Buying Guide
Photo-Based Relining Quotes: What a Photograph Proves and What Must Be Measured
A photograph can settle most of a slideway relining quote without anyone visiting the machine, and it cannot settle the numbers the repair is built on. This guide sets out the shot list that answers the geometry questions, the readings that still have to be taken with an instrument, and how long strips should be packed so they arrive flat enough to bond.
Direct answer: photos answer geometry, instruments answer dimensions
A photograph is excellent evidence for configuration, access, damage location and what is already on the machine. It is poor evidence for thickness, wear depth, flatness and clearance, because none of those can be read from an image without a scale and a datum that the camera did not record. The efficient quote is therefore a photograph set that removes the geometry questions plus a small number of instrument readings that answer the dimension questions, sent together.
What a photograph settles
| Evidence | What the photograph proves | What it still cannot prove |
|---|---|---|
| Overall view of the axis | Machine type, axis arrangement, whether the way is flat, dovetail or box, and how much access the job allows | Any dimension, because there is no scale in the frame |
| Close view of the running face | Whether the face is bare metal, previously lined, scored, fretted or has a step at the edge | How deep the wear is, or whether the surface under the scoring is still sound |
| Edge of an existing liner | Whether the strip has lifted, whether the failure is at the bond line or in the material, and how far it has spread | The residual thickness of the remaining bonded area |
| Oil groove layout | Groove pattern, spacing and whether the grooves are cut into the way or the liner | Groove depth and whether the pattern still delivers oil to the loaded area |
| Gib end and adjustment | Gib type, whether it is straight or tapered, and how much adjustment screw or shim remains | The clearance the adjustment is currently holding |
| Machine nameplate | Make, model and often the year, which fixes the original way geometry | Nothing further, and it is the cheapest item on the list to photograph |
The shot list
| Shot | How to frame it | Question it answers |
|---|---|---|
| 1. Nameplate | Straight on, readable, whole plate in frame | Which machine and which generation of way geometry |
| 2. Whole axis, three-quarter view | Whole slide in frame with the ways visible, camera at working height | Configuration, travel length and access for the repair |
| 3. Running face at about 45 degrees | Raking light along the face so wear and scoring show as shadow | Where the wear is and whether it is local or along the travel |
| 4. Existing liner edge, close up | Fill the frame with the edge and 30 to 50 mm of surrounding face | Failure mode: bond line, material, or mechanical damage |
| 5. Oil groove detail | One straight section of groove, square to the camera | Pattern and whether the grooves can be reproduced on a new strip |
| 6. Gib, end on | Show the screw or shim stack and the gib face together | Gib type and remaining adjustment |
| 7. Wear step with a straightedge and feeler | Straightedge laid on the unworn section, feeler blade in the gap, both in frame and in focus | The wear figure, readable from the blade marked in the photo |
| 8. Bearing land with a rule | Steel rule laid across the land, zero end visible, camera square to the face | The land width that the pressure calculation needs |
Marking the photograph so it can be read
- Put a scale in every shot that will be used for a dimension. A rule or a feeler blade is enough, but it has to be in the same plane as the feature being photographed.
- Label the stations A, B and C on the machine with tape before photographing, then use the same labels in the measurement record, so the photograph and the readings describe the same positions.
- Photograph the same view before and after any work, from the same position, so a change can be seen rather than described.
- Include one wide shot that shows where each close-up was taken, otherwise a close-up cannot be located on the machine.
The readings that still have to be taken
- Wear depth at each labelled station, taken with a straightedge and feeler gauges or with an indicator on a surface plate.
- Gib or slide clearance at both ends of the travel and at the middle, with the instrument named.
- Bearing land width across the face, measured rather than taken from a drawing.
- Flatness or straightness of the way along the travel, with the straightedge length stated.
- Load carried by the face with the workpiece in its worst position, so pressure can be calculated on the measured area.
- Working temperature at the way and the fluids that reach it, because both decide the surface preparation and the adhesive choice.
Those six items are the difference between a quote and a guess. Where the repair is being planned from photographs alone, the accuracy after relining guide shows what the finished job is measured against, and the contact pattern guide explains why the photographed wear pattern has to be read as evidence before the strip is ordered.
Packing long strips so they arrive flat
Liner strip is supplied on rolls of 5, 10, 15 or 20 m with cut-to-length available, and a strip that has been rolled tightly for transport carries curvature when it is unrolled. That curvature has to relax before the strip can be bonded flat, and a strip forced flat while still curved will lift at the edges once the clamps come off. Two packing decisions reduce the problem: ask for a core diameter large enough that the bend radius stays gentle for the thickness ordered, and where the job allows, ask for long strips to be packed flat rather than coiled.
| Packing point | Why it matters | What to state on the order |
|---|---|---|
| Core diameter | A tight core sets a permanent curve in a thin strip that outlasts the journey | Ask for a core sized to the thickness, and unroll and relax before measuring |
| Flat packing for long strips | Removes roll memory altogether for strips that can travel straight | State the length and ask whether flat packing is available for it |
| Edge protection | A crushed or nicked edge cannot be bonded cleanly and cannot be trimmed back without losing width | Ask for edge protection and inspect the edges on arrival, before signing |
| Moisture barrier | The treated bonding face is what the adhesive keys to, and a damp pack invites contamination | Ask for a sealed pack and store it closed until the job is ready |
| Identification of the treated side | The two faces are not interchangeable, and a strip bonded the wrong way round cannot be recovered | Ask for the treated face to be marked and keep the marking visible through handling |
Thickness and width should be written on the order in the form set out in the slideway liner specification guide, so that the packing and the dimensions are confirmed against the same document rather than against a message thread.
Frequently asked questions
Can a relining job be quoted from photographs alone?
The geometry and the failure mode can be, and often are. The thickness cannot, because it depends on measured wear, target clearance and finishing allowance. A quote built only on photographs will be a range rather than a firm size.
What is the single most useful photograph to send?
A close, raking-light view of the running face with a straightedge and feeler blade in frame. It shows the wear pattern, the depth and the condition of the metal underneath in one image, which is most of the engineering question.
How long should a strip be left to relax after unrolling?
Until it lies flat under its own weight at the workshop temperature, checked by eye along the length rather than by a fixed interval. A strip that still curves when laid out will bond with that curve built in unless it is clamped hard enough to distort the adhesive layer.
Does a photo of a lifted liner edge tell you why it failed?
It separates failure at the bond line from failure within the material, which is the first division in diagnosis. Preparation faults, contamination and thermal movement all look similar at the edge, so the photograph narrows the cause but does not by itself identify it.
Send the set together
Send the eight photographs, the six readings and the machine details as one set, and the size, the colour and the preparation can be confirmed in a single reply instead of a week of questions. The TEBAK range covers the Blue PTFE slideway liner and the Brown slideway liner used on rebuild work, the matching two-part epoxy adhesive, and the Tuschierpaste for the contact check after machining.