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Ultra high speed air grinder

Bluechipx

Hot Rolled
Joined
Dec 29, 2008
Location
W. Mich
Does anybody else have one of these? There was a lot of them on ebay cheap, I think $60, but they have disappeared for some reason. It was 450,000 rpm and took .060" burrs, either carbide or diamond. When I bought it I also bought 100 various burrs in diamond for $18. Even the most seasoned machinist could hardly believe how incredibly smooth and 100% vibration free they were. Truthfully, at speed, when the burr touched the part, there would be sparks and the feel was no different than if you touched a part without it turning, no exaggeration. I have a Nikon stereo microscope and it is amazing how detailed of work you can do with one of these under magnification. I tried it out on a penny and could easily and quickly remove the mint mark or retouch Lincolns nose or beard. I rounded Lincolns nose, receded his hairline and shaved him a bit and he actually looked like Fred Sanford from Sanford and son. I'm not an artist but it was easy. I highly recommend one of these inexpensive tools for gunsmiths or any craftsmen for small detailed work. One of the best cheap investments I have ever done.f.jpg
 
It seems to be everything that the ones a dentist has, leaving me wondering why a dentist charges so much. 18 cents ea. for burrs seems to be the norm.
 
It seems to be everything that the ones a dentist has, leaving me wondering why a dentist charges so much. 18 cents ea. for burrs seems to be the norm.

convince banks to give them free loans while they study in med school, convince Porsche to drop their prices by at least 50%, convince judges to throw all silly malpractice lawsuits, and then convince the dentist himself that he has to work for the good of the people, and not profit

easy... oh, and while you're at it, please make those 10000 parts from the other topic for me for 0.99$ :D
 
HEEYYY, I recognize that tool.
I was a dentist once, and yes I still run mine every day under the scope to do delicate work of all kinds.
Sad thing is, mine cost me the best part of a thousand bucks when I was still in the game.

I've recommended these from time to time on this forum, and as Bluechipx has remarked, they are the best thing since sliced bread for delicate handwork.

A couple of additional tips you all may be unaware of.
Not only can you buy carbide burs in all sorts of shapes for these, you can also buy diamond burs and silicon carbide embedded rubber polishing points (like miniature Cratex points) all on 1/16" shanks.
The best brand of diamond points I've found are Premier Two Stripers, and the best polishing points I've found are Shofu Brownies and Greenies.
I use SS White carbide burs.

It's hard, at least in Canada to get them from a Dental Supply House if you're not a licensed dentist, but sometimes they can be talked into selling to you.
If not, you can always twist your dentist's arm and get him or her to order for you.

I use diamond points for hand grinding custom carbide form cutters under the microscope from time to time (less now than before because I have a wire EDM now), and you can get them in extraordinarily fine grits; ideal for picking out the tiniest details and putting a fine edge on carbide.

If you have a good relationship with your dentist, ask them to set aside the crown and bridge diamonds they use, once they're too worn for their own use.
A busy practice will toss these by the hundreds a month and if you can score them for nothing, they will be super useful to you.

I still have boxes full and I retired from dentistry in 1998.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining


PS: Why dentists charge so much: In 1998 my overhead for a 3 chair practice on the main health care street of my town was $44,000.00 per month.
I was billing out at $270.00 per hour and if I had a good month I'd be up 25 grand.
If I had a bad month I'd be in the hole about the same.
3 bad months in a row and I was fucked.
Three good months in a row and I could start looking lustfully at that Porsche or Ferrarri
MC
 
Fixed costs - at the root of a lot of things.

Anybody know where to order such things online low hassle in the US? (Hopefully less weird in refusing to sell here.) Good brands to look for?
(Maybe just point me to one of your old posts implmex?)
 
Implmex, I ran the math on your $44,000 a month expenses. $270 per hr x 8 hrs = $2160 x four weeks or 20 days = $43,200 and your expenses were $44,000??? I asked my doctor to explain why he charges so much and he drew this quick pie chart to explain the high costs of running a doctor/dentist practice and why they need to charge so much for their overhead; graph%20(2)graph.jpg
 
A friend of mine was a specialist surgeon in the us, he has been retired for at least 20 years now. When he was practicing his insurance premium was $250,000 a year.... have charge allot to cover that.
 
I'm just having a little fun with the doctor/dentist price thing. The services they have provided for me especially the Mayo clinic have resulted in me still being here, I can't put a price on that. I went from 175 lbs to 135 lbs and local doctors couldn't find anything wrong with me. I was wasting away when my wife set up an appointment with Mayo in Rochester MN. All my life I had health insurance except for just before this thing came about. I made an appointment with a Priority agent and all went well, he asked about family history of high blood pressure , diabetes, etc then he asked about pre-existing conditions and I said I needed a quarter of a million dollar procedure in six weeks. Priority actually took me on and paid it. With my premiums I would have to live to ninety for them to break even. I still don't know if they had to insure me or not, but Priority is number one with me.
 
Being a doctor or dentist ain't what it used to be.

You now have millions of dentists and doctors streaming in this country from all over the world, glad to undercut your pay structure, i.e. work for less.

Rapidly changing technology....it costs money to stay on top of all that. Conferences, association membership fees, etc.

And lots of lawsuits, as mentioned.

Then, you have a bunch of fat-ass nurses who constantly talk shit behind your back about how great they are, how much they know, and how you hardly do anything.

That's not all bad, as it has forced some doctors to get their shit together...less arrogance and less than 60 minutes sitting on your ass in their waiting room every time you go.

But regardless, medical care has evolved into a state much like a bunch of other professions - the people actually doing the work (doctorating) are taking second teat to the people running the business side - the 'admins'- who rake in the serious dough. While the doctors spend all the time looking at disgusting innards, the admins spend all their time figuring out new and better ways to milk the system.
 
Hi Bluechipx:
You wrote: "Implmex, I ran the math on your $44,000 a month expenses. $270 per hr x 8 hrs = $2160 x four weeks or 20 days = $43,200 and your expenses were $44,000???"

Yeah, I sometimes had to work more than a 40 hour week.
However, some procedures I was billing out at up to $1000.00 per hour (dental implant disaster recovery).
I had a pair of hygienists working for me and billing every hour too (and demanding wages every hour whether they were working or not)
Surgery, prosthodontics, endodontics, implant placement, implant disaster recovery etc etc; all of those more advanced procedures billed out considerably more money, but for routine fillings and other basic dentistry the going rate in those days (early 1990's) was $270.00/hr.

I have no idea how nuts it is now.
A buddy of mine who has a high end practice in San Francisco is bleeding money because of Covid 19 at a great rate...I think his monthly rent alone is north of $30,000.00 (top floor highrise heritage building Nob Hill).
He's thinking about unloading some toys.
There's probably a good deal on a couple of luxury cars and maybe a boat or an airplane in the San Francisco area just now.

Overall the point is, that like big machine shops, these enterprises look very lucrative from the outside, but they're balanced on a huge assumption set, and that is that nothing will go wrong.
The gravy's great when all is humming, but it hurts big time when it's not.

The other thing is the way all this stuff is pricing itself out of the market.
Ordinary folks are finding it less and less affordable, so they are going backward in regard to "optimal dental health".
As a result, many dentists are catering to a smaller and smaller (and richer) slice of the population.
Cosmetic dentistry, botox injections, Restylane and Juvederm face fillers...before you know it they'll be offering tit kits and butt lifts as they find less and less legitimate turf to milk.

It's kind of disgusting!

However, this is all kind of a hijack of the original thread, so let me pull it back and make it relevant again.

Something you may want to consider:
Probably every dentist I know, has a whole drawer FULL of obsolete high speed handpieces.
In the 1990's push button collets became popular, and sterilizable handpieces became mandatory.
A gazillion wrench and chuck key units were retired, and dentists being natural hoarders, most retired to the junk drawer.

This is your opportunity.
You can probably still pick up an old key style Midwest unit (or something like it) for free, just for the asking.
You might have to replace the turbine for a hundred bucks.

I have two 30 year old Midwest Traditions that I still use; as one goes in the toilet, I break out the other, until I run out of good ones, and then I replace the turbines as a batch.
I typically shitcan a turbine once every 5 years or so (the bearings go).
Replacing a turbine is child's play and takes 10 minutes.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining
 
Many years ago, I had a re-work job that came up too frequently....I would cover up best I could, glasses, face shield, weld jacket, long gloves etc.
Using a normal 1/4" shank die grinder, I would have to lean inside, head & all, a 36" dia bore (laying horizontal) and grind out bad welds.
The leetle chips would fly right up and around the bore, dropping all over me.

I used to say "I'm doing dentistry on Shamu".....:D
 
I'm just having a little fun with the doctor/dentist price thing. The services they have provided for me especially the Mayo clinic have resulted in me still being here, I can't put a price on that. I went from 175 lbs to 135 lbs and local doctors couldn't find anything wrong with me. I was wasting away when my wife set up an appointment with Mayo in Rochester MN. All my life I had health insurance except for just before this thing came about. I made an appointment with a Priority agent and all went well, he asked about family history of high blood pressure , diabetes, etc then he asked about pre-existing conditions and I said I needed a quarter of a million dollar procedure in six weeks. Priority actually took me on and paid it. With my premiums I would have to live to ninety for them to break even. I still don't know if they had to insure me or not, but Priority is number one with me.

What was wrong? Can pm if you don't want to "say" here.... The reason I ask is I went from 265 to 250 in a couple years, then went for 250 to 185 in about 6 months. Can't afford (literally, scope down in the gut, which they said would take all of ten minutes is over$5000 out of pocket with my current ins) the testing at this point... :angry:
 
@implex - the "pick one up used off ebay or from a dentist" sounds fine, but the local dentists are barely open and I don't really know any of them, and I'm a buy one off the web kind of guy. May just buy one of the fancy NSK units and call it good enough.
 
The bearings in these grinders have a limited life, so replacement cartridges are available. In the mid 60s, when I worked with them, they were $35. I made a housing that mounted on the compound of my Derbyshire jeweler's lathe, creating a tiny tool post grinder. I used it to make air gauge spindles for measuring the area of .020" ID micropipettes.

I know people who tried to use these grinders for deburring, but found it was too easy to remove too much metal.

Bill
 
It's because of the bad breath, silly. :rolleyes5:

:D

ROFLMAO!

We had a couple of retired grey-hairs of long acquaintance - a Dentist and an Ob-Gyn - going at that very subject over drinks, after dinner one night!

The Dentist said his life's work had been the worst job between them.

The Ob-Gyn had to agree.

HIS patients had at least BATHED before their office visit, if not also douched with floral scented solutions!

Besides he smirked.. if he happened to nudge the "starter button" and got "bitten" in the course of a "pelvic"?

It was a damned sight more pleasant with no sharp and broken decayed TEETH in the game!

Leave it to a former Royal Air Force fighter jockey, later Cathay-Pacific "Heavy" left-seater to chime-in that he wouldn't want to bet anything too valuable on the bit about the lack of teeth!!!

:D
 








 
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