Help me plan and execute auto 4-8 way joystick replacement?

[Bramlet]

Well, I got my robocop arcade hooked up to the pc. The 8 way games are great but the 4 ways are a little frustrating. I would like to switch to an automated 4-8way joystick setup without messing up the machine too much. It has a metal control panel. I have already purchased some servos and some servo controllers. I should only need one of each but I got 3 extra servos and an extra controller to play around with afterwards.

Since it is a metal control panel I am unsure of how to mount things. I have not chosen a joystick yet, because I would like some input from those who have done this before. I have never actually built my own arcade controls so I am very new to even installing new buttons.

With a wood panel you can screw into the wood, but with a metal control panel do I want to weld some kind of mounts for the servo and controller?

[Bramlet]

Reserved for links of interest.

Related BYOAC wiki article: http://wiki.arcadecontrols.com/wiki/4way_to_8way_Auto-switching_Joystick_Mod

darthpaul tutorial thread: http://forum.arcadecontrols.com/index.php?topic=113249.0
another thread: http://forum.arcadecontrols.com/index.php?topic=104762.0

[TopJimmyCooks]

The pro way to do it - weld some threaded studs onto the bottom.  very strong and permanent, but it will mess up your overlay if you're keeping it.

The way I would do it:  cut a 1/2" piece of plywood to a shape that fits where you want to put the servo and epoxy it to the underside of the metal cp.  Make sure it's clean and dry and maybe hit the metal with sandpaper or a wire brush.  then, you'll have a place where you can woodscrew your servo and controller and move it around if you need to.  Keep in mind where your buttons and control arm will be so you don't block yourself.  it can get tight under there.

[Bramlet]

Here's what we're working with, the canvas as it were. The overlay is already in bad shape. You can see the original blue in the underneath pic, and many cracks.

[TopJimmyCooks]

cut a piece of plywood that fits between one set of the red/blue buttons and the curve of the CP front.  You'll be set.  Even if I had welding capability, I would do it this way.  Good luck.

[darthpaul]

Here is another good link, http://forum.arcadecontrols.com/index.php?topic=104762.40 this was the inspiration for my set-up.

[mgb]

As far as mounting, I have the same control panel. for mounting some stuff on it like a lighting controller, I epoxied a small piece of wood inside the cp and then used small screws to attach the controllers.

Also just a note, if you change the joystick and go to reuse the mounting studs that are currently there, your new stick may be slightly angled. the mounting studs there are on a slight angle and the dataeast stick is slightly counter angled. So if you mount something like a Sanwa Jlw, you will find that when you press the up direction, it will press a little to the side direction.

Best way to deal with that is to cut off and grind down the existing studs and drill for the new joystick mounting and just use carriage bolts to mount the new stick.

[Bramlet]

How slight of an angle are we talking about here? I don't notice anything just looking at it. Hopefully its not enough of a bother, but at least I will understand why.

I'm still shopping for a joystick. Any suggestions?

[Le Chuck]

I don't think welding is necessary so +1 to the JB Weld wood brace suggestion but some prep work ahead will save you headache later. 

Get the controller first.  Your choices are pretty much the two listed in the wiki you mentioned.  I'm a huge fan of the Omni2, I really like it's movement. 

Figure out where you'll need to be putting the brace for the servo and cut it to shape, then route or drill out the middle to fit the servo.  Go with a tight as tolerance as you can and leave a small channel for the data/power cable so it doesn't get all bent to hell.  When you go to mount you're going to epoxy the brace into position then seat the servo down all the way to the metal and epoxy that to the metal and the wood around it.  This will take care of any lateral movement from the servo.  If you do this right you won't even have to bolt your servo down. 

No idea on the angel offset for your old mount holes but I've seen a lot of guys use some 16g or 18g rolled stock and make their own offset mounting brackets.  Takes a few hours at the most. 

[Bramlet]

OK, I got my servos and controllers, I know I only need one of each but I got extra to play with. I soldered up the connectors on one of the 6 channel controllers.

I also got about a dozen of these universal wall wart power adapters. I can do 3, 4.5, 6, 7.5, 9, or 12 volts at 500mA. These servos supposedly use 450mA at 6v and 350mA at 4.8v with no load operating. Does this mean my bonanza of free wall warts are duds or can I use one for this project?

[Le Chuck]

OK, I got my servos and controllers, I know I only need one of each but I got extra to play with. I soldered up the connectors on one of the 6 channel controllers.

I also got about a dozen of these universal wall wart power adapters. I can do 3, 4.5, 6, 7.5, 9, or 12 volts at 500mA. These servos supposedly use 450mA at 6v and 350mA at 4.8v with no load operating. Does this mean my bonanza of free wall warts are duds or can I use one for this project?

Use the 6v one and all will be well.  The trick is to have enough mA.  Having 500mA on the line will not affect the device using 450mA, it will just take what it needs... like an electron buffet.  Just make sure you get the polarity straight from wart to servo or you'll need that spare.

[Bramlet]

So there is no load really with this project but for the other ones, if I have a load on the motor and I'm using these adapters will I have problems do you think?

[Le Chuck]

No, the most those servos draw will be 6v 450mA.  No matter the application it won't go above that for that servo so the wall wart providing 6 at 500 will suffice for all.  Don't worry about the no load draw.  

Edit:  For example, I'm running mine (a 6001HB) on a 5v 500mA source with no issue and it rates 6v for load but everybody at the Pololu forums indicated that running under will only cause it to tap out earlier.  Considering that stall torque @ 4.8V is 5.8 kg·cm it could probably move 4 joysticks in line before stalling out and I'm doing just one. It's being powered through the USB via a belkin hub and runs like a champ.  Since the warts were free I say rock on with those and don't sweat the power.  You've got it covered.