gametechmods

Off-Topic => Real Robotics => Real Robotics Discussion => Topic started by: Zyro_Falcon on October 19, 2015, 06:18:27 PM

Title: Not all motors can spin in both directions?
Post by: Zyro_Falcon on October 19, 2015, 06:18:27 PM
Looking up the Perm 132 yielded this image, from the Robot MarketPlace (http://www.robotmarketplace.com/products/EMS-PMG132.html):

(http://www.robotmarketplace.com/products/images/store_PMG132_512.jpg)

The arrow seems to indicate the direction it spins, and this Youtube video (https://youtu.be/B0TwmbnLm6U) seems to demonstrate so. Not all motors can spin in both directions, then? Can one have two Perm/PMGs spinning in opposite directions? Can you reverse its direction during operation?

I've only IRL experience building and driving one (Tamiya) 1/10 RC race car~
Title: Re: Not all motors can spin in both directions?
Post by: R1885 on October 19, 2015, 07:53:41 PM
Brushed DC motors can be biased to spin in one direction faster than the other(Either due to design or discrepancies in manufacturing) referred to as motor timing. On some motors, the difference is inconsequential, but on others, they can spin noticeably faster in one direction than the other to effect performance drastically, to the point that the manufacturer might recommend one direction over the other. The arrow on the PERM refers to what its timed for(CCW). You can reverse the motor direction like you would with a regular brushed DC motor, it just won't spin as fast. You can alter the motor timing by messing with the brushes, but unless you're an experienced electrical engineer and have a strong notion of what you're doing, I don't recommend it.

The differences in timing are only noticeable in two wheeled bots, which are more vulnerable to minor wheel speed changes. Four wheeled bots and onward are a lot less vulnerable to motor differences.

Also, why are you looking at the PERM? Its a terrible motor for combat.
Title: Re: Not all motors can spin in both directions?
Post by: Zyro_Falcon on October 20, 2015, 06:52:58 AM
Because RA2/DSL/IF is the only experience I have now, and the Perm was in them...?
Title: Re: Not all motors can spin in both directions?
Post by: The Red Blur on October 20, 2015, 06:58:15 AM
Because RA2/DSL/IF is the only experience I have now, and the Perm was in them...?

Either way, the perm is a bad motor, you're better off using other motors if you want good performance.
Title: Re: Not all motors can spin in both directions?
Post by: cephalopod on October 20, 2015, 07:03:16 AM
Because RA2/DSL/IF is the only experience I have now, and the Perm was in them...?

Click based a lot of DSL components on real life components, even if they didn't act exactly like their IRL counterparts. This was like 10 years ago, when I think some people had used Perms in combat.

Perms aren't bad in DSL/Ironforge just to clarify, unlike what TRB seems to be saying.