NST

[Anttazz]

Re: NST

Its gonna be absolutely terrifying with a brushless motor in there :shock: Gonna need something special to keep it in the arena.

[sam_smith]

Re: NST

Just some finishing touches to the ti front piece, rounded edges, hex counterbored to captive nuts under where the bar assy spins and countersunk holes ready for bolting together.

Below is the new Scorpion brushless motor and speed controller. They look very nicely engineered so i'm hoping that with a good quality custom gearing arrangement the new system should improve the power and reliability of the machine.

I'll keep posting as this upgrade develops

[james...venom]

Re: NST

SWEET! that ti piece looks amazing. I think NST with the brushless setup is going to be terrifying in battle. really nice work sam!

[sam_smith]

Re: NST

Thanks James, much apreciated!

Design calcs suggests it'll be noticably more powerful, but the shaft drive design is possibly a bit risky, will hope that stays reliable. Testing will at least tell if there are any balance issues in the drive shaft (which will be spinning up to around 10,000rpm !!

Anttazz, your absolutely right, even more chance of flying out of the arena now. Will have the variable controlled throttle so may have to be patient in comp battles not to push it too much! Theres room for more magnets but i very much doubt i'll have any spare weight for them.

Some more build pics of the progress over the last few days...

brand new top bearing support for the bar assembly now with bevel gear fitted. This probably makes it clearer now what i've been going on about shaft drive transmission from the back of the robot instead of the chain drive previously fitted.

[gizz]

Re: NST

Wow looks very well made!

[PJ-27]

Re: NST

Looks amazing! Is that a big ol' needle roller bearing inside the arm?

[Laser]

Re: NST

That is amazing!

[Max]

Re: NST

Damn!
My new robot looks the same as yours (but much less well engineered!) Sorry I wasn't trying to copy you, I guess great minds do think alike!

[sam_smith]

Re: NST

Thanks guys!

Yes PJ, I was forced to change to a needle roller bearing in this upgrade make space for the hub supporting the bevel gear.

The lower support still has an original single track ball bearing.

Some more progress to NST...

wish I could say this was just the 14 hours spent making it today, but it seems to have taken the best part of a week of spare time to design....

The first piece of the custom scorpion gearbox.

[PJ-27]

Re: NST

What have you got against needle rollers? Not as free spinning? Or are you complaining about the needle thrust bearing? I plan on doing the exact same thing on the arm of spinza. They are the only things thin enough.

[sam_smith]

Re: NST

I find that needle roller bearings have more 'play' and they wear the shaft and they can't take any axial load. But apart from that good low profile and load capacity.

Not too sure how they compare in friction/free running properties, don't imagine it'd make a lot of difference.

Some more progress today, got a couple of gears machined... will update photos next time.

[sam_smith]

Re: NST

Here is the next installment of NST's Scorpion Gearbox upgrade...

Front gearbox plate machined and all internal gears shafts and bearing installed. Taken a good deal of time over this, hopefully won't need to rush the rest too much lol.

[Eventorizon]

Re: NST

Note to self: Bring bin bags on friday...

[sam_smith]

Re: NST

Just noticed that I haven't posted any updates since before the UK champs....

Seeing as the old Dewalt set up proved so successful, I've decided to stick with it and leave the brush-less set up to one side for a future machine.

It was time to improve a couple of things on the machine which have been bugging me...

First of all some pics of the new custom built Solid state relay. successfully trialed at the Robo-challenge awards ceremony and testing days.

Hoping that the extreme rating of this unit will guarantee that it doesn't get overloaded at all and so should never fail short like all the off the shelf SSR's I've tried previously.

[sam_smith]

Re: NST

Next up the complete replacement Dewalt front end & gearbox. I decided to rebuild this to save a little weight and because the mounts were getting a little tired.