Gs Nanoweight.......?

If Fleaweights are just too big...

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Ant
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Joined: Tue Dec 13, 2016 10:51 am

Gs Nanoweight.......?

Post by Ant » Wed Feb 06, 2019 12:38 am

So, at Ant Freeze my son, G, discovered Nanoweights and seem to have gathered lots of information from Peter and Shakey's Nanobots.
All this information was down loaded to me on the (long) return journey :-? and Tinkercad has been in overdrive since!

For our first attempt we are looking at:

Drive: https://hobbyking.com/en_us/hk-5320-ult ... 075kg.html

RX/ESC: control boards from the HXT900 or 500. with https://hobbyking.com/en_us/orangerx-r6 ... opter.html (if available)

However, the RX47 that Peter mentions in his thread sounds the lightest/most compact way of rx/esc - just need to figure out which version is best suited.

Flipper/lifter either a Turnigy 1440A or 1370A - depending on stock and weight!
Batteries: tbc

I realise that this will not be very fast, but should keep him busy over half term

Thanks
Anthony & G
Team-G

AntRoboteer
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Re: Gs Nanoweight.......?

Post by AntRoboteer » Sat Feb 09, 2019 1:29 pm

The drive servos look good; you don't actually have to use separate ESCs as each servo includes a built in ESC. You just have to replace the potentiometer with two resistors in this order with the board oriented chip on top, blue potentiometer wires on the bottom:

1.4k ohm resistor from centre to rightmost pin
1k ohm resistor from rightmost pin to leftmost pin

You can then remove the potentiometer itself as the main output gear 'glides' along the top plastic well enough to run smoothly without further support.

The gearbox has loads of gears and shafts which are really tiny; if you get a chance to get a picture before the whole lot falls apart, do, because they are very fiddly to get back together and most of the gears look similar.

Not very easy to do due to the small size of everything but possible. The challenge is cramming everything back in the servo without shorting anything together (even more difficult than soldering the points).

As for the receiver, anything without pins tends to be ok (pinless version of the LemonRx is absolutely fine within the size and weight for example).

Battery wise, any small 1s LiPo with a plug on it should do just fine. The lifter servo should be absolutely fine as well, go for the lighter one if you can would be my advice.

Good luck, hope everything works out!

Ant
Posts: 5
Joined: Tue Dec 13, 2016 10:51 am

Re: Gs Nanoweight.......?

Post by Ant » Wed Feb 13, 2019 9:23 am

Hi
Thanks for the feedback.
Waiting for the parts from hobbyking and will have a play with the drive servos. Modifying the board on a 1.7g servo does sound a challenge of dexterity!
Cheers

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peterwaller
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Re: Gs Nanoweight.......?

Post by peterwaller » Wed Feb 13, 2019 10:47 am

It is not always necessary to remove the pot. I don't know this particular servo but if you mechanically disconnect the pot from the the drive you can leave it in circuit and then you don't need to add the two resistors. What I usually do is adjust the pot to give no movement with the stick centered and then add a blob of hot melt glue to stop it moving in combat. See extract from Small Combat Robots book: Another shameless plug I will sell one yet. :wink:
Image
It is possible to modify most standard servo to what is normally call 360 degree operation to use them as drive systems. First you need to remove any mechanical end stops there are so it can rotate continuously. Then mechanically disconnecting the feed back pot from the output shaft, marked in orange on the diagram above, and set the pot to mid point (1.5 ms pulse) and fix it with a small blob of glue. Now as the pulse length from the receiver is varied the motor start to move in the associated direction but as the feed back doesn't change the motor drive keeps going. Also because the drive speed is dependent on the difference in pulse lengths the more you move the stick the faster the motors drive.

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