I used Foredom and Fingst flex shaft tools for decades, but tried a 50,000 RPM micromotor around fifteen years ago for a particular job. The micromotor is fast, light and handy, so I bought more types of handpieces. I still use the flex shaft tools for some things.
NSK is an excellent and expensive maker. I use several Marathon (Korea) micromotors, equally excellent and less expensive. I have had them for many years and never had a problem with them. I do not use them every day though. I call my Marathon Handy 700 my thousand dollar Dremel because some sellers get about $1000 for them. It has a 50,000 RPM brushless handpiece that can use collets for burs with up to 1/8" shanks. The controller has a second outlet to allow a second handpiece to be connected and a switch selects which handpiece is in use. The controller has a max RPM setting in case you want to run a larger diameter tool at less than the highest speed that the handpiece is capable of. The foot pedal varies the speed from zero to the max setting. I have several less expensive Marathon 35,000 RPM handpieces that only take 3/32" long shank tools. One has a contra angle end for RA type dental burs. These lower cost handpieces can be bought on eBay for amazingly low cost and include a simple controller. I only use my 700 controller.
The 700 is sold by tool dealers, some with Foredom or other brand names, for high prices. I got mine years ago from Lion Dental Supply and see their price today is $729, but the extra 1/16" and 1/8" collets are sold separately. Dental labs generally only use 3/32" long shank tools originally designed for use in belt driven "lab engines."
lionsdentalsupply.com
Here is the Foredom-badged version of the 700 for $1080. They have the optional 1/8" collet for sale.
two-port brushless micromotor
www.foredom.net
EBay listings for the lower cost Marathon units. Search for Marathon micromotor.
Find many great new & used options and get the best deals for Dental Marathon Electric Micromotor Polisher 35K RPM Handpiece NSK STYLE MX at the best online prices at eBay! Free shipping for many products!
www.ebay.com
Find many great new & used options and get the best deals for Dental Marathon Electric Micromotor Polisher 35K RPM Handpiece NSK STYLE MX at the best online prices at eBay! Free shipping for many products!
www.ebay.com
For filing, I have Engis Di-Profil (Sweden) tools, which are pretty good. I use the flex shaft model.
The picture shows some of the investment castings that prompted me to buy the Handy 500 for the cleanup work. I was able to use the Di-Profil for a little bit of the job, but 50,000 RPM and tiny carbide burs were the thing for all those tiny openings.
Larry