For quite a while now, I’ve been roaming your site, itching to get started with some decent robotics. I’m a big fan of your work.
I’ve come to the stage of actually ordering the bits, and would like some advice on this matter, if that’s not too much to ask?
I’m looking at a tri-track base with PS2 wireless control, an arm mounted on top, and a pan/tilt mounted somewhere on thesame base rotate with some SES brackets for a wireless camera mount.
Questions:
You offer several (maginificent) arms. What one would you recommend to be put onto the tracked chassis? Powerwise and sizerelated? I’ll be using standard mounting method for the base rotate, and would like to be able to reach sideways over the tracks at least. I do not intend to pick up any cars or punch through walls with it, before you ask.
Same question for the wrist rotate.
Batteries. As I understand it I’ll need a 6V battery to power the servo’s and logic (bot board 2), and a 12V battery for the track motors. They come in various sizes, so what ones would you recommend for said setup? With the botboard, PS2 receiver and sabertooth installed inside, what battery combination would/wouldn’t fit inside? It is rather important everything will fit inside smoothly, and I couldn’t find the internal sizes of the tracked chassis with electronics installed.
If all goes well, the next project will involve self-docking and charging. This’ll be greatly easier if I only had one battery type and voltage to take care of, so do you have any suggestions for any 12Vdc to 6Vdc converter setups for this, or is running the whole thing on 12V battery voltage plus converter a bad idea?
Also, what spike amps would I be expecting for the converter to handle? Full load example lifting up an object at maximum range?
Perhaps it’s wiser to just start off with the standard battery setup?
Camera. To be added later, but I’d thought I’d throw it in- I’d like live feed coming from the robot, to be visible on the apple Iphone. I’m a bit unclear as to what options work the best. As I gather there’s two distinct different systems used. One uses a camera with onboard WIFI, and transmits directly into your WIFI router and hence easy to pick up on computer or Iphone. The cameras do seem rather bulky though.
The other one uses smaller cameras that transmit over radiolink to a seperate transmitter. How would this one end up on my Iphone, and what option would be recommended?
I realise that’s a lot of questions, sorry about that
Thanks for your time reading through, and keep up the good work!
Not sure if that configuration would really fit. You might have to choose either the arm or the pan/tilt, not both. Not without modification, at least. The base rotate kind of covers the spot where the pan/tilt assembly would otherwise go.
Not sure what you mean by “powerwise and sizerelated”, but as far as arms that can reach over the tracks, I would go with either the B or D arm, the D arm being the larger/stronger of the two. The A arm can barely reach over the tracks, but it might also work for you.
If you’re trying to just use one voltage of battery, it might be easier to use three 6v 2800mAh batteries instead of a 12v battery. With some clever wiring, you could charge them up as three 6v batteries, and use them as a 12v battery and a 6v battery, if that makes sense. I can draw up a diagram if that isn’t clear.
This one’s out of my knowledge. I’ll leave it to someone who perhaps has an iPhone.
You are indeed correct, the pan 'n tilt won’t fit on the base, I’ll be doing some modifying to get it on there somehow. However I’m looking at some camera’s that actually have pan’ntilt built in, so that mod is on hold until I decide on the camera type If all else fails it’ll just be mounted on the arm as most seem to do.
Very helpful, so the A-arm is definitely out.
2,3. Excellent idea! Would 2 1600mAh (combined for 12V) and one 2800mAh do, or should I go for 3 2800mAh ones? I have no real idea what kind of currents or power drain to expect from a fully loaded arm. I’ll never say no to a diagram if that’s not too much to ask Haven’t quite looked into how to charge it using a dock of some sort yet so no rush, thought I’d get the bot up and running first, heh.
Oh, will they all fit inside though?
That all depends on how much run time you want. The 1600mAh batteries will give you slightly more than half of the run time as using 2800mAh batteries. It’s all up to you though. The arms don’t draw too much current either. They are powered with a 2Amp wall pack, and they normally draw much less current than that.
I’ll leave it at this until you’re ready for creating the charging station. We’ll chime in if you end up needing help later.
Ah, yes, that’s not a problem, I thought you ment the wiring for the charging. Still have to have a bit of a brainstorm about that at some point. I’m thinking charging all the batteries in series might mess up a smartcharger’s voltage and battery status detection… I’ll have to have a brainstorm about that at some point. Thanks for the assistance! Parts ordered, time to make room on the desk!
I’ll open up a new project topic in the more suitable tracked or rover forum when construction starts, so you can all enjoy the sparks and black smoke with me.
In the meantime, a few more product-related questions if you don’t mind:
What program do you use to make the electronic schematic pictures? I’m looking for something easy and free Mainly so I can share all my scribbled paper schematics with you all without you needing to decypher my cat paws. Scanned post-it notes with egyptian hieroglyphs might be just a bit unprofessional.
I’ve acquired the AL5D arm. Will it be able to rotate a full 360 degrees? I seem to have a desire to manipulate objects directly behind my bot. If no, I assume I could mount it a bit off-center?
In roaming these forums of vast knowledge, I bumped into one post stating you were working on a wifi module to add to your electronics boards. What’s the status on that, before I start looking into alternatives?
When charging a 12V bat and a 6V bat with their individual respective smartchargers, can I put the commons together, or will that mess up the deltaV detection?
I’m looking at designing a docking station and charging the batteries while they’re still connected inside the robot. In regards to this:
I’m thinking of hooking up the 12V batt and the 6V batt to two individual smartchargers individually and electrically disconnecting them from the bot boards. So far I’ve found relays that’ll serve the purpose (a 5V 3PDT will do if I can put the battery commons together, a 4PDT seems easier to find) however you supply several relay options too. I’m specifically looking at your BM-02 power switch… are those double throw, and can you get them with more than one switch? One could string them together but seems a bit of a waste of space and power. It would be bloody easy if I could just hook the coil up to the botboard though!
The one I’m looking at is this one:
I’ll slap together a schematic with the relay when I find a drawing program for it. It should work quite well in theory, allowing the bot to sit on the docking station permanently, charging and maintaining both batteries at thesame time, to the best abilities of the smartcharger you use, AND keeping the arm and electronics powered with 6VDC. There should only be 4 contacts to be made when docking: common, 12V batt charger, 6V batt charger and 6VDC. This is a bit of a complicated and expensive way to do it though.
Obviously I could go for simpler trickle charging and leave the whole thing connected, but then I’m assuming I can’t leave the thing charging continuously. Thoughts?
