Countersink Sharpening Fixture

I have three different sizes of countersinks that pretty much cover everything I need to do; I noticed a while back that a couple of the most commonly used countersinks were not cutting very efficient anymore and I would soon be making a decision on whether to buy new ones or to make a re-sharpening fixture for the surface grinder, good countersinks are relatively expensive I just couldn’t see paying for new ones which would have been around $90.00 when all I needed to do was touch up the cutting edge a little on the old ones.

All my countersinks are 82° and single flute; I have used multi fluters over the years but the single fluters work the best in my personal opinion, so naturally this fixture was made with a one lobe cam to sharpen only single flute countersinks, but it could be made to sharpen multi fluters easily with the appropriate cams, a three flute countersink would need a cam with three lobes a four flute would need four lobes and so on.

I didn’t want to spend allot of time making this fixture nor did I want to take out a loan, so it was manufactured from what was available on the shelf. everything was made from 1018 steel except for the single lobe cam which is hardened 4140 and the aluminum rotating knob.

The cam has a .030” axial movement for one complete revolution of the spindle; this is what gives you your cutting edge relief.

This fixture will sharpen single flute countersinks with 82°or 90° angles, the spindle of the fixture was made to accommodate 1/2” shank cutters, I made two additional collets that was 1/2" O.D. with 1/4” I.D. and 3/8” I.D.holes to accommodate cutters with 1/4” and 3/8” shanks, the base of the fixture is machined on each end with 82° and 90° angles clearly stamped, all that is required to use this fixture is to sit the base down on the magnetic chuck with the corresponding angle you want to sharpen up against the back rail of the magnet, align the cutting edge of the countersink with the cam lobe, then lock down the set screw and sharpen away.

I have included a couple photos of the setup and machining along with a short demonstration video of the setup and sharpening process.

As always thanks for looking and happy machining
Doug

Attachment 25276 Attachment 25277 Attachment 25278

Attachment 25279 Attachment 25280 Attachment 25281

Attachment 25282


https://www.youtube.com/watch?v=gwN5SfrXbjk

Excellent tool,Ive' been looking for one that is not complicated. Most of my countersinks are piloted, they are a pain to sharpen.Think I will try a single
flute and copy your tool. Thanks for a great idea !

Great job Doug!!!! I'd like to see the inside workings of this. How exactly did you get it to stop feeding the bit at .030"?

Nice. If you keep this up I'm going to be tempted to start looking for a surface grinder! :-)
How did you create the cam?

nice little fixture. Something like this should be extended to do two lip drill bits. Thanks for the great video.

Once again, nice work & a good video,

So ingenious, well done, video explains nicely, thanks again doug

Quote:

---

Originally Posted by big o

Excellent tool,Ive' been looking for one that is not complicated. Most of my countersinks are piloted, they are a pain to sharpen.Think I will try a single
flute and copy your tool. Thanks for a great idea !

---

Thanks big o
I like those piloted c.sinks too but like you say they are a pain to sharpen

Doug

Quote:

---

Originally Posted by MountainMan

Great job Doug!!!! I'd like to see the inside workings of this. How exactly did you get it to stop feeding the bit at .030"?

---

Thanks MountainMan
How it works is the cam has a .030" lift in a 360° revolution at the end of the revolution there is a .015" undercut done with a 3/16" end mill, so beings it's spring loaded when you rotate it 360° it stops at the undercut

Doug

<!-- BEGIN /var/www/html/homemadetools/protected/modules/zeus/views/tool/postUpdate.php -->
Thanks rossbotics! We've added your Countersink Sharpening Fixture to our Machining category,
as well as to your builder page: rossbotics's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/homemade-countersink-sharpening-fixture"> <img src="/uploads/217315/homemade-countersink-sharpening-fixture.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/homemade-countersink-sharpening-fixture">Countersink Sharpening Fixture</a> <span> by <a href="http://www.homemadetools.net/builder/rossbotics">rossbotics</a></span> </div> <div class="tags">tags: <a href='http://www.homemadetools.net/tag/sharpening'>sharpening</a>, <a href='http://www.homemadetools.net/tag/fixture'>fixture</a>, <a href='http://www.homemadetools.net/tag/countersink'>countersink</a> </div> </div> </div> </div>
<!-- END /var/www/html/homemadetools/protected/modules/zeus/views/tool/postUpdate.php -->

Great write up, pics and the vid made it real clear, Doug. Honestly, I've never seen chips that good from a New countersink...that is Impressive...made it look like shaving butter with a scalpel! Am curious how well it cuts CRS or harder material. Love that you take that simple approach to your designs and versatility of a tool and would never have thought about the cam idea for that operations, let alone how much of a cam.

Once again I learned a bunch in 10 minutes and ever grateful for you sharing your work and the forum! Thank You!

:hattip: PJ

Quote:

---

Originally Posted by Saltfever

Nice. If you keep this up I'm going to be tempted to start looking for a surface grinder! :-)
How did you create the cam?

---

Thanks Saltfever
I should have made a video of the cam manufacturing, it's relatively hard to explain, a visual would clear things up, I'll work on a video

Thanks Doug

Quote:

---

Originally Posted by wizard69

nice little fixture. Something like this should be extended to do two lip drill bits. Thanks for the great video.

---

Thank you wizard69
It could be converted to sharpen a drill with the appropriate cam

Thank You
Doug

Quote:

---

Originally Posted by rossbotics

I should have made a video of the cam manufacturing, it's relatively hard to explain, a visual would clear things up, I'll work on a video

Thanks

---

I too would be grateful for a video about making the cam. I cannot think of an easy way to do it.......

Thank you.... Lornie

Quote:

---

Originally Posted by Metallurg33

Once again, nice work & a good video,

---

Thank you Metallurg33

Doug

Quote:

---

Originally Posted by Stevohdee

So ingenious, well done, video explains nicely, thanks again doug

---

Thanks for your comment Stevohdee

Doug

Quote:

---

Originally Posted by PJs

Great write up, pics and the vid made it real clear, Doug. Honestly, I've never seen chips that good from a New countersink...that is Impressive...made it look like shaving butter with a scalpel! Am curious how well it cuts CRS or harder material. Love that you take that simple approach to your designs and versatility of a tool and would never have thought about the cam idea for that operations, let alone how much of a cam.

Once again I learned a bunch in 10 minutes and ever grateful for you sharing your work and the forum! Thank You!

:hattip: PJ

---

Thank you PJs
My first attempt at creating the cutting edge relief was not so good, I originally made a spindle with an eccentric hole of .030" offset for the countersink, I could never get the timing right, so that's when I came up with the cam idea, the cam worked perfectly, for me to explain the cam making process would get pretty lengthy, a couple other members asked the same question so I'm going to make a video and post it. BTW the countersinks are made by KEO and they work just as well on steel

Thanks PJs
Doug

Nice job Doug! will you be adding this to your plans for sale

I can't see the detail in the photo of the 0.030 cam, which I believe is the surface with a 0.030 helix.
Attachment 43850

Hi Doug, I made a copy of your fixture. It was fun to make and worked really well. The only thing I did different is design and 3D print the cam. I wasn't sure how to get the 0.030" helical slope machined in metal, but the plastic cam works perfectly. I made a youtube video for it on my channel and gave you credit and added a link to your channel. Take good care, Gilles
https://youtu.be/uwotg_fzaos

<!-- BEGIN /var/www/html/homemadetools/protected/modules/zeus/views/tool/postUpdate.php -->
Thanks Lets Roger That! We've added your Countersink Grinding Fixture to our Machining category,
as well as to your builder page: Lets Roger That's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="https://www.homemadetools.net/homemade-countersink-grinding-fixture"> <img src="/uploads/258869/homemade-countersink-grinding-fixture.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="https://www.homemadetools.net/homemade-countersink-grinding-fixture">Countersink Grinding Fixture</a> <span> by <a href="https://www.homemadetools.net/builder/Lets+Roger+That">Lets Roger That</a></span> </div> <div class="tags">tags: <a href='https://www.homemadetools.net/tag/grinding'>grinding</a>, <a href='https://www.homemadetools.net/tag/fixture'>fixture</a>, <a href='https://www.homemadetools.net/tag/countersink'>countersink</a> </div> </div> </div> </div>
<!-- END /var/www/html/homemadetools/protected/modules/zeus/views/tool/postUpdate.php -->

very good work Roger that, it will cut steel if you have a HSS countersink

Doug

Doug,
Do you anticipate providing plans for this fixture in the future?
As usual nice work.
Phil

Quote:

---

Originally Posted by rossbotics

I have three different sizes of countersinks that pretty much cover everything I need to do; I noticed a while back that a couple of the most commonly used countersinks were not cutting very efficient anymore and I would soon be making a decision on whether to buy new ones or to make a re-sharpening fixture for the surface grinder, good countersinks are relatively expensive I just couldn’t see paying for new ones which would have been around $90.00 when all I needed to do was touch up the cutting edge a little on the old ones.

All my countersinks are 82° and single flute; I have used multi fluters over the years but the single fluters work the best in my personal opinion, so naturally this fixture was made with a one lobe cam to sharpen only single flute countersinks, but it could be made to sharpen multi fluters easily with the appropriate cams, a three flute countersink would need a cam with three lobes a four flute would need four lobes and so on.

I didn’t want to spend allot of time making this fixture nor did I want to take out a loan, so it was manufactured from what was available on the shelf. everything was made from 1018 steel except for the single lobe cam which is hardened 4140 and the aluminum rotating knob.

The cam has a .030” axial movement for one complete revolution of the spindle; this is what gives you your cutting edge relief.

This fixture will sharpen single flute countersinks with 82°or 90° angles, the spindle of the fixture was made to accommodate 1/2” shank cutters, I made two additional collets that was 1/2" O.D. with 1/4” I.D. and 3/8” I.D.holes to accommodate cutters with 1/4” and 3/8” shanks, the base of the fixture is machined on each end with 82° and 90° angles clearly stamped, all that is required to use this fixture is to sit the base down on the magnetic chuck with the corresponding angle you want to sharpen up against the back rail of the magnet, align the cutting edge of the countersink with the cam lobe, then lock down the set screw and sharpen away.

I have included a couple photos of the setup and machining along with a short demonstration video of the setup and sharpening process.

As always thanks for looking and happy machining
Doug

Attachment 25276 Attachment 25277 Attachment 25278

Attachment 25279 Attachment 25280 Attachment 25281

Attachment 25282


https://www.youtube.com/watch?v=gwN5SfrXbjk

---

I like your fixture and would like to build it. The big question is how is the cam made? My shop is totally manual with no CNC capabilities. Do your plans include making the cam sans CNC?