NST

Thanks Alex thats a good idea, any chance you can PM me rick maas's email?

Cheers Lian


I've done an experiment to see how current thirsty the motors are..... by putting a 25amp power supply on each drive motor and then pushing down on the robot so it does a burn out (on the kitchen floor lol). The motors defo had more to give when being limited to 25 amps each, so a controller capable of 40 amp peaks should do the job without limiting the machines acceleration or pushing power much. The XXL is a very useful size, i'd really struggle to fit a 25A sabertooth in.

An XL/XXL upgraded to at least XXL spec sounds like the perfect solution.

maasrick (at) hotmail.com

Thanks John!

NST will have some upgrades installed over the next few weeks.

This is an armour modification from the weekend....

Might be forced to paint this version if theres any spare weight, or polish the hardox sides and back armour.

its got Alpha angles!

I was thinking exactly that!

you used my advice then sam :P ... did you sort out the issue of the front plate bending?

I thought NST already had a slanted back like that?

it did, the slanted corners are the new edition :)

looking good

Addition not edition :blush:

Aye Dave, that was good advice from you and Grant.

The chassis bend is the next job on the list. Hopefully will be able to get the repair done over the weekend. Got a design, just hope it turns out to be strong enough!

Now you mention it Alan, it does have a hint of alpha, hopefully it'll have some of the resilience.

That nasty spinny bar and proper hardox armour,it should be renamed FNST. :uhoh:

Nice work some, Looking forward to seeing it tested when you've comleted all the mod's. Clive, your probably right on that :)

Lol, Clive thats a great rename for this mk of NST! hope it lives up to the name.

Aye, me too Grant :proud:

This front chassis part has taken the best part of the weekend. Just got to machine the recipricating features out of the front of NST's front chassis/baseplate now (where the bottom support for the main shaft locates).

Dammit man! We're roboteers, not artists!

In other words, it looks beautiful :)
NST could be in with a good shout this year, considering you're tinkering and improving an already evil and reliable machine.

Thanks Jamie!
Thought I should get that part posted up while its shiny 8) and because when its assembled most of the decorative features will be hidden.

If it'll just stay in the arena, it could do alright...

The baseplate modification has been completed tonight, thankfully that repeated the test piece and fits the new ti part as planned.

Beautiful piece of work, building Robots should always be art based

Thanks Gabe01!

I've been progressing further with the modifications to NST with some minor progress to the front bar chassis support and i've finally decided on the major modification to the weapon....

Think theres just enough time to pull it off... its going brushless and shaft drive 8)

A couple of pics to follow...

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

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

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

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.

Wow looks very well made!

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

That is amazing!

Damn! :angry:
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! :lol:

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.

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.

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.

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.

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

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.

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.

The original unit was made in a hurry for the first NST only a few weeks before the 2010 champs. It was made with things I had lying around. This time better choice of parts have been used.

Slightly downsized the bearings from 12mm to 10mm.

New grade 5 titanium shaft replaces the old 12mm silver steel one.

lightening pockets added and lightened bevel gearwheel.

Also forgot how long it takes to make one of these....

So you are swapping out the chain drive for the direct drive system? And all this weight you keep saving here and there, where is it going to go?

This version has got back to the chain drive for now as it was at the open day as it proved to be reliable. Extra weight can go in many areas like bigger batteries for higher voltage to the disc, bigger magnets, or heavier teeth :)

The plan is also to stick with the chain drive set up as I know it works well enough.

It does seem a shame to abandon all the shaft drive components, but to use them with the Dewalt, i'd have to build a whole new gearbox.

That is a very good question. I'm not 100% sure yet how the weight will pan out. But for certain I need to add some decent chain tensioners to the weapon chain also need to support the back of each drive motor to improve reliability as they loosen from their gearboxes over a competition.

Depending on what's left, I've thought of 4 options:
- Bigger weapon battery (higher capacity)
- Go up to 8 cell on the weapon (& alter chain drive ratio => faster spinup & higher top speed)
- Improve some of the weaker armour
- Bigger teeth

Thanks Grant, I almost forgot about adding extra magnets :)