Grinding the ways of a 618

[WCraig]

A steady rest or a follower?

I sold the (repaired) steady rest. Never had a follow rest.

Craig

 

[RJSakowski]

I have an Atlas/Craftsman 6x18. Grinding the top surface will not affect the headstock or the tailstock. The carriage will sit lower which will affect the relationship with the lead screw and the rack. The lead screw could lowered by opening up the mounting holes in the bearings, providing there wasn't too much material removed. The front and rear shims which prevent the carriage from lifting were available for different clearances to accommodate for wear and custom shims could easily be made

I don't believe the rack is adjustable as the mounting screws are precision countersunk screws and there is a spring pin for locating the rack. The pinion assembly would be difficult to accommodate a change due to grinding as the bearing for the carriage travel gear is located by two spring pins. This is going to be the sticking point unless a minimal amount of material is removed.

Another way of compensating would be to add shims to the lower side of the carriage to compensate for the material removed by grinding. These shims would have to be fixed in place somehow, possibly by bending the ends up to form ears. This would be the simplest way to restore geometry.

However, before undertaking such a project, I would evaluate how much wear you actually have. The tregion under thwe headstock is pristine and will serve as a reference. Also fairly true for the region to the far right of the bed. There are two narrow strips down the length of the bed that do not see any wear as they are non-contact areas. Do some careful measurements to assess the condition. My lathe has seen many years of use and some abuse and wear in the most used region is about a thousandth. However of the previous owner attemped to regrind or resurface the bed, all bets are off.

 

[machinistnoob]

I have an Atlas/Craftsman 6x18. Grinding the top surface will not affect the headstock or the tailstock. The carriage will sit lower which will affect the relationship with the lead screw and the rack. The lead screw could lowered by opening up the mounting holes in the bearings, providing there wasn't too much material removed. The front and rear shims which prevent the carriage from lifting were available for different clearances to accommodate for wear and custom shims could easily be made

I don't believe the rack is adjustable as the mounting screws are precision countersunk screws and there is a spring pin for locating the rack. The pinion assembly would be difficult to accommodate a change due to grinding as the bearing for the carriage travel gear is located by two spring pins. This is going to be the sticking point unless a minimal amount of material is removed.

Another way of compensating would be to add shims to the lower side of the carriage to compensate for the material removed by grinding. These shims would have to be fixed in place somehow, possibly by bending the ends up to form ears. This would be the simplest way to restore geometry.

However, before undertaking such a project, I would evaluate how much wear you actually have. The tregion under thwe headstock is pristine and will serve as a reference. Also fairly true for the region to the far right of the bed. There are two narrow strips down the length of the bed that do not see any wear as they are non-contact areas. Do some careful measurements to assess the condition. My lathe has seen many years of use and some abuse and wear in the most used region is about a thousandth. However of the previous owner attemped to regrind or resurface the bed, all bets are off.

Thank you. That was very informative.