US-105 vs US-103

[DaveH6818]

I have an older 2000 Super Grind 2000.  The Support has micro-adjust, but is not threaded at the end to add a tool stop.

Do i replace it with the US-105?  has the 105 always had a threaded hole at the end for the stop to screw into?  What is the overall length for the 105 (my support is 12" long??

[Ken S]

Welcome to the forum, Dave.

The US-103 is designed for the T4 size grinding wheels (200mm x 40mm). The US-105 is designed for the thicker 250mm wheels (50mm thick) The US-105 is 10mm to allow the end stop to work properly. The US-105 is the proper length for the SuperGrind 2000, T7 and T8.

This came up on the forum years ago.I just remembered how Jeff Farris responded.

Ken

[ega]

Ken S:
Greetings from the UK!
I was puzzled by your saying that "The US-105 is 10mm to allow the end stop to work properly". Can you elaborate, please?
I was surprised that Tormek resorted to the acme thread; I would have thought that a soft-headed pinch screw would suffice to protect the thread.
Tormek say that the US-105 "Can be placed in these positions:

    Vertically for sharpening towards the edge.
    Horizontally for sharpening with the edge.
    Horizontally at the honing wheel side for honing."
I recall your mentioning in another thread that you had tried the "fourth dimension" of horizontally at the rear of the machine and found that water spillage made this otherwise attractive idea impractical.

[cbwx34]

Ken S:
Greetings from the UK!
I was puzzled by your saying that "The US-105 is 10mm to allow the end stop to work properly". Can you elaborate, please?
I was surprised that Tormek resorted to the acme thread; I would have thought that a soft-headed pinch screw would suffice to protect the thread.
Tormek say that the US-105 "Can be placed in these positions:

    Vertically for sharpening towards the edge.
    Horizontally for sharpening with the edge.
    Horizontally at the honing wheel side for honing."
I recall your mentioning in another thread that you had tried the "fourth dimension" of horizontally at the rear of the machine and found that water spillage made this otherwise attractive idea impractical.

It probably should be phrased... The US-105 is 10mm longer to allow the end stop to work properly with the wider wheel.

As for  the "fourth dimension" of horizontally at the rear of the machine"... if you hold a knife horizontal and sharpen where the wheel is turning toward the knife/tool, water will quickly build up on the knife and run off to the side.  If you sharpen in the normal position, this is less of an issue (still happens, but not as much).

[ega]

cbwx34:
Thank you.
I have two of the earlier generations of the US and am not familiar with the end stop - perhaps I should be!
I can well see that a longish knife would provide a route for water to spill sideways but wonder whether a chisel or plane iron would create the same problem

[Ken S]

Ega,

From the frame out, the shafts of the T4 and T8 size Tormeks are identical. The outsideof the 250mm (T8 size) wheels have more indent, so either size can be mounted. The end screw keeps the square edge tool in the jig from falling offof the grinding wheel. CB is correct; it is better stated that the US-105 is shorter to compensate for the narrower grinding wheel.

The flat acme thread surface provides more bearing surface for the locking knobs on the sleeves. It also increases the production cost slightly; however, the quality is also increased. Going by memory, the pitch of the acme 12mm thread is 1.5 mm for the microadjust. I believe the standard M12 thread pitch is 1.75mm.

My "fourth dimension" support bar position idea is now in my "brilliant, but of very limited use" file. Forum member, Robin C Bailey, invented and made an extended support bar. It has the longest vertical legs of any support bar ever produced. I purchased one from Robin years ago and have found it useful. The vertical legs are long enough to be inserted in the horizontal sleeves from the far side. While this caused excessive water spillage, it actually works very when used dry with diamond or CBN wheels. Although Robin sold these for a reasonable price, the shipping cost from the UK to the US discouraged many sales. It also has no threads. I never found that a problem is actual use, although some thought differently from arm chair thinking.

Ken

[ega]

Ken S:
Thanks for the further information. I will look into the Robin Bailey support (I wonder if he is descended from the plane man).
Interesting that Tormek opted for the acme form as the metric equivalent is normally the 30 degree trapezoidal thread (Sweden was, of course, a late convert to "metric" driving on the left of the road).

[ega]

PS I should, of course, have written from the left of the road!