Contents
The contact wheels for the belt sander.
In this post we talk about contact wheels, pneumatic wheels and expansion wheels although the focus will be mainly for the contact wheels of abrasive tapesanders.
The contact wheels, are rubber wheels or vulkollan that provide the support base of the abrasive tape.
The standard width used in the knife shop is 50 mm
There are a variety of types and hardness of the wheels and it is therefore very important to choose the ideal characteristics of the wheel, as it affects the cut and yield of the tape.
They can be smooth, grooved (which, because of the range of empty and full spaces allows the tape to liven up and thus increases its durability) or in vulkollan, a very flexible material and therefore excellent for the processing of sweet metals such as brass, aluminum and zama.
We also have expansion wheels and inflatable air wheels on which sleeves are mounted for use with portable or fixed machines.
The contact wheel is the basis on which the abrasive tape rests when it works.
Choosing the correct contact wheel affects the performance of the tape and the finish you will be able to achieve.
It is therefore important to choose the correct contact wheel according to the material to be processed and its shape, the type of abrasive you are using and the degree of finish you want to achieve.
You can find them of various sizes ranging from 100 mm, 150 mm, 200mm , 250mm , 300mm in diameter.
Smooth rubber contact wheels 
The smooth rubber contact wheel is suitable for any type of processing.
The smooth rubber wheel is generally the best choice in combination with fine-grained abrasive ribbons.
- Hardness from 30 to 90 shore.
- The particular composition of the rubber makes it resistant to all hydrocarbons.
- Aluminium hub covered in smooth rubber has a standard coating height of about 15-20 mm.
- It adapts to all types of metal finishing, iron and non-ferrous, depending on the hardness of the rubber and the type of abrasive tape employed.
- As I told you, it usually has fine-grained ribbons.
- It can be used for dry and wet processing.
- It can be used on both manual and automatic machines.
- Clearly you can choose different wheel diameters based on the range you want to use on your knives.
Grooved rubber contact wheels
Eraser grooved on an aluminum hub.
Suitable for any type of processing, manual or automatic, dry or wet, on ferrous and non-ferrous materials, depending on the hardness of rubber used (from 30 to 90 shore) and the type of abrasive belt.
- The presence of grooves improves the cutting capacity of the tape, while extending its life by preventing the vitrification of the abrasive.
- The particular composition of the rubber makes it resistant to all hydrocarbons.
- Aluminium hub covered with grooved rubber with a square tooth with a coating height on standard hubs of about 15 – 20 mm.
- It adapts to all grinding in general and can be used for dry and wet processing.
- Used for all types of metals, iron and non-ferrous, it serves both to drool and to finish depending on the hardness of the rubber coating.
- It can be universally used on both manual and automatic machines.
The use of a grooved coating wheel, thanks to the effect of the full/empty ratio, greatly improves the cutting action of the tape(constant revitalization), prevents its polishing and consequently prolongs its operational life.
Vulkollan ® rubber contact wheel
Contact wheel made with Vulkollan slats® on an aluminum hub. Mainly for manual or automatic processing on soft metals such as brass, aluminum,zama and bronze.
The flexibility of the Vulkollan slats® makes it the optimal choice for finishing profiled parts, ensuring the best performance of the tape while extending its useful life.
On demand the angle and thickness of the slats can be varied.
Available in three different hards (A-20/25 shore, B-30/35 shore, C-40/45 shore) and smooth version.
Inflatable contact wheels or Inflatable Expansion Roller
Contact wheels so that the abrasive tape can fit perfectly, which is stopped in place by the air pressure inside the contact wheel.
Inflatable contact wheels are used on both fixed and portable machines, they can easily follow surfaces, and therefore are the right choice for finishing shaped parts, interior edges and wooden parts.
The inflatable expansion roller is the perfect accessory for the satin to smooth, sand and polish flat surfaces, but above all fold, edges and corners.
The expansion roller can be inflated easily with a bicycle pump or air gun and a compatible adapter, so the desired degree of hardness can be easily adjusted.
The great flexibility of the roller is also in its processing: thanks to the use of an elastic eraser, the expansion roller adapts even more to the shape of the surface to be worked.
The roller is compatible with various abrasive tapes and grinding sleeves that can be applied to the roller and replaced very quickly.
Compatible sleeves include zirconia, pyramidal structure, Trizact, vello 1FOR2, sC fleece, merino wool felt or BRIGHTEX brand.
During use, the expansion roller absorbs vibrations thanks to its elastic rubber and therefore allows you to do a precise job.
The inflatable expansion roller can be used with all commercially available electrical instruments equipped with a 19 mm spindle.
The roller has a width of 100 mm, a diameter of 90 mm and can be used professionally thanks to the achievement of 3000 rpm.
Centrifure expanders for sleeves
To drag abrasive ribbons from the side of the abrasive grain.
Conical expanders for abrasive anellini (sleeve holders), both reinforced and unreinforced.
The pin is 6 mm in diameter, except for the diameter of 75 mm and 100 mm (pin diameter 8 mm).
Suitable for both reinforced and jointed anellini.
There are also versions
The hole of the expanding wheel
Clearly depending on the pin where the wheel is installed you have to choose a correct type of hole.
Internal Hole options:
- ID 25 millimeters—25 millimeters through the hole used on engine shaft or axle grinder.
- For 6202 bearings—-35mm inner hole with safety rings (Bearings not included)
- B 12.7mm installed—- Wheel installed by bearings with 12.7mm inner hole (OD35 bearings – ID12.7 th11mm)
- B 15 millimeters installed—- Wheel installed by bearings with 15mm inner hole (OD35 bearings – ID15 th11mm)
- For 6004 bearings—- 42mm inner hole, 12mm thick, with safety rings (Bearings not included)
Conclusions
Choosing any contact wheel affects the cut, finishing, timing and cost of the operation and therefore must be made according to the:
- Material
- Hardness
- Surface
- Form
- speed and
- Size
that is more suited to the processing to be carried out.
After analyzing all the parameters that affect its performance:
- Finishing the workpiece
- Work speed (quantity of material removed or number of parts worked in the time unit)
- Tape Yield
you can make the choice and thus determine the costs of grinding.
In this way it is possible to objectively determine the best operating conditions and the best balance between the wheel and the tape in order to obtain results of maximum effectiveness and cost-effectiveness.
All too often this choice is made in a risky and discontinuous manner; a wrong choice, in fact, can double or triple the cost of the operation.
The contact wheels should be chosen on the basis of the material, hardness, surface, shape, speed and size that are best suited to the particular processing required.
The evaluation of all these factors, one no less important than the other, will allow to find the “balance point” to maximize the yield of the materials used at the lowest cost.
Are you experience?
Andrea
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