- Contents
- Simple Dressing
Q: Being a rubber grinding stone, doesn't Daiwa Rabin wear out soon?
Surprisingly, Daiwa Rabin has a long life.
(Of course, as is often said "a grinding stone does not cut without wearing out", it does wear out.)
It is not rare to see that the selection of a material matching the condition of the work piece, and setting favorable usage conditions results in a longer life than a grinding wheel.
* Usage conditions have a big impact.
There are cases where the life has increased by two to three times only by changing the conditions, and the wear-out of a grinding stone that had been used for a long period of time hastened by increasing the rotation speed of the grinder.
Due to blending of rubber, the tires of a car do not wear out soon even under a large load.
Although the reason for a long life cannot be answered clearly, since evidence is better than debate, please try it out for yourself.
Q: What are the recommended conditions?
This is extremely important, but at the same time, the most difficult to answer question, which cannot be answered easily.
Although it is unfair to be unable to give a clear answer to this question as a manufacturer engaged in tool manufacturing, in the case of our products that have a specific feature called rubber elasticity, the formula and theoretical value of the grinding and cutting theory of grinding wheels and cutting tools cannot be used as is.
Rubber elasticity is characterized by deformation according to the load as well as a high amount of deformation, and its behavior is very different from general elasticity (it is also referred to as superelasticity). We feel sorry for providing a simple explanation, but Daiwa Rabin bends simply by pressing with hand. (The CM type has this kind of softness!) It gets deformed due to the load during use and the contact surface area changes.
Although we do not have a clear understanding of how the repulsive force of the deformed rubber affects the polishing mechanism, upon coming in contact with the surface, the abrasive grains blended in rubber cut the work piece due to the rotation and the repulsive force of the rubber. (?) The condition of this deformation varies according to the polishing pressure and also according to the angle formed with the work piece.
... Because the action on the work piece differs depending on the method of use even when the same grinding stone is used, it is difficult to generalize the conditions. Being an elastic rubber grinding stone, its use on the conventional grinding machine that was used at a high-speed rotation was difficult, because of which the collection of data was also difficult (*). A theory unique to an elastic body might be necessary.
* High-speed use has become possible with Daiwa Light.
The answer would be that we request to "change various conditions and try out".
* We have realized through various examples that the usage conditions are very important, and that the results vary by a large extent depending on the usage.
- Upon being informed that "10,000 work pieces could be processed after finding out the favorable conditions" during the de-burring process on the NC lathe, we were pleasantly surprised, in spite of the fact that it was the top order (although initially we thought that one digit of the figure might have been wrong!).
- We received a query indicating that "the grinding stone was reduced to half only after processing five to six work pieces".
"At what rotation speed did you use it?" A: "The rotation speed was indicated to be 10,000 and that's what we did."
"Why don't you try reducing the rotation speed?" "There is a problem as only the drill press can be used."
Later, we were informed on the phone that "it would last a month!" ... Unfortunately, we could only give a forced smile as it did not result in business.
(FCD450 cylinder inner surface, hole de-burring, φ-20 spherical shape)
* Cases where the life could be increased by two to three times only by changing the conditions are definitely not rare to be seen.
- Another aspect is that due to the deformation caused by rubber elasticity, it can be used even when the load is too high.
Q: What are the tools and required conditions for truing and dressing?
- The dedicated tools used with general grinding wheels and diamond wheels are not needed.
Setting up detailed conditions is also unnecessary.
* The fact that dressing can also be performed easily is also popular among users.
- Dressing can be performed by reducing the rotation speed and rotating the grinding stone, and bringing in contact a simple object such as paper wrapped around a square bar.
You can also use a commercially-available square grinding stone for dressing, or the side face of the grinding wheel used in the past in duplex grinders. - When a constant profile accuracy is necessary and when the processing amount is large, Daiwa Rabin may be used for truing by preparing electro-deposited diamond grains, and in such a case, the cost is lesser as compared to the case when it is purchased after profile processing.
* As the binder is made of rubber, take note that there must be surface contact rather than point contact, and there must not be too much deformation due to over-pressing.
Q: What is the recommended grinding fluid?
You can use oils and aqueous grinding fluids and coolants used commonly for cutting and grinding.
If you use too much quantity, it would hinder the process, on the contrary.
Because high-speed rotation is not performed, the amount of heat generation can be controlled, which enables its use in a semi-dry condition as well.
During free-hand grinding, the use of Daiwa Rabin in dry condition is also quite common, and the fitting with respect to the work piece is also believed to improve.
