A key measurement?

[LarsHansen]

Hello. New user here as you may guess reading this post.
Please bear with me if the answer is common knowledge.
I searched the forum for info on this topic, but with no luck.

I would like to know if the vertical distance between the center of the shaft and the center of the USB (in the horizontal position) is a constant for all Tormeks - or maybe for all 200 and 250 mm models respectively?

Thanks very much for answers or links to info.

Lars in Denmark

[Ken S]

Welcome to the forum, Lars. Good question. I had a very busy schedule when my T4 arrived. I didn't have the time to sharpen with it, only sit it on my bench next to my T7. That turned out to be a very good learning experience. The end sections of both shafts are identical, as is the 12mm diameter. The only difference is the length within the frame. In fact, if you remove the water trough on the T4, an SG-250 fits on the shaft and can be tightened. The 10mm width difference is only at the edge of the wheels. The indented portion of the larger wheel makes the diameter at the bore almost identical. The length of the threads easily compensates for the tiny difference in wheel thickness.

The vertical distance is the same.

Ken

[LarsHansen]

Hi Ken.
Thank you for the friendly welcome.
Obviously, my English skills are limited, so I'll rephrase my question:

A) If you measure the height from the table to the center of the USB (in the horisontal position)

B) and measure the hight from the table to the centre of the shaft

What is A minus B?

and

Is that number the same on all Tormeks?

Your's,
Lars

[cbwx34]

Hi Ken.
Thank you for the friendly welcome.
Obviously, my English skills are limited, so I'll rephrase my question:

A) If you measure the height from the table to the center of the USB (in the horisontal position)

B) and measure the hight from the table to the centre of the shaft

What is A minus B?

and

Is that number the same on all Tormeks?

Your's,
Lars

Not the same between a T-4 based model and a T-8, but based partly on some indirect evidence, I believe the measurement between a T-8, T-7 and Supergrind 2000 is pretty close... only around a mm or so difference in examples I've seen.  (I don't have actual numbers available.)

[LarsHansen]

@cbwx34:
Thank you vey much!

A friend of mine has measured the hight difference to 40 mm on the grey Anniversary model (a T7 in disguise).
That would be 1.575" or 1" and 37/64.

In TormekCalc3, I believe the number I'm looking for is called "Constant HH" and the value 41 (1.614" or 1" and 39/64), suggesting that my friend isn't too far off.

If someone owning a Tormek in the T3/T4-size would be so kind as to check, I'd be very glad to hear the result.

Lars

[cbwx34]

...

In TormekCalc3, I believe the number I'm looking for is called "Constant HH" and the value 41 (1.614" or 1" and 39/64), suggesting that my friend isn't too far off.

If someone owning a Tormek in the T3/T4-size would be so kind as to check, I'd be very glad to hear the result.

Lars

Yes, it's the HH measurement, and the value for the T-4 there is 29mm.

Not sure what you're trying to do, but you can double check by measuring directly to the wheel (T_usb in TormekCalc) for verification of most setups.

Being within a mm is probably more than adequate.

[Ken S]

Hi, Lars.

Sorry, I have never measured to the frame, although I know that others do with far more extensive math knowledge than I have. I started measuring to the grinding wheel ten years ago, and have never understood a need to use the frame.

I don't know if frame measurements would be any more precise. I also question what level of angle precision we need. Tolerance standards are critical in industry for parts fit and interchangeability. A knife edge does not have fit with another metal surface like a bolt and nut do. I like bevel angles which are consistent and repeatably. Wheel measurements provide that.

Ken

[LarsHansen]

Thanks again to both of you, very helpful.

Lars

[cbwx34]

I don't use the horizontal setup (since I use an FVB), but I input the variables from TormekCalc into Calcapp, (the "Honing" variables, and keep in mind that "horizontal" and "vertical" are reversed).

I then set the USB using the distance to the top of the sleeve ("USB to FVB"), and checked it with the "USB to Wheel" measurement, (T_usb in TormekCalc) and everything basically seemed to line up.

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Mostly just for my own curiosity.