# Lathe hss bit grinding jig



## Mike8623 (Feb 10, 2021)

Does anyone know of a simple homemade jig or fixture for grinding your lathe hss tool cutters. The simpler the better.


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## mmcmdl (Feb 10, 2021)

Are looking for an actual fixture or a gage to measure the tools ?


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## Mike8623 (Feb 10, 2021)

Looking for the plans or a picture of a fixture that will allow me to accurately grind the angles for lathe hss cutting bits. I've got items to measure angles. Looking for the simplest jig I can make.


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## mmcmdl (Feb 10, 2021)

I take it you have a surface grinder ? Most bits are simply ground by hand on a bench grinder or abrasive belt .


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## Mike8623 (Feb 10, 2021)

I'll be using a bench grinder.


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## Mike8623 (Feb 10, 2021)

Just had to add this gal


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## DAT510 (Feb 10, 2021)

If you are looking for a "Jig" type of method to grind your HSS lathe bits, you might look into Tangential cutter bits.  There are a number of designs out there that position the HHS in a jig that creates a Diamond faced cutter bit, which is then held in a tool holder that places the bit at a tangent with the work piece.  

Here's a company that makes both the Grinding fixture and tool holder, but there are numerous diy designs floating out there on the web.



			The Diamond Tool Holder
		


Hope this helps.


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## Mike8623 (Feb 10, 2021)

I thank you so much for your input


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## Nogoingback (Feb 10, 2021)

+1 on the Diamond Tool holders.  The grinding jig that comes with them isn't a universal tool grinding jig, but rather
useful for the specific grind required by the Diamond.  They are useful tools however: I use mine all the time.


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## benmychree (Feb 10, 2021)

The grinder, the fingers, and the eyes are all that are required.


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## mikey (Feb 10, 2021)

Here is the reproduction of the South Bend tool grinding jig. I have not used one but lots of guys used the original SB one. 



benmychree said:


> The grinder, the fingers, and the eyes are all that are required.



Personally, I'm with John ...


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## benmychree (Feb 10, 2021)

I might add that after a tool is ground and used, that an observation of what really worked and how well it worked has to integrate the mind into the equation to fine tune the clearances that need to be applied to the facets of the tool.  So far as the SB gage is concerned, remember that it works with the angles incorporated into the Armstrong type toolholders and would not be completely in tune with the Aloris type holders that most of us use, particularly in the case of front clearance.


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## WCraig (Feb 11, 2021)

MrPete did a Youtube video with a HSS tool grinding jig:






Craig
(I haven't made one of these.  I just drew a couple lines on my grinder tool rest and tilted the rest to the other angle.)


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## Canus (Feb 11, 2021)

I built a unit similar to the one shown in the MrPete video and one with a 90 degree combined angle face.  Added the guide ledge he mentions and also built in the side angles so that I don't have to set the angle on the grinder.  Have been happy with them.  You will need a mill to build them tho.


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## Mike8623 (Feb 11, 2021)

I appreciate all the input guys. I learned to grind tool bits years ago in gunsmith school. Now I know it wasn't near as intense as most of you machinist went through but I sure got tired of measuring the exact angles just to be told it wasn't quite good enough... and then over and over again....I do grind them by eye now but was hoping someone would suggest or have a picture of a simple fixture, jig,

How about it guys. I'll never be a master machinist just hoping for a simple jig.


Canus said:


> I built the units shown in the MrPete video and have been happy with them.  You will need a mill to build them tho.


I do have a milling machine


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## Mike8623 (Feb 11, 2021)

Yah I need the 90 degree cutting bit fixture not 60 degree v thread one


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## Mike8623 (Feb 13, 2021)

I want to thank everyone that responded


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## Illinoyance (Feb 13, 2021)

I believe South Bend's "How to Run a Lathe" had an illustration of a jig that could be used on a bench grinder.  Bear in mind that such a jig would most likely grind only one type of tool.


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## finsruskw (Feb 13, 2021)

The last few bits I have ground I just left them in the tool holder.
Much easier to hold onto and follow the degree marks on the grinder tool rest.
Clamp a small piece/strip of flat stock to the tool rest to gage and guide  the grind to the correct angles your grind calls for.
Gets you really close quickly.


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## yendor (Feb 16, 2021)

finsruskw said:


> The last few bits I have ground I just left them in the tool holder.
> Much easier to hold onto and follow the degree marks on the grinder tool rest.
> Clamp a small piece/strip of flat stock to the tool rest to gage and guide  the grind to the correct angles your grind calls for.
> Gets you really close quickly.





Illinoyance said:


> I believe South Bend's "How to Run a Lathe" had an illustration of a jig that could be used on a bench grinder.  Bear in mind that such a jig would most likely grind only one type of tool.


There is a company making a reproduction of the South Bend Jig. I have one and it works very well.


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## yendor (Feb 16, 2021)

yendor said:


> There is a company making a reproduction of the South Bend Jig. I have one and it works very well.


whoops forgot to attach the link.






						Reproduction South Bend Lath Works Grinding Gage and Jig
					

Alisam's reproduction of South Bend Lathe Works grinding gage and jig



					www.alisam.com


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## Tozguy (Feb 16, 2021)

Mike8623 said:


> I do grind them by eye now but was hoping someone would suggest or have a picture of a simple fixture, jig,


I have never seen simple ones for a bench grinder. Belt or disc sanders can have a simple protractor guide and tilt table to get precise angles. Of course the abrasive have to be changed out for metal grinding. 
For example: https://www.grizzly.com/products/shop-fox-4-x-36-belt-6-disc-combo-horizontal-vertical-sander/w1855


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