Motor Test 4

 

Surplus Center #5-1754
http://www.surpluscenter.com/item.asp?item=5-1754&catname=electric 

Description

500 RPM 12 VDC GEARMOTOR

New, permanent magnet, right angle gearmotor. Cast aluminum gear housing with steel motor frame. Hollow square thru-drive output shaft. Two bolt rubber isolation mount. Two pin male integral Packard power connection (female half of plug not available from Surplus Center).

 

SPECS:

• Speed 500 RPM no load

• Speed 250 RPM at rated torque

• Voltage 12 DC

• Amperage 16 Amps

• Torque 8.5 in-lbs

• Rotation Reversible

• Duty Intermittent

• Mount 3/8" dia. two bolt on 2.2"centers

• Hollow Thru-shaft 5/32" (4 mm)

• Size 5-1/4" x 3-1/8" x 2-1/2"

• Shpg. 3 lbs.

Price for one - $13.99 Shipping for 1 - $11.98

Price for ten - $13.99 each Shipping for 10 - $24.51

 

PROS -

• Quiet
• High Torque
• Compact
• Good mounting points
• Electrical connection is relatively easy to get to. Will accept slightly modified push on crimp connectors
• This motor had enough torque to spin the 8oz test weight at high rpm without strain.

 

CONS -

• Shipping for a single unit is relatively expensive.
• Designed for intermittent use - See my comments below
• The output of this motor is via a square shaft or hollow shaft.
• High current requirements - I can't believe the posted spec.
• If you add a crank arm it can interfere with the electrical connections.

 

Modifications -

I cut away shroud over the electrical connection with a hacksaw.  Then it was easy to use spade connectors to wire the motor. 

 

I screwed/beat a 10-32 screw into the round half of the shaft and used Locktite hold it.  Then I cut off the head of the screw and ran a lock nut down the shaft.  I then tapped and threaded the crank arm the 10-32 shaft.

 

Comments -

While designed for intermittent use, I've left this motor running for hours under light load with no sign of heating up.  This motor requires at least 2 amps of current at 12 volts to run.

The metal of the OE shaft seems pretty hard and I was unable to thread the inside of the hollow shaft.

 

The high RPM of this motor means you'll probably need a PWM controller to reduce the speed.  Motor buzzes when PWM is used at low speed.

I really wanted this motor to be the new big thing.   It is going to take someone coming up with a better means of getting the output shaft connected to the prop than I've come up with.  The 2+ amp current requirement forces a bigger (more expensive) walwart or power source.

Still, in a group buy situation; this motor could easily power a flying crank ghost.  Figure $10 for the power supply, $16.50 for the motor, and $10 for the PWM controller, you get an easy to control prop motor for under $40

Unverified rumor has it that for larger orders you can contact them directly and they will work with you on the shipping cost.