Noob build questions

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Kustom
Posts: 7
Joined: Mon Apr 24, 2017 11:36 am

Noob build questions

Post by Kustom »

Hello all,

Long time stalker first time poster.

My son and I are looking to build some antweights to compete with.

Ideally we'd like to start with some of Shakey's fine flipper offerings to get us up to speed in terms of driving ability. My son wants to go stright in with a spinner so im trying to temper his enthsiasm slightly as we dont have an arena to practice in.

For our second bots im starting to build a spec of what to get:

TX - Im looking to get a pair of Spektrum DX6i so we can be flexible with regard to DSMX or DSM2
RX - Lemon Rx Featherweight seem to be available
Body - I have a 3D printer so that will cover most of it, with the addition of some polycarbonate and or titanium sheet.
Flipper Servo - Ive had a look around and the EMax ES9256 HV seems up to spec. 3.0Kg.cm stall torque and 0.06/60 degrees no load operating speed. Does anyone else have any better suggestions that are currently available?
Motors - N20 in either 300 or 500rpm form. (Depends on driving ability)

Parts still TBC
ESC, the NanoTwo would be the obvious choice but these seem in rather short supply, what other options are people using?
Battery - What are people using for these, ive had a search around on the forum, but a lot of things seem to now be conituned.

Also presuming we move onto more powerful weapons we would need change the flipper servo to a brushless ESC and motor. Again from looking around the forum the some of the previouslt suggested ESC's seem to be discontinued, are there any recomendations for these?

Thanks for the help.
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LimaHotel
Posts: 258
Joined: Fri Mar 16, 2018 10:30 am
Location: West Devon

Re: Noob build questions

Post by LimaHotel »

For the battery you want a 2s 180mah lipo. Sadly the turnigy ones I used to recommend have been discontinued, however any 2s 180mah lipo will do.
You'll also need a lipo charger of course, and a lipo bag / box. (Get a box. It's so worth the extra tenner)

ESC: Awescv4 are great from ARC, though a little intimidating. If you don't mind starting at the cheap end, then Bustophedon 10a escs are overkill and heavy (and you need 2 per bot as they're only 1ch), but they're £3 each. I use them in one of mine - at least I never need to worry about them breaking!
There are a number of chinese escs available online - I'd talk to Kyro about those. He's the king of cheap chinese ESCs!

You could also use servo boards, which is a cheap and low weight solution, though a little more involved. Either get a 360 degree continuous rotation servo board, or remove the potentiometer and replace it with a resistor. I don't recommend this path given the number of escs available.

I will say avoid Dasmikro. I use 2 dasmikros, but that's 2 out of like 6. They just are not reliable.

TX: I know nothing of the Spektrum, but I use a Devo7e and it's great.

RX: Lemon Feather no-pin are great. The end pins are nice for beginners as they don't need soldering, but the weight (And moreso space) taken up by the pins is significant.

Servo: I recommend a Kingmax servo. You'll find links to it dotted around (Most recently T_Y's build log?).

3D Printing: I don't. Like, No. Urgh. *Shudders*
IF you're printing, put thought into what you're printing in. Prints can delaminate. Prints can crack. prints can fail. I know Shakey uses ABS to great success, and T_Y uses PLA+ to... mixed... success, but PLA is just too brittle. Oh, PeterWaller uses Nylon filaments primarily I believe, and they're crazy tough. OR you could make like me and use roughly cut bits of polycarb and recycled metal that you've bolted together with M3 bolts (And the occasional M2).

Brushless ESCs: Afro 12a race esc is the standard to the best of my knowledge?
A grabber? I CHALLENGE IT WITH JIGGY!
James Williams
Posts: 94
Joined: Tue Jul 03, 2018 5:07 pm

Re: Noob build questions

Post by James Williams »

Hi. welcome to the forum!

Firstly I would recommend looking at the recommended parts list on Bristol Bot Builders (BBB) for components;

https://bristolbotbuilders.com/parts.html

Regarding specifics, most people use 180mah 2S lipo batteries. Just search for that on Ebay & you'll find plenty of vendors. ESC's is a little more complex, depending on your skill/confidence with soldering. If you are good at soldering the AWESC is great https://www.arc-robotics.org.uk/shop/ & dasmikros are also a popular choice due to being cheap & light, but are known to be unreliable. If not then BBB have a couple of options. Nanotwo's are great but Rory & Shakey are in the middle of making a new batch so they won't be ready for a while yet.

Speaking of Rory & Shakey due to some discontinued components their flipper ants won't be restocked for a while either. As luck would have it Will from team Shock has an antweight flipper for sale on Ebay right now, but there are only a couple days left on it so you'll have to act fast. https://www.ebay.co.uk/itm/GREEN-Shockb ... SwIWBd9gLh As someone who owns one of Will's old flippers I can promise they can be very competitive!

Otherwise I think your list looks pretty good, looking forward to seeing what you come up with. :)
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Kyro
Posts: 412
Joined: Fri Jan 18, 2019 12:36 am

Re: Noob build questions

Post by Kyro »

hello, alleged king of chinese esc's here (-_-)

if weight is not an issue then i too recommend the bustophedon esc's... they are practically bombproof.

however for simplicity there are 2 esc's that i use in most of my bots...
this 5a one
https://www.ebay.co.uk/itm/Dual-Way-Bid ... SwZl5db43x

and this 1.8a one which is smaller and lighter
https://www.ebay.co.uk/itm/1-8A-Brushed ... Sw4SJdtouw

i have had great success with both of these.

although, if you use the hp n20 motors then the 1.8a one will not be safe to use for 4wd, however if you use standard n20's then the stall current is fine for 4wd.

for some idea on the success of these esc's:

Dominus ran the 5a dual esc and won robot club 1&2 as well as strugglebots (all small events so not as good as it sounds)

Mantis runs the 1.8a dual esc and won the bbb 2v2 event and came second in antweight open 2019 (much larger event)

Esper runs 2x bustophedon 10a esc's and finished 3rd at aws60 (the biggest antweight event in the uk)

so i can happily recommend all of these esc's, knowing that i have only ever had 1 fail which was one of the first i ever purchased and i lost reverse on 1 of the channels.

these esc's have all been through many events as well as many many hours of fighting at home with friends and family (and my dog that loves to chew on antweights when she catches them) and have been moved from bot to bot as i have rebuilt and redesigned my builds...

there are smaller and lighter esc's available, but best bang for your buck, are the dual channel ones i linked above for cost and reliability
Team Rocket
Trappist 1(4wd grab 'n' lift)
Ton 618 (4wd expanding bot)
Io(4wd flipper)
Kustom
Posts: 7
Joined: Mon Apr 24, 2017 11:36 am

Re: Noob build questions

Post by Kustom »

Thank you all for the warm welcome and taking the time to share the info.

Ive had a quick look on ebay and there seem to be a lot of Turnigy nano-tech. Not many seem to have JST connectors, what is the most common type of connector on an antweight?

Ive got an old Turnigy Accucell-6 charger somewhere if I can find the right leads for it but I'll need to get a lip bag/box.

I was planning to use the Devo7e but I read that the new ones have issues when they are flashed with the update, so I went for what seemed to be the next most common the DX6i

Ive mainly gone for 3D printing as it allows me a way to teach my son some CAD skills but I see your point regarding brittleness, I was planning on using ABS initially to combat this. If i get to anything like a competitive level I could always progress to some carbon reinfoced plastic.

Thanks for the tip on the Afro 12a.

The AWESC looks like a good alternative to the Nanotwo so ill look into that.

Kyto thanks for those links, they look like a great starter esc's.

Quick question regarding motors there seem to be a lot of very similar n20 motor available on ebay, and ive not seen any hp n20's is there a prefered supplier or are they all much the same.

Thanks
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Kyro
Posts: 412
Joined: Fri Jan 18, 2019 12:36 am

Re: Noob build questions

Post by Kyro »

for n20 motors, its pololu that sell the high power ones that i know of (there may be more)

popular speed ranges from about 500-700 rpm at 6v (1000-1400 rpm if they are 12v motors)

i only work in rpm so i dont know what these equal as a ratio... i only know that 30/1 is popular.

i get mine from ebay from a uk seller at a decent mark up although you can get some cheaper from china.

jst connectors are the most common connector used in ants although i mostly solder mine directly to my esc to save some weight and space...

as for transmitters, i use the flysky fs-i6 as its cheap, reliable and really easy to set up... plus the best bit is getting a tiny 4 channel receiver that weighs less than a gram (flysky fs2a)

a good thing with this hobby is you don't need the very best and most expensive of parts to have fun and build a capable machine.
Team Rocket
Trappist 1(4wd grab 'n' lift)
Ton 618 (4wd expanding bot)
Io(4wd flipper)
Kustom
Posts: 7
Joined: Mon Apr 24, 2017 11:36 am

Re: Noob build questions

Post by Kustom »

I think to start I’ll still use connectors for the battery so I’ll look for Jst ones.
Would you mind telling me who you use on eBay for the motors?
Thanks again
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Kyro
Posts: 412
Joined: Fri Jan 18, 2019 12:36 am

Re: Noob build questions

Post by Kyro »

there are a few different sellers i buy from...

one which i recommended to another forum member who tested the rpm and found them all to be consistent was from this link

https://www.ebay.co.uk/itm/DC6V-12V-N20 ... 4728545005

the ones tested were the 12v 1000 rpm which all came out to about 510rpm on a 6v nimh iirc...
Team Rocket
Trappist 1(4wd grab 'n' lift)
Ton 618 (4wd expanding bot)
Io(4wd flipper)
MichaelG92
Posts: 71
Joined: Sat Apr 14, 2018 8:10 am
Location: Surrey

Re: Noob build questions

Post by MichaelG92 »

To give my two pence worth:

I second James here; BBB's recommended parts list is very useful, and the guys over there are really helpful if you have any questions on anything. They've even started stocking N20s, most people use 6V 30:1 motors, 50:1 motors are useful if you want more control. I know of one person who uses 10:1 motors and they're, well, fast!

Receivers

I'd recommend looking at the REDCON receiver, which I've used on all my robots so far, and the Flysky FS2A, both of which are cheaper than the Lemon Rx. The REDCON is about the same weight, but crucially is flat so makes it easier to fit inside your robot. The FS2a is the lightest, cheapest and smallest receiver, although you need a Flysky transmitter to use it. I'm planning on using those in future.
https://www.ebay.co.uk/itm/REDCON-CM421 ... SwjSpdCL6d
https://www.ebay.co.uk/itm/FS2A-4CH-AFH ... Swb~xd76NC

ESC

I vouch for Kyro in that the Chinese 5A ESC is a good alternative to the NanoTwo, which is the best ESC out there if you can get your hands on one. I've used it and never had any problems with it. Just make sure you don't touch the wires together when testing it or it WILL go up in flames, as I found out the hard way! I've never tried an AWESC, and as for the Das Mikro I couldn't even give one away at the last BBB event which tells you what people think of them!

Servo

I'm currently using this, the KST DS215MG. Yes, it's a bit pricey, but a very fast servo so will give your flipper a bit extra oomph. https://www.ebay.co.uk/itm/KST-DS215MG- ... SwVzRaq4s7

Battery

I get mine from Component Shop, either the 120mah or 200mah ones, depending on how much weight I have left. Definitely worth looking around on the internet though https://www.componentshop.co.uk/batteri ... packs.html

Good luck!
Michael - Team MG Robotics

Fledgling Surrey based roboteering team

Antweights:

MicroNewton - flipper
ArmamAnt! - pusher
GFB - flipper (under construction)
Fight or Flight - flipper (under construction)
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LimaHotel
Posts: 258
Joined: Fri Mar 16, 2018 10:30 am
Location: West Devon

Re: Noob build questions

Post by LimaHotel »

A grabber? I CHALLENGE IT WITH JIGGY!
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