Anyone use a high speed air turbine hand piece to drive 1/16"-3/32" burs? I am interested in how they compare to the many electric micro motors that are available.
What make and model are you looking at? Lindsay?
Is it something like the below?
I looked at this GRS rotary handpiece because it is compatible with my GRS air system
and can be used as either a rotary or hammer handpiece.
But if I recall correctly i decided against it because i was told that it was not as good for burring out larger stone seats…something like that…torque…? Similar comments for the micromotors…?
i basically needed another rotary tool (with forward and reverse) at my engraving/ stone setting bench…i didn’t really need it for a hammer handpiece as I already have an old badeco…and the GRS engraver can act as a hammer handpiece as well. And I already have 2 rotary handpieces…a QC with a duplex spring (not a big fan) and a #30…
so, i narrowed it down to a micromotor…or a SR (forward/reverse) foredom flex shaft…
the micromotor has the narrow handpiece and forward/ reverse, and no flex shaft to wrestle with…
the foredom was the better price option and had forward and reverse, and since I already had a second handpiece, that is what I went with.
i think the deciding factor for me was “torque”…if that is the right word…
but now i have been looking at narrower QC handpieces…and i still wrestle with my flex shaft cable…
plus, once i add up the foredom flex shaft purchase, and a narrower handpiece, I am almost at the price for one of the lower priced foredom micromotor…
soo…i am now kinda wishing I went with the micromotor…narrower handpiece, no flex shaft to wrestle, plus forward and reverse…
just talking out loud…
My Foredom SR is my choice for most of the work that I do, but I am looking for a way to remove background when I am engraving. The best I can tell, the more speed the better. The air turbines that I have looked at claim to run in the 3000,000 RPM range. I can’t imagine what that feels like, but I am told by my engraving friends that you need high speed to get the control over a bur that you need to remove very fine areas of background. Some micro motors run in the 35,000 RPM range. That may be enough, I just don’t know, hence my question. All the air turbines that I have looked at are in the dental equipment market Steve Lindsay has one, but it is out of stock. The NSK Presto II looks nice and the Buffalo Dental #220 has been around a long time. Johnson-Promident also has one similar to the Lindsay, but they have discontinued it. May explain why the Lindsay is out of stock. If anyone has experience with any of these turbines, I would appreciate hearing about it. I have been considering a micro motor for a long time and would go that way if it will also allow me to remove very fine areas of background and forget the turbine. Reminds me of going to the dentist anyways…Rob
i think some micromotors might go up to 50,000…but, i think the bur speed rating dictates…
The maximum speeds that I find for dental burs is 40,000 RPM, so I am not sure what good a 300,000 turbine is other than an accident waiting to happen. Still researching with my enagraving community.
Well, that speed are probably neccessary to overcome the lack of torque.
But of course you can only use tools designed for these speeds. Which for the most cases will be small diameter dental tools or similar.
I doubt these tools are usable for anything else than engraving, unless you have a ton of patience and time on your hands
What do the folks who engrave presentation pieces in the firearms industry use?
Different engravers use different tools to do the same job, just as you and I go about making the same piece in different ways. Some use simple hand gravers that they have designed and made themselves, others use purchased gravers that they reshape and sharpen. Most use either a hammer and chisel technique or more likely a pneumatic tool with gravers that fit into the tool. Background removal leaves a texture that may or may not be desirable requiring additional finishing with special gravers (stippling) or even punches and stamps. The rotary tool is very efficient at background removal and texturing depending on the type of bur that is used. Do a search on Steve Lindsay Engraving or Sam Alfano engraving. You find links to some amazing engravers, many of whom engrave guns. This is my current obsession before I get busy getting ready for Christmas…Rob
I have since found burs that run at much higher speeds. Torque vs speed appears to be an issue. A bur running at 1,000 rpm will catch on a polished surface and skitter over it making a mess. That same bur running at 10,000 rpm will, with a light touch, make the desired surface change and not make a mess. Other than practicing with my flex shaft, for me this is all theoretical, but it makes sense. I am looking at ways to make artistic marks on my highly polished silver surfaces and engraving is one way to do it. It is also a lot of fun. My guess is that I will buy a micro motor, but not until I have researched turbines as I have a ready source of regulated compressed air at my engraving bench. More when I know it…Rob
just a few thoughts…try running your SR in reverse…and in addition to speed changes, try burs with varying degrees of “cut”…ie: fine cut burs versus single cut burs…etc
running in reverse reduces the bur teeth “grab” which are directional…
another thing that “i have heard/ read” is that with the high speed micro motors especially, you contact the metal with the bur already “at speed”…
this is a habit i will eventually have to develop…i dont always do that…
I just had another thought…perhaps also try non directional, finer grit “diamond” burs…in forward and reverse…?
and there are also my new favorites…the busch very nice fine cut “finishing” bur kits in round, flame and cylinder (assorted size) kits at otto frei…especially in reverse, these burs are very…“smooth running”…? especially in reverse.
here are the links to Otto Frei, which is the only place I have seen the economical assorted size kits…
assorted size, fine cut flame finishing bur: (for tight spaces…?)
assorted size, fine cut cylinder finishing bur:
i am sad to inform you that the round bur kit is not currently showing up, but here are links to individual size packs…
and and the larger
I would strongly recommend going with a micro motor, preferably a brushless one, they have much more torque. The best I have found is the nakanishi E-Max Evolution, with the scr variable speed foot petal. We use 6 of them in our facility.
Running burrs in reverse will likely dull them unless you use very light pressure and a lube. In reverse, they are essentially harsh-ish burnished more than burrs. You can also use polishing compounds suitable for hard metals to deliberately dull and polish the teeth, which makes them truly burnishers…
If I’m not mistaken, I think Gerry the diamond setter demonstrated a practical use of burs in reverse.
It may have been another setter though, so it has its use, but maybe not for prolonged time.
But to the point of interest.
Make sure you use the correct burs certified for these speeds. If you have experienced runaway excenter burs, you will know what I mean.
And at these speeds more likely than not something may breake and explode in front of you. Make sure to use proper protection all the time.
You are describing what worries me about running just any bur at these speeds…Rob
Just to clarify, the burs I mentioned above are just regular flex shaft type burs, and are probably not rated to be used in the faster micromotors or air turbines you are looking into.
I just thought you might want to test out running a regular bur, in a regular flex shaft, in reverse, cautiously…not to fast…
I should have also mentioned to definitely use proper safety gear! Running the burs in reverse is not the designed use of the burs, and so safety and caution should be foremost!