VEVOR Drill Bits Sharpener, 3-13mm Drill Bits Grinder Sharpener, Lip Relief Angle & 95°-135° Point Angle Adjustable Drill Bit Re-Sharpener, Portable Sharpening Machine with 11 Collets, CBN & SDC Wheel

I have purchased the MR-13B model. It is cheaper on Amazon than model A and it is better in my opinion. There are several YouTube videos, describing both models in detail. Somehow you led to believe that model A splits the point and model B just thins the web. This is not true. Model B in my opinion is an improvement over model A. It allows you to achieve a true split point and has several ways of doing it. I am not going to write about every detail, but will concentrate on staff, which is not well described and is important in my opinion.This little machine is well engineered and constructed. It weighs 17.7 lb with collets, chuck and grinding wheel. There is no plastic anywhere except some electrical parts. The power supply is 120 VAC, 60 Hz. The cable can be separated from the unit. Electric part is very simple - there are a power receptacle, switch, rectifier bridge and a 110 VDC motor. There is no other electronics in the unit, so it has to be reliable. All parts are mounted on a 7 mm thick steel plate. They are steel (no aluminum here), machined and ground where necessary. That is how you achieve the accuracy needed for drill sharpening.For sharpening you have to setup each drill in the setup station at the left side of the machine. You use a chuck and a collet of the appropriate size. The collets are standard ER20 for sizes above 5 mm. For smaller sizes the collets are modified to include an extended nose and relieved bore. Drills smaller than 4 mm are very difficult to setup properly in this station and I would recommend to do a visual setup or just grind them by hand. The chuck has 2 bearings to reduce the collet clamping torqueOnce your drill is setup in the chuck you move it to a sharpening station, where you sharpen both lips by rotating the chuck back and force. This station has a bearing as well for easy rotation. If you want to split the point after sharpening, move your chuck to the top station and again rotate the chuck left and right. This operation is adjustable for the depth and width of the cut. The produced split point looks somewhat different from factory drills, but works the same way. The difference is because this machine uses just one wheel for sharpening and point splitting. The finished drill has 4 distinct cutting edges, just like the factory split points.This machine comes with CBN and diamond wheels, model A includes only CBN wheel The wheel is steel with plated layer of CBN or diamond grit. On the attached pictures I show the diamond wheel. It is 3" in diameter, 10 mm wide and has approximately 1/2" bore. The wheel is clamped to the adapter, which is attached to the motor shaft by 3 set screws. I have only tried the CBN wheel for HSS drills. It cuts very aggressively, but leaves an acceptable finish for bigger drills. For small drills you better find a different way of sharpening.Overall my level of satisfaction with this machine is very high. I am getting good drill grinds and nice split points. But don't fool yourself into thinking that it will do the grinding for you. You need to know what a good grind looks like and adjust the machine accordingly.

After re-sharpening a couple of dozen 118- and 135-degree drill bits, I'm generally impressed with the results. Grinds are symetrical, bits cut evenly on both faces, holes have minimal "wobble". The included instructions are pretty useless -- you'll need watch a YT video to get up to speed. The collet collection covers 1/8 - 1/2" bits. Collets are ER-20 and ER-25 style. Dialing-in the bit-diameter (web-diameter) is pretty low-precision -- the alignment arrow is an inch away from the dial. My biggest complaint is safety-related: while grinding the point angle on the side port, the abrasive wheel is visible in the top port and it's pretty hard to find a position that's out of the "line-of-fire". Eye/face protection is a must, and the same goes for respirator masks. The collet storage is okay (unless you transport the sharpener 'cuz all the collets will fall out of their retainer holes) but there's no place to put the workholder, kind of a big oversight IMO. All that aside, the unit consistently delivers sharp, well-formed drill bits, which, if you'll excuse the pun, is the whole point.

If you are considering this, I would suggest reading the review, and then just buy it. It is a great machine, and very easy to use once you get some experience with it. This Vevor Drill Sharpener, made by MRCM, compares very favorably with machines costing ten and 20 times the price. I paid full price for the sharpener.Pros:It is very precise and accurate, and able to grind many different points on bits, including accurate splitpoints (aka crankshaft grind) The components are all well machined and heavy duty.It is solidly built. (Which enables accurate and precise grinding)The standard grinding wheel is cubic boron nitride, CBN, which is an extremely hard abrasive, and, if you take your time, it is easy to get a surface finish that rivals new bits.MRCM makes a broad range of professional sharpening tools, and I think that the quality of the engineering in this drill sharpener shows, and makes it easy to use.Cons: The manual is limited. (E.g. the knob to adjust the split point center, and the Allen set screw to hold it were not documented in the manual that I have, but they do work, and enable you to adjust the grind axis to have precisely ground split points bits.)I recommend watching a video or two on YouTube (hint: look for videos of MRCM drill sharpeners). If you are new to drill sharpening, I also recommend any of the Cleveland Twist Drill pamphlets available various places, or the book that the pamphlets came from. I think that drill sharpening is not perhaps rocket science, but like any tool sharpening, does require attention to detail by the user.The holders for the bits are industry standard ER20 collets. You can also buy ER20 collets in SAE/Imperial sizes. It doesn't matter much for larger bits, but may be helpful for smaller bits.Replacement grinding wheels both CBN and diamond are available if you look for them, as are replacement chucks.MRCM is also known as Zhejiang Meiri Intelligent Machinery Company.

This is the coolest tool I own! (and I have alot of tools) Very well made and easy to use. Sharpens drill bits from tiny up to3/4". Puts and amazing sharpness on bits. Takes 1-2 minutes to use per bit. We have lots of bits in a plastic tub that have been waiting for this machine for years. It can pay for itself . I have an old DRILL DOCTOR. I threw that in the trash! Do not mess around. Get this one. Well made and solid. Packed well...Fast shipping. Nice to find a new tool that is engineered well and fun to use.