Drill Doctor DD500X Twist Drill Bit Sharpener - 3/32" to 1/2" - Electric Sharpener - High Speed & Portable - For Steel, Masonry, Carbide & Tin-Coated Drill Bits - Adjustable 118° or 135° Angle

If you're looking to be able to ram your bit through the grinding wheel as fast as you can, don't get this. If you're more in tune with the current universe, read on. I've bought a couple of these, though not because the first one wore out! This should be the last drill bit sharpener you buy IF you take care of it and actually read the instructions. Very inexpensive considering no more drill bit purchases (unless you just break them). It IS often possible to sharpen a broken bit back into use if there is enough of the bit left. I have used this sharpener to do that several times. Use this on my high speed steel as well as Cobalt bits that have a standard shank. Always take any burrs off of the bit shank when sharpening. Is important to not rush or overload, then all is fine. Gives great results when used correctly. Doesn't need an "install" schmamazon getting its nose out of joint again. Plenty durable when not pushed too hard. Easy to get new stones and parts for. Good documentation. Great value for the money. The size is as stated again, schmamazon, wtf? Accuracy, well, I do not have the lab to be able to measure this but I CAN say the sharpened bits DO cut very much cleaner and faster! So empirically this works well! Never sharpen a bit so fast that it turns blue, or it is ruined. Never drill until it is blue either for the same reason. Never use the "hammer" mode on your drill using steel or cobalt drill bits or you will ruin them and possibly injure yourself. Use ONLY carbide tipped bits designed for hammer drilling with this function. This sharpener has a diamond wheel so it CAN sharpen carbide tipped bits!

Works great. Just sharpened 75 drill bits and what a difference a sharp drill bit makes. Very easy to use. Well worth the money invested. Think I just paid for it sharpening these bits.

I bought this machine a few months ago. I've used it to sharpen quite a few bits, 50+ ranging from HSS to masonry. I will emphasize that you MUST read the instructions thoroughly, and watch the DVD as well. It is important to know how the tool works, and why you will ruin bits if you don't follow the instructions. To sharpen standard 118* bits couldn't be easier. This machine does an excellent job of it, and since I use most of my drill bits to drill in wood, this is the perfect angle for me. Split points can be ground on 118* bits, and I have done this with success. To sharpen masonry bits is also very easy, and the machine does an excellent job in this regard as well. Where it gets tricky, for me anyway, is in sharpening 135* split point bits. These days nearly all bits sold are this type and it's nice to be able to recreate the same angle and split point. While I have sharpened bits of this angle with success, I haven't been able to get perfect results all the time. Proper alignment is critical. Trying to adjust the relief angle seems to make proper sharpening more difficult and I would not recommend it to someone who just got his hands on this machine. The relief angle is adjusted by putting the chuck to either side of the 118* alignment slot (the + and - increase and decrease the angle). This is to allow a more aggressive or less aggressive cut. Fiddling with this adjustment seems to throw off the split point when it is being ground as well, taking off way too much material. If too much material is removed during the split point procedure, subsequent sharpening of the bit will not yield the same angle since the alignment fingers will not hold the bit from is flutes, but from the newly ground area behind the split point. It is hard to visualize this, the mistake must be made to understand it fully. Changing the diamond wheel is straight forward and easily done. The machine has a somewhat loud squeal when running, but it isn't too bad. I have sharpened broken bits with success, so that feature definitely works. Also, unless a bit really damaged during a botched sharpening attempt, it can most probably be sharpened to at least a 118* point again, though it will take a while and several alignment and sharpening procedures. I recommend the 100 grit wheel for when this must be done as it will take less time, and then a follow up can be done with the standard 180 grit wheel. The 750X has more features than just being able to accommodate larger bits, so in my opinion it is definitely worth it. I wish I had gotten that model instead, and I believe sharpening 135* and split points would be easier and faster. This is a quality product though, that I must say. **EDIT 7/26/08** After using my DD extensively during a project to sharpen a masonry bit, I noticed something that I hadn't observed earlier. When sharpening the bits according to the instructions, the machine does not put opposing angles on the tip of the bit. That is, it grinds both sides of the tip to an arrow point, and this is NOT conducive to easy drilling. In fact, I realize that I put unnecessary load on my drill using the "sharpened" bit. Perhaps experimenting with bit alignment might help, but that can just as easily ruin a bit you're trying to breath more life into. **EDIT 8/3/10** I am adding an edit to this review, mostly to address other reviews and comments about people needing to read and follow the instructions. On *MY* machine, only the 118* angle is indicated on the alignment port. There is NO mention of 135* angle, and this is why I had problems with aligning and sharpening 135* split point bits. After much experimentation and frustration, I finally got the 135* angle by inserting the chuck into the "-" slot, then putting the sharpening port at 135*. I don't know if my machine had a quality control issue, or if all the DD500X units are like this. To split the point on 118* or 135* bits, you need to align the bit at 118* regardless of the angle you sharpened the bit to. In splitting the point, it must be done carefully to avoid under-splitting because if that happens, the bit will NOT cut. For 135* bits, if the point isn't split, it really won't cut unless you're drilling into a very soft material like plastic or wood. A long review for certain, and a good machine, but not without faults. After owning my machine for a couple of years and using it extensively I feel my four star review of "very good but not excellent" is fully justified.

Works amazing! Sharpened all my bits I thought were worthless. Was going to buy new expensive bits and now I don't have to. Easy to use and pretty fast too

Just received this today and very pleased with this purchase. Despite some other reviewers comments, the instruction manual is comprehensive, easy to understand and fully explains the operation of the Drill Doctor. I had no trouble setting up for 118 or 135 degree point angles. I resharpened some 34 drill bits from 3/32" to 1/2" that were blunt and changed one from 118 degrees to 135 with a split point. It took about 1 hour and 15 mins in total. After, they all were sharp, exactly to specification and cut through wood and steel like they were brand new. The 135 deg split point drill bit I cut (5/16") produced the perfect Curly Q's as shown in the photo, when cutting through a 1/4" mild steel bar with my drill press. I've always tried to hand grind my drills or bought new. While they were fairly sharp and drilled OK after my hand grinding, they certainly looked hand-ground and weren't like a new drill bit with a well-defined chisel edge, relief angle, even cutting edges and a perfect point angle. With a couple minutes work in the Drill Doctor, I have perfect bits. Points to note: - The 135 deg point angle setting is the one notch to the right of the 12 o'clock positioned 118 degree notch in the alignment port. The other 10 deg notches are to fine tune the chisel edge and relief angles, which 99 times out of a 100, you won't need to adjust. - Make sure the spring steel jaws in the alignment port snap into the drill at its narrowest point across the width of the flutes. Rotate the drill bit as required to make this happen. This ensures the correct angular position of the bit in the chuck for grinding. - After finger snugging the bit in the chuck in the alignment port, remove it and hand tighten. That way the drill doesn't move from its perfect alignment for grinding. - Keep rotating the chuck in the grinding port with light pressure down and keeping the chuck against the cam pin, grinding until the grinding sounds stop occurring. The bit at that point is fully ground. - Eventually the grinding wheel will wear down. You can remove it and turn it around to get another 100 or so drills sharpened before having to replace the wheel for about $20. After doing all my 34 drills, I could feel that the roughness of the grinding wheel was less that the other unused end, but it was still easily capable of grinding bits. - Grinding dust does spill out onto the bench through the gaps around the transparent cover under the grinding wheel. After all my bits, I had a tiny heap on the table, with more inside the machine. I cleaned the Drill Doctor before putting it away, per the instructions. - Don't mash the bit into wheel, especially for making the split point. Treat it gently and pulse it until the sound stops. I've now got a way to have sharp drill whenever I need them. I always had to make do or go buy yet another drill bit. The Drill Doctor is not a cheap tool, but it is well-made and sturdy. Once you have it, you can really appreciate its value. No regrets at all. I will never need to buy bits again until I've worm them down to an unusable length and by then, that will have paid back the cost of the Drill Doctor many times over!

This is my second Drill Doctor. They are fantastic sharpeners. The first one was a DD 250. It is still in use after 25 years. I have sharpened maybe 300 or more drill bits with it. It still has the original stone. I received my new DD 500 yesterday. It is basically the same machine but, upgraded, and can sharpen masonry, and split point bits. Sharpened about 20 steel bits in about 20 minutes or so. Also, tried sharpening masonry bits. Takes a little getting used to but, after a couple of tries it worked great. On the masonry bits I would recommend starting with a bit about 1/4" or so until you get the hang of it before you try any smaller ones. They are a little harder to sharpen. I sharpened bits down to 1/8". I would recommend this sharpener to anyone looking for drill bit sharpener. They are very well-built and easy to use machines. Just follow the directions, and you will do fine.

This is my 3rd Drill Doctor, the first one I sold on a garage sale because I needed money, 2nd was pretty much wore out before I bought it from a garage sale. This new one is my favorite the 500x and I opted to buy a secone chuck that would go to 3/4 it was cheaper to do it this way that buy a 750x. I work in plastics and have to sharpen my bits due to drilling sometimes close to 1k holes in a day. With that in mind plasitics are the worst to set up for, they require an anle of about 118 degrees, with a split point and a pretty severe angle from face to heel. We drill as large as 1/2" not pilot hole so bits need to start quick and cut rapidly otherwise they just clog up with plastic. The 118 most closely simulates the best working drill bits we use. It does however take a bit of studying and the use of a black sharpee marker to get it set up and figure out how to get it to produce the correct angles. Coat the tip with sharpee then setup your bit at zero. If you look at the alignment port there are several slots for the chuck to go in, the one in the middle marked 118 is the 0 advance or retard of the bit, the port is marked + on the left and - on the right. As I said coat the cutting end with sharpee ans make about 1 to 2 full revolutions then check to see if they cut looks right. if the cutting edge is getting rolled over or the back angle is too flat, insert the chuch turned more to the left + side this will cut deeper to the heel and stop the roll over. If you have problems read the instructions they are not too bad and experiment with clocking your bit timing in the chuck. If you desire to split point your bit after using a clocked setting you will need to reset you bit in the chuck at the zero 118 degree position before or the split point will mess up your nicely sharpened edges. Takes a bit of playing to figure out how to make it work but all in all when you get it sorted it works well and sharpens well.

A VERY quality piece of machinery. Great instructions. Easy to set up. I sharpened every bit that showed signs of use in my shop! I highly recommend it.