EC-PACK EC-JET 2000, Manual

Page: 98 / 107

User Manual The1.1 version of 2018 Guangzhou EC-PACK CO.LTD
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Wheel Circumference = Distance the product moves for one revolution of the encoder. This may
be 3.14 x roller diameter, or 3.14 x star-wheel diameter, etc., depending on the application.
The encoder pitch will be multiplied by a whole number to give the actual raster pitch. By
selecting a suitable encoder and gearing, the actual raster pitch can be made close to the required
raster pitch.
Actual Raster Pitch (mm) = Encoder Pitch (mm) x Pitch Factor
Where:
Pitch Factor is a whole number.
This will probably require trial and error.
For each encoder pitch you try, the starting point for the pitch factors can be:
Pitch Factor= Required Pitch (mm) (rounded to the nearest whole number)
Encoder Pitch (mm)
Using the example from Step 1, the required raster pitch is 0.373mm. A standard EC-JET encoder
and wheel will be used to try to achieve this.
No
Shaft / Shaft Wheel Encoder Pitch X Pitch Factor = Actual Raster Pitch
1 2500ppr/188.2mm 0.075mm 5 0.375
2
5000ppr/188.2mm 0.0375mm 10 0.375
3 10000ppr/188.2mm 0.0188mm 20 0.375
For this example, the actual pitch using EC-JET standard encoder wheel and the resulting two
encoder are close to the desires pitch, taking into account the higher pulse value, the higher cost
encoder, we will start with 5000PPR encoder with EC-JET standard encoder wheel (diameter
60mm, perimeter 188.2mm) factor 10 (this is covered in later sections).
Step 3: Check the Expected Print Performance
Any difference between the required raster pitch and the actual raster pitch will influence the print
performance. There is also a limitation due to the frequency of the encoder signals. In particular,
the printed message length and the maximum line speed must be checked. If there are any
problems with these, the selection process must be repeated.
Printed Message Length(mm) = Number of Rasters x Actual Raster Pitch (mm)
Where:
Number of Rasters = as calculated in Step 1
Actual Raster Pitch = as calculated in Step 2
Max. Line Speed (m/s) = Actual Raster Pitch(mm) x Raster Rate (kHz)
Where:
Actual Raster Pitch = as calculated in Step 2
Raster Rate = Maximum Rate of Raster Production (see the following table)