DIY Tool Post Grinder for Quick Change Tool Post

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Well-Known Member
HMEM Supporting Member
Mar 8, 2019
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Charlottesville, VA
On the helpful advice of forum members, I recently got a no-name AXA QCTP for my Grizzly 10x22 bench top lathe.
Gotta say, I love, but I need to get a bunch more tool holders. Luckily, they can be found cheap.

When making tiny parts on the lathe, I often had thought how handy a tool post grinder would be, but never looked deep into it. Then my 3 jaw chuck started loosing its "center" and I decided to cobble up a grinder to I.D. grind the hardened jaws. Here is what I came up with.

I had this antique engraver that has long been replaced by a Dremel. But the spindle and motor were still good.
With a couple of flanged bearings, and a 5/8" O.D. tube, I made a spindle cartridge that fit perfectly into the 5/8" boring bar holder for the AXA. I made some o-ring pulleys and that was pretty much it.

It did a fair job on the 3 jaw chuck, but where it excelled, was grinding a small pin out of a hardened drill blank with a conical taper to seal inside a tapered hole. No way this could have been done with conventional turning... at least not with my equipment.

Lessons learned. I will probably rebuild this with proper angular contact bearings and use an Erikson ER9 holder for the spindle. Runout from the Fairchild piece was a pain.


This is what I started with.

Parts and pieces

The finished spindle

Installed on the AXA boring bar holder

Itty bitty pin ground from a drill blank. Skinny portion is .031" diameter. (0.79mm).
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That looks like it is just the thing to meet your need. Good job.

Thank You for posting,


Thanks, Shop Shoe. I am looking at your avatar with all the chips stuck in the soles of shoe. A dead giveaway for a machinist.
Back in the 1980's I worked in a specialty gear-house in Detroit. This was when the suede "desert boots" with the soft crepe rubber soles were popular. A young guy (ha, I was young too) came to work there and was wearing those desert boots. He worked in an area where there was cutting oil all over the floor. In a week the soles of those desert boots had softened up and swelled out like snow shoes with hundreds of chips stuck in the bottom. Worked great in the icy winter parking lot, LOL.
Nice work Lloyd! I use a similar setup with a flexible shaft hooked up to an older dremel for very fine work, the shaft is a perfect fit in my AXA boring bar holder and is more accurate than the older die grinder (worn bearings) I have that’s set up in another tool holder.

You didn’t explain how you mounted the motor though!

John W
edit ...........

You didn’t explain how you mounted the motor though!

John W

John, The special nuts that are used with the boring bar clamp-bolts have just enough M5 thread available on the bottom to allow 3 or 4 turns of a bolt to attache a motor mounting plate. It is just a piece of heavy gauge sheet metal with a couple of ears shaped and bent on it. the pass-thru bolt in the motor also had just enough threads for the ears to attach. The pulleys were aligned by slipping the spindle cartridge in and out till everything looked good. Fussy work, but not difficult.