Questions For Josh, Please

Question

hey Josh!

I have written many questions unanswered by you. I guess you have been busy. I figured I would put them all in one place so it would be easier for you to find them. I have forgotten many. Here are some of them:

Have you actually tried the schematic where you had two twelve volt and two six volts hooked in such a way that you could charge both at once? I guess the secret was the floating ground on the 6volt battery. Am i right? Did you ACTUALLY do that? Did it work?

What was you saying about putting the drive train backwards on the Omni2K? How did that work out?

 Have you used 12vdc on the drivetrain? how did that work? Are you Happy with how your robot works?

 I think I saw a microphone in your stuff. Have you used this? Has it worked good? do you use it for localized sound input?

 I am trying to build the Omni3000 bot. I am gathering all the parts now and have done somewhat of a build.

Thanks,

LOL

Mel

Rich · Answer

All of those answers are already in the forum dude. The 6v/12v circuit has been explained in some depth, wire it up as the schematic you posted and it will go bang as you are directly shorting out the 6v batteries. I have provided you with 3 alternative options for this. However I would advise against considering it if you are still confused over the schematics posted as there is a lot of room for error and error could be very bad. Drivetran backwards reduces the rocking on both the Omnibot 2000 and on the 5403. Lexi originally had her drivetran reversed, it's explained in the Omni 3000 project showcase. 12v has run fine on the 5403 drivetran and I'm sure I've seen Josh say that Jarvis has 12v to his drivetran. If it's too much you can always PWM it down which improved some drivetrans on a few other projects, I believe they were rad based. I hope I haven't spoken out of line here since this was addressed for Josh but I believe that if the community has answers then the community should answer and not rely on a single person for those answers. Please, by all means wait for Josh to respond too but as I said, the answers are all in the forums already in various other topics and posts.

MovieMaker · Answer

No, Rich, that's "ok". I welcome any input. Thank You! LOL Mel

jstarne1 · Answer

Hello Mel , I assure you I was not ignoring your questions , I guess I thought they were answered in project update posts. 6 to 12 volt. Two 6 volt batteries must be in series to get 12 volts. They can only be parallel or series but not both. Wiring both causes a short. I believe I solved this back in the charger post by running everything 12 volts and I have buck step down converters for the servos. The omnibot drive train works very well on 12 volts and further research on the specs from the manufacturer revealed that the motors are 12 volts to begin with. Tomy just undervolted them. Reverse drivetrain - yes I found reversing the drive train and adding two idler wheels it made the base feel very solid and now Jarvis modified 2000 base moves smoothly. I reduce the play in the wheels by dremeling out the area under the gear box and remounting lower to the axle. Also I locked it in high gear where there is less play , lower gear adds two more gears the power must be transferred through every added gear adds a small amount of play. I compensated for the change by replacing the stock motors with more powerful new ones from Roomba. There are two motors meshed to each input gear. In demonstration videos you see it moving 45 pounds if weights effortlessly after the mod. As Rich said PWM is a great option to slow the robot down which is what I am using. I'm happy so far with performance of the drive train but I honestly would love to get motors from a wheel chair one day because they are so quiet. Even with the sound deadening there is an unavoidable plastic mechanical noise and electric motor hum. You can get the volume very low but it's just the nature of plastic gearboxes , they are not made with high enough tolerance to avoid harmonic resonance. @Rich ,it's cool to work together to answer questions but sometimes a member may want to ask about personal experiences which is more direct. Most questions can be answered on the forum but if there is something left lingering I didn't see you can always email me and link the thread. Kandyred@gmail.com

jstarne1 · Answer

The microphone I've not really used yet , I have a built in Mic on my laptop. I dont have any experience with the Sony stereo condenser Mic yet.

Robot Doc · Answer

The newer 500 model Roomba drive motors make less noise than the earlier 400, 4000 models.

Robot Doc · Answer

Yes, the 500, 600, and 700 wheels are the same.

jstarne1 · Answer

The roombas 500 to 700 series are as quite as you can hope for. Since the 500 to 700 series had scheduling options they needed to be quite to run at night or day without really making a racket. The gears and motors are made in higher tolerances than toys. Running the 12 volts and pwm to dial speed I believe you will like it. It's a way cheaper option than everything required to make that previous setup work. In the brewsters video he has a 400 series and it's not really noisy in his video on hard wood floor. Your most difficult part of installing 4 wheels is getting them level with each other.

MovieMaker · Answer

You guys are Great! All of you were tremendous help. I appreciate it. I have the roomba wheels, but quite frankly, I am scared to open up the drive train. The last time I did that, things jumped out everywhere. I would rather leave it sealed if I can. But, on the other hand, Sunshine MUST be able to run properly. @Josh, I did not think you were ignoring me on purpose. I just thought that you were busy. Thanks! Mel

MovieMaker · Answer

Thank You!

MovieMaker

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