Precision Drill Sharpener

[Mark_f]

Another change will be the use of the type M collet nut and Chuck.

This photo shows the difference in the two types of nuts.

Because there is a difference in the outside diameter of more than .250", this will create a lot more clearance between the collet chuck and grinding wheel. In the original design there were a lot of instances where the larger nut would hit the grinding wheel. This should eliminate that problem .

 

[Mark_f]

I looked at many other builds of this drill sharpener and there are many variations using the same concept but with various methods of doing the same thing. I intend to take the best features from many different builds and roll them into one great machine. Another feature that I will change is the setting of the angles for the trunnion table. The original design used some simple blocks to set the angle. While this works just fine and is very simple, I saw another method I found interesting and it is a more solid setting that cannot move when set.
This method uses an arc in a plate that will have a clamp bolt with a handle to loosen and tighten the setting. I still have to make the clamp bolt, but I really like this setup. There will be an adjustable stop at the primary angle and another at the secondary angle. Another advantage of this setup is I can set any angle desired where the original design set the angles and they really weren't adjustable.The range of angles is adjustable from -5 degrees to +40 degrees.

 

[NEL957]

Mark
Very nice, I like the alteration and more degree to set it to. Very nice.
Be well my friend
Nelson

 

[Mark_f]

I made the clamp bolt and the adjustable stops.
The rear stop is set at 8 degrees for the primary grind and the front stop is set at 25 degrees for the secondary grind. Everything works great so far.

 

[NEL957]

Mark
That is going to be better than top shelf. I like the improvements. Can not wait to see the finish sharpener.
Be well my friend
Nelson Collar

 

[FOMOGO]

Mark, how did you cut the curved profile on the adjustment plate and the slot? Thanks, Mike

 

[Mark_f]

Mark, how did you cut the curved profile on the adjustment plate and the slot? Thanks, Mike

That was tricky!
I made the piece that gets the slot as a rectangular piece of .250 thick steel. I clamped it where it gets mounted and put a pointed screw where the clamp screw goes. I then raised the table to scribe a line where the slot goes. This was the only way I could think of to lay it out because the pivot point and arc are in a different plane. ( I couldn't measure it).I then put the piece on the rotary table and kept moving it until I got the tool to follow the arc when rotating the table. Once that was done, I cut the slot, moved over and cut the outside edge. I hope this helps.

 

[FOMOGO]

Quote: I made the piece that gets the slot as a rectangular piece of .250 thick steel. I clamped it where it gets mounted and put a pointed screw where the clamp screw goes. I then raised the table to scribe a line where the slot goes. This was the only way I could think of to lay it out because the pivot point and arc are in a different plane. ( I couldn't measure it).I then put the piece on the rotary table and kept moving it until I got the tool to follow the arc when rotating the table. Once that was done, I cut the slot, moved over and cut the outside edge. I hope this helps.

Thanks for the explanation, that makes perfect sense. Cheers, Mike

 

[Mark_f]

I got all the linear bearing parts in so I got that set up.
I removed all the SHCS and replaced them with flat head screws on the bottom of the sliding table. This gives me a flat surface and won't interfere with mounting the bearings. In the above photo all the bearing holes are drilled and tapped.
The linear bearings are mounted with 6-32 SHCS.

The unit slides nicely and smooth. Also notice there is an adjustable bearing on the front and rear. I thought these would be a good idea, but now I think they are not needed. The idea was to put a little "drag" on the slide but it gets "jerky" when you adjust them too snug. The system works fine without them.

I will address a topic before someone brings it up. The linear bearings and grit from the grinding wheel. I know from using the previous sharpener I built that there is minimal dust when using a diamond wheel. I also usually put a small cloth on the table under the wheel to catch any grit, so in my opinion this won't be a problem. Then I could always make way covers.

 

[jeff_g1137]

Hi
Nice work yet again