Exceeding T3 Motor Duty Cycle

[taberwald]

Will exceeding the T3's 30 minute duty cycle cause any damage to the motor?

Thanks.

[Jeff Farris]

The biggest danger is not damage to the motor (which would take a long, long time).  But, the heat generated by the motor can transfer to the plastic frame via the motor mount and cause some serious problems. 

It's a very good idea to respect the 30 minute duty cycle.

[Fineline]

The biggest danger is not damage to the motor (which would take a long, long time).  But, the heat generated by the motor can transfer to the plastic frame via the motor mount and cause some serious problems. 

It's a very good idea to respect the 30 minute duty cycle.

I do not know to what extent the T4 plastic frame covers.

Even though the T4 has a zinc top, the spec still rates it at 1/2 hour duty cycle.

Also, what does 1/2 hour duty cycle mean?

If I use it for 15 mins, rest 5 mins, use 15 mins, rest 5 mins, use 15 mins, rest 5 mins, use 15 mins, rest 5 mins; that makes 1 hour of use with 20 minutes break. This is one scenario and there are countless.

Sorry, I don't have the manual or actual unit so I am guessing.

Any comments?
Thanks.

[Ken S]

Welcome to the forum, Joe.

The fifty percent duty aspect of the T3 and T4 motors has not been fully addressed. The handbook doesn't really differentiate much between the T4 and T7. I own a T7 and am testing a T4. Major computer problems have delayed me from much testing.

My initial impression of the T4 is that it is a very solid machine. I was surprised that almost all the T4 parts are interchangeable with the T7. The shaft is the same diameter. The T4 comes with a seven year guarantee. The guarantee is not for industrial use, like the T7 guarantee. However, this does not mean the T4 is only for "hobby"use. My ongoing impression for choosing between the T4 and T7 remains the work location, not cost. A permenant location in a large shop would dictate the T7. In a smaller shop or a more mobile envoronment, I would choose the lighter, more compact T4. Both models use the same jigs.

I believe in most cases the operator might need a break before the motor. For a home shop or small sharpening service, how often would the work load realistically approach the motor duty point?

I hope Stig will post with some factory testing information. This question warrents a thorough discussion.

Ken

[Herman Trivilino]

Also, what does 1/2 hour duty cycle mean?

As I recall it means 1/2 hour on, 1/2 hour off.

[Ken S]

I would be curious to know how many motor repairs were actually caused by overuse. Perhaps Stig might have some information. As I recall, the smaller motor of the T3 was primarily available in Europe, with 50 Hertz current. I don't recall it being available until recently in the US. My paper copy of the handbook (Edition 9.5, 2007) states that at that time, the 1200 model, the version of the T3 at the time, was not available in 115 volt. Therefore, it was not available for the US market.

Ken