Best reduction I would achieve

[mattsdragons]

Whats the best reduction I could achieve With the motors below on 50mm wheels on a single stage reduction?

http://www.ebay.co.uk/itm/300511267976

Had a look on technobots but ive never used gears before so am a little unsure

[PJ-27]

Re: Best reduction I would achieve

http://www.technobotsonline.com/robot-s ... lator.html

Put in figures, get answers.

I've considered this to quite some length and with MOD1 gears you start to run out of weight and space around the 6:1 mark, 4:1 is more possible. Similar story with chains and sprockets.

50mm wheels are tiny though and means you need less reduction, but most gears will be bigger than that!

[grant_ploughbot]

Re: Best reduction I would achieve

What you'll find is that with a single stage ratio you don't have alot of choice. You just need the biggest gear that can fit on your wheel and the smallest that can fit on your motor shaft. Normally that's around 5:1

If you go with bigger wheels and bigger gears on the wheel you will still get the same speed.

[Danjr1]

Re: Best reduction I would achieve

I ran those motors with a 7.5 to 1 ratio (12t pinion and a 90t Spur, mod 1). The bot ran on 120mm diameter wheels. I believe Will from team shock ran them in one of his featherweights on a smaller gear ratio so might be best to check the build diaries.

[mattsdragons]

Re: Best reduction I would achieve

Those motors at 18v with about the biggest reduction I could got on 50mm wheels 40:12 (3.3333:1) would get a theoretical 18mph out of it.... bit slow

Though slight problem, 50mm wheels and invertable with motors 52mm diameter, not going to happen

[maddox10]

Re: Best reduction I would achieve

52mm diameter. Sounds like Speed 900 or clone.

Means also 3 diameters of axle. 5, 6 or 6.35mm.

With the 6.35mm you could use , in theory a gear with a root circleof 8.5mm. With mod 1 that is Z10 (Mod*Z-(2M*1.25)). A rare and expensive size.
Also, it means a gear with undercut. Meaning the teeth are weaker than what the norm allows.

If we drop to a Technobots available size in steel, mod 0.7 Z12, root circle 8.4mm, that could be survivable. On a 60mm wheel, you could add a mod 0.7 Z80 gear(outer diameter 57.4mm). Giving you a gearratio of 6.667/1

But technobots goes only to Z72. And that's 6/1

So, if I use the data from my measurments, a 6.35mm axled Speed 900 clone runs 12Krpm@12V
6-1 gearratio to a 60mm wheel = 22km/h

I must admit. I don't know how mod 0.7 stands up in the Featherweight class. Never used anything else than mod 1.

[PJ-27]

Re: Best reduction I would achieve

I hope Will doesn't mind me saying this but he made up his own drive units for his latest robot with those 900Clones and given the Voltage, Motor RPM, Reduction and Wheel size that robot has a top speed of around 30mph, but in the drive test video moves around nicely!

Most people would consider 10mph a good/high top speed to aim for. Food for thought.

[Ellis]

Re: Best reduction I would achieve

Getting there and maintaining is what matters. Tormenta 2 does just 10mph, but it reaches it in about 3 feet of floor space, and it has the torque to maintain it once it has hit another machine. That's why it appears quite fast. In a straight line it is easily outclassed by robots like Satanix, though.

I'd suggest aiming for a 2 stage gear reduction. It's harder but also easier, in a way. Bit heavier but allows for a stronger setup. With it you could gear those motors to say 12mph, a good deal faster than 90% of your opponents, and if others have geared to 30mph and the machine moves around well, imagine what it would be like with the freedom of torque and acceleration at 12mph.

[mattsdragons]

Re: Best reduction I would achieve

Thats all good but with 52mm diamerter motora in an invertable robot with 50mm wheels, they wont fit inside the body

[Ellis]

Re: Best reduction I would achieve

I don't understand how you managed to get this far without thinking about that, mate.

Why so set on 50mm wheels?

[maddox10]

Re: Best reduction I would achieve

Thats all good but with 52mm diamerter motora in an invertable robot with 50mm wheels, they wont fit inside the body

Go for a speed 700 then. Those don't run much faster than a Speed 900 clone.

And why 50mm wheels?

Also, you could go for Big Nipper or Hard setup.

[mattsdragons]

Re: Best reduction I would achieve

Only just noticed their too big xD

Its from the 6wd crusher I bought, turning them into 2 robots, one with big armour and the other with a big weapon

[Anttazz]

Re: Best reduction I would achieve

Why not just build it that way it was supposed to be built or start from scratch?

[mattsdragons]

Re: Best reduction I would achieve

Want to use the 6wd set us as its far too awesome not too use but is designed for 50mm wheels and would rather get 2 better robots and use the 6wd set up for invertablility

[typhoon_driver]

Re: Best reduction I would achieve

what machine is this?