Posted by rebecca at 1/19/2001 3:21 AM EST
Student on team #192, gunn robotics team, from gunn high school.
back in the “can i drill a hole in a motor shaft” thread, a few people mentioned having complete interchangability pertaining to motors. What kind of system allows that? set screws?
what we’ve done is have a keyway w/ key and keep a spare modified motor on hand. If we burn that spare too, we are screwed. But we’ve never even needed the one spare so…
Is there is a better way?Posted by Matt Berube at 1/19/2001 7:44 AM EST
Engineer on team #49, Delphi Knights, from Buena Vista High School and Delphi Automotive.
In Reply to: Interchangable Motors?
Posted by rebecca on 1/19/2001 3:21 AM EST:
: back in the “can i drill a hole in a motor shaft” thread, a few people mentioned having complete interchangability pertaining to motors. What kind of system allows that? set screws?
: what we’ve done is have a keyway w/ key and keep a spare modified motor on hand. If we burn that spare too, we are screwed. But we’ve never even needed the one spare so…
: Is there is a better way?
In the past we have used the 2 flats on the van door and globe motors to turn a modified gear/sprocket.
Matt B.
T49
Posted by Andy Baker at 1/19/2001 7:49 AM EST
Engineer on team #45, TechnoKats, from Kokomo High School and Delphi Automotive Systems.
In Reply to: Interchangable Motors?
Posted by rebecca on 1/19/2001 3:21 AM EST:
: Is there is a better way?
When a gearbox goes out or when a pinned shaft shatters, you don’t have to just change the motor.
If you design the motor within an assembly, you can have a spare assembly made up, ready to install into your robot if something goes wrong with the motor/gearbox/pin arrangement.
This way, it doesn’t matter how risky your attachment to the gearbox shaft is.
Andy B.
Posted by ChrisH at 1/19/2001 10:47 AM EST
Engineer on team #330, Beach 'Bots, from Hope Chapel Academy and NASA JPL, J & F Machine, Raytheon, et al.
In Reply to: Interchangable Motors?
Posted by rebecca on 1/19/2001 3:21 AM EST:
: back in the “can i drill a hole in a motor shaft” thread, a few people mentioned having complete interchangability pertaining to motors. What kind of system allows that? set screws?
: what we’ve done is have a keyway w/ key and keep a spare modified motor on hand. If we burn that spare too, we are screwed. But we’ve never even needed the one spare so…
: Is there is a better way?
Rebbeca,
What we do is design around the existing output of the motor. So for the drill motor we design a fitting that will fit on the gearbox output shaft as it is. Then we attatch gears or whatever to that.
For the window motor we use a gear with the right pitch and presure angle to mate with the existing gear. Sorry I don’t remember what they are right now but a local gear distributor would be able to help if you need to figure it out. Or somebody could post it I think I’ve seen it here before.
For the seat motor we use a 1/8 square shaft and for the van door or globe motors we broach a flattened hole. Admittedly our machine shop had to get a custom broach made for this, but it wasn’t that hard and we still have it.
The Fisher-Price motors are a different story all together, (and in our case a trade secret) but I think you can get the idea.
Chris Husmann, PE
Team 330 the Beach 'Bots
Posted by Matt Berube at 1/19/2001 2:50 PM EST
Engineer on team #49, Delphi Knights, from Buena Vista High School and Delphi Automotive.
In Reply to: Re: Interchangable Motors?
Posted by ChrisH on 1/19/2001 10:47 AM EST:
The window motor has a 16 Diametral Pitch gear on the output. You can make this to another 16 DP gear in a traditional sense, or you can get really ambitious and try to use it as a spline like it gets used in the tape drive.
Matt B.
T49
Posted by Joe Johnson at 1/19/2001 9:59 PM EST
Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.
In Reply to: Window motor
Posted by Matt Berube on 1/19/2001 2:50 PM EST:
The gear is a 12 tooth, 16 diametral pitch, 20 degree
pressure angle, stub tooth.
This gear can mate with a standard gear by either
increasing the center distance a bit. This increases
the backlash a bit too, but nothing too bad considering
the typical FIRST robot. Another method is to shaft off
.4/D.P. (in this case .4/16=.025") the diameter of a
standard gear. Alternatively, you can have a stub gear
cut from legal kit materials.
Joe J.
P.S. Come to think about it, the last option is the
only real option this year since, to my knowledge,
mating gears (standard, stub or otherwise) are not sold
by Small Parts and gears are not on the Additional
Material List.