I have the older DD750, now referred to as a "Classic. It worked fine for many years, but as you might guess being primarily made of plastic it eventually started to wear and would no longer sharpen bits properly. In all fairness I probably over worked it. At the time I was sharpening about 50 bits per month. At 50 bits per month for over 10 years it did in excess of 6,000 sharpening's before I gave up on it. I put the DD on the shelf and started searching for a better machine. The drills piled up for nearly a year as I was in no rush to shell out big bucks.
As luck would have it a shop in our area was moving to a new location. They had purchased a Black Diamond drill grinder as part of an auction lot and never used it. The thing sat in a corner for over 3 years before they decided it was time to go. They knew I was in the market for a grinder and gave me a call. We agreed on a price, and my problem was solved.
I now have and use Black Diamond model BW65 drill grinder. It was originally built in 1974 for a local National Guard repair depot as part of a military contract. I have no idea why they purchased it in that the machine is 220 3phase, and there was no 3 phase power in their building. It sat unused in the shop from 1974 to until around 2010 when it was sold at auction. It sat unused another 3+ years in the new owners shop before he offered it to me.
When I acquired it about the only thing I had to do was clean off the dust, add a static phase converter, repair a damaged switch, and put it to use. It's made sharpening drills a whole lot quicker and easier. The first week I had it was the most boring week of my life. I literally spent days at a time sharpening my backlog of drills. In total I would guess there was between 300 and 500. I still sharpen a fair amount of drills, but I'd guess todays volume is somewhere half of what I was doing. If I do them on a more regular basis it takes less than an hour a month to keep up to speed.
I guess the whole point of this rambling is that depending on the volume of bits you need to sharpen there are options. If you're in the 5-10 bits per month the DD will probably be all you'll ever need. If the volume gets near the range I've experienced there are better, albeit more expensive, longer lasting alternatives. In our area the Drill Doctor 750X with the accessories runs around $150.00. I paid slightly over $300.00 for the Black Diamond with the roll around cabinet, all the collets, accessories, and a spare wheel. I do see occasionally see machines similar to the one I purchased at similar prices. I doubt you'll find the exact model in that it was a 3 phase machine built for a military contract. All other Black Diamond machines I've seen are 220 single phase.
Here are a couple pictures of my Black Diamond machine.
View attachment 341312View attachment 341313