Service Home How To Procedures Horizontal Plane Linear Guide - Replacement
Last updated: 12/01/2018

Horizontal Plane Linear Guide - Replacement

Introduction

This procedure tells you how to replace the Z axis linear guide on the ST machine. This procedure also applicable to other machines as the linear guide mounting methods are the same.

Remove all of the sheet metal parts that obstructing the access to the linear guide before performing this procedure.

 Note: Only replace one linear guide at the time.

Horizontal Plane Linear Guide - Replacement

1

Remove the fasteners

Back off all of the cams [1] that pushes the linear guide [2] against the machined shoulder [3].

 Note: If the linear guide is replaced due to the crash, inspect every cam for damage and replace if necessary.

Move the axis to one end of the travel and remove all of the accessible plugs [4]. Remove all of the accessible bolts [5] except the one at the end of the linear guide [6].

Move the axis over the part of the linear guide that has the bolts removed and remove remaining plugs and bolts on the other side of the linear guide. Leave the bolt [7] at the end of the linear guide tight.

Move the axis to the position that will allow the best access to the linear guide trucks.

Detach the lubrication lines [8] from the trucks.

Loosen the bolts [9] that secure the wedge to the trucks.

2

Remove the linear guide

Place the jack [1] under the wedge.

Loosen the bolts [2] that secure the ballnut housing to the wedge.

Support the weight of the wedge with the jack just enough so you can slide the linear guide trucks [3] under the wedge.

Remove the bolts [4] that secure the trucks to the wedge and slide the trucks away from the wedge.

Remove the two bolts at the ends of the linear guide.

Lift the linear guide up and over the machined shoulder and get it out of the machine.

3

Install the new linear guide

Clean all of the mating surfaces [1].

 Note: Any debris or burrs will affect the straightness of the linear guide. Use the stone to clean the mating surfaces on the base. Make sure that all of the cams are in place before installing the linear guide.

Install the linear guide on the base with the grounded side [3] of the linear guide truck facing outwards.

 Note: Make sure that the linear guide is laying flat up against the reference shoulder.

Install all of the accessible linear guide mounting bolts. Run the bolts down until they just make contact with the linear guide.

Slide the trucks under the wedge. Attach the lube lines to the trucks and install the wedge mounting bolts [4]. Leave these bolts loose.

Remove the jack [5] and move the axis to the end of the travel and install remaining bolts.

With the linear guide mounting bolts snug, torque the cams [6] to 10 ft.lbs.

 Note: When torquing the cams, start from one end and work your way to the other end.

Torque the linear guide mounting bolts.

Install the plugs flush with the top surface of the linear guide .

Torque the wedge mounting bolts [4].

4

Replace the second linear guide.

Repeat the steps 2 and 3 for the second linear guide.

5

Float the ballnut

With the ballnut mounting bolts snug, move the axis over the full travel multiple times.

 Note: Use the Jog Lock function or command the slow movement with the G code. Do not use the jog wheel.

Torque the ballnut mounting bolts.

Check the machine alignment after replacing the linear guides.

Refer to the Haas Fastener Torque Specifications for the torque values.