Search found 218 matches

by MarkR
Sun Sep 08, 2019 7:47 pm
Forum: Antweights
Topic: MichaelG92's Build Diaries
Replies: 28
Views: 4125

Re: MichaelG92's Build Diaries

red touching black=bad. The easiest test to do on a multimeter, is to measure the resistance. If it's an "auto range" meter, then you need to understand the display, if not, set it to the correct range, which will be something like 100 Ohms. A N20 motor will typically have, when not moving, between ...
by MarkR
Sat Sep 07, 2019 10:27 am
Forum: Antweights
Topic: ESC Sanity check
Replies: 20
Views: 896

Re: ESC Sanity check

Ok, it is super difficult to get info about the MX2020b IC. It is made by Chinese company sinotech, whose web site http://www.mixic.com.cn/ blocks access from outside China. There is a 1688 (Chinese ebay thing) page which contains some info here: https://detail.1688.com/offer/596031371053.html LCSC ...
by MarkR
Fri Sep 06, 2019 11:50 am
Forum: Antweights
Topic: MichaelG92's Build Diaries
Replies: 28
Views: 4125

Re: MichaelG92's Build Diaries

If you know what chip it is, then it looks replaceable, if no tracks on the board are damaged. The problem I always had with Dasmikros was the tracks lifting and making a short. Personally I'd suspect a short circuit somewhere. If your motors aren't shorted now, perhaps they were briefly during your...
by MarkR
Wed Sep 04, 2019 1:45 pm
Forum: Antweights
Topic: ESC Sanity check
Replies: 20
Views: 896

Re: ESC Sanity check

Yes, in general capacitors are usually there to even-out spikes in load caused by motors turning on and off. There may be some smaller caps on the PCB which will do well enough. Usually there is a capacitor on the 5v regulator too, which is where you mostly need it, because it's vital that the elect...
by MarkR
Wed Sep 04, 2019 10:47 am
Forum: Antweights
Topic: ESC Sanity check
Replies: 20
Views: 896

Re: ESC Sanity check

Not bad, I notice:

* Yay, through-hole pads for the motor wires :)
* Boo, surface pads for the battery connector (would be super-bad if it comes loose and shorts)
* They use my favourite chip, rz7899

Did it come with the big electrolytic cap or did you add it?
by MarkR
Mon Sep 02, 2019 11:58 am
Forum: Antweights
Topic: Team BLEEP build diary
Replies: 123
Views: 18201

Re: Team BLEEP build diary

Nice wheels / tyres. Where did you get them/ make them?
by MarkR
Fri Aug 23, 2019 9:37 pm
Forum: Antweights
Topic: Team BLEEP build diary
Replies: 123
Views: 18201

Re: Team BLEEP build diary

I'm using 20:1 motors and my robots are a bit fast but still work. I did some adjustment in the firmware and got the speed about right.
by MarkR
Sun Aug 18, 2019 10:56 pm
Forum: Questions (and answers)
Topic: ESC battery and motor paring
Replies: 3
Views: 700

Re: ESC battery and motor paring

It's not clear if those are brushed or brushless motors, but in any case, brushed motors only draw their maximum current when stalled (i.e. at startup), so you won't get anywhere near the peak current unless all of the motors on one side are stalled, which is probably a bad situation anyway I think ...
by MarkR
Sun Aug 18, 2019 8:52 am
Forum: Questions (and answers)
Topic: 3D printing
Replies: 5
Views: 373

Re: 3D printing

1. Material choice "basic" PLA is nice and easy to print but has dubious mechanical properties. It's generally OK I think for internal parts of the robot where there is armour of something else outside. Don't expect it to last long if it takes a direct hit. PLA is also quite brittle and tends to cra...
by MarkR
Sat Aug 17, 2019 10:15 pm
Forum: Questions (and answers)
Topic: Graphene Batteries
Replies: 3
Views: 340

Re: Graphene Batteries

I get the impression that Hobbyking / Turnigy would claim their batteries contained Mithril and Dilithium crystals if they thought people would believe it :) I'm sceptical that this actually makes any difference, I think they're just normal lipo really, with a layer of unobtanium to make them sound ...
by MarkR
Thu Aug 01, 2019 6:52 pm
Forum: Events
Topic: RoboShowdown
Replies: 9
Views: 1897

Re: RoboShowdown

IF I can make it, I'll bring Betsie and Stacie.

Then we can have that Betsie vs Mantis whiteboard you suggested. I love Mantis, it's brilliant (although it was my poor driving / weird control system which let me down last time)
by MarkR
Thu Aug 01, 2019 12:18 pm
Forum: Antweights
Topic: ESC Sanity check
Replies: 20
Views: 896

Re: ESC Sanity check

It's very difficult to produce a compact layout which doesn't have wires leaving from several edges of the board. With power, signal and motors, there have to be quite a few things. e.g. Dasmikro has awfully tiny nasty pads which are terrible to solder to, but still on both ends. It's a really good ...
by MarkR
Thu Aug 01, 2019 10:18 am
Forum: Antweights
Topic: ESC Sanity check
Replies: 20
Views: 896

Re: ESC Sanity check

Very interesting... it is the RZ7886, the DIP8 version of my favourite rz7899

https://lcsc.com/product-detail/Motor-D ... 28852.html

They should be as tough as old boots, if the other rz chips are anything to go by.
by MarkR
Wed Jul 31, 2019 8:38 pm
Forum: Antweights
Topic: ESC Sanity check
Replies: 20
Views: 896

Re: ESC Sanity check

It does look a little bit on the large side for an antweight ESC, and 5A per channel is definitely excessive, my N20 motors stall at about 0.5A, so even with two stalled in parallel that's still only 1 amp. I also noticed, on closer inspection of the pictures on various sites, that these ESC have a ...
by MarkR
Wed Jul 31, 2019 3:29 pm
Forum: Antweights
Topic: ESC Sanity check
Replies: 20
Views: 896

Re: ESC Sanity check

Do you have a multimeter? If you connect the ESC to the power and nothing else, the red and black wires on the servo-type plug (3-pin dupont connector) should give +5V from the regulator (BEC). Assuming that's ok, then can you measure the resistance between the various wires (with power off) - the b...