Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: megaman935 on June 30, 2007, 01:53:28 PM

Title: Good weight for base
Post by: megaman935 on June 30, 2007, 01:53:28 PM

Hi I'm making a wooden base and I'm wondering what a good weight would be. My base right now is a little over a pound.(will get lighter once I get parts- it's very large right now and 3/4" thick)

Title: Re: Good weight for base
Post by: Steve Joblin on June 30, 2007, 03:52:11 PM

It all depends... two approaches:

1.  build the base to the "sturdiness" you need, and whatever weight it is, it is.  Then find motors that will work with that kind of load.
2.  pick the motors you want and let the specifications determine how heavy your base can be.

Title: Re: Good weight for base
Post by: megaman935 on June 30, 2007, 04:50:11 PM

These are the specifications for the motor:
Physical Details
Gearbox Type      Spur
Reduction Ratio      54:1
Reduction Stages      
Gear Material      All Metal
Weight (Gearbox only)      0.5 oz (15g)
Weight (with motor)      1.1 oz (32g)
Length (gearbox only)      0.6 in (16mm)
Length (with motor)      1.7 in (43mm)
Gearbox Diameter      0.6 in (16mm)
Width (mounting block)      n/a
Shaft Diameter      0.118 in (3mm)
Shaft Length      1.5 in (38mm)
Shaft Keyway      n/a
Shaft End Tap      n/a
Mounting Holes      2 x #2-56


Motor Details
Motor      FF-050
Operating V      4.5v - 8v
Nominal V      6v
No Load RPM      276 rpm
No Load Current      0.3A
Stall Current      1.8A
Stall Torque      50.3 oz-in (355 mN-m)
kt      27.94 oz-in/A (197 mN-m/A)
Kv      46 rpm/V
What is the weight 2 of these can handle?

Title: Re: Good weight for base
Post by: maverick monk on June 30, 2007, 05:48:17 PM

i would go as lite as possible, those are small motors, look into using basswood as a base, its going to be the lightest wood you can go with without breaking as easily as balsa

Title: Re: Good weight for base
Post by: Brandon121233 on June 30, 2007, 09:37:12 PM

yeh those motors work perfectly for my 22 oz robot, and I think they could handle up to about a 2 pound robot, but since just your base is a little over a pound you might want to consider a lighter base material such as expanded PVC, or get motors more fit for the heavy job.

Title: Re: Good weight for base
Post by: sotu on July 01, 2007, 07:54:50 AM

Is this for a SocoetyOfRobot contest robot?

Title: Re: Good weight for base
Post by: megaman935 on July 01, 2007, 05:16:24 PM

Quote from: sotu on July 01, 2007, 07:54:50 AM

Is this for a SocoetyOfRobot contest robot?

ummmm... no.

Quote from: Brandon121233 on June 30, 2007, 09:37:12 PM

yeh those motors work perfectly for my 22 oz robot, and I think they could handle up to about a 2 pound robot, but since just your base is a little over a pound you might want to consider a lighter base material such as expanded PVC, or get motors more fit for the heavy job.

doesn't 50.3 oz-in mean about 3 pounds per sq. in.?

Title: Re: Good weight for base
Post by: RobotBuilder on July 08, 2007, 07:28:27 AM

A little info dont put anything that gets hot on the base.

Or ull have a bon fire.

I REPEATE A BON FIRE!!!!!

Title: Re: Good weight for base
Post by: Brandon121233 on July 08, 2007, 09:19:58 PM

Ummm...lol not quite, pounds per square inch is usually associated with pressure and not so much a torquing force, read up on admins statics and dynamics sections, it will help you a lot.

Title: Re: Good weight for base
Post by: sotu on July 13, 2007, 05:05:43 AM

Quote from: RobotBuilder on July 08, 2007, 07:28:27 AM

A little info dont put anything that gets hot on the base.

Or ull have a bon fire.

I REPEATE A BON FIRE!!!!!

I seriously doubt that a wooden base will turn into a bon fire because, eks: u run a servo at to high Voltage and it gets hot, i've never heard about it though