360 - mini hypnodisc

[calumco]

u chop your old shell up?

[Mouldy]

yup

[PJ-27]

What happened to the paint job! It's didn't even have a chance to get scratched!

Looks really good by the way.

[jonny]

looking good, how much does it weigh at the moment?

[Mouldy]

was like 14.2... lost 500g choping the front out, will loose 400 changing the top for 2mm titanium... so should be ok.

PJ- the paint got totaled at the last few expo events lol

[RogueTwoRobots]

Nice to see a beater back again. Hope this one survives a bit longer!
Just out of interest, where did you get your one-way bearing from? After seeing PJ's home-made one for Bitza (and talking to Graeme Dawson) I'm thinking it's something worth looking into, but there seem to be a few different types online. I'm also not too sure how it all fits together; have had a look at a few online articles and the picture of yours but I'm struggling to visualise incorporating a timing pulley into it yet still managing to secure the whole setup on a motor shaft

[Mouldy]

What one way bearing? :P it failed under the first big hit in testing so I binned it... In a robot like ls4 etc I guess you can get away with a smaller one... As they turn the throttle off before hitting someone... And they have like a 7:1 ratio so there's not much force getting to it in there application... For a drum with a high ratio it's not worth doing unless you plan to turn of your motor before a hit...One way bearings carnt take much radial load compared to a normal bearing of the same size.

It works like this;

On the output of the motor shaft you put the bearing.. Then you'd need to bore your drive pulley out and put the one way bearing inside that... Or something to that effect...

So basically if you turn the motor... The bearing locks in one direction... So it's like the pulley is just attached directly to the shaft... But if you turn the pulley on the motor shaft with the bearing in it, in the same direction, it can rotate freely...this means the drum can free wheel without spinning the motor.

The bearing has to be locked via a keyway or press fit onto the motor shaft and the inside of the pulley.

I came up with the concept when I had to develop a starter motor setup for a shell Eco marathon car ... So the starter motor could start the engine then disengage once the engine kicked in.... Can take a minuite to get your head around the mechanics of it, it's a pretty simple concept.

I got it of the Internet somewhere, not sure where but I remember it was around £22 a bearing... Not cheap!

Does drumroll take a while to spin down?

[RogueTwoRobots]

Interesting. In that case I'll probably see how things go without it. It's not something I'd really considered until it was mentioned recently, then seeing the new Bitza updates made me think I should look into it.
Not sure on spin-down times as I've not got the brushless setup in yet; the drum's currently with Kenny awaiting some new endcaps. I'm just trying to plan things a bit more in advance for once and see if it makes a difference.

Got my head around the concept more now, that explanation helped. I was trying to work out how to attach everything without using keyways (I'm used to just drilling through a pulley and sticking a grub screw in) but I was forgetting about the press fit options for securing the bearing to the shaft. Makes more sense now

[Mouldy]

Mine was just press a press fit... I think the best option to make brushless setups reliable lies in esc capacitor upgrades... Shock proofing and keeping cable runs short. Read a few pages back in the build thread and you'll see it, ive got some suitable caps spare that I could send you... Keep meaning to send Gary one too lol

[RogueTwoRobots]

Yeah I've read that capacitor mods seem to help. There was a thread on the Aussie forum talking about adding capacitors to keep the esr low, but I've forgotten most of what it's about and its benefits so that's on my research/reading list. Between your thread and the older Buzzbar thread I've picked up a few pointers about cable lengths and shock-proofing so will need to bear them in mind and improve the quality of my wiring

Is there a particular rating of capacitor to use or does it depend on each ESC? I've ordered an eZRun 150A Hobbywing model, same as Buzzbar after Graeme recommended it. I'll read through the esr stuff again and see about capacitor sizes but if the ones you've got are suitable, then a spare one would be grand