I’m looking into getting a 4wd3 to develop an autonomous robot. I already have an L6 arm to put on it, I’m just looking for a bit more info if anyone can help.
First, I would like to know the dimensions of the platform (internal mostly).
Also, I want some more powerful motors in it, does anyone know if you can order it with the high power 12v ghm (GHM-12) instead, and just pay a little extra?
I’m going to get the add-on-deck with servo holes (AOD-04) for my arm and other things, I was wondering if you can fit servos in the side holes without them hitting the wheels (looks pretty close)?
Thanks for your help in advance,
Steve.
By the way, if anyone is interested, I’m planning on using a WiPort to have wireless control, with video feed back. So it will have autonomous option, or controlled from my laptop, or pda.
I’m using an ATMega 128 microcontroller, so I’ll have plenty of processing power too. This robot will be full of gadgets and autonomy and stuff like that.
I’m planning on using LiIon batteries out of a power tool pack to make my own battery pack. It will be a 12v 6000mAh and not much bigger than a normal 7.2v stick pack (6 x 4v cells. 3series, 2parallel).
The internal space is roughly 7" x 7" x 2.5". We may be able to swap out the motors for you. They will fit.
I don’t have a 4WD3 assembled here, this is unusual for me, but I believe the servos will fit if installed from the top. All of the 4WD rovers are getting major work done.
I am very interested in hearing about the wireless control of the robot, AND video back to the operator. Let us know how it goes.
Hey do Li-ion power tool packs generally have over charge and over current protection circuits in them? If they do then this might be a very interesting way to apply Li-ion power to small robot platforms. Hmm…
What kind of work is being done, if you don’t mind me asking? Will it pay for me to wait for a new model, or upgrades or something?
Hi Eddie, These packs don’t have that protection. Charging is usually done by a good Li-Po charger as these cells have more capacity than standard Li-Ion cells (4v per cell). These cargers are not cheap, but I already have one that I use for all kinds of different batteries. It keeps Li-Po’s safe, and the life of other batteries up. These batteries are a lot more stable than older Li-Ion, or Li-Po’s, so they won’t explode on you, but it is still recomended that you charge them properly.
In terms of current, they have been reported to handle between 10 and 15C discharge. So each 3000mAh cell can handle from 30-45Amp discharge, which is plenty for a small robot if you ask me. I will be using them in paralel, so I will be able to get over 60A if I wanted, but I’m sure I will never use it. So the discharge thing is not really a problem, I’m really after a good run time.
“I don’t have a 4WD3 assembled here, this is unusual for me, but I believe the servos will fit if installed from the top. All of the 4WD rovers are getting major work done.”
I will go into some detail, but I know people are going to hammer me for when when when… Stuff takes as long as it takes. We are going as fast as we can.
12vdc motors and battery packs. The motor controllers are a little more stable at higher voltages because there is more “overhead” for the built in logic regulator. Plus this will provide many motor options, including one with a built in 12 CPR (on the motor, not the output shaft) hall effect quadrature encoder. I have received some samples of the encoder equipped motors, and am currently waiting for new samples with improved bushings on the output shaft. I have the battery packs (1600mAh 12vdc) on order.
Black anodized 0.06" aluminum side, front, and rear panels. I do not have samples yet, but they are in process. I will post images as soon as I can. The side panels have integrated PEM nuts and the front and rear have matching holes to build the chassis. The top and bottom panels will be Lexan at least at first as I have more freedom to experiment with the placement of servo, SES, and PC board mounting holes. The panels will also use the PEM nuts to mount. This allows easy battery replacement by just removing 4 screws. There are SES hole patterns on each aluminum panel. The chassis is just thick enough to encapsulate the motors, batteries, and motor controller. Additional mounting space will be handled by add-on decks. There are two overall sizes which match the current 4WD1 and 3 sizes. An additional short front and rear parts will allow the 4WD2 to be made. We will be adding 6WD versions as well.
Tires, rims, and hubs are totally redesigned as discussed in the 115 post Off Road Tire thread…
I will not answer any questions regarding when these new rovers will be available as I expect it to be a minimum of 8 to 10 weeks. Hold on, total rover nirvana is on the way! 8)
No sir, sorry. As soon as I receive the sample 4WD rover parts, they have been delayed a week, I will throw more energy in the rover direction. Hang tight.
I really want a Lynxmotion 6WD Rover that I can put up against my friend’s Machine Lab MMP-8. He bought it completely assembled, which is the only way you can get the basic unit, and I want to show him that a Lynxmotion kit unit is just as robust as the MMP-8 and for less bucks!
Stuff takes as long as it takes. We are going as fast as we can.