6 axis post processing
The 6 axis post processor (06)
This option can be selected from the post processing menu. Operation of the 6 axis post processor is similar to the standard 4 axis system. The roll and yaw axes are used to keep the tows aligned on the payout eye and to remove twist of the tows between eye and mandrel. This allows wider fibre bands to be used without the band narrowing due to fibre twist when winding across dome ends. Some twist is normally experienced with 4-axis winding. The vertical axis is used to provided greater clearance between the winding head and the mandrel as the head shape on 6 axis machines means that positioning the feed eye close to a dome end is not possible due to head clash with the mandrel shafts. If the vertical axis is not used a very long payout eye extension is required. The position of the payout head will either be above or below the horizontal plane through the mandrel axis dependant upon the direction of rotation of the mandrel. The direction of rotation is dependant on if the fibre track was started going up or down the screen. The head geometry may dictate which option (above or below) works best.
For 6 axis winding, using the correct value of payout eye extension is essential as when the yaw axis is moved there must be compensation in the carriage and cross-feed axes due to the rotation not being centred on the end of the delivery eye.
Using the six axis post processor and when viewing along the winding axis, the fibre from mandrel to payout point on the head has no component of direction in the 'Y' axis and the fibre makes a 90 degree angle to the payout roller viewed along the axis of the roller. This post processor asks for The 6 axis transformation angle the default value is 90o. The user can specify the contact angle of the fibre around the payout roller. Values less than 45 degrees are not recommended. The best value is 90 but in some instances where there are problems due to limited vertical travel. Other values between 45 and 90 can be used to reduce vertical travel.
The 6 axis post processor- Method 2 (07)
The alternative 6 axis post processor is similar to the 6 axis post processor except that the payout eye is constrained to move in a plane that contains the winding axis that is inclined at an angle to the X-Y plane. This can allow a larger diameter to be wound than is usual or my give better clearance if the payout head has an unusual configuration The angle of inclination is from the value entered when the 6 axis transformation angle is requested. The default value is 45 degrees. Using this option radial mandrel clearance can be optimised for example if the Z travel is 300mm And the Y travel is 600mm from the mandrel centre line the angle would be optimal at arctan(300/600) and the maximum radial clearance would be (6002+3002). The standard 6 axis system should usually be used in preference to this option.
The 6 axis, horizontal fibre (16)
In the option the fibre exits the mandrel in a horizontal direction i.e. in a plane perpendicular to axis 6 (on a conventional setup with the cross-feed axis horizontal). The exit point from the mandrel will be the upper most or lower most edge dependant on the direction of mandrel rotation. The eye-yaw axis is used to align with the fibre direction and keep the fibre central on the exit roller. The eye-roll axis is used to keep the band twist free between mandrel and payout roller. On a cylinder the eye-roll would be flat whilst at the pole of a dome it would be at 90 degrees. The eye roll can be configured in the SM file but the output removed to give another 5 axis post-process variation. Suitability of this option depends on the payout geometry as if the payout is wide it may give greatly reduced clearance when winding with low angles. This option has no special/specific post-processor inputs.