GOT IT...TKS for the info...was hoping the galfer rotors were 320 as I hate to buy them and not use them....700 miles on the dymags-comes with sprocket...any bearing changes/spacers needed?
hope I win the auction....
With 700miles on them I doubt they need new bearings. But you should check that with the seller to have a possitive answer on that. He cannot lie otherwise those wheels will be "item is not as described" on arrival.
However I am not sure if the RC's wheel axles will fit. That is something you should expect to happen.
And of course you'll need RC spacers which are very easy to have them made on lathe.
If you have to swap bearings eventualy due to misfitting inner diameter, consider the option to use 2mm larger I.D. bearings so that you can make captive spacers instead of standard ones.
Broke down and bought NEW BST's with ceramic bearings for the RC-couldn't find anyone that knew or sold carriers and RC sized axle bearings to convert wheels to fit...motomummy has a great price now..2990....usually I see 3300-4000 a set.
This is a common question nowadays when talking about machine tool spindles. Although most manufacturers will tell you the ceramic ball has far more advantages than the steel ball. In most cases that may be true, but is it necessary for your application? Quantum Precision is not looking to sell you the most expensive bearing for your application. We’ll work with you to provide a bearing that will perform under your conditions, and at a reasonable cost.
Provided below are som FAQ's about ceramic bearings vs. steel.
What Is A Hybrid Bearing?
A hybrid bearing is made up of metal rings and silicon nitride ceramic balls with lubricant and retainer appropriate to the type of bearing and application. The silicon nitride balls typically allow for higher speeds, lower operating temperatures, extended lubricant life and many other performance enhancements.
Why Do Ceramic Silicon Nitride Balls Improve Bearing Performance?
Compared to steel balls, Ceramic balls are lighter, smoother, stiffer, harder, corrosion resistant, and electrically resistant. These fundamental characteristics allow for a wide range of performance enhancements in bearings.
Are Ceramic Balls Brittle and Fragile?
Silicon Nitride ceramic balls do not have as high a toughness or ductility as steel. But, due to their high strength, stiffness, and microstructural make-up, they are actually much more durable than steel balls.
Compare The Material Properties of Silicon Nitride Balls to Steel Balls.
Ceramic balls are >60% lighter, >50% stiffer, >70% smoother, and much, much harder than steel balls. Ceramic balls have >100X better rolling contact fatigue life in comparison to Vacuum Melt 52100 Steel.
What Applications Use Hybrid Bearings?
The most common application today is angular contact bearings for high speed machine tool spindles. End-users are seeking higher speed, longer life, reduced lubrication, and decreased total operating costs. Ceramic balls are used in a very wide range of applications from dental handpieces to surgical saws to wing-flap actuators to electric motors.
Are Ceramic Balls More Expensive Than Steel Balls?
Yes. In direct comparison, Ceramic balls are clearly more expensive than steel balls. BUT, when assembled into a hybrid bearing, the price of the bearing assembly is actually quite competitive when compared to all steel bearings. On a Total Operating Cost basis, hybrid bearings typically always pay for themselves many times over in extended life time, enhanced performance, or increased durability. Over the past 15 years, Ceramic balls have steadily become more and more affordable for a wider range of applications as the volumes have climbed.
How Do You Make a Ceramic Ball?
Ceramic balls are made from an ISO-9000 certified process starting with micron sizes powder which is compacted and then densified at extremely high pressures and temperatures. The densified blanks are then precision finished using free-abrasive diamond lapping procedures. Grade 3 and 5 precision levels are typical in high volume batch sizes.
How Are Precision Balls Specified?
Ceramic balls (and any other finished ball from all materials) are specified by using ABMA, ISO, JIS, ASTM or other standards. The sphericity, surface finish, lot diameter variation, etc…. are precisely defined by these standards into various “Grade” levels. The highest typical Grade is 3 (denoting 3 millionths sphericity or better), then 5, then 10, etc….. Bearing companies use different grades depending on the bearing precision and application.
How Much Longer Life Can Be Expected From Hybrid Bearings Vs. Steel?
This is a tough question. Generally speaking, one can expect 2 to 5 times longer life for most applications, but it is highly dependent on operating conditions, bearing design, etc….
What Ceramic Ball Sizes Are Available?
This is an easy question. Ceramic balls are readily available from 0.5 mm (about 1/64”) to 25mm (1”) in a variety of ball grades. Ceramic balls can be made up to 3” (75mm) in diameter. The most popular sized balls tend to be from 1mm to 13 mm in terms of quantity used.
How Can I Buy Ceramic Balls?
We’re so glad you asked!! You can use the contact us inquiry page on this web-site
What Are The Draw-Backs Or Limitations To Using Ceramic Balls?
We’d like to say there are none, but Ceramic balls cannot be used for every application. A stiffer ball can increase contact stresses if raceway curvatures are not adjusted. For extremely high load applications, silicon nitride balls may not be suitable since they may accelerate steel raceway fatigue. Also, silicon nitride balls are more costly than steel balls and while they continue to be more and more affordable, they may not be economical for every application despite longer life and enhanced performance.