Precision Drill Sharpener

I turned the collet block for the drill sharpener.image.jpegAfter boring the block to fit the collet chuck, the rear end must be faced to be square with the bore.

image.jpeg The block and chuck assembly is put in a vise and the rotation of the block is checked for being exactly 180 degrees. This is important so the flutes will be equal and alike.
image.jpeg The assembly is then set on the trunnion table with a half flat bar in the chuck. The chuck is shimmed up so the two half bars match. This will tell how thick the pad needs to be so everything is centered on the axis of the trunnions.

image.jpeg The pad is fastened to the collet block once it is the proper thickness. The pins are also installed. These are held in place with lock tite.

image.jpeg A .125 dowel pin is inserted in the rear face of the collet block. This is the stop pin for the 180 degree rotation.
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image.jpeg The linear bearing supports are fasten to the base plate which has been painted like the sliding table.
This pretty much completes the assembly. Now it will be set on a base and the motor will get mounted with it.

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I made the handle to move the table.
image.jpeg I started by turning a piece of 1/2" steel bet down to 5/16" diameter, leaving the end for the grip.

image.jpeg The handle and linkage is finished. I used a grip left over from other projects.
image.jpeg This portion of the machine is complete.
 
Beautiful work Mark, thank you for sharing.
 
My new drill sharpener s almost complete. I got the steel today for the motor mount plate.
image.jpeg I cut slots so the motor can be moved forward or back 1/2" in each direction. There are two rails, one on each side to capture the motor. I used this method on my previous build and it worked really well.
image.jpeg On the bottom the slots are recessed 1/8" to hold the 5/16" bolts.
image.jpeg I thinned the head of the bolts to .125"

image.jpeg There is a push bolt in the read to finely adjust the motor position. The thin strip of brass you see is sort of like a fib. It is wedged in the side tight. This makes the motor slide tightly and very accurately. This is a simple system but works very well.
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image.jpeg You can see two brass stop collars , one on the outer front bar and one on the inner rear bar. These set the table travel limits so the wheel cannot hit the trunnions.

image.jpeg The new collet chuck came in today also. You can see how much smaller the M toy nut is than the A type nut. This allows a lot more clearance around the grinding wheel.
image.jpeg Here is the new collet chuck installed.

image.jpeg The machine is complete except for mounting on a base. A friend is making me a walnut base similar to the one on my previous build.
image.jpegThis machine is a great improvement over the first one. It is bigger, heavier, maybe a little better tolerances, and a more powerful motor to make grinding easier. I will post some final photos when I get the base.
 
Mark
Help me out if you could. The position is to the right a quite a bit and I think you are going to have some sort of stop to keep the table from move too far and hit the inside of the wheel. The other thing I was thinking about is maybe a second hole to the left to bring the holder closer the wheel for smaller diameters of bits without sliding the table all the way to contact the wheel. I must say I love the new sharpener.
Glad you are doing better. Be well my friend
Nelson Collar
 
Mark
Help me out if you could. The position is to the right a quite a bit and I think you are going to have some sort of stop to keep the table from move too far and hit the inside of the wheel. The other thing I was thinking about is maybe a second hole to the left to bring the holder closer the wheel for smaller diameters of bits without sliding the table all the way to contact the wheel. I must say I love the new sharpener.
Glad you are doing better. Be well my friend
Nelson Collar
Yes. In one of the last posts, there are two bass stop collars that set the travel limits. The total table travel is about 1 3/4" to 1 7/8". Another hole is not needed because the table does not move that far. Besides, if you get too many holes, it can get confusing and you could set the fixture in the wrong hole. " keep it simple" is key here. As soon as I get the base this week, This will be finished and I will post some more photos. I am working on adding point splitting to this one. I learned a lot building the first one and made subtle changes to hopefully improve the machine while keeping the simple concept that makes it a great machine.

EDIT: I think the photo makes it look farther to the right than it actually is.
 
Looking great, Mark! I still find it amazing to see the quality, quantity, and usefulness of work that you put out...especially with the small machines that you use. Your work is VERY inspiring to someone like me, who can see the finished product in my head, but has limited resources to make it. Seeing what you do on a regular basis gives me hope that at some point, I may be able to do similar work on my meager machines!
Thank you again for sharing all of this with us. Be well and continue improving!
Randall
 
The drill sharpener is finished and it works great. I'm very pleased with the outcome. The only problem is , the 100 grit grinding wheel is too rough for small drills. I am going to try a 180 grit and see how much better it is.
Here are some pics of the finished machine.
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Very nice build! For small drills I use 400 grit. Still fast enough. That's what I happened to have - not by rational decision making....
 
Hi,

Very nice and well done project! First of all I would like to apologize for my so poor English but I'm French (near Paris…) … Like many of you, I'm tired of junking my "old" drill bits and I plan to realize a drill sharpener as you. That's why I'm a few question for you especially concerning the grinding wheel:

- You use a diamond grinding cup wheel but I think that it is not well suitable for steel (iron seems to chemically react with carbon… Something like that!). I think that CBN wheel (Cubic Boron Nitride) would be more suitable: What is your opinion? What about the prize difference?

- From the operator point of view, the cup rotates (I think) in a clockwise direction. Considering the position of the drill bit, the cup will grind it pulling the cutting edge backward: Is it true? Is it the right direction/process in the case of a diamond grinding wheel? Using common grinding wheels (made with abrasive aggregates), I think that the right direction is when the cutting edge is pulled foreward.

Thanks once again!

Sincerely,
 
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