Rebuilding
Conversion Cartridge
Tapered Inserts

Users of large horizontal boring mills have all experienced the long downtime and high costs associated with the repairing or replacing of spindle sleeves (and spindle bars), in their machines. Locher, Inc. has designed a repairable and replaceable tapered insert that is installed into the spindle bar. See figure 1 below.

This procedure can be accomplished while the machine remains "in-place," at your facility. The process takes approximately 5 days in-plant with test cuts being performed on the 5 day. These inserts are installed into spindle bars on machines with (or without) tool changers and with collet (or drawbolt) tool retention systems.

Figure 1

The advantage of this retrofit is that the tapered area of the spindle bar, which is the wearing area, is replaceable. In the event of a machine crash that damages the taper area of the spindle bar (beyond the in-place regrinding limits), a new insert can be quickly installed by the machine owner, allowing the machine to be up-and-running again, with minimal downtime.

The Insert Retrofit Process

1. Dimensions are taken from the old spindle bar. A complete set of drawings or blueprints are made from this information.
2. The insert is manufactured (with a spare) and a third insert is machined to a rough state.
3. All machining equipment is loaded into a truck, brought on-site and positioned in-place for retrofit.
4. All machining operations are completed on the spindle bar, in-place.
5. The insert is installed into the bar and an inspection is performed.
6. Test cuts are made with the machine to complete the inspection.
7. All machining equipment is loaded back into the truck and returned to Locher, Inc.
8. An extra insert is left with the customer, to be used as a spare.