt was a pretty decisive failure. One of the tabs broke off of one of the pots after I got everything set up.

I had previously noticed that one of the other tabs was already missing, but that that one had some sort of scratch job with a wire lead already in place.

I have two of these joysticks and it looks like the other one also has a tab missing, and some similar improvised fix:







Perhaps changing out the pots would be possible and easier at this point. .. I'm not sure how far I want to take the experiment with what I've got though. I'm not really trying to repair this existing Vectrex controller, just using it for testing the sticks. These two that I have are so sexy, but unfortunately they have the goofy setup for anti-centering springs, (hence I removed the springs). That combined with the sorry state of the (incorrect value) pots might be a deal breaker.

They are nice looking and better than anything I've been able to get my hands on so far though:







.. It does look like it would be necessary to change or eliminate the resistors to use this stick. On the axis that did not break I was eventually able to center it, but it was still barely able to signal (left) at all and (right) less than half way, according to the Test Cart controller monitor.

.. I might try one of these and also go ahead and get seperate components, (buttons, resistors, trim pots. 9 pin cable..), (using the old existing Vectrex original doesn't really end up being that convenient):







www.ebay.com/itm/191733590747?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[kokovec]

Funny how the design hasn't changed after all these years.