Eric - Build Diary

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Rambling
Posts: 7
Joined: Mon Jan 08, 2018 10:58 pm

Eric - Build Diary

Post by Rambling » Tue Jan 16, 2018 10:52 pm

Hiya,

I've already had the fortune of asking a question on here last week about transmitters, batteries etc, but now I have most of the parts I thought I'd start a build diary for my first time build...

A flipper called...

ERIC

I think in this begining post I'll just go over all the parts I've purchased for this.

For starters, the TX and RC (transmitter/receiver). I purchased the Turnigy 9x set from HobbyKing found: here.
I went for mode 1, because I'm left handed and wanted to control the steering with my left hand.

This set works perfectly for me, together with a 6v NiMH battery (here). I went for the 120mAh flat version (Futaba connector), because I felt that should last long enough, and its light enough. When it arrived and I placed it into my temporary rubbish cardboard and electrical tape build, it lasted for more than the 3 minutes needed, so its fine for me. Oh, and I bought two, so while one spends a while charging I can have a few minutes of play with the other.

For the charger I went for a LiPro balance charger (here) because this one will do my NiMH batteries fine, and will future proof me, allowing me to use LiPo batteries for future projects (meaning I wont need to purchase another charger).

For the drive motors I used some 360 micro servos, the cheap ones you can get off ebay. I didnt want to have to have two ESC's in my machine at this stage of learning about antweights, and these servos negate the need for them. My personal issue is having to find splitters for the batteries to connect into the ESC's. Not a real issue, but still, saved me some money. It is slow, but I dont really mind, I got it to turn fast when on a full charge.

The wheels I just searched around and eventually got some from here. They are large, so it might be best for me in future to buy some servo hubs and glue them to lego wheels for a lower ground clearance. (I might actually do that and just use these wheels for testing purposes etc.)

I then also purchased a simple switch, so I can power on the bot when I want to, and power off when it needs to be off.

I'll post some pictures in the next post here, but for now just know I got them all working perfectly together, although I do need to keep trimming the controls here and there, might have something to do with me driving around a robot stuck together with not properly sticky sticky tape, and a square of cardboard.

All in all I'm happy with it so far, and I'm happy to answer any questions you have?

Thanks

Rambling

Rambling
Posts: 7
Joined: Mon Jan 08, 2018 10:58 pm

Re: Eric - Build Diary

Post by Rambling » Thu Jan 18, 2018 9:59 pm

Howdy!

So, yes, the pieces.

Heres the TX and RX, nice, all works very well
Image

Image

Here are the drive motors, nice 360 servos.
Image

Some wheels. Now these are quite large, and each one is 12 grams, to relatively heavy.
Image

The battery
Image

And here be the switch to turn it on and off.
Image

And here is the charger for the battery, works nicely
Image

I built a prototype cardboard box with all the bits stuffed in it and taped together, and it came to 93 grams. Im worries. Thats heavy... quite heavy. Thats without the armour, and without the flipper or even the servo for the flipper.

Any ideas on shedding some weight? I know geared motors might be lighter, but the ESC adds weight, i cant shed the battery or the RX or the switch.
I need to find smaller, lighter wheels that i can glue or screw onto the arms that come with the servo, that might work.

Let me know if you can think of anything.

Thanks guys

Rambling

Paulmchurd
Posts: 223
Joined: Sun Dec 10, 2017 4:39 pm

Re: Eric - Build Diary

Post by Paulmchurd » Thu Jan 18, 2018 10:08 pm

Once you trade out the card board weight for the plastic I think you will be fine.

These are the wheel i used.

https://www.ebay.co.uk/itm/N20-Micro-Me ... 2749.l2649

Rambling
Posts: 7
Joined: Mon Jan 08, 2018 10:58 pm

Re: Eric - Build Diary

Post by Rambling » Thu Jan 18, 2018 10:19 pm

Ah thanks.
Any idea how heavy those wheels are? Im gonna buy myself the set and glue them on to one of the servo arms, hopefully should be fine.

The cardboard box was a 3inch by 2inch by 2inch box, doesnt feel like it weights anything, I hope youre right about it being lighter once i get plastic. :P

And is there anywhere I can go to find out the estimated weight of plastic sheets of a size, so i can work out how much weight I have left to spare for my flipper servo (i want a relatively high powered one. even if it doesnt flip the other robot, i at least want to lift it with speed)

Paulmchurd
Posts: 223
Joined: Sun Dec 10, 2017 4:39 pm

Re: Eric - Build Diary

Post by Paulmchurd » Thu Jan 18, 2018 11:40 pm

Not sure on weight. don’t buy the set, as they are only 30rpm motors. Super slow

Derek Dudge
Posts: 135
Joined: Thu Dec 07, 2017 9:32 pm

Re: Eric - Build Diary

Post by Derek Dudge » Fri Jan 19, 2018 12:04 am

The a4 sheets of 1.5mm poly that I bought and which seem to be pretty standard for ant armouring are 115g per sheet.

I have made the entire body of my ant from the stuff, and ended up using approx 60g or so. It's about as big as an ant can be at that, although I have drilled a fair few (150 or so lol) holes in the lid and underchassis to keep that number down.

Perhaps you will be able to mix the 1.5mm with thinner stuff for various places on your bot etc, and maybe your robot would use less than my very boxy design. But if you just looking for a rough number - 115g for a full a4.

Edit - rereading your post I think maybe you meant is there somewhere to calculate weight of smaller pieces. Alas if there is I do not know.
My robots:

Third Law (antweight) - push/ram bot
Manticore (antweight) - hammer bot

Rambling
Posts: 7
Joined: Mon Jan 08, 2018 10:58 pm

Re: Eric - Build Diary

Post by Rambling » Fri Jan 19, 2018 10:31 am

Hiya,

Thanks for the weights you gave me, still very helpful!
When I said set, I should of specified I meant the set of wheels.

I think I'm gonna look around for a motor or servo that weighs no more than 30 grams to act as my flipper drive. I wanted a nice strong motor, but it was 60g which was a bit much.

Rambling

Derek Dudge
Posts: 135
Joined: Thu Dec 07, 2017 9:32 pm

Re: Eric - Build Diary

Post by Derek Dudge » Fri Jan 19, 2018 4:46 pm

I've seen folks on here recommended this servo for flippers. 21g according to the site

https://hobbyking.com/en_us/turnigytm-t ... tore=en_us
My robots:

Third Law (antweight) - push/ram bot
Manticore (antweight) - hammer bot

razerdave
Posts: 1520
Joined: Mon Jan 02, 2006 9:40 pm
Location: Carterton, Oxfordshire
Contact:

Re: Eric - Build Diary

Post by razerdave » Wed Jan 24, 2018 5:36 pm

I presume this was a low cost ant? Good first attempt, fair play :)

Also: I strongly recommend a name change. The Robot name “Eric” is already in current use in heavies (and in fact has reached Facebook meme status), so it’s probably a good idea to change it.

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