Motor coupling

[archiver]

Posted by Andy Baker at 1/26/2001 7:50 AM EST


Engineer on team #45, TechnoKats, from Kokomo High School and Delphi Automotive Systems.


In Reply to: I forgot: remove the lock washer after machining!
Posted by Andy Baker on 1/26/2001 7:17 AM EST:



Another thing:

Yous guys and your set screws... geesh!

A set screw looks like a small threaded shaft with one end that is kinda pointy and the other end HAS NO HEAD ON IT! The non-pointy end with no head has a socket in the end so that you can turn it with a wrench.

If you see any of these menacing screws lying around your shop, get rid of them!

There are three types of machine screws that some of you may be thinking are "set screws".

A SOCKET HEAD CAP SCREW is a machine screw with a head on it that has a socket for an allen wrench. This head looks like a stubby cylinder.

A BUTTON HEAD SCREW is a machine screw with a flatter, rounded head on top of a screw. This head also has a socket on it for an allen wrench.

A FLAT HEAD SCREW is a machine screw with a cone-shaped head that fits down into a counter-sunk hole (not counter-bored, that's a hole for the socket head cap screw). This cone shape also has a socket on it for allen wrenches.

So, now you know the deal. Talking about set screws is like nails on a chalkboard to many of us.

The screws on the side of the SPI gearbox couplings are socket head cap screws... not set screws.

Andy B.

[archiver]

Posted by Ken Leung at 1/25/2001 2:00 PM EST


Student on team #192, Gunn Robotics Team, from Henry M. Gunn Senior High School.


In Reply to: No, no, Anton... set screws inhale!
Posted by Andy Baker on 1/25/2001 7:34 AM EST:



I am wondering why aren't you guys using key/keyway... I mean, I know both method will work really well, but I tend to think that a key is more reliable than a pin or set screw. I am sure you guys already talked about this, but... What factors contribute to your decision of drilling a hole and put set screw through?

And when you said you've been using this for the past three years, I assume you are talking about custom made couplings... or do I not know Small Parts have been providing those couplings for a few years now?

[archiver]

Posted by Andy Baker at 1/26/2001 7:20 AM EST


Engineer on team #45, TechnoKats, from Kokomo High School and Delphi Automotive Systems.


In Reply to: why not a key way?
Posted by Ken Leung on 1/25/2001 2:00 PM EST:



We've been pinning the gearbox shaft for three years. It is just hard to do, that's why we have not directed people to do the same (we wasted many gearboxes trying to do it ourselves).

We are using the keyway for the other end of the coupling.

Andy

[archiver]

Posted by Joe Johnson at 1/26/2001 9:59 AM EST


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


In Reply to: We've made a custom shaft, not a coupling
Posted by Andy Baker on 1/26/2001 7:20 AM EST:



We have always managed to use either the double D's on the motors or the gears that are on the motors already or press on new gears/sprockets or used a trantorque type clamp on coupling.

We have yet to cut a keyway.

Haven't seen the need as of yet.

FYI.

Joe J.

[archiver]

Posted by Ken Leung at 1/24/2001 10:41 PM EST


Student on team #192, Gunn Robotics Team, from Henry M. Gunn Senior High School.


In Reply to: Motor coupling
Posted by Athena on 1/24/2001 7:40 PM EST:



: We are attaching the motor coupling to our motor. There is no hole in the shaft for the screw. Is drilling a hole in the saft a good idea or should we do something else?
: thanx ^.^

Looking at the graph of the motor coupling, and I assume you are talking about the drill motor coupling, I believe you are talking about the 1/16" hole for the spring roll pin. It is intended to lock the coupling in place by preventing it from unscrewing. So yes, you will need to drill hole in the shaft, and yes, it is safe and a good idea to drill holes on the shaft for mounting this coupling as well as a common way of mounting sprockets on output shafts.

You want to make sure the hole on the shaft to be as small as possible, because the hole will weaken the structure of the shaft according to the size of both the shaft and the hole, and make sure you drill the hole through the center of the shaft. One method of making sure that happens is to use a short countersink bit to start a pilot hole to guide the 1/16" drill bit from sliding randomly on the curvy surface of the shaft.