Mechanical retrofitting, past the original spec

A retrofit on worn ways is money spent on top of a problem

This is the part we would rather say early, because it is the one that turns a good job into a wasted one. New screws in worn ways still follow the worn ways. A faster spindle on a slide that rocks makes a worse finish faster. Every upgrade on this page sits on top of the machine’s geometry, so if the geometry has gone, that comes first.

Often the honest answer to a retrofit enquiry is a geometric rebuild of the one axis that is worn, with the retrofit going on afterwards. We measure before quoting so you can see which half you are buying, and why.

What we fit, and what it changes

These are the mechanical upgrades worth doing on a machine with good iron under it. Most jobs take two or three of them at once, because the machine is already apart.

Ball screws and nuts

In place of acme screws, sized and preloaded for the machine and aligned to the ways. Backlash out and position held, which is the reason most people ask.

Variable speed drives

A modern drive and motor where there was a gear head or a step pulley, so speed is set at the panel and held under load rather than chosen from a chart.

Gear train and drive work

Worn gears, bearings and shafts through the head and the feed train. Quieter, and accurate at the feeds the machine is actually run at.

Spindle upgrades

Higher speed, a different taper, or a cartridge that is still available. The spindle is set true to the machine afterwards, which is the half that gets skipped.

Lube, coolant and way covers

Central lube where there were oil cups, telescoping covers and wipers where the ways were open. The cheapest way to protect everything else on this list.

Guarding and controls at the panel

Interlocks, stops, and switchgear brought up to something a modern floor will sign off on, without changing how the machine is run.

The mechanical half, and the control half

Modernising an older machine usually means both. New drives and a new control want screws and ways that can use them, and new screws want a drive that can hold a feed. Controls, drives and motors are on our CNC repair and retrofitting page, because the questions there are different ones. When a machine needs both halves, it is one crew and one visit, which is the whole reason we do both.

Toolroom and production lathes, knee mills and bed mills, boring mills, vertical turret lathes, surface and cylindrical grinders, broaching machines and press brakes. The test is not the badge, it is whether the castings are sound and whether your people already know the machine. If yours is not here, ask.

Questions we get

What is the difference between a rebuild and a retrofit?

A rebuild takes a machine back to the specification it was built to. A retrofit takes it somewhere it never was, a finer feed, a faster spindle, a screw that holds position where the original never could. Most jobs that are worth doing at all are some of each, because there is no point improving a machine that has lost its geometry.

Will a retrofit fix a machine that will not hold size?

On its own, no, and this is the one we would rather say early. New screws in worn ways still follow the worn ways. If the geometry has gone, the ways and the alignment come first and the retrofit goes on top of a machine that is true again. We measure before quoting so you are not paying for the second half of a job without the first.

Can you fit ball screws to an older machine?

Usually. Ball screws and nuts in place of acme, sized and preloaded for the machine rather than the catalogue, and aligned to the ways instead of bolted to the brackets and hoped for. Backlash and lost position are the reasons people ask, and both come back if the alignment is skipped.

Do you do control retrofits as well?

Yes, controls and drives, and the mechanical rebuild that goes with them. That side of the work is on our CNC page, because the questions are different. When a machine needs both, it is one crew and one visit rather than two vendors disagreeing about whose half is at fault.

Is retrofitting cheaper than buying a new machine?

It usually is, and it turns on the castings. An older machine tool was built heavy, and that stiffness is what holds accuracy. Where the iron is sound, putting modern screws, drives and guarding onto it returns a machine that a new one at the same money will not match. Where the machine was light to begin with, we will tell you to buy.

Which machines are worth retrofitting?

The ones with good iron and a long life ahead, and the ones you already have people trained on. Lathes, mills, boring mills, grinders and broaching machines all come through. If you are unsure whether yours is one, tell us what it is and what you want it to do.

Reviewed September 2026 by Cavco Machine Tool Rebuilding, LLC.

Tell us the machine and what you want it to do

Call, or send the make and model and what it cannot do today. We answer the same day.