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# Wear modifiers: nozzle and build plate maintenance that follows what you print

A nozzle that prints carbon fibre wears out far sooner than one that prints PLA, and PETG is harder on a PEI plate than PLA is. Wear modifiers let SimplyPrint's maintenance count that. A usage-based task like "Replace nozzle, every 500 print hours" comes due sooner or later depending on what each printer actually printed.

This article covers what wear modifiers are, how to add the recommended ones, how to build your own rules, what each condition reads, and how the adjusted hours show up on your tasks.

|| Wear modifiers are part of the maintenance feature, which is available on the Print Farm, School and Enterprise plans.

## Table of contents
- What wear modifiers do
- Where to find them
- Add the recommended wear modifiers
- Build your own wear modifier
- What each condition reads
- How material classes are found
- When a printer setting is not set
- How the hours are counted
- Tasks that count wear
- A worked example
- Things to know
- Related articles

## What wear modifiers do
A [task template](https://help.simplyprint.io/en/article/task-templates-define-reusable-maintenance-procedures-358nuv/) with a usage-based trigger comes due after a number of print hours. Without wear modifiers, every hour counts the same. An hour of abrasive carbon fibre through a brass nozzle counts exactly like an hour of PLA.

A wear modifier is a rule that says a part wears faster or slower under certain conditions, for example:

- A nozzle wears 400% faster when the nozzle is brass or plated brass and the material is abrasive.
- A build plate wears 30% faster when the build plate type is Textured PEI Plate or Smooth PEI Plate and the material is PETG.

When a print finishes, SimplyPrint checks it against your wear modifiers. A 10-hour print that matched the first rule above counts as 50 hours toward the nozzle task. The task then comes due when the nozzle is actually worn, not after a fixed number of hours.

Wear modifiers only affect tasks that are set to count the wear of a part. See [Tasks that count wear](#2-tasks-that-count-wear).

## Where to find them
Go to **Settings > Maintenance** and scroll to **Wear modifiers**. The section shows when maintenance tracking is enabled for the account.

- Users with the **View maintenance** permission can see the list.
- Adding, editing, switching off and deleting wear modifiers needs **Manage maintenance**.

Wear modifiers apply to the whole account. Every printer and every task that counts wear uses the same rules.

![](https://storage.crisp.chat/users/helpdesk/website/-/f/f/2/2/ff22a914001c1000/wear-modifiers-article-wear-mo_rvmw2c.png)

Each rule is shown as a sentence, with a nozzle or build plate icon in front. A rule that is switched off is greyed out.

## Add the recommended wear modifiers
|| The recommended wear modifiers are rough estimates, rounded on purpose. They follow the direction of nozzle and build plate makers' guidance, not measurements. Add them, then adjust them to what you see on your own printers.

Under **Recommended**, SimplyPrint lists the suggested rules you have not added yet:

| Part | Wears | When |
| ---- | ----- | ---- |
| Nozzle | 400% faster | the nozzle is brass or plated brass and the material is abrasive |
| Nozzle | 50% faster | the nozzle is hardened steel or stainless steel and the material is abrasive |
| Nozzle | 10% faster | the nozzle is tungsten carbide or ruby-tipped and the material is abrasive |
| Nozzle | 20% faster | the material is wood-filled |
| Nozzle | 100% faster | the material is glow-in-the-dark |
| Nozzle | 25% slower | the nozzle is hardened steel, tungsten carbide or ruby-tipped and the material is not abrasive |
| Nozzle | 15% faster | the nozzle is high-flow |
| Build plate | 30% faster | the build plate type is Textured PEI Plate or Smooth PEI Plate and the material is PETG |
| Build plate | 20% faster | the material is TPU or TPU-AMS |
| Build plate | 20% faster | the material is PC or PA (nylon, including PA-CF, PA-GF, PA6-CF, PA11 and PA66) |

To add them:

1. Click **Add** next to a single rule, or **Add all** to add every rule in the list.
2. The rules move up into your own list and start counting from the next print that finishes.

The PETG rule covers plates the slicer calls Textured PEI Plate or Smooth PEI Plate. Bambu Lab's Smooth PEI Plate is a High Temp Plate to the slicer, so if you print PETG on one, add a rule with **Build plate** set to that plate and **Material type** set to PETG.

A recommended rule carries an **Estimate** badge for as long as it is unchanged. Once you edit its percentage or conditions, the badge goes away, because the figure is now yours. If you delete a recommended rule, it shows up under **Recommended** again, so you can add it back later.

## Build your own wear modifier
1. In **Settings > Maintenance > Wear modifiers**, click **Add wear modifier**.
2. Under **Part**, choose **Nozzle** or **Build plate**. Only tasks that count that part's wear use the rule.
3. Under **Wears**, choose **Faster** or **Slower**, and enter the percentage under **By (%)**. Faster goes up to 1900% (20 times the hours), slower up to 90% (a tenth of the hours).
4. Under **When**, pick a condition type on the left and one or more values on the right. Click **Add condition** to add another. A rule can have up to six conditions, one of each type.
5. Click **Add wear modifier**.

![](https://storage.crisp.chat/users/helpdesk/website/-/f/f/2/2/ff22a914001c1000/wear-modifiers-article-materia_ezyzkx.png)

How conditions combine:

- **All conditions must hold.** "Brass nozzle" and "abrasive material" together only match a print that used both.
- **Within one condition, any of its values is enough.** A nozzle type condition with "brass" and "plated brass" matches either.

To change a rule later, use the icons on its row:

- **Switch** turns the rule off or on. A rule that is off is kept but stops counting.
- **Pencil** opens the rule for editing.
- **Bin** deletes the rule after asking you to confirm.

## What each condition reads
Each condition shows a short line under it in the form, saying what it reads. In full:

| Condition | What it matches | Read from |
| --------- | --------------- | --------- |
| Material type | PLA, PETG, PA-CF and so on | the material type of the material profile the print used, or of its spool. If neither is known, the type recorded with the print |
| Material class | abrasive, not abrasive, wood-filled, glow-in-the-dark, carbon fibre, glass fibre, metal-filled, high-flow material | see [How material classes are found](#2-how-material-classes-are-found) |
| Material profile | one or more of your material profiles | the material profile the print used, or the one its spool belongs to |
| Nozzle type | brass, hardened steel, tungsten carbide and so on | the printer's nozzle settings, for the nozzle that printed the material |
| Nozzle flow | standard flow or high-flow | the printer's nozzle settings |
| Nozzle size | 0.4 mm, 0.6 mm and so on | the printer's nozzle settings, or the printer's nozzle diameter |
| Build plate | an exact plate, such as one brand's textured PEI sheet | the build plate set on the printer |
| Build plate type | a type of plate, such as Textured PEI Plate or High Temp Plate, whatever its brand | the type the slicer gives the printer's build plate, including custom build plates |
| Printer | specific printers | the printer that printed |
| Printer model | specific printer models | the printer's model. A rule for a model also matches printers of its variants |
| Printer brand | specific brands | the printer model's brand |

**Build plate or build plate type?** Plate names alone don't say which ones behave alike. Bambu Lab's Smooth PEI Plate, for example, is a High Temp Plate as far as the slicer is concerned. **Build plate type** groups plates the way the slicer does, so one rule covers every brand's version. The picker names some of the catalogued plates under each type, so you can see what a type covers.

![](https://storage.crisp.chat/users/helpdesk/website/-/f/f/2/2/ff22a914001c1000/wear-modifiers-article-build-p_pxju54.png)

**Printer model** lists the models you own first, under **Your printers**, then every other model under **All printer models**.

## How material classes are found
A material can be in several classes at once. SimplyPrint looks in three places:

1. **The material type itself.** A type such as PA-CF is carbon fibre, and PA-GF is glass fibre. Fibre and metal fillers always count as abrasive.
2. **The Open Filament Database.** If the spool is linked to a filament or colour in the Open Filament Database, or the material profile is linked to a brand filament, the traits recorded there count. For example, a filament marked as containing carbon fibre, glass fibre or metal, or marked abrasive, counts as abrasive. Filaments marked as containing wood, glowing or high-flow count as wood-filled, glow-in-the-dark or high-flow material.
3. **The name.** "wood" or "glow" in the material's name makes it wood-filled or glow-in-the-dark, so "PLA Wood" counts even without a database link.

**Not abrasive** means any known material that is not abrasive. A print where nobody recorded the material matches no material condition at all, not even "not abrasive".

| Linking your spools and material profiles to the Open Filament Database gives wear modifiers the most to go on. A plain "PLA" type with no link says nothing about fillers.

## When a printer setting is not set
Nozzle and build plate conditions read the printer's own settings. If a printer has no nozzle type, nozzle size or build plate set, a rule that needs that setting can't match it. The rule then counts that printer's prints as 1×, as if the rule weren't there.

So you don't miss it, the task says so. For example: "Nozzle type not set: counted as 1×" or "Build plate not set: counted as 1×". Set them in the [printer's settings](https://help.simplyprint.io/en/article/finding-the-printer-settings-17tbtqt/) on the **Advanced** tab: **Bed type**, and **Nozzle Type**, **Nozzle Size (mm)** and **Volume Type** (the nozzle flow) under **Nozzles & extruders**. Later prints are then counted with the rule. If the printer uses a custom build plate, give that plate a type as well, or a build plate type rule can't match it.

A missing nozzle flow isn't named in the task, since a printer without one nearly always has a standard-flow nozzle.

## How the hours are counted
When a print finishes, SimplyPrint works out one factor per part for that print:

1. **Every material on every extruder is checked on its own**, with the nozzle of the extruder that printed it. On a multi-material or multi-extruder printer, an abrasive filament on one nozzle doesn't count against the other.
2. **The rules a material matches multiply.** A hardened steel nozzle printing a glow-in-the-dark material that isn't abrasive matches "25% slower" and "100% faster": 0.75 × 2 = 1.5×.
3. **The materials are weighted by grams.** A print with 60 g of an abrasive material and 40 g of PLA is weighted 60/40. If the grams of any material aren't known, the materials count equally.
4. **The factor is kept between 0.1× and 20×**, however many rules match.

The print's hours times that factor are added to every task that counts that part's wear on the printer.

## Tasks that count wear
### The "Counts wear of" field
Wear modifiers only change tasks whose template says which part they count. In the [task template](https://help.simplyprint.io/en/article/task-templates-define-reusable-maintenance-procedures-358nuv/), choose **Usage based** as the trigger type, enter the **Print hours**, then set **Counts wear of** to **Nozzle** or **Build plate**. Left at **None**, print hours count as they are.

![](https://storage.crisp.chat/users/helpdesk/website/-/f/f/2/2/ff22a914001c1000/wear-modifiers-article-counts-_9k9xqp.png)

### Default templates that count wear
Two of the default task templates already count wear. Add them with **Import defaults** on the **Task templates** tab:

- **Replace nozzle**, every 500 print hours, counts nozzle wear.
- **Replace build plate**, every 1,000 print hours, counts build plate wear.

### The adjusted due reason
A usage-based task shows how far it has come since it was last done. When wear modifiers changed the count, it also says which ones and how many hours were actually printed:

"305 h of 500 h (adjusted: +20% wood-filled; 289 h printed)"

Here, 289 hours were printed since the nozzle was last replaced. Some of them were wood-filled, so they count as 305 hours toward the 500. Up to three rules are named, the ones that applied to the most hours first. A rule you have deleted since still shows, by the name it had.

![](https://storage.crisp.chat/users/helpdesk/website/-/f/f/2/2/ff22a914001c1000/wear-modifiers-article-adjuste_1uywafj.png)

You see this reason on the task in a maintenance job, when you add tasks to a job, in a schedule's preview, and in the task history on the printer's maintenance profile.

### Raw hours are kept
Wear modifiers never change the hours a printer has actually printed. The printer's runtime, print count and statistics stay as they are. Only the task's count toward its threshold is adjusted. When the task is completed, both counts start again from zero.

## A worked example
Farm 11 has a standard-flow brass nozzle, and the recommended wear modifiers are added. Its "Replace nozzle" task counts nozzle wear, every 500 print hours.

1. A 10-hour print in a PLA marked as containing wood finishes. "20% faster when the material is wood-filled" matches. The task counts 12 hours.
2. A 10-hour print in PA-CF finishes. PA-CF is carbon fibre, so it's abrasive, and "400% faster when the nozzle is brass or plated brass and the material is abrasive" matches. The task counts 50 hours.
3. A 10-hour print in plain PLA finishes. Nothing matches. The task counts 10 hours.

After 30 printed hours, the task stands at 72 h of 500 h. If Farm 11 had a hardened steel nozzle instead, the same three prints would count 9, 15 and 7.5 hours, 31.5 h in all. "25% slower" applies to both PLA prints, because neither is abrasive, so the wood-filled one counts 1.2 × 0.75 = 0.9×. "50% faster" applies to the PA-CF.

## Things to know
- **Rules count from when they are on.** A rule you add, edit or switch on applies to prints that finish after that. Nothing is recalculated backwards, and hours already counted stay counted when you edit, switch off or delete a rule.
- **Schedules' own print-hours triggers aren't adjusted.** A [schedule](https://help.simplyprint.io/en/article/maintenance-schedules-automate-recurring-maintenance-i4of7u/) triggered every 200 print hours counts raw hours. Wear modifiers change when a task that counts wear is due, and a schedule that picks tasks by their triggers includes that task once it's due.
- **Templates from a partner.** When a partner, such as your reseller, pushes task templates to your account, a template keeps its **Counts wear of** setting. The partner's wear modifiers are not copied, because wear modifiers belong to each account. Until you add your own, such a task counts 1×.
- **A rule needs at least one condition.** A rule that applies to every print would just be a different threshold, so change the task's print hours instead.

## Related articles
- [Printer maintenance: keep your fleet running smoothly](https://help.simplyprint.io/en/article/printer-maintenance-keep-your-fleet-running-smoothly-1vr27om/)
- [Task templates: define reusable maintenance procedures](https://help.simplyprint.io/en/article/task-templates-define-reusable-maintenance-procedures-358nuv/)
- [Maintenance schedules: automate recurring maintenance](https://help.simplyprint.io/en/article/maintenance-schedules-automate-recurring-maintenance-i4of7u/)
- [Maintenance jobs: scheduling and completing printer maintenance](https://help.simplyprint.io/en/article/maintenance-jobs-scheduling-and-completing-printer-maintenance-gu6vev/)
- [Finding the printer settings](https://help.simplyprint.io/en/article/finding-the-printer-settings-17tbtqt/)