[How do I?] Grinding Form Tools On A Gorton 375

[leeko]

Hi all,

I have a very nice Gorton single lip grinder, model 375-2, which i picked up at auction a while back. I finally got around to cleaning it up and playing with it. I'd like to use it for accurately grinding lathe tools, and occasionally making single lip milling form cutters. I have a couple of quick questions:

- for grinding a 60 degree threading tool, how is the right side of the tool ground? The tool holder has just enough swivel motion to get the tool the 30 degree off axis, but then the "plunge" motion of the holder assembly is in the wrong direction. If anyone can direct me to some examples of actually using this type of grinder, I'd really appreciate it! There are only a few examples on youtube, mostly in chinese.

- grinding a ball-end cutter (or a convex radius lathe tool) seems pretty straightforward using the included radius swivelling holder. Is it possible to grind a concave tool with this machine though? I can't figure out how that would be done, but it seems like it would be the more commonly useful type of tool (corner-rounding, for example)

Thanks very much!

Lee



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[lvflats]

Ran one for many years but only for milling cutters. I did make some lathe tools but, only to cut on one side. Like you described.
It is pretty much a single purpose machine. We actually used it with a finger and resharpened end mills or added a corner
radius. Works well for sharpening the bottoms of end mills. For a corner rounding lathe tool you might have to dress the
wheel to the radius you want and just use it to dress up your free hand grinding. If that makes any sense? For that I have also
used one lip of a milling cutter. The fact that the upper slide only travels in one direction from center line make what you want
to do pretty much impossible. Out side of pantograph or mold making shops I don't recall seeing any.
Art

 

[f350ca]

Have never used the real thing Lee but built one loosely copying their design. For the right side I keep the angle (30 deg) the same, flip the cutter over and reset the clearance angle over the other way (toward the wheel). Not sure if you can do that on yours or not but might give you some ideas.
In the photo I have it set to grind an Acme cutter.


Greg

 

[leeko]

Thanks for the replies guys, sorry for the late response - didnt get a notification.

Wow f350 - that's an impressive build looks great. Great advice on flipping the cutter, too - I'll definitely give that a try. Should be easy enough - my holder is a collet indexing head.

Do either of you guys know of any manuals, videos or other literature on how to use one of these single lip grinders? I really want to make the most of it, and it seems like it could be really useful. I also just picked up a bunch of carbide tipped spotfacers at a lucky auction - just waiting to be repurposed

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[caspaincmonster]

Check out a manual for the Deckel S0 or S0e which this is very similar to, you can getting both concave and convex curves. I think they are easily found online but if not I can provide one.
Luke

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[Toolmaker51]

re a little confusion; Gorton #375 is more tool grinder than their #265.
A #265 looks similar to the uninitiated, it IS a single lip grinder like the Deckel SO and the chineseium copies.
#375 will by means of sliding collet holder and indexing guide-finger sharpen helical flute cylindrical and taper cutters, re-size drills, ball-end or radiused corner endmills etc. The same collet holder has 24[?] hole indexing with a bushing or square collet, easily can produce perfect single point lathe cutters; RH & LH [yes, radiused too] 29°ACME & 60° Vee threading, small boring bars even the tapered protrusion. The complete tool holder rotates and inclines for any logical clearance combination desired. The trick for boring bars; a shop made eccentric bushing to fit collet of your choice, creates the protrusion off center the round or square shank.
Only slight issue is securing a ready supply of tool grinding wheels; especially flats and cups. They secure to the spindle in the common arrangement, just smaller proportions than a typical 6 x 12 surface grinder.
The SO copies, I think connect to the misinformation about #375's vs #265's, thinking they'd capitalize on a popular machine that's no longer produced [375]. Lol, hard to believe that many pantographs are floating around, beyond the need for normal tool grinding. I'd guess a 100+ common endmills are ground for each single lip cutter, though hobbyists/ horologists use "D" bits in quantity.
The copies also think they'll capitalize by underselling on the big money a Deckel commands. Looks the same isn't same as "equal".