I would think WP_RADIUS would be mostly independent of the vehicle. You will surely have to start from scratch with compass and gyro calibration, then tuning, starting with the throttle, then steering, using @rmackay9’s tutorials. Then work on the NAV L1 controller. It is critical to get the lower-level stuff working well first.
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@dkemxr @David_Boulanger @ktrussell @iampete @count74
Hey guys, as you know I purchased the Lynxmotion A4WD1, managed to transfer over my setup from the previous rover & it’s working well. Only problem right now is it’s not turning 360 degrees on the spot. On my kitchen floor it can do it but not on carpet or grass.
I have provided some links I recorded. The first is someone else who has the same rover. It rotates just fine on carpet:
The following two links are my rover:
As you can see on the second link when I pick it up the wheels can turn in skid steer but not when it’s on the floor:
are you running the max rated voltage?
Good question & I don’t know. Do you mean the max rated voltage of the Sabertooth? I have the following version:
And the following battery:
So would you say it’s due to not enough power being sent to the motors? Here are the specs for the motors:
Voltage = 12vdc
RPM = 200
Reduction = 30:1
Stall Torque = 63.89 oz-in (4.6 kg-cm)
Outside Diameter = 37mm
Weight = 5.44 oz.
Would you say if I got a 24V lipo that should solve the issue?
you want to be running at the minimum max voltage if you see what I mean. I think in your case it would be the motors at 12v. So your battery is only 7.2 volts so you have less power (60% of full). Get a 3s lipo (12v). If you get a 24v lipo it will be very powerful but not for very long.
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With the 22.2V battery’s I’ve been looking at you mentioned
Can you please explain further on why? I was thinking of getting the following battery:
if you go over the max rated voltages it will all get too hot and go melty, that battery is probably overkill anyway if you get a smallish 3s and monitor the current draw you can calculate how large a battery you need to drive for a set time or distance
I’m an overkill kinda guy but would you say this battery I’m considering could potentially damage everything? The Sabertooth rated voltage is 24V and this battery is 22.2V so I would have thought I’d be in the safe zone, but if you say it would be bad then I can find something smaller like the 14.8V version:
Your motors are only rated for 12 volts.
Also I will be driving at around 0.50m/s so if it stays at those speeds would the 22.2V battery be acceptable then?
So the 22.2V battery isn’t a good option. I would have thought the voltage from the 22.2V battery is divided into the 4 motors that are 12V. So 22.2 divided by 4 12V Motors = 5.55V per each motor.
I’m guessing that it doesn’t work like that
No it does not work that way. get a 3S LiPo and power module and everything will be good
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Ok will do. Wanted to find a lipo with a large mAh capacity for decent runtime. So a 3S lipo with a 12V rating is what I will look for. Thank you👍🏼
You can use a couple 3S LiPo’s and run them in parallel for even higher mAH Capacity. I have at times run six 3S 8000mAh batteries together for a long operating time.
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I can see that 3S lipos are 11.1V.
Would the one I mentioned that’s 14.8V be ok or still way over the limit?
That comes with 20,000 mah so would save me having to purchase multiple lipos to achieve a higher mAh capacity.
Bare in mind the dimensions of the Lynxmotion rover are pretty small so I need all the space I can get
is not as simple as that. They are nominaly 11.1v, but the voltage changes as you use them. So a 3s lipo will go from (3.3 * 3) 9.9v to (4.2 * 3) to 12.6v. A 4s will go from (3.3 * 4) 13.2v to (4.2 * 4) 16.8v. So a fully charged 4s battery is a long way over your max rated voltage.
How’s this idea, I purchase the 22.2V lipo & also purchase a step down voltage module:
That way if the lipo is fully charged above the max rated voltage it will still supply the correct voltage via the module. Not sure if 20A is ok which is the max this module can supply
your just adding more stuff to go wrong and reducing efficiency. Get a 3s lipo. I should think on that 4s it would literally last all day, as in 24 hours, so its needlessly big in any-case, not to mention lots of extra weight.
If you don’t mind could you show me me a 3S lipo that’s suitable with a large mAh capacity? What’s the best that’s out there I can use?
get this
edit: not the best or highest capacity. But it is a good price for what you get
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