Team Ions build diary

All things antweight

Moderators: BeligerAnt, petec, administrator

minionhunter
Posts: 158
Joined: Fri Nov 04, 2016 5:36 pm

Re: Team Ions build diary

Post by minionhunter »

MarkR wrote:
Sat Feb 22, 2020 4:14 pm
minionhunter wrote:
Sat Feb 22, 2020 12:04 pm
Just got in my banggood package which obviously traveled through 2 war zones and was sat on by a hippo.
I think in the present circumstances, you should be glad they sent it at all. As China is mostly on lockdown a lot of workers are not permitted to go to their place of work, or are on reduced hours. So probbaly they had like, 1 day to pack 200 packages and had to do a bit of a rush job.

Also I just got some components from LCSC, they were somewhat delayed but otherwise fine (LCSC are more professional than a Banggood seller though).
Definitely glad I got it, I think I missed the lock down by a couple of days.

What is LCSC? I don't know that site yet. Electrical components online?

I'm really looking forward to your esc! I re-read it and I think I finally understand it, when you pull this off it will be outstanding! I want to make sure I still have one of your originals reserved.

minionhunter
Posts: 158
Joined: Fri Nov 04, 2016 5:36 pm

Re: Team Ions build diary

Post by minionhunter »

I also thought about it and I was over thinking it. I'm going to order one of everything else I need from US suppliers and that way I can test out all the tx and rx to make sure they are working while I wait for the slow shipping orders to arrive. Quads seem neat, but I really want to spend my time building antweights, not helicopters.

So, one set of expensive parts won't kill me, I will still order everything else cheap. My usual habit is to order in bulk with the cheapest shipping, it really adds up after just a few orders. At least that's my philosophy on buying stuff.

User avatar
MarkR
Posts: 346
Joined: Mon Dec 18, 2017 12:46 pm
Location: Reading Hackspace
Contact:

Re: Team Ions build diary

Post by MarkR »

minionhunter wrote:
Sun Feb 23, 2020 1:31 am
What is LCSC? I don't know that site yet. Electrical components online?
Yes lcsc.com they are a Chinese electronic components seller, like Digikey, but more Chinese and the stuff is *much* cheaper. Probably not of much interest to most robot builders because they don't sell components which we use (like motors, batterys, esc) but for people who do electronics (like me). The "Asian brands" parts mostly cannot be bought from western suppliers and are a lot cheaper and sometimes better, but of course they may have worse documentation or get discontinued without warning.

Also many "western brands" parts are actually made in China so the suppliers can sell them cheaper etc. It's all a bit of a subsidy by the Chinese government to get western makers hooked on Chinese parts, I think, but I'm not complaining :)

The "western brands" parts usually have better documentation (more likely to be in English, or understandable English) and maybe more accurate data sheets etc. I suspect that some of the CN parts data sheets are a bit "optimistic" on things like maximum current.
Robots: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?
Stacie - tidy flipper; 4wd driven by hair bands

minionhunter
Posts: 158
Joined: Fri Nov 04, 2016 5:36 pm

Re: Team Ions build diary

Post by minionhunter »

Hi everyone!

I'm fine. Nearly Everyone is self quarantined at my work. The change to teaching and administrative course management from home is very tedious and time consuming. I haven't had much time for robots and my chinese parts were mia.

I also haven't finished ordering stuff like batteries or wires yet.

However the motors and killer diller servos just arrived!

I was sent the wrong servos and need to figure out what to do about it. They are the alternative model in the line and weirdly some boxes say the alt model and some say the regular model. I received the kingmax KM1203MDT instead of the KM1203MD which I ordered (MDT is faster but has less torque). Hope aliexpress is good with return/adjustments.

The motors arrived but I have no idea what/if they are what I ordered. There are no markings. Is it safe to use the 9v battery trick to test them (just to see if they work)? I saw someone check the direction of spin (and mark it) with a 9v on n20s once. Said it was so he could quickly know the polarity and speed up repairs at tournaments.

Any suggestions on buying wire and fasteners?

Any suggestions on buying batteries (I'll get lipo bags to store them) if you would buy domestic to save hassle or ordered form China to get cheap prices?

Thanks for your help again, and I might just wind up with a little more time to get these bots rolling soon! I can't wait!

Hope you are all safe. I'm guessing the virus has forced the tournaments to be canceled. Here they have banned gatherings of more than 20 people in my state and restaurants only take out. I wish you all the best.

Sincerely

Ion

User avatar
LimaHotel
Posts: 249
Joined: Fri Mar 16, 2018 10:30 am
Location: Mold / Chester

Re: Team Ions build diary

Post by LimaHotel »

The km1203mdt is, as far as I know, just a different gearing. 6kg torque is still crazy high for an ant, and the faster speed means you can use a less aggressive linkage for the same flip. Personally I wouldn't bother swapping them out, but it's up to you. Getting sent the wrong thing is always annoying.
Motor wise, I see no issue with that?
Battery wise, sorry I got no clue. The turnigy nano tech ones that come from hobbyking now use weird balance plugs (I believe) and I haven't looked into alternate batteries yet. I'll be interested to watch this space.
Wire I actually use scavenged stuff mostly - just whatever small wire I've ripped out of broken electronics! Otherwise you want what, 24gage ish? I think I heard someone say they use 26gage.
I use m2 and m3 nuts and bolts on all my bots, and I just order them on ebay.
Covid wise, the government has finally started to take some actions, although early actions (EG announcing a mortgage holiday for home owners but not any support for renters in the private sector) suggest the tories might be using this to push their ideological class war. Bread for the rich, crumbs for the poor.
Jiggy Sawdust
Jammin' Good with Weird and Flippy
The Pushbot from Mars

User avatar
MarkR
Posts: 346
Joined: Mon Dec 18, 2017 12:46 pm
Location: Reading Hackspace
Contact:

Re: Team Ions build diary

Post by MarkR »

minionhunter wrote:
Thu Mar 19, 2020 1:35 pm
The motors arrived but I have no idea what/if they are what I ordered. There are no markings. Is it safe to use the 9v battery trick to test them (just to see if they work)?
Absolutely safe. 9v will not kill the motors, especially with no load. Also a 9v battery probably has quite high internal resistance (so it is "kinder" to to the motors than a lipo).

It is super difficult to judge the speed by looking. You could try attaching a piece of tape to the shaft, clamping the motor in a vise or something, then videoing it on your phone running (off a known voltage) to compare the different motors.

Usually they have no markings but subtle differences exist which are visible.
Any suggestions on buying batteries (I'll get lipo bags to store them) if you would buy domestic to save hassle or ordered form China to get cheap prices?
Lipo cannot be shipped internationally in general. Get the lipo from Hobbyking, their prices are excellent and I've not had a bad batch.

Like LH said - the latest 180mah 2S packs from Hobbyking have a super tiny (JST-PH) balance plug which is not compatible with the majority of chargers. The obvious workarounds are

a) Replace it with a standard balance plug - requires crimping tool, crimps, or splicing (be super careful with splicing lipo wires, short circuits are a Bad Idea) - I've spliced one pack.
b) Make up an adapter cable - I've done this. This is ideal because you'll then get a pack with a slightly smaller, lighter balance plug in your robot.
c) Charge it through the discharge plug - not recommended as it won't balance the cells - probably if you need to do this, stop lower than 8.4v so you don't overcook it

Exercise caution when modifying battery packs, it's a useful thing to do though.
Robots: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?
Stacie - tidy flipper; 4wd driven by hair bands

User avatar
Kyro
Posts: 387
Joined: Fri Jan 18, 2019 12:36 am

Re: Team Ions build diary

Post by Kyro »

just thought i would add, if you look closely at the back of an n20, inside a circle will have a little + so you can see the polarity without needing to test.

as far as im aware they all have this (every one of mine has)
Team Rocket
Esper(4wd flipper)
Mantis (4wd grab 'n' lift)
Dominus (Vert SPINNAAH)
Breakout(modular cluster)
Remembering Rex (antweight cassius)
Fennec (4wd flea) former world champion

User avatar
MarkR
Posts: 346
Joined: Mon Dec 18, 2017 12:46 pm
Location: Reading Hackspace
Contact:

Re: Team Ions build diary

Post by MarkR »

@Kyro: yes, the N20s all have a (+) on the back, but are they always wired up the same way internally?

Given the huge number of variations on the N20 motor, I wouldn't be surprised if they're 50/50 :)
Robots: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?
Stacie - tidy flipper; 4wd driven by hair bands

MySolderIsOlder
Posts: 151
Joined: Mon Jul 30, 2018 1:22 pm
Location: Kent
Contact:

Re: Team Ions build diary

Post by MySolderIsOlder »

Personally I wouldn't risk buying cheap imported/unbranded LiPOs, even if they were shippable. Too much of a potential fire hazard.
AFAIK, Hobbyking are now only doing the 2S 180mah nano-tech (standard power pack inside a large proportion of UK ants) with a funny little 2-pin Molex 'E-Flite' (?) discharge plug and a 3-pin JST-PH balance charging plug. On the plus side they're very good batteries and currently dirt cheap (less than a dollar each).
As others have noted however, those plugs present challenges. One option, as Mark suggested is to replace the Molex with a standard JST-XH power plug (requires crimping). Personally I've taken to removing the discharge leads entirely and using just the balance plug for powering the robot as well as charging the LiPO (NB. when cutting LiPO leads, snip one wire first and seal the end with heat-shrink tubing, before snipping the other lead to a slightly different length, then seal that one too and tape the loose ends up to the battery). Might be a bad idea with a big 6S pack, where the dischange connectors and leads are heavier duty but with these little 2S packs, all the leads are the same thickness (24 AWG I think), so it's not a problem. I have now replaced the old JST-XH connectors in all my ants with 3-pin JST-PH sockets, using only the outer two pins. Saves almost a gram and is a lot easier to fit in where you have a cramped layout. Only downside is that you can't get in-line crimp housings for the male side of JST-PH connectors, only PCB headers - so I solder wires to the pins and add a dab of epoxy glue to stop them getting pushed out, then protect with heat-shrink.
As for the charging leads, etc, I crimp my own but you can also buy various ready-made adapter or extension leads then cut & splice these to make what you need. Might have to get creative - for example my charger won't work unless something is plugged into the discharge connector as well as the balance board, so I've had to make a couple of 'Y'-connector leads.
Involves some hassle - but given current prices on the 2S Nano-techs and limited other options for small 2S Lipos, worth the effort I think.
Stuart (Anthony's dad)

Post Reply