Why not DBS-22 with a Diamond Disc?

[Pietje]

Hello forum!
Tormek gives the advice to use the DBS-22 with the SB-250, the black disk.
Why is no one using a diamond disc DC-250 for the DBS-22 to grind HSS-drills?
Pietje

[Ken S]

Good question, Pietje.

The SB-250 blackstone was introduced in August of 2008. The DBS-22 was introduced in November of 2010. The diamond wheels were not introduced until March of 2018.

I see no reason why the diamond wheels would not work with the DBS-22. I suspect that Tormek just has not updated the recommendation.

Ken

[Pietje]

Thanks for info.

[RichColvin]

The diamond wheels work greatly with the DBS-22. In particular, the extra fine one is great for very small bits.

But I will also add that there are times when I finish a drill bit on the SJ grindstone.

Rich

[RickKrung]

I cannot imagine why the diamond wheels (or CBN) should not be used for drill bits.  Good ones are HSS and should benefit greatly from the harder abrasives.  The DBS-22, drill bit jig was a major motivator in my decision to buy a Tormek, for the the way it holds the drill, they way the jig moves the bit across the stone, the multi-facet grind capabilities and the finer grind finishes.  I am a bit surprised that I hardly sharpen any drill...   

One reason, that I like to tell myself  , is that I think I take care of my drills and don't abuse them.  I don't know how much of a factor it is, but, another is that when I DID try using the diamond wheels, I was dismayed that the surface of the wheel was not flat.  It was lower in the center than near the edges.  I felt this to be the case because when sliding the drill back and forth, as it began to reduce the amount taken off, it started to contact only closer to the sides, not in the center.  That was around two years ago and I haven't sharpened a drill since. 

I haven't tried finishing any drill bits with the SJ wheel, but I want to.  A highly refined grind finish was one of the key factors in my decision to get a Tormek.  I'd tried a Drill Doctor twice and was horrified at the coarseness of the grind finish (among other things), so was ecstatic when I discovered the Tormek with the DBS-22.  I look forward to trying the SJ wheel when I do get around to sharpening some bits.

Rick

[Ken S]

Rick,

Your reply remind's me of something in Leonard Lee's sharpening book (my favorite sharpening book, which should be a part of all of our sharpening references). His recommendation about having sharp drill bits is to purchase high quality hss drill bits made in the US. Presumably, this would or should also imply taking good care of them. (Having been a working telephone man for thirty five years, I am embarrassed to admit that my drill bits were frequently abused over the years.)

I remember reading reports from Derek from Perth and our own Wootz about hollows being worn in early CBN wheels.
Rick, if your diamond wheels are not flat within tolerance across the face, you should contact support. You certainly have the machinist skill to do this. I do not expect any grinding wheel, diamond or not, to last forever. I do expect any wheel, used properly, to have reasonable longevity for its design. (I have not read these reportsin recent years.)

The silicon carbide SB-250 seems to have been largely eclipsed by the diamond wheels. However, I consider the eclipse to be only partial. Unlike single layer diamond wheels, the grit goes all through the SB. A nasty accident wcich would sideline a diamond wheel can easily be remedied with the TT-50 truing tool. It also has some grit flexibility like the SG-250.

Sorry, I don't think I have simplified your question.......

Ken

[RickKrung]

My drills are all HSS, most all sets of Precision Twist Drill, letter sets, number sets but I do have one chain hardware store branded set that I use for wood.  I initially got the SB stone for use with drill bits, because of them being HSS.  I take your point that the grinding matrix goes all the way through, but when it doesn't cut fast enough, it hardly matters. 

The one diamond wheel that doesn't contact consistently across the surface is within tolerance, I believe, so I think it is not something Tormek support is going to take action on.  It is more of a psychological thing.  With regard to wear of the diamond wheel, if anything, I've worn the edges more than the centers. 

I agree, you didn't simplify anything, but I didn't really have a question that needed simplifying...   

Rick

[Elden]

May I suggest grinding your bits on your bench grinder or belt sander  prior to putting them on the Tormek? I have done them free handed for years. This would take care of the "damage" much more quickly. Jan's  drill jig would allow one to have more precision with hand grinding if one is not comfortable with true free hand grinding.

[RickKrung]

May I suggest grinding your bits on your bench grinder or belt sander  prior to putting them on the Tormek? I have done them free handed for years. This would take care of the "damage" much more quickly. Jan's  drill jig would allow one to have more precision with hand grinding if one is not comfortable with true free hand grinding.

Yes, absolutely.  Taking the heavy stuff off before bringing them to the Tormek is paramount and fueled my search for those methods, taking me through the traditional grindstone on the Tormek, slow speed bench grinder, belt grinder and finally an 80 grit CBN wheel on that slow speed bench grinder.  Some may recall that I set the DBS-22 on the bench grinder as part of that effort.  I even set up the DBS-22 on the Viel belt grinder, although the photo below is not of drill bit grinding. 

I do not care for free handing, I prefer the more consistent and precise angle control afforded by the jigs and am willing to put up with whatever difficulties that brings. 

[Elden]

For extremely damaged bits, I have used an abrasive cutoff wheel as the first step. By the way those came from an auction in that condition. I try not to abuse my bits like that. I kind of enjoy free handing bits.

[RickKrung]

For extremely damaged bits, I have used an abrasive cutoff wheel as the first step. By the way those came from an auction in that condition. I try not to abuse my bits like that. I kind of enjoy free handing bits.

Ah, yes, Ye Ole' abrasive cutoff wheel.  It hasn't come to that yet, but it is always there.  I received  half dozen almost that bad that from a friend, which were good quality bits, he just was putting them through a challenging operation.  I put six-facet points on them and they've held up much better. 

If I was any good at free handing bits, I might enjoy it too.  My father was quite good at it, a traditional, old-school Tool and Die Maker.  Guess that was one thing I didn't pick up from him. 

Rick

[tgbto]

Some will have heard this from me before, but here again, I only use the dimond wheels when I have no other choice. The SB is relatively cheap compared to the diamond wheels, and works a charm with my HSS bits. I prefer the feedback of the SB, and if you think about it, it will be hard to keep applying the very light pressure that is recommended on the DC/DE/DF because the area of contact of the bit on the stone is quite small...

So I'll say it can definitely be done, with a lot of care, and when you don't have a choice (because you don't have the SB or you have a special carbide bit).

Cheers!

Nick.

[Ken S]

Good thoughts, Nick.

For some reason, Tormek has remained almost silent about the SB and almost as silent about the SJ. The two wheels shared one paragraph in the handbook and one short video by Alan Holtham.

In the non Tormek sharpening universe, while diamond stones are popular, Arkansas stones and Belgian waterstones continue to command premium prices. There are a plethora of quality waterstones. I think there is room in the Tormek universe for different kinds of grinding wheels.

Ken

[RichColvin]

Some will have heard this from me before, but here again, I only use the dimond wheels when I have no other choice. The SB is relatively cheap compared to the diamond wheels, and works a charm with my HSS bits. I prefer the feedback of the SB, and if you think about it, it will be hard to keep applying the very light pressure that is recommended on the DC/DE/DF because the area of contact of the bit on the stone is quite small...

So I'll say it can definitely be done, with a lot of care, and when you don't have a choice (because you don't have the SB or you have a special carbide bit).

Cheers!

Nick.

Nick,

I've also had great success with the SB grindstone.

Kind regards,
Rich