THE SHOP, INC
The following information is put forth not only to promote our products, but to secure an industry with the use of the best possible clipper blade sharpening methods. Please direct any questions or comments via E-mail to mail@theshop-inc.com.
Clipper blade sharpening has, since its inception, had problems with consistency.
This has been true of manufacturers as well as sharpeners. This highly competitive
product requires a degree of accuracy beyond its value. Nevertheless, a good
cutting and long lasting clipper blade is a must in the hair industry.
The two primary elements required for good cutting and
long service life of the clipper blade are:
-removal of dull
cutting radius on tooth edge
-even tooth contact on every tooth
All other considerations, though important, are secondary.
The inconsistencies that have plagued the industry are
most often a result of:
-insufficient amount of metal removed to fully sharpen
cutting edge
-uneven metal removal, resulting in uneven tooth contact pattern
To remove the dull tooth radius .001" or more of metal
removal is necessary. Consistent metal removal of .001" or more requires
knowing your grinding rate on fresh and ending charge. Inspection of cutting
edge and teeth tips will determine if more than .001" of metal has to
be removed to fully sharpen blade.
To know if you have achieved even and equal tooth contact the blade must be
rubbed on an accurate test plate after grinding to display the areas of contact.
Visual inspection of a freshly ground surface without rubbing on a test block
is just guesswork. Test cutting does not reveal tooth contact.
The elements needed for even metal removal and tooth contact are:
-a known accurate disc surface
-accurate transfer of disc surface profile to blade
What ensures these requirements?
-use of a validated disc surface
-use of an accurate test/rubbing block to check tooth contact
The usual sharpening disc honing area is 5" to 6" wide and lathe cut to a semi precision plane. Varying surface finishes exist. The risk with this semi precision plane is that you do not know how good or bad it is. The showing of high or low spots (uneven wear of the surface) after some use indicates the original inaccuracy (a true surface always wears to an even curve with no high or low spots). This variance of accuracy has been a contributing factor to the inconsistency in sharpening clipper blades.
Three years ago The Shop, Inc. introduced a precision machine scraped disc
surface that is verified, by the scraping process, a true plane, eliminating
this risk. All other systems on the market use an unverified disc surface.
We sell only verified disc surfaces. We season each disc, sharpen blades on
it and then check the tooth contact pattern to be absolutely sure that the
disc you receive is accurate and will make good blades immediately. No other
manufacturers test their disc surfaces before shipping. We do not expect the
customer to do our quality control for us.
A 5" to 6" honing band also makes it more challenging to produce the optimum straight tooth contact pattern. You must follow as straight as possible the hollow grinding ridge for a greater distance than on The Shop's 3 1/4" honing band. Fatigue has a definite effect on the quality of result when sharpening manually and the shorter stroking distance is a definite plus to lessen errors due to tiredness. A straighter, far less crescent pattern can be more easily achieved. The more even and equal the tooth contact, the better. The scraped 3 1/4" band also has a more efficient grinding rate than a 5" to 6" band on the same diameter disc due to a higher average surface speed and more grit grinding by sitting on a more accurate and solid surface.
What is tooth contact pattern?
'Tooth contact pattern' refers to the 'footprint' of the blade. How the teeth
will contact the teeth of the opposing blade determines how well and for how
long a blade will cut. The optimum contact pattern is an equal amount of surface
contact on all the teeth. This distributes the spring pressure and cutting
load equally and will allow for even wear. Each tooth will cut the same as
the others, lessening the tendency of one or more of the teeth to fail prematurely.
By rubbing a freshly ground blade on an accurately ground test block, the
high points will be burnished and can then be seen visually. This reveals
the 'tooth contact pattern'. On a hollow ground blade, the contact should
be primarily the tips of the teeth and at the back of the rear rail. The amount
of hollow grind and how much pressure is used in the rub test will determine
how much contact area is burnished and how far down the teeth it shows. On
a flat ground blade virtually the whole surface should show contact. This
test procedure checks both the integrity of the disc surface and the grinding
technique used. Test cutting does not reveal tooth contact.
We believe hand sharpening can be done skillfully most of the time, but all of the time is what is required. Precise control of the blade as far as placement on the disc and maintaining even pressure as the blade is being ground is imperative for an accurately sharpened clipper blade. We manufacture our automatic mechanism to eliminate the inconsistency of doing blades manually. By traveling back and forth on the disc parallel to the centerline of the disc with constant and equal pressure on the blade, the true profile of the hollow grind ridge is accurately ground into each and every blade. The result is superior cutting and maximum blade life.
Disc diameter does not determine the hollow grind or blade life. There is
a misconception by many people that disc diameter and grinding speed play
the determining factors in the hollow grind and sharpness of blades. We have
proven results that show that better than factory results can be achieved
on discs of any diameter clear down to 6" if the proper angle is machined
into the plate and then the surface scraped for accuracy. Any amount of hollow
grind can be achieved no matter the disc diameter. It is the angle that it
is machined to that determines the amount of 'hollow' it will grind into a
blade. Keep in mind that the disc profile is somewhat irrelevant unless it
is accurately transferred to the blade by using proper sharpening techniques.
Remember…
Your customer will not know or care how fast
you did their blades, just how well.