Pulverizer Build Diary

[daveimi]

God that spins really fast!!

[Mega Masher]

At full speed it was around 300rpm.

[Mega Masher]

Well, when I say 300rpm, I don't know for sure. I'll know for sure when I fit the accelerometer. To fit said accelerometer, I will use a modified version of a J2O bottle lid.
http://i1280.photobucket.com/albums/...ps754eb0e9.jpg
http://i1280.photobucket.com/albums/...psfafc2b64.jpg
I'll cut some foam to fit the inside of the lid, then put the accelerometer in with the wires all soldered, and zip-tie it all down.
http://i1280.photobucket.com/albums/...psfc59ba88.jpg
http://i1280.photobucket.com/albums/...ps28631296.jpg

[Mega Masher]

How are these for batteries? I'll use 2 of these 3 cell packs to get 22.2v, and 8000mah. Anyone got any experience of these?

[plargen]

are the individual battery's 8000mah

[Mega Masher]

Sorry, forgot to add the link. Here it is
http://www.robotmarketplace.com/products/0-TRA2849.html

[Mega Masher]

btw, tom posted this on 360's build diary:
"Youd never get a translational spinner anywhere near as good as one of the others"
I see this as a challenge ........

[Ellis]

There's no need to purchase from the US, postage will be ridiculous, you can get quality lipos from places like optipower.co.uk, and if your pocket isn't quite so deep, some of the packs on hobbyking.com and giantshark.co.uk will do nicely.

Also, battery maths don't work like that. When you wire in series, you double the voltage, but the capacity is that of a single pack. When wiring in parallel, your capacity and discharge figures double, but the voltage stays the same. You can't get 8Ah and the equivalent of 6s from two 4Ah 3s packs, it's a one-or-the-other thing.

[Mega Masher]

Yeah, I don't know much about batteries.
I've heard that hobbyking isn't trustworthy. Is this true?

[Ellis]

Their products are cheaply made. But then, they're also cheap to buy. With most things I am of the philosophy that, for example, if you can buy 5 Hobbyking brushless motors for the price of a single high end mark motor, and their performances are the same, I'd prefer have slightly reduced reliability and 4 spares.

That said, very cheap LiPos could be a safety hazard, so get the best you can afford, and run as far below their rated figures as you can. We're using super cheapy packs originally from HK, that were also second hand (generally considered a nono), and they've been perfectly reliable, very powerful, and completely worth the 12 quid (yes) we paid for them each.

As for Hobbyking themselves being reliable, there are some who claim they're terrible as a company, but I can't really say if that's the case or not. I'll let others who have dealt with them before say more. I ordered a package a while ago from them, but due to a shipping issue (not their fault), it never arrived. I have been in an email conversation with the HK support team for a while now, and whilst it hasn't been resolved (they haven't received confirmation that the package was returned to their warehouse, yet), they have been very friendly and apologetic.

In short, if you're smart with your choice, cheaper products from places like HK will do the job fine.