Drill Motor Max RPM with Gearbox?

FIRST General Forum
1

Posted by Scott Strickland at 1/10/2001 9:51 AM EST

Engineer on team #21, ComBBAT, from Astronaut & Titusville High School and Boeing/NASA.

Double checking some calculations…

Drill data given by FIRST says drill RPM is 0-400rpm, 0-1200rpm.

Dr. Joe’s Motor Spreadsheet says drill’s freespeed with gearbox is 1000RPM in high and 300RPM in low.

Which should I use for max speed?

Thanks for the help,
Scott

2

Posted by Michael Ciavaglia at 1/10/2001 3:14 PM EST

Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Interior Systems.

In Reply to: Drill Motor Max RPM with Gearbox?
Posted by Scott Strickland on 1/10/2001 9:51 AM EST:

Scott,

I read the info given by Bosch in the FIRST packet. The free speed for the motor alone is 20,000 RPM.

The gear box gives a 20:1 reduction in high and a 64:1 reduction in low.

To find the speed for the combined motor and gear box simply take the motor free speed divided by the gear ratio.

Motor with Gear Box in High:

  20,000 RPM / 20 = 1000 RPM

Motor with Gear Box in Low:

  20,000 RPM / 64 = 314 RPM

I don’t know how Bosch can claim higher speeds than these. I trust these numbers.

Mike C.