T-7 overheated!

[tylers]

Hello All,

I just purchased a T-7, set it up, and started to practice and refine my skills. I had run the machine for about 4 hours, having turned it off and on 4 to 6 times. The last time that I turned it on, I had used it for about 30 seconds, then let it run for about 20 minutes, when I heard an audible 'click' and the machine shut off. It would not re-start for about 90 minutes. I assume that it had overheated, and had some sort of internal breaker.  Has anyone out there heard of this before? If so, what was the 'fix'?

[SharpenADullWitt]

I have an older 2000, which also has the continuous duty cycle motor (no overload switch), so I will watch this with interest.
I would be more suspect of the on/off switch, being tripped. 

[SteveG]

I have a 2000 that I have run for 2 hours at a time without it shutting down.

[Ken S]

Welcome to the forum, Tyler and Steve. I have wondered if any of the Tormek motors have an over ride cut off switch. I have not read about such a switch on a Tormek. Hopefully Stig will post on this.

I am curious.....not critical, just curious.....What are you sharpening which would involve four hours of continuous motor running? Keep in mind, I'm from the generation which was taught to turn out lights, even though we often spent more in bulb replacement than we saved in kilowatts. A typical chisel resharpening might involve a few minutes, with the motor generally turned off during setup or switching to honing, if using the jig.

Do keep posting.

Ken

[jeffs55]

I thought that they were rated for 24/7 usage, or at least running. We all know that no one is going to have one under continuous load without an assistant.

[grepper]

Did you buy it used?  If so, I guess you could check the obvious like turn it over and make sure the wiring all looks ok and that the motor is not full of crud from the wheel.  You will probably have to pull the grindstone to have a good look into the motor.

Is it getting good power?  Are you plugging it directly into the wall?  Does the power cord look ok?  Does the cord get hot?

Does it spin freely and smoothly?

Can you measure the current draw when it's running?

[tylers]

Hi again,
I bought the machine new, and had only ran it this first session. I had the machine for about a week.
First I want to say that I contacted my retailer and Tormek with an email to the problem. My retailer contacted the wholesaler also. It was suggested by the retailer to the wholesaler to send me a FedEx shipping label to send it back. This was backed up by Tormek. The T-7 is on it's way back. I appreciate the response time, but it sounds like it's going to be 3 weeks before I get it back. I bought this machine, plus some others in order to get geared up for commercial sharpening as soon as possible.

Steve, I had this up and running as I practiced my skills/technique on several types of knives and tools, and moving between paper wheels, waterstones, and leather pad strops all the while examining each grind/polish with both a 14x hand lens and a high powered microscope, and keeping notes. I know....a bit overkill, but I'm a semi-retired scientist with a propensity for detail. I had turned it off 4 to 6 times during this 4 hour period, with probably the longest run time being 40 minutes.
Thank you all for your thoughts and advice.
As   'Ahhnold' said..... "I'll be back"
T

[tylers]

Oops, sorry.
I addressed the last para to Steve when it should have been to Ken.
Thanks again.

[grepper]

"all the while examining each grind/polish with both a 14x hand lens and a high powered microscope, and keeping notes. I know....a bit overkill..."

Not overkill here!  Other folks including myself have done the same.  I found it very informative about what is really happening at the edge.   Here's one I sharpened to about 1000 grit and then honed with Tormek compound.  The blue line was just so I could photograph the same blade area during various steps in the process.

http://23.archivec.com/1311/1620/127/VbJ41F.png

[Ken S]

Tyler,

Since you state you need the Tormek machine for business, I would suggest contacting either your dealer or the agent for your country. Ask them if they can send you another new machine more quickly.

One of the things I enjoy about this forum is the diversity of the members' life experiences. These experiences have pushed back the frontier in some areas of the Tormek. One example of this is Herman's HK 50 (his designation) small knife jig. Herman had his jig functioning before Tormek introduced their small knife jig. The two work differently; a proper sharpening service should have both, as each does slightly different small blades more efficiently.

Stig recently noted another use for Herman's jig ( for head knives). I believe the small platform can be adapted to many new uses.

Ton ("Dutchman") has produced a very well done booklet of triginometry for use with the standard knife jig. I believe Ton's work will produce interesting and more efficient techniques of sharpening knives with the Tormek. This might be of special interest to you with your sharpening business. (higher productivity=higher profits)

There is much fertile ground in this ancient technology for scientific and technical minds. Please keep posting.

Ken

[mike40]

Wow, I have to say that I am always astounded and impressed at the lengths some of you guys go to get great edges. It's almost like the sharpening is a hobby unto itself! My mind doesn't work that way, but I do respect the effort that goes into pursuit of the perfect edge. It's all very informative, but I am just hoping that I will keep my focus on my woodworking and not become obsessed with the sharpening as I am pretty slow at my age and I doubt I have the time for both! Meanwhile I am thankful to learn on the cheap from those of you who take the time to research your results and try new things.

[Fineline]

Extract from the manual

"The Motor is Running Hot
The heat developed by a single phase motor is considerable – even when idling when it
actually reaches its highest temperature. Our motors are designed for continuous operation
(except model T-4 which is rated for 30 minutes/hour), and there is no risk of overheating.
The electrical insulations are rated to operate at a temperature up to 135 °C (275 °F) with a
safe margin against overheating.
This means that the surface temperature of the motor can be quite high, approx. 70 °C
(158 °F), which means that you will burn yourself if you touch it. This temperature is normal
and there is no risk of overheating."


It says at idling it actually reaches its highest temperature.
Does this mean the motor is actually under greatest stress when there is no load?

[Jan]

Welcome to the forum Tyler.
It is very good to have a scientist here.  Sometimes we discuss various physical phenomena relevant to sharpening and we would like to hear more opinions on different issues or even be corrected by those who know more.
An apparently simple question "Why do scissors cut?" may be an example of underlying complexity.

Ken is right in his conclusion concerning sharpening

There is much fertile ground in this ancient technology for scientific and technical minds.

Regards
Jan

[tylers]

Ken,
here is what I sent to the retailer, wholesaler, and Tormek. I have yet to get a reply:

"Hello again,
As you all know, I had problems with my new T-7 within the first 5 hours of running. I have sent this back to xxxxxxx. In the meantime, I am now going to be delayed at least three weeks on getting my business up and running.
I would like to make a suggestion that you put in place a policy of replacing a T-7 that needs repair within the first 30 days of ownership with another new T-7 as soon as possible, as to not cause this delay in in the future.
I appreciate your timeliness in addressing the problem, but I am now losing possible income....
Thank you,
Tyler xxxxxxxx
Never a Dull Knife and Tool Sharpening
a Division of Good Shepherd Enterprises LLC

Hi Jan,
two things; be careful what you ask for. We all have our opinions and with mine you will get what you pay for! I appreciate the thoughts though.
Ken,
thanks much for the ideas and thoughts also.
Fineline,
I too picked that up in the manual. That was why I was so surprised that it stopped running for a while.
Grepper,
Great pic! I am working on trying the same sort of photography. Got rid of my old film cameras where i used to collect and photograph minerals, but now have a digital and don't yet have the capability of that sort of pic....soon I hope! When I get to that stage, I will be back asking questions on how to 'archive' pics to share with everyone who is interested.
Great forum! Now, on to the Twice As Sharp Scissors machine!

[grepper]

Tylers,

Unless you are otherwise inclined, you don't need to make taking those types of images difficult or expensive.  You don't happen to have access to an SEM do you?  I just used a USB microscope.  They are available from $20 – hundreds, but a $35-$50 one will work just fine.  Just Google it.  If you have questions, I'd be happy to help.

When you wish, we can help with archiving and posting images.  It's easy.