www.robowars.org

RoboWars Australia Forum Index -> Technical Chat

Motors and speed controllers
Goto page Previous  1, 2, 3, 4, 5

Post new topic   Reply to topic
  Author    Thread
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8511
Location: NSW


 Reply with quote  

More windings should have more torque too Smile
_________________
https://www.halfdonethings.com/

Post Tue Jul 17, 2007 9:18 pm 
 View user's profile Send private message
ffej
Experienced Roboteer


Joined: 22 Jun 2004
Posts: 595
Location: Kurrajong, NSW


 Reply with quote  

The comm on a 12V Bunnings XU1 Ive got here is marked 27T

BTW, im running 18V DSE's rate limited to 45% off a full A123 pack and all is good, just gotta make sure you drop the dead band way down, otherwise theres like half the stick that does nothing. Actually, now I think about it, doing that with the 120Hz victors could be a really bad idea lol.
_________________
Jeff Ferrara
fb@ffej.net

ffej.net

Post Tue Jul 17, 2007 9:19 pm 
 View user's profile Send private message Visit poster's website Yahoo Messenger MSN Messenger
Valen
Experienced Roboteer


Joined: 07 Jul 2004
Posts: 4436
Location: Sydney


 Reply with quote  

Re the torque thing. If the iron gets saturated when its stalled (or nearly so) then more turns won't improve the torque. Saturated is saturated.

@jeff, I had a look inside the other Jeff's victor. They are just 16F628A's the baby brother of the PIC we use in our radio. It would not be infeasible to up the PWM frequency (or just totally re-write the firmware to do whatever you felt like (got mixing?))
_________________
Mechanical engineers build weapons, civil engineers build targets

Post Tue Jul 17, 2007 10:48 pm 
 View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger ICQ Number
Nick
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW


 Reply with quote  

@ Jeff: Yeah, I have 50% limiting and Victors Sad - Jolt is very twitchy at low speed. I think it affects the mixing as well and I want to be rid of it! From the feedback, the 45T motors at 24V should perform a bit like slightly over volted 12V motors. I set up email notification when the motors come into stock and will get a set ASAP.

I don't know if it will matter, but all these motors have a flat on the shaft. Pressing on a pinnion might not be as secure as on the drill motors...
_________________
Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Post Tue Jul 17, 2007 11:48 pm 
 View user's profile Send private message
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8511
Location: NSW


 Reply with quote  

Found this little site on a Google-venture...

http://home.comcast.net/~milemarkers/Motors-ESCs-Brushed.htm

I like the look of the last two motors as alternatives to Dewalts in cheap bots Razz
_________________
https://www.halfdonethings.com/

Post Mon Aug 06, 2007 4:20 pm 
 View user's profile Send private message
cerberus3112



Joined: 05 Dec 2005
Posts: 497
Location: Mt Druitt,Sydney,NSW


 Reply with quote  

Okay can any one tell me for future reference which motor has more
torque to speed etc
300 watt scooter motors or dewalts
p.s sorry if its been answered
_________________
A journey of a million miles begins with a single step followed by a hell of a lot of other steps so get walking

Post Wed Aug 29, 2007 4:19 pm 
 View user's profile Send private message Send e-mail
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

i reckon the 300w motors would have more power to them for sure.

but considering that an entire dewalt setup with the wheels mounts and bearings tips the scales at just about 1kg and the scooter motors alone are nearly 2kg its a bit of an unfair comparison Razz
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Wed Aug 29, 2007 4:49 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
cerberus3112



Joined: 05 Dec 2005
Posts: 497
Location: Mt Druitt,Sydney,NSW


 Reply with quote  

umm nearly mine weight 2kg for the motor X2 and about 2kg for the sproket axle etc Laughing
Could you use brushless motors for drive??
_________________
A journey of a million miles begins with a single step followed by a hell of a lot of other steps so get walking

Post Wed Aug 29, 2007 5:40 pm 
 View user's profile Send private message Send e-mail
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

theoretically yes if you could find a reversible controller. and at this time they dont exist for the price we can afford Razz Shocked
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Wed Aug 29, 2007 6:07 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
nick_75au



Joined: 22 Oct 2007
Posts: 11
Location: Brisbane


 Reply with quote  
Rewinding motors, my application off topic

This is relevant to some earlier posts.
Its not hard to rewind the drill motors. I rewound a 14.4v 550 drill motor, it originally had 27 turns, I changed it to 45 turns of wire about 2/3 smaller in diameter for a direct drive propeller, it reduced its rpm by 3/4 at the same voltage but its torque didn't rise (to me anyway) I'm also only running it on 6 volts. I could have used thicker wire if I had it available and I believe that would have improved the toque. That boat and prop can push a 70 Kg tanker model sideways into the wind and it only weighs 4kgs.
Regards
Nick

Post Mon Oct 22, 2007 9:38 pm 
 View user's profile Send private message Send e-mail
Spockie-Tech
Site Admin


Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia


 Reply with quote  

Dewalt is a brand - like Ford - there are quite a few different motors under the DeWalt name. Here is a link to some of them
http://www.robotmarketplace.com/marketplace_dewalt.html

In general though, nearly all of them make more power than the scooters do - most drills make between 0.5hp (370 watts) up to 2hp (1500w) depending on what voltage you run them at.

<more info>
http://www.enigmaindustries.com/links.htm

I'm not certain as to whether the scooters watts are input or output watts (taking in account motor efficiency), but if its input watts, then the output has to be less than 300, if its output, then its still less than most drills.

The big advantages of scooter motors are reliability and power consumption. If you are not building a ram/pusher then you dont need kilowatts of output power, and scooters are much easier on your batteries and ESC if you can handle the weight penalty.

In fact, scooters power/weight is even worse than they first seem, since the power ratings are at 24v for scooters, meaning you need to carry more battery cells to get the rated power.

However, like they say, its not how much power you make on the first lap, but how much you make on the last lap that counts. Drills are fragile, amp hungry beasts that break often, but are cheap, easy to use and light.
_________________
Great minds discuss ideas. Average minds discuss events. Small minds discuss people

Post Mon Oct 22, 2007 10:09 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Valen
Experienced Roboteer


Joined: 07 Jul 2004
Posts: 4436
Location: Sydney


 Reply with quote  

like i said, you won't see increased torque if the motor is saturated.
you should see reduced current draw though.
While you can re-wind drills the problem is balancing them again after, that is non-trivial.
_________________
Mechanical engineers build weapons, civil engineers build targets

Post Tue Oct 23, 2007 12:45 am 
 View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger ICQ Number
nick_75au



Joined: 22 Oct 2007
Posts: 11
Location: Brisbane


 Reply with quote  

I don't know anything about saturation unless you count the time I forgot to seal a hole in the boat Embarassed . I didnt balance the motor, it only turns about 3000 rpm in comparison to the 30 odd thousand it used to do. There is absolutly no vibration from the motor. I do understand where your coming from I just didn't bother for this application.
I can run it under load for about 6 hours on 6 volt 8 AH batteries.
Regards
Nick

Post Tue Oct 23, 2007 9:05 pm 
 View user's profile Send private message Send e-mail
Valen
Experienced Roboteer


Joined: 07 Jul 2004
Posts: 4436
Location: Sydney


 Reply with quote  

basically when you stall the motor you get the maximum amount of magnetic field that the laminations will take. By upping the turns you can up the amount of magnetic field you make for a given voltage (IE more torque) up to the point when you saturate the steel. It doesn't matter how many more turns/amps you put through there you wont get more torque and all your producing is more heat.
If the motor is running it should be fairly moot.
wrt balancing yah at lower RPM it becomes less important.
_________________
Mechanical engineers build weapons, civil engineers build targets

Post Tue Oct 23, 2007 10:32 pm 
 View user's profile Send private message Visit poster's website AIM Address Yahoo Messenger MSN Messenger ICQ Number
Philip
Experienced Roboteer


Joined: 18 Jun 2004
Posts: 3842
Location: Queensland near Brisbane


 Reply with quote  

What is a good way to replace a drill motor and gearbox?

I would like to use a motor with belt or gear reduction. I don't need a lot of push. Weight is important to me. What would people recommend?
_________________
So even the rain that falls isn't actually going to fill our dams and our river systems

Post Thu Oct 25, 2007 7:52 pm 
 View user's profile Send private message
  Display posts from previous:      

Forum Jump:
Jump to:  

Post new topic   Reply to topic
Page 5 of 5

Goto page Previous  1, 2, 3, 4, 5

Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

 

Last Thread | Next Thread  >
Powered by phpBB: © 2001 phpBB Group
millenniumFalcon Template By Vereor.