Thread: My 3 axis skull...in progress

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I know, I know...........but that is why I like my Parallax boards...2 3 axis skulls , with moving eyes in each, and they play great in VSA..........BTW- That's 11 servos running off of a single board with 4.5 volts powering the servos............

Originally Posted by bfjou812

I know, I know...........but that is why I like my Parallax boards...2 3 axis skulls , with moving eyes in each, and they play great in VSA..........BTW- That's 11 servos running off of a single board with 4.5 volts powering the servos............

We started with a Parallax board but ran out of channels when we added more props. At this point we have 3 unused channels on the SSC-32 board. I'm not sure what happens when we go over 32 servos. I'm guessing we have to use something like Exorcist and bring our pararllax board back into service.

Here is an interesting update on my problem. Just for "grins and giggles" I hooked up to my 2nd computer which has 2GB of RAM and used all of the same settings as on my 1st computer (my control unit only has 1GB of RAM both run XP sp3). I used my same power setup also and got this to run! I still plan on using 2 separate power units, one for logic and one for servos, but this was fun for me.
Thank you all, once again, for your help and input.
Sparkey

[ame="http://www.youtube.com/watch?v=-8Lj1bvH-Zc"]YouTube- Re_Your_Brains.AVI[/ame]

Sparkey, great setup for the video - good to see both VSA and the skull acting together!

- Hook

Anyone ever try to use a VOLTAGE REGULATOR to supply power to the SSC-32?
I found this: http://www.hobbycity.com/hobbycity/s...idProduct=6233 on line and it will reportedly take 12VDC and bring it down to a constant 6VDC with a max of 8 amps constant. This would allow me to use just one power supply for both the skulls and the controller.
Any thoughts?

I always recommend using computer power supplies. They've got both 12v and 5v, and copious amounts of current. Here's some from allelectronics.com

$6.50 12V @ 5A, 5V @ 5A

$19 12V @ 12A, 5V @ 25A

The only difference, is that with 6V, you'd have a slightly higher top speed from your servos. But they'd still have just as much torque.

- Hook

Thanks for the info. but I am using an ATX power supply (I started on post 1881) which according to everyone doing the 3AS (3 axis skull) is my problem - 5VDC instead of 6VDC. Seems that the SSC-32 board requires 6-9VDC or the communications get wonkey. I was hoping to use just one power supply for my whole rig but now it seems I'll be using my ATX for the servos and a 9VDC wallwart for the SSC-32 voltage logic. It's not a problem I just felt it would be cleaner to have less parts (just one power supply). Thanks again for the links.

To answer questions...

buckaneerdude... I am using 2 SSC-32 boards now. It's no problem. Just add a second serial port to the computer or use a USB to Serial adapter. It will give you a second COM port. Just direct the new devices to that COM port (whatever the number) and you will be fine.


And Sparkey....

That is a great idea about using a voltage regulator to get a 6VDC 8 Amp output. That would work perfectly. 6VDC is the only voltage that you can safely use with an SSC-32 board when powering both the board and servos with the same supply. I wrote a detailed Tutorial on hooking up the SSC-32 with one supply and two. It is here: http://www.graveyardskulls.com/assembly/Tutorial01.html

The only reason I default to the 2 Power supply solution is because 6VDC power supplies with enough current are rare and expensive compared to the availability of 5VDC and (VDC supplies. Your solution solves that problem.

Re: SSC-32 board. That's good to know! Thanks H'Bob!

I can testify to the rarity of 6vdc power supplies with 4amp capacity. I have two of them one rated 6vdc 4amp and the other 6.5vdc 6amp (one of them was an old printer power supply I had and the other I found at a local Marvac electronics store) I was reinstalling everything into a new enclosure I built and when things didn't work I started testing components. I discovered that the 6vdc 4amp unit was putting out nearly 10 volts. I had no idea why it would start putting out so much voltage so I started shopping for another one. Wow, after literally hours searching, I found one in Australia.

I don't understand much at all about voltage, current and such electrical things but something told me to try measuring the voltage of the faulty power supply when actually connected and under load. Well, isolated the unit tests at 9.8 volts and when connected to the SSC-32 it tests 7.2 volts. I have no clue why that is but all of the servos, I think there's 28 now, work perfectly.

I think though I need to go to 5 volt power on the servos and connect a 9volt battery to the logic terminal. I just wonder if I'll have to reprogram everything. Since the routines were created with 7 volts, would running them with 5 volts affect the motion?

Originally Posted by buckaneerdude

I think though I need to go to 5 volt power on the servos and connect a 9volt battery to the logic terminal. I just wonder if I'll have to reprogram everything. Since the routines were created with 7 volts, would running them with 5 volts affect the motion?

The routines should not have to change at all since they control the servo position data only. Changing servo voltage only changes the speed and torque, not the position.