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Precision Drill Sharpener

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mark_f

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#31
I picked up the power plant for the new drill sharpener at harbor freight.
image.jpeg image.jpeg It's a 1/3 hp grinder. Runs really smooth. It even has a built in light which I may use . ( I have another light I was going to use.) you can also see the 100 grit diamond wheel sitting there. It came in today also. I looked at a USA made diamond wheel that looks identical to this one. The same weight and same diamond density. It looks and feels identical. The wheel was $185.00. :eek: The wheel I bought was $20.00. ( bet you can guess where it came from) :rolleyes:. Now I can get moving on this project also.
 

Billh50

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#32
Since I have both issues that have the prints for this grinder (less your changes of course). I may just have to attempt making one. Will have to check a few parts real good after since I don't have a real mill. But with a little work I should be able to do it.

by the way Mark, you do real nice work. And I have that same diamond wheel.
 

mark_f

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#33
Since I have both issues that have the prints for this grinder (less your changes of course). I may just have to attempt making one. Will have to check a few parts real good after since I don't have a real mill. But with a little work I should be able to do it.

by the way Mark, you do real nice work. And I have that same diamond wheel.
That wheel is a beauty isn't it.
I actually built my first one without a mill at all. It can be done. If you build it and need any help, just let me know. ( I have figured out every way to do this stuff without the right equipment.) I can tell you some shortcuts to make it easier. The design is very forgiving. You can change a lot and it will still work. You just have to keep the concept.
 

NEL957

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#34
Mark
Looking good and do not tell me you got the wheel from Harbor Freight. I will be very nice with that big light shining down. Keep it coming.
 

mark_f

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#35
Mark
Looking good and do not tell me you got the wheel from Harbor Freight. I will be very nice with that big light shining down. Keep it coming.
No...... HF is too low on the totem pole.

It came from China....but the grinder came from HF.... It is really nice.
 

kvt

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#36
This looks like it is fun. I may have to try and find the docs so I can try it.
Keep up the good work I like watching your projects as they give me a lot to try and do in the future.
 

mark_f

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#37
This looks like it is fun. I may have to try and find the docs so I can try it.
Keep up the good work I like watching your projects as they give me a lot to try and do in the future.
This is an easy to build machine you will get a lot of use from and it works great.
 

David VanNorman

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#38
Nice job looking to see the finished product.
 

NEL957

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#39
Well I guess someone did not like my reply to the China made tooling. I myself am sold on them. I just bought a tap .275 x 40 and the price for the USA made one to sit in my tool box most of the time is ridiculous. Comparing the China tap to any of my good taps (Butterfield) the China won hands down. I will try some of the standard UNC and UNF and see how they do. I was tapping stainless steel and it cut like butter.
Cheers
 

mark_f

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#40
Well I guess someone did not like my reply to the China made tooling. I myself am sold on them. I just bought a tap .275 x 40 and the price for the USA made one to sit in my tool box most of the time is ridiculous. Comparing the China tap to any of my good taps (Butterfield) the China won hands down. I will try some of the standard UNC and UNF and see how they do. I was tapping stainless steel and it cut like butter.
Cheers
I buy a lot of Chinese tooling, particularly end mills. Everything holds up as well as any top brand I have used and a fraction of the cost. We have to be frugal on our fixed incomes.
 

Bamban

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#41
Mark,

I've read all your projects, one of these days I will try to copy some of the less complicated ones. With my limited skills it would be a challenge I am sure. This sharpener would probably be the first on my list as I am fast accumulating a few drill bits that need sharpening

You do great work, sir.
 

mark_f

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#42
Mark,

I've read all your projects, one of these days I will try to copy some of the less complicated ones. With my limited skills it would be a challenge I am sure. This sharpener would probably be the first on my list as I am fast accumulating a few drill bits that need sharpening

You do great work, sir.
This is not too difficult. And if you have questions, I would help all I can.
 

mark_f

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#43
I started to work on the spindle for the drill sharpener. I bored the index ring to fit the spindle which is 25 mm.
image.jpeg Believe it or not .... This thing took me 3 hours to make. After boring the hole , half the diameter( 1.470") plus half the index pin diameter (.125") has to be milled off to make the spindle index to exactly 180 degrees. This must be within .0005" to sharpen drills accurately. So to do this.... I set it up on the mill, touched of on the front edge, figured the diameter (1.470") divided by 2 is .735" minus half of the .125 pin diameter which is .0625". This makes the finish size of the milled off part .6725". To be able to measure this I used my scale (.033" thick ) across the opening and mic the distance which figured out to .6725" - .033" = .6395". Now why did I bother to explain all this? There is something you all don't know about me. I CANT WORK WITH NUMBERS! .... I am dyslexic when it comes to numbers. I have to figure , figure again, check my math , and figure again ..... and I get a different answer every time. That is why it took 3 hours to make this little piece. Dyslexia is a problem for me on everything I build. ( I think that is why it takes me so long to make something .... LOL)
 

kvt

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#44
Mark, it may take you a while, But you do such nice work, in which I can say I would have trouble even getting close to. You could ask Bamban I am slow as well, I check and recheck things all the time, but my work does not come out that nice.
 

Billh50

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#45
It is always better to take your time and do something right than to have to do it over because you missed something or made a mistake.
 

tertiaryjim

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#46
Math has always been a problem for me. Not dyslexic but used to have to review even basic math, fractions n such, at least once a year or I couldn't do it.
My head just don't do math without extreme effort.
At one point I spent most of my spare time over a couple years learning some basic algebra from books. It's amazing how powerful and useful that was.
For the most part I was simply plugging numbers into a formula from the machinists hand book but a few times found use for comparative and other formulas.
Kept a folder of machinist/ mechanical formulas and information as I couldn't retain them in my head.
Found it funny that several of my co-workers referred to some of the simplex math problems I had to deal with as " High Math".
Seems most of us find it difficult at best.
Not many can preform the caliber of work you do even if they are good at math.
 

mark_f

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#47
I finished up the Index ring and made the lock screw for it. I will check the 180 degree function once the block is made.
image.jpeg


This is the grinding wheel adapter. I spent hours making this and while machining to length ripped it from the chuck and chewed it up. I had to cut off all the damage and changed my design so I could still use it.
image.jpeg

The diamond wheel mounted.
image.jpeg image.jpeg image.jpeg
 

kvt

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#48
If it still works it is good, And from the pics, you cannot tell it was changed. Looks like is was supposed to be.
 

mark_f

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#49
If it still works it is good, And from the pics, you cannot tell it was changed. Looks like is was supposed to be.
That's what a good machinist does. Mistakes become revisions.:grin:
 

Billh50

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#50
That's what a good machinist does. Mistakes become revisions.:grin:
I used to tell all the guys working for me. If you screw up don't scrap the part til you talk to me. If the mating part is not made yet we can always change things to fit rather than make a new part. Especially if it was a part that took a while to make. Then I would give engineering the new changes.
 

mark_f

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#51
I turned the collet block for the drill sharpener. image.jpeg After 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.
image.jpeg
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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mark_f

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#52
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.
 

firestopper

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#53
Beautiful work Mark, thank you for sharing.
 

mark_f

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#54
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.
image.jpeg

image.jpeg

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.jpeg This 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.
 

NEL957

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#55
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_f

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#56
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.
 

Randall Marx

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#57
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
 

mark_f

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#58
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.
image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg image.jpeg
 

Joe in Oz

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#59
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....
 

Noufab

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#60
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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