Accuracy Diagnosis - Mechanical Factors

Mechanical issues that can affect accuracy on Stuga machines

Accuracy

Back To General Accuracy Guidelines

The Mechanical systems on a machine are all prone to wear and tear, maladjustment, alignment, swarf ingress, lack of lubrication and collisions.

It is vital that all mechanics of the system are fully checked out and set and working correctly before any software adjustments are carried out

Mechanical Issue	Description	Link to Page	Common Symptoms	Affected Machines
Recent gripper crash - alignment	Following a gripper crash with profile, gripper position is out / does not grip properly		Gripper does not pick up profile correctly Gripper assembly is loose	All Particulalrly Autoflow
Backlash in Ring	Ring gearing is worn and has developed backlash		Operation position in Y and Z varying randomly	All Except Autoflow.
Clamp Pressures - MH and Saw	Clamp pressures have been incorrectly adjusted and profile is not clamping correctly - ie not pushed to backfence /		Grip slip , X axis stalling or followling error,Operational position in X,Y and Z vary.	All
Backlash Racks	The X axis Gripper or/And Saw pusher can be moved Back and forth when the drive is enabled.		Operational position in X axis will Vary, Slots may not be Very Square or Round. Also Saw backtoback Varying.	All
Pinion gear wear	Backlash cannot be eliminated from the rack and May effect the Main Scaling of the Rack		Operational Position in X axis will Vary along with Saw Backtoback Varying.	All
Gripper nose / gap	The Gap to Switch coming off is important for the amount of Grip Slip Allowed, 1mm is the normal amount allowed. Grip Nose should always be in front of Step on Gripper Jaw when bottomed out		Doesn't get onto grip switch correctly after a Trim Start. Large grip Gap will not help solving Backtoback accuracy issues.	All
Clamp / Rollers alignment	Rollers Seized up. Out of Alignment .		Lots of Grip Slip Alarms. Operations at Beginning or End of Bar differ from Middle of bar ,	All
Saw Clamp parallelism	Following a Profile Clash or Jamb the Front Rollers known as Saw Side/Centraliser Clamp is not Parallel to the Rear rollers		Known to Affect the 1st or Last Arrowhead on a Bar length and Cause inconsistent saw Sizes due to the change in friction.	All
Saw kerf	The Amount of waste Cut at 90 degrees, Basically the Saw Blade Thickness		Will Have a major affect on all Sizes and Accuracy setup if not entered correctly. Care must be taken on Older setups where it is a Shared Component.	All
Saw angles	Any error in the saw angles will cause a bad setup of machine.		Sizes are incorrect, Pieces do not weld up correctly.	All
Rear Rollers -Parallel to G axis - ZX4	G axis not Parallel to Rear Roller fences on Zx4 used for the V notch setup		V and Y Notches at Beginning of Bar or V and Y notches at the End of Bar will differ from those in middle of Bar.	ZX4
G axis parallel	Gripper axis must be Parallel to all rear roller/fence alignments within machining/cutting area's.		Operations at End/Beginning of Bar are not the same as Middle of Bar. Gripper knocks profile when unclamping and re gripping on Microline saw.	All
G axis datum	Position of Centre of Gripper jaw from Rear Fences		Profiles will Slip or not get gripped correctly, will cause Laser Measure Accuracy issues.	All
Laser alignment	Used where Machine cannot do a Trim Start and is the Datum point End of Bar	Laser Setup on Flowline/ZX3 for Laser Holes	Laser Hole Errors, Operational position in X axis varying randomly	ZX3 and ZX4 Non All in One Versions
Rack alignment / height
V Notch bed height alignment (ZX4)	Small Platform on the Newer Machines with 200mm blades where a Bottom Bed is moved into position with the V or W axis. Must NOT be higher than Under rollers. Normally 0.2mm to 0.5mm lower than straight edge placed accross Under rollers,		V notch Depths will be wrong, And possible V and W axis errors.
V notch blade setup
Seized rollers
Saw bed alignment
Zip gate to grip height
gripper slip
grip height to underrollers
zip gate opener fitted wrong way
Journals
Infeed grip / pull pads
Saw infeed lift / load alignment
Z blocks sticking out / badly adjusted
Datum sensors
Zero pulse on motor working
Keyways
Grubscrews loose
Sync pulse on Beckhoff systems
Centraliser not getting to position
Saw damper
Grip finger angle
Grip push too far
Saw top clamp pressure - Hi / Low

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