Let's Talk Drill Bit Grinders!

[darkzero]

I've got a DD750X. It takes a bit of learning but doesn't take long to learn. It's loud but works well for what they cost. I have even sharpened carbide drills with it. Surface finish is not great but it sharpens well enough for them to drill well. I'm using the stock coarse wheel. The 750X does split points, looks different from factory grinds but again they drill well enough for me.

I also purchased the LH chuck but haven't tried sharpening any LH drills yet. The stock RH chuck says it works with up to 3/4" but I haven't been successful at sharpening S&D drills with it. No matter what I did it keeps grinding a negative relief. Maybe it's just the helix angle on my S&D drills, I don't know but whatever, I haven't tried S&D drills again.

Here's a HSS-CO drill that was really beat up that I did on the DD.

I wanted a real Darex or Lisle 91000 but none of the Darex models ever pop up used around here. The Lisles do occasionally but sellers ask for way too much money & they are always missing parts. There was a few used Sterlings that came up for $400-$500 ea from the same seller but I don't know anything about them. By the time I decided to go check one out they were all sold.

I ended up purchasing a OTMT branded MR-13D on sale for $500 last year from the local Travers. Comes with a CBN wheel & I purchased a SDC wheel for it. Uses ER-20 collets & goes up to 1/2". Relief & split point angle is adjustable as well as drill point angle. I haven't really used it yet though. Can buy the MR-13Ds directly from China for $300-$350.

 

[Weldo]

Ah man, I think the Sterling machine is beautiful! I've watched a few YouTube videos about them awhile ago and it seems like a great grinder! It's got a really nice style too. I'd love to have one! As far as I can tell it operates just like the Lisle 91000.

I'm curious about some of the Chinese machines like the one you pictured. Some of them can do end mills! And I like the amount of adjustability they give you as far as point and relief angles and such.

 

[Weldo]

Here's a pretty good deal on a Sterling! 3 phase motor though...

Sterling Drill Grinder

They claim it can do any bit from 1/8" to 2-1/2" and multiple point angles. I love the micrometer style in-feed also!

 

[C-Bag]

I think the Drill Doctor is a good concept but since it's marketed towards the DIY and homeowner market it's not very robust. Darex makes a few different grinders that work on the same principle but are much more solidly constructed.

What about machines like this...

View attachment 313124

If I'm not mistaken, it seems this type of machine is based on the old Deckel design. Most, if not all, of the new machines on the market are from China. They look to be of decent quality and I like their versatility. With the included attachments one can sharpen twist drills, end mills, and even HSS lathe tools. I suppose you could even use it to do some grinding on parts if you needed to, say grinding a closely controlled flat spot on a small shaft or something.

These type of machines look like they can do a lot. Does anyone have experience with one?

I and several others on HM have those Deckel clones. These can vary in quality depending on who you go through. I bought mine on eBay and it was a mixed bag. I'm pretty sure the one in the pic is a direct clone in that it uses the same metric collets like the Deckel. Which for me didn't work because I wanted to be able to chuck up to 3/4" and the standard collets go to 12mm so it won't even do 1/2". I ended up getting one that uses R8 collets because my mills uses them and I had a complete set. In order to do drill bits you need the special attachment which the cheaper setup doesn't come with so there's a LOT of details to watch for. If I had it to do over I'd go with the U3 through Shars as it uses the 5c collets and has all the attachments. Around $1300 with shipping. All in I think I ended up around $750.

I've not done any drill bits yet but done many end mills and even a couple mill flutes. It takes some getting used to and creative problem solving but it's really nice to have. I never have to worry about stalling a job because a bit has gone dull. I got a handful of dull endmills with my old mill drill and was able to sharpen them all. It will do carbide and HSS with the right wheel. Made a couple of counter bores with it. Some custom grinds and made some custom dog point screws that were missing on my old shaper. Oh and found square ID 1/4" and 5/16" R8 collets for it and have done some precision ground HSS lathe bits for my lathe and shaper.

 

[mikey]

Man, you guys are making me want yet another machine ... BUT I only sharpen drills occasionally and only for myself so my trusty old Drill Doctor (I have the old 500 model that does up to 1/2" drills) will continue to serve me well. It is accurate enough, does 118 and 135 points and splits them in a few seconds. I am only on my second wheel in, what, 25 years?

If I ever do decide to step up to something else, it will probably be this one.

 

[Weldo]

The drill to be sharpened needs to stick out about 1/2 the diameter. The base is slotted to accommodate for this. I had to get a little creative on my setup to make this happen.

I think the instructions say to drill a mounting hole 2-1/4” from the face of the grinding wheel. Have you found that to be good or did you do something different?

 

[pontiac428]

The drill to be sharpened needs to stick out about 1/2 the diameter. The base is slotted to accommodate for this. I had to get a little creative on my setup to make this happen.

The extension (stickout) matters some, but there is a lot of wiggle room. That's why you can have a permanent mount that establishes the distance between the pivot axis and the wheel face- which means by changing drill diameter, you need to change extension in order to reach the wheel. Does this hurt anything? Not really, according to Harold Hall. It just changes the clearance angle.

 

[Shootymacshootface]

Thank you for the graphics, very informative.

I think the instructions say to drill a mounting hole 2-1/4” from the face of the grinding wheel. Have you found that to be good or did you do something different?

The base of the grinding tool has a generous slot in it, so ballpark on that is ok.

 

[pacifica]

The extension (stickout) matters some, but there is a lot of wiggle room. That's why you can have a permanent mount that establishes the distance between the pivot axis and the wheel face- which means by changing drill diameter, you need to change extension in order to reach the wheel. Does this hurt anything? Not really, according to Harold Hall. It just changes the clearance angle.
View attachment 313338

Also if you first grind a full flatter clearance angle, then partially grind a tighter clearance angle (it helps to use a stop) you can create a 4 facet grind. I have done it and it works, but I did have to use a stop for accuracy of the secondary facet.

 

[pacifica]

I think the instructions say to drill a mounting hole 2-1/4” from the face of the grinding wheel. Have you found that to be good or did you do something different?

I drilled 3 holes since drills over 1/2" can be very long.