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Thread: Learn me about super hispeed dental grinders for shop use

  1. #1
    Join Date
    Feb 2011
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    939

    Default Learn me about super hispeed dental grinders for shop use

    I seems as if you can buy a small right angle air powered grinder for around $40. These turn an amazing 400,000 rpm. MAYBE they use a carbide bit with a 1.6 mm diameter shank that cost around $1 each. When you go to buy these on amazon,it is very confusing. None of the grinder specs tell the shank size. Instead of showing the actuall angle of the head,they use terms such as contra angle? Also it seems that if you buy some of these on ebay ,they want you to have a food and drug permit?And then their are electric powered ones ,some used by dentists and some used by the people at nail salons. It seems that dentists and nail salon people don't know how to measure anything ,so all the sizes and shapes are in some kind of code. There is a youtube guy that uses one of these in the shop ,but no measurements. He is whiteling a hole thru the side of a 3/8 tap..Any help would be appreciated. Thank you Edwin Dirnbeck

  2. #2
    Join Date
    Aug 2009
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    6,659

    Default

    Dental grinders don't have a lot of power, may be OK for small delicate mold work etc. on soft materials. Not sure how well the bits will hold up to steel. Then there is the issue of the fine cutters clogging up. Would you want to push coolant through it??

    JL..............

  3. #3
    Join Date
    Mar 2005
    Location
    El Paso , TX
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    Default

    These may be more appropriate...

    http://nskamericacorp.com/product/ca...ookieSupport=1

    https://highspeedengraving.com/produ...engraving-kit/

    I have the old Paragrave unit. It works great on glass and aluminum with 1/16 shank nibs. Both carbide and diamond. Not a hogger by any stretch. Only for detail work.
    Illigitimi non Carborundum
    9X49 Birmingham Mill, Reid Model 2C Grinder, 13x40 ENCO GH Lathe, 6X18 Craftsman lathe, Sherline CNC mill, Eastwood TIG200 AC/DC and lots of stuff from 30+ years in the trade. Now I boil oil

  4. #4
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    Default

    1.6mm (sometimes designated as 1/16") shank burs (so called FG (friction grip) burs) are used with all high speed air powered dental handpieces and some (not all) electric contra angle handpieces.

    There are also latch-type burs, but they are used for some low speed air-operated latch head contra angles and electric implant handpieces. Those burs wobble, and I'd avoid them for any metal work.

    $40 air turbine handpiece will be a complete junk. But even $400 ones have quite delicate bearings and provide only very light torque. In metal work they can be used for engraving and similar applications. Electric contra angle handpieces have much lower rpm, but significantly more torque. Those for FG burs are very expensive, yet not nearly as strong as the ones mentioned below.

    For metal work, the most useful are so called straight (HP) handpieces that take HP burs. Those burs are much longer (from under to over 2"-long) and their shanks are 2.35mm. The working head of the HP bur can be made out of carbide (surgical burs or large grinding lab heads) or it may carry a wheel, disk, polishing point, diamond point, etc.

    The best electric handpieces/controls are made by NSK, Kavo, and some other companies. But they are quite expensive. A reasonable alternative for a HSM user would be something like Marathon with a straight HP handpiece sold on e-Bay: https://www.ebay.com/itm/USA-Dental-...0AAOSw241YlCOb Although, professionally, I'm spoiled by the very best handpieces of different types, I found that my workshop Marathon serves me very well.
    Last edited by MichaelP; 08-24-2019 at 05:38 PM.

  5. #5
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    Dec 2015
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    Chilliwack, BC, Canada
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    Default

    I've had one for years. Got it running at one point and played with it and then never used it again. Torque is the thing. It cut well, if slowly, on hard woods and obviously would be good for doing scrimshaw or the like. And with small diamond points would be OK for very light work on metal. Think polishing out very small details or doing something like engraving letters and numbers freehand. But it's VERY slow going. You say there's a video of someone drilling a hole through a 3/8 tap. With the small offset head unit that does up around your 400K I don't think I'd live long enough to manage that. The points on that unit are a simple friction press fit into the "chuck".

    The other "big" inline unit is slower and uses 3/32 shank points. It has a proper collet and tightening nut. It has a lot more torque than the little turbine in the head model. It's got more torque than the small high speed unit but it's MUCH less torque than something like a Dremel. So perhaps good for some small detail finishing work but not really useful for anything involving removal of metal that would be left as chips of any sort. It too I got running, tried it on a few things, found it to be so slow to remove material that I put it away and never used it again.

    For someone that worked on small things like plastic models I think these would be useful everyday tools. But in the metal shop I'd say save your money unless you're needing them for something very specific and involving very small amounts of metal removal.

    The small turbine head unit does have three small holes around the head which can be used to shoot directed jets of air or water in dental use. And with the right thin style of coolant would work too. It would need to be very thin though. Like the stuff I use which is clear and mixes at 10:1 with water and looks like water when it's mixed.

  6. #6
    Join Date
    Jan 2014
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    In the desert
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    The high speed NSK spindles are popular for making CNC cut wax masters in the jewelry business, but for manual hand held work they use plane old (although usually higher quality and more expensive) rotary hand pieces. I used to manage security, phone, video, network etc for a couple jewelers until I retired from contracting. I spent more than a few hours standing around in the back shop chatting with the guys working. I have one hand piece in that class (they consider it low end) and it was a couple hundred dollars. For most of my work I can't tell the difference in results between it and a cheap rotary handpiece. Some shaft and motor.
    Last edited by Bob La Londe; 08-24-2019 at 03:47 PM.
    *** I always wanted a welding stinger that looked like the north end of a south bound chicken. Often my welds look like somebody pointed the wrong end of a chicken at the joint and squeezed until something came out. Might as well look the part.

  7. #7
    Join Date
    May 2015
    Location
    Somerset UK
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    One of several specifications we had to adhere to at work with aircraft parts was rotary engraving. We had a pneumatic engraver which ran at 250000 rpm and sounded exactly like a dentists drill. The difference was that ours was straight, and the exhaust blew forward. It used five flute 0.5mm diameter carbide push in drills, they had round ends. We used it exclusively on steel for writing, but it was capable or cutting pretty fast if you wanted to use it for other purposes. Some people avoided visiting the fitting shop if it was being used.

  8. #8
    Join Date
    Feb 2011
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    939

    Default Mechael,thank you a lot

    Quote Originally Posted by MichaelP View Post
    1.6mm (sometimes designated as 1/16") shank burs (so called FG (friction grip) burs) are used with all high speed air powered dental handpieces and some (not all) electric contra angle handpieces.

    There are also latch-type burs, but they are used for some low speed air-operated latch head contra angles and electric implant handpieces. Those burs wobble, and I'd avoid them for any metal work.

    $40 air turbine handpiece will be a complete junk. But even $400 ones have quite delicate bearings and provide only very light torque. In metal work they can be used for engraving and similar applications. Electric contra angle handpieces have much lower rpm, but significantly more torque. Those for FG burs are very expensive, yet not nearly as strong as the ones mentioned below.

    For metal work, the most useful are so called straight (HP) handpieces that take HP burs. Those burs are much longer (from under to over 2"-long) and their shanks are 2.35mm. The working head of the HP bur can be made out of carbide (surgical burs or large grinding lab heads) or it may carry a wheel, disk, polishing point, diamond point, etc.

    The best electric handpieces/controls are made by NSK, Kavo, and some other companies. But they are quite expensive. A reasonable alternative for a HSM user would be something like Marathon with a straight HP handpiece sold on e-Bay: http://<br /> <br /> <br /> <br /...0AAOSw241YlCOb Although, professionally, I'm spoiled by the very best handpieces of different types, I found that my workshop Marathon serves me very well.
    This is EXACTLY THE INFORMATION THAT I AM LOOKING FOR.There is so much knowledge on this forum,and good people that are willing to share. Edwin Dirnbeck

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