Taber Abraser Calibration Verification

Abrasion Wear testing has been the standard test for determining relative hardness/wear resistance of coatings in the metal finishing industry, especially Type III anodize. The instrument most commonly used is the Taber Rotary Abraser manufactured by Taber Industries, most commonly referred to as Taber Abrader.

The taber abrader, a very sturdy, simple and seemingly indestructible instrument, having two movable arms, which hold weights, abrader wheels and a round table somewhat like a record player that rotates at approximately 70 rpm on which test specimen and abrader wheels ride and a revolution counter. That pretty much describes the instrument.

Being so simple and bullet proof, quite often ignored when it comes to maintenance or tracking verification. What in the world could go wrong with this thing, the arms move and the table turns, what more could a person ask for. Well, we thought that way until we started operating multiple machines. We started finding, using the same operator, analytical balance, weights and abrader wheels on the different machines, considerable differences in results. This was puzzling because what could be causing this problem when the machines are from the same manufacturer albeit different ages, what could cause them to render substantial differences in results, (knowing of course, the instruments were simple and indestructible).

At this point, we became curious as to the differences between the four units we were using, aside from variation in hard coat application of reference panels. Clients were sending their monthly test panels to verify the quality of their work and were depending on us to deliver accurate, reproducible results on which their production and continued military approvals depended. You only send in equipment/instruments when they are in need of repair or calibration. Why or what would you calibrate on a taber machine when the arms armed, wheels wheeled and rotating table rotated, where do you go from here. Taber Industries informed us they have a calibration verification kit, used to check wheel alignment.

The kit we received allowed us to verify the following:

  • Longitudinal alignment of Abraser arms
  • Transverse alignment of Abraser arms
  • Wheel tracking and wear pattern
  • Bearing integrity (tracking pattern compliance)
  • Vacuum nozzle orifice size
  • Minimum vacuum nozzle suction force

Alignment of abrader wheels is somewhat like the alignment on cars front wheels, you are concerned with Toe-in, Toe-out, Caster, and Camber.

We ran all six tests on each of the four-taber abraders operated and found considerable differences.

Noting that all four machines were within tolerance, albeit two of them borderline. The primary difference between each of the four abraders was alignment. After sending them in for adjustment, correlation between instruments was re-established. We were able to reproduce results, within limitations of duplicate anodized panels prepared just for these comparison tests.

The Taber Abrader, even though look bullet proof, are very fragile in certain aspects, arm alignment, table flatness, weight spindle alignment with arm, etc, and should be treated as an instrument requiring T.L.C.

The following tracking cards, may give you an idea of visual data obtainable from the verification kit.

Figure 1

Figure #1: indicates a table, which is not flat. Either the table is warped or shaft is bent. Note the difference between left and right side of the tracking card. This condition will increase the wear on one side as opposed to the other.

Figure #2: Indicates, abrader wheels are riding on inside half of their width. This applies more pressure to a smaller area, increasing wear rate.

Figure #3: Indicates the opposite of Figure #2, abrader wheels are riding on the outside half of their width. This again applies more pressure to a smaller area, increasing wear rate.

Figures # 4, 5, & 6: depict uniform distribution of weight and wear. If, after running a tracking card on your instrument, you are unable to obtain a trace similar to that of Figures # 4, 5 or 6, results of tests conducted on the instrument are questionable, instrument should be sent for re-align and adjust.

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

I highly recommend, anyone using the Taber Rotary Abraser, check out the alignment on a regular basis, in order to maintain quality results the equipment is capable of generating. If any of the verification tests fail, have the instrument re-aligned by Taber Industries, before any further testing is conducted.

One note, if the arms are ever allowed to fall from their up-right position and impact the rotary table, I would highly recommend you run the wheel alignment test to confirm no damage has been done and resurface abrader wheels to remove any possible flat spots.

Just because the arms arm, turntable turns, does not mean you are playing music. Take care of your equipment, and your equipment will take care of you.