# End Mill Sharpener ?



## rdean (Apr 7, 2016)

I have been watching mark_f's post (Another Tool and Cutter Grinder) with great interest.  He makes some beautiful useful tools and this one just caught me.  Maybe I could make something that resembles an end mill sharpener that might even work.  I watched a lot of videos and many other threads here and on line and there are many different designs to get the same results.  A member here (coffmajt) made a sharpener a few months back that uses a table top grinder.  I have a HF model similar to his so that is what I will try to use. He was kind enough to answer some of my questions and was a big help.

I have no experience what ever in sharpening end mills so this project may be just for fun and entertainment but here goes.  ( I have trouble sharpening a pencil)

I have made some morse tapers recently and wondered if I could make a end mill holder with a R8 taper.  Found the angle of the taper and went to the Machinists Handbook to get the sine measurement and set up my lathe.  I started with a piece from the scrap bin that I think was from an old office chair.






I figured about 7 1/2" long should be about right and had a go at the R8 taper.





Well that worked out really well so I got a 1/2" bolt and cut it down in the lathe.  I single pointed some 7/16" 20 threads, cut off the head, and added a handle.




It looks like this might work so I made a collar to press on to the barrel but first I drilled 4 holes 90 degrees apart to use for locating holes.  Well as long as I had it set up I also added 2 more holes 120 degrees apart from the first just in case I  have a three flute mill to sharpen.















We will have to see what happens from here but so far I have had a lot of fun

Thanks for looking

Ray


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## Andre (Apr 7, 2016)

Is this going to be linear/rotary unit for sharpening flutes or just used for indexing to sharpen the ends?


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## 34_40 (Apr 7, 2016)

I cannot imagine what you're up to!
So, I'll just keep watching.  I was watching Marks tool as well, but I haven't kept up.  Once I fell behind in how it was to work..

I just stopped watching.


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## CraigB1960 (Apr 7, 2016)

Very interested in this as well.


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## rdean (Apr 7, 2016)

Thanks guys if it works it will do the flutes and the ends.
More tomorrow.

Ray


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## rdean (Apr 8, 2016)

I am very pleased with the way the barrel turned out so on to the next step something to put the barrel into.   I am trying to make this project with out buying any materials just using what ever I can find around the shop that was left over from other projects.
This is what I found for the housing.





This piece was perfect because it was the only piece I had.
I put the 4 jaw on the lathe and preceded to bore the hole for the barrel.






I could not have gotten a better fit.  The barrel slides through like glass and I am quite pleased.  I also drilled and tapped a couple of holes for the locking pin.

This housing needs to be angled for different cuts so this is a good time to add a part with some lines scribed on it.  I originally started cutting
the lines every 2 degrees but very quickly found my technique would not work that close together.  ( I really screwed it up)
The lines are 5 degrees apart.





Drilled and countersunk 4 mounting holes and a center tapped hole for the lock bolt.





This is what the housing looks like.






Here is what it looks like assembled.











I made an adjustable locking tab and pin.
Coming together nicely.

Now for something to mount it to.
Tomorrow maybe

Thanks for looking
Ray


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## rdean (Apr 10, 2016)

Got some more done on the sharpener.  First thing I didn't really like the handle I had on the barrel so I made this for it.






I like it much better.
So I need a post or support for the barrel and found this.  It is a table leg and mounting bracket I bought at a yard sale a couple of years back.  It is a little large in diameter and way too long but still had pretty nice chrome on it and I can cut it off. 






I have been cutting some rollers out of some nylon circles for another job and this is one of the leftovers.  Just couldn't bear to throw it out so I will try to reuse it for this.






More to come

What do you think?

Ray


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## Rick Leslie (Apr 10, 2016)

So far it looks great. And I really like repurposing as much as possible. (The cost should be manageable on this one.) I'm curious to see how you handle the indexing for sharpening the sides of the cutter.


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## FOMOGO (Apr 10, 2016)

Following along with interest, looks good so far. I'll be going down this road myself at some point, so the more I can learn watching others the better. I imagine after a few years of watching different designs evolve we will eventually see the penultimate machine. Mike


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## rdean (Apr 11, 2016)

Rick I haven't figured that out yet and I have a couple of ideas but want to wait on that until later so it isn't in the road of something else.

I chucked the nylon in the lathe to make it round  and bored the center hole to fit the leg.  I cut off one side to make a flat mounting face and drilled and tapped the other side for a locking spider.















I used another piece of left over nylon for a top cap with an adjusting threaded screw.






You can just see the screw handle on top.  That's the one I took off the barrel a couple of days back.  Looks and works much better up there anyway.
I am sure I will have to shorten the leg and adjusting screw but until I get this mounted on some type of X Y table I will leave it as is.  
I also need to add a slider pole on the apposite side of the screw to keep the top and bottom in line and the screw straight.

I don't have an X Y table and don't want to buy one so I'll just make it.  (can't be that hard right?)

Thanks for looking

Ray


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## Rick Leslie (Apr 11, 2016)

No one would ever guess that you didn't sit down and plan this out. Everything fits together like a system, not a random arrangement of surplus goods. 

Mine would probably look like the swarf bucket threw up.


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## FOMOGO (Apr 12, 2016)

Thanks for chuckle, got my day off to a good start. Mike 



Rick Leslie said:


> Mine would probably look like the swarf bucket threw up.


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## rdean (Apr 12, 2016)

I take big pieces of scrap and make little pieces out of them.
I found a nice piece of 3/8" aluminum I had hidden away 3 years ago so that will be my top mounting plate.  I found 1 linear rail and bearing and although it is a good idea for the table one is not enough so I will try something else.







I had a 1/4" steel plate with several brackets welded to it that I could use for the bottom mounting plate so out came the torch and the brackets are gone but the face of the plate was not flat anymore from the welding.    Put it in the mill and leveled any place that I might need for mounting the rails.






All painted up and nice.






I thought I could use some 5/8" X 1" plastic strips (had these almost 25 years) to make dove tails that would slide against each other for the rails.






They cut really well and looked fine until I took them out of the vice and they curved badly.  I thought maybe I could still use them if I put several mounting bolts to hold them in a straight line.






Well that didn't work!!
Either it was too tight and I couldn't move them or way too loose.  Worked on these a whole day and a half and now they are in the scrap bin.
Started on plan "B".

Thanks for looking

Ray


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## FOMOGO (Apr 12, 2016)

Perseverance Ray, remember Dr. Frankenstein didn't make his monster in a day, and had to throw out a few body parts before he was finished. Mike


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## Mark_f (Apr 12, 2016)

I find this extremely interesting, and it actually looks like it will work. how accurately I am waiting to see, but it is very interesting.


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## rdean (Apr 12, 2016)

thank you all for the kind words.

Mark my workmanship is no way near your great projects but I am getting better.

As I said at the start I have no idea what I am doing just looking at many different designs.  The final result will be determined by what materials I have on hand.  So far I have bought one spray can of paint and one 3ft piece of 1/2" rod.  
I just need to have a project going to be happy.

Ray


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## rdean (Apr 14, 2016)

On to plan "B"
While looking through my mess I came across two of these.






I also found some dials that were marked with each division being 0.001 of movement.  The acme thread is 1/2" X 10 which will work perfectly.  I have decided to try and make the X Y table using 1/2" steel rods.   I am trying to keep the overall height as low as possible so I can't use the acme nuts.  I thought I should probably see if I can cut a 1/2" 10 acme thread in one of the plates before going too far.





Got out the 4 jaw and it worked better than expected so continue on with the Y axis of the table.
This is the Y axis and top table assembly that has about 3 1/2" of movement.  I made a knob and used one of the dials with a thumb screw for a lock. 
I did turn the diameter of the rails down some to clean them up and then sanded and polished them before drilling the holes.  (1/2" rod from the HD is not round or a consistent diameter)
I found that no matter how accurate you measure and drill the rail holes they will not line up perfectly.  I ended up clamping all 4 plates together and reaming to get the holes to line up and run smoothly on the rails. 





This is the top view.





These are some of the parts for the X axis.






Thanks for looking

Ray


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## Mark_f (Apr 14, 2016)

It's amazing what we can do from the contents of our " junk" box. You have done an amazing feat of engineering here.


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## rdean (Apr 15, 2016)

This shows all of the blocks and rails for the X axis.  I numbered them so I wouldn't get them mixed up or turned end for end.






Here they are mounted on the Y Axis.  You may notice the 4 mounting bolts are a little thin and cut down.  Well in my attempts to keep the unit as low as possible I didn't leave enough clearance for the bolt heads so I had to thin them down.






Cut another 1/2" 10 acme thread in the right mounting plate and it turned out much better than the one for the Y axis.  I think I have the cutter just about right now so I will store it away for safe keeping but will probaly forget where I put it if I need it again.

Three pictures of the completed table with X axis dial installed. 
















The table turned out to be quite a challenge but it ended up well.  I have some backlash in the acme threads but not as bad as some I have seen and if it proves to be a problem I may have to remake them.  The table top is very stable in all directions and locations so we will have to see how it works.

What do you think?

Ray


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## HBilly1022 (Apr 15, 2016)

I'm impressed!!!! 

Can't wait to see the finished product.


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## Mark_f (Apr 15, 2016)

very nice. Not everyone can make an X Y slide and make it work. You have done great so far. A little backlash wont hurt anything, you just want as little as possible.


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## rdean (Apr 16, 2016)

I found that in fact the table was too high even after trying to keep it low it just wouldn't work.  With the barrel tipped up 20 degrees the end of a long end mill was well above the grinder center line.  So I raised the grinder 1 1/2" with a 2 X 12 block.  (can't lower the table so raise the grinder)
I cut about 6" off the tower that wasn't needed and lagged it all to the work bench.  The bench was made about 10 years ago for the wife as she wanted somewhere to do her own thing.  Well that lasted about a month until she had her own 12X24 workshop delivered.  (if mama isn't happy then nobody is happy)
So this work bench was mainly for the grinder.






Time to make the indexer pin that follows the end mill spiral. 
This is what I started with.






And here it is installed and after making a couple of passes.





First one with flutes sharpened.






Tried another mill with the before and after pictures.









All of these end mills had been sharpened professionally several times before and were past their minimum size specifications so I got them really cheap.

I then grabbed a 3/8" 4 flute end mill and tried to sharpen it.  I noticed that when I started to grind a flute the end was not touching the wheel but at the shank end it was cutting quite deeply.  I continued on until I knew there was something wrong.  I had made a tapered end mill.  The barrel lock was not holding and the barrel had tipped down about 10 degrees which brought the cutting end closer to the wheel and so it cut deeper or in a taper.
Now to stop and fix some of the problems I have found. 
#Barrel Lock
#Move the table 2" closer to the grinder
#Make a lock for each of the X and Y axis  (they don't stay where you put them)
#The index pin shaft needs to be longer
Probably 10 other things I haven't found yet.

Question I have the center line of the end mill set about 1/2" above the center line of the wheel.  Is this about right for sharpening the flutes?

Thanks for looking

Ray


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## Mark_f (Apr 16, 2016)

If you are grinding the flutes on the periphery (outside) of the wheel, you start with the center of the spindle the same height as the center of the wheel. The flute rest is also set at this height to start.Then depending on the diameter of the end mill, you LOWER the flute rest several thousandths. The diameter of the wheel also enters into it. I have a chart somewhere that I downloaded giving some of these values. That is the reason I grind mills on the face of the wheel. It is much easier to set up. No fussing with the curve and diameter of the wheel. When sharpening you have to watch the width of the lands. If they get too wide then you must also grind the secondary angle.

I have been making an instruction manual for sharpening tools from info gathered from many sources. I will send what I have so far if you want, but it deals with grinding on the face of the wheel.


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## rdean (Apr 16, 2016)

That would be great.
PM sent
Ray


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## HBilly1022 (Apr 17, 2016)

This whole build has been very impressive!!! Bookmarked for a possible future project. But first there is a lot of learning and practice required.

Thanks for posting this Ray.


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## JR49 (Apr 17, 2016)

mark_f said:


> I have been making an instruction manual for sharpening tools from info gathered from many sources. I will send what I have so far if you want, but it deals with grinding on the face of the wheel.


        I would just like to say that I, and probably many, many others would be very interested in seeing your instruction manual, once it ie completed.  Hope you will post it, for all to benifite from your extreem knowlage.  Thanks, and happy machining,  JR49


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## atlas ten (Apr 17, 2016)

I'm sure many would like to see it  download section. I have a few carbide em needing sharpening. Another project on the long list.
Jack

Sent from my SGH-I337M using Tapatalk


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## rdean (Apr 17, 2016)

Here are two pdf files 
The first from mark_f  and the second from coffmajt 
I hope they don't mind me sharing with youall.

I haven't digested them yet myself, much more to learn

Ray


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## rdean (Apr 18, 2016)

Reworked the barrel lock by moving the stop 1" out from the center.
This is the plate and the plate installed so problem solved.










When doing the flutes the X Y table is adjusted where you want them and then not moved again until all the flutes are cut for each pass.  My tables were moving on me and I needed a lock to hold them in place but because of the way the table is made on the rods there is no simple solution.  I made up this cam just to see how it would work and try to incorporate it into the design.  I may not do any thing else to it as it works so good and is only needed when doing the flutes.  Even in the locked position I can still adjust the Y axis for each pass on the flutes.









I was always told that when sharpening anything you should push the metal back into itself but with end mills that is just the opposite.  I put the grinder in reverse and all my problems with the flutes disappeared.  The wheel direction helps to keep the index flute against the index pin and smooths things out.
Up until now I have been just playing around with different settings and angles to see what works best. Did a lot of reading and studying so here goes the official full end mill sharpening.   I chose a 3/4" two flute and a 1/2" four flute end mill for the test.










Sorry didn't get any pictures of the 1/2" 4 flute but the real test is how does it cut?





Cuts were made on a old RF31 and fed manually so I could feel how hard it was cutting.  As you can see from the large chips both worked great with little effort.
The 3/4" slot was 0.075 deep and plunged in nicely.  The 1/2" didn't want to plunge much more than 0.025 so I just restarted off the edge of the metal at a depth of 0.125.  I still need some work on cutting the negative angle to the center of the end mill.

Well that's about it I still need to make a few changes to get it more user friendly and I don't think I will be sharpening anything smaller than 2 flute 1/4".  It does work but would be better with a heavy manufactured X Y table and a different stone.  It will be just fine for my needs and total out of pocket including a diamond wheel dresser is $30. 
I had a great time building and learning from this project and appreciate all the help along the way.
Thanks again for looking.

Ray


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## Mark_f (Apr 18, 2016)

Very nice Ray,
I'm impressed. I was worried about how well the flutes would sharpen because of the siding holder. That is why air bearings are widely used because if the slide sticks and doesn't move smooth your flute will have uneven edge and would show when cutting with the side of the mill. The are some sharpeners that do not use air bearings but they have a well lapped slide. I'm glad yours performed well. It is recommended to grind so the wheel direction helps keep the flute against the rest. It is recommended to stone the tiny burr left on the edge but it will come off when cutting. In the photos, your lands look a little wide. They should be around .030". If too wide it hurts the cutting efficiency. But all in all I think you have done a fantastic job. The hard part is learning to use it now.


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## rdean (Apr 18, 2016)

Yes Mark I have found that practice is a big part of getting a good sharpening.
Thank you again for the kind words.

Ray


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## Baithog (Apr 18, 2016)

So, you're going to host an end mill sharpening party??


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## rdean (Apr 18, 2016)

Sure anytime.

Ray


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## rdean (May 11, 2016)

It has been a little over a month since I started this project and a couple of weeks since I updated it.  
I was not happy with the grinder as I could not sharpen two end mills in a row and make them come out the same.  There was too much slop in the table and it would move by itself in both the X and Y axis.  The cam I made to lever the table solid did not work out too well as there was no way of positioning it in the same place each time so out it goes.  I made a tab that would be used when doing the flutes that slid between the table and a stationary post to raise the table up and hold it against another post on the other side of the table.  I thought this tab would solve the problem of the table creeping on me and it did make the table more stable but the creep was still there.  I dissembled the entire table and added thumb screws  to both X and Y axis along with removing any play I could in the slides.  This seems to have done the trick as I had three identical 1/2" end mills that needed the ends sharpened.  I was able to setup the first and then just change end mills to sharpen the others with out changing the Y axis.
I also made up a set of templates to use for setting the angle to the wheel for both end and flute cutting.











I have learned a lot about end mills and sharpeners in general and only now feel I can do a reasonably good job but there is more to learn.

Thank you
Ray


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## Ulma Doctor (May 16, 2016)

excellent use of materials and machinery, as well as great mind putting them to use. 
very nice work.


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## benmychree (Aug 30, 2016)

If I were you, I would redesign the tooth rest so that it can rotate concentrically with the spindle, and graduate the mounting in degrees.  This allows for clearance to be set for different diameters on end mills when grinding the OD.  just lowering the tooth rest to achieve the same result causes binding of the rest on the flute of the cutter.  This is how Harig's air bearing fixture is designed.  I use it for all my end mill sharpening on my #1 Norton cutter grinder.


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## rdean (Aug 30, 2016)

After using it for several months now I agree your suggestion would make sharpening easier.   I may look into a redesign in the future but since I am only sharpening a small number of mills for my self it works fine for now.

Ray


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