Stratasys H350 User manual

DOC-01005 Rev. C
H350 3D Printer
A SAF Selective Absorption Fusion Powered Product
User Guide

User Guide
Page ii
© Copyright 2022 Stratasys. All rights reserved.
Information
Before commissioning the machine, all information in this instruction handbook is to be
carefully read and understood.
Make sure that the instructions below are read and understood, kept up to date according to
the machine and that the instructions are always followed when working on or servicing the
machine.
Attention
This instruction handbook contains instructions for installing, starting up, operating and
maintaining the machine.
The instructions are made available by the manufacturer to provide information and to show
the tasks that must be performed.
Copyright Statement
Copyright © 2022 Stratasys Ltd. All rights reserved.
No part of this document may be photocopied, reproduced, or translated into any human or
computer language in any form, nor stored in a database or retrieval system, without prior
permission in writing from Stratasys. This document may be printed for internal use only. All
copies shall contain a full copy of this copyright notice.
Patents
The Stratasys H350 3D printer is manufactured, kept, used, distributed and sold under a
license from Loughborough University Enterprises Limited and Evonik IP GmbH under the
following and/or related patents and patent applications and their family members: EP2739457,
EP3539752, EP1648686, EP 1740367, EP1737646, EP1459871. Further details including live
and in-force status of family members may be found at:
https://worldwide.espacenet.com/patent/search/family/.
Trademarks Acknowledgments
Stratasys, the Stratasys Signet logo, GrabCAD, GrabCAD Print, H350, H-Series, SAF,
Selective Absorption Fusion, HAF and Big Wave are trademarks of Stratasys Ltd. and/or
subsidiaries or affiliates and may be registered in certain jurisdictions.
All other product names and trademarks are the property of their respective owners.
Liability Statement
Stratasys shall not be liable for errors contained herein or for incidental or consequential
damages in connection with the furnishing, performance, or use of this material. Stratasys
makes no warranty of any kind with regard to this material, including, but not limited to, the
implied warranties of merchantability and fitness for a particular purpose. It is the responsibility
of the system owner/material buyer to determine that Stratasys material is safe, lawful, and
technically suitable for the intended application as well as identify the proper disposal (or
recycling) method consistent with local environmental regulations. Except as provided in
Stratasys' standard conditions of sale, Stratasys shall not be responsible for any loss resulting
from any use of its products described herein.

User Guide
Page iii
© Copyright 2022 Stratasys. All rights reserved.
Disclaimer
Customer acknowledges the contents of this document and that Stratasys parts, materials, and
supplies are subject to its standard terms and conditions, available on
http://www.stratasys.com/legal/terms-and-conditions-of-sale, which are incorporated herein by
reference.
The specifications and/or information on which this document is based are subject to change
without notice.
www.stratasys.com
Comments: [email protected]

User Guide
Page iv
© Copyright 2022 Stratasys. All rights reserved.
Revision Log
Translations of this guide are updated periodically. If you are consuming a translated
version, please check the English version for latest revision and list of updates.
Revision Release Date Description of Changes
A DEC 2021 Initial Release (software version v0.92.6 and below)
B MAY 2022 Updated vacuum cleaner reference. Added information for GrabCAD Print
client. Clarified information for GrabCAD Print server.
C OCT 2022 Updated powder-related information. Updated kit information. Updated
various screens. Extensively changed post-build maintenance section to
reflect changes to cleaning wizard. Updated roller cleaning procedure.
(software version 1.0.5 and above)

Page v
Contents
1 Service and Support ........................................................1
Intended Use ................................................................................................. 1
Reasonably Misuse ....................................................................................... 1
Objective........................................................................................................ 1
Reading Instructions ...................................................................................... 1
Knowledge ..................................................................................................... 2
Availability...................................................................................................... 2
Symbols Used................................................................................................ 2
Nameplate ..................................................................................................... 3
Abbreviations ................................................................................................. 3
User Groups and Qualifications..................................................................... 4
Operator .............................................................................................................................. 4
Operator Requirements and Qualifications .............................................................. 4
Service........................................................................................................... 5
Software Support ........................................................................................... 5
User Guide Terms.......................................................................................... 5
Safety Instructions ......................................................................................... 6
Hazardous Situations During Intended Use ........................................................................ 6
Hot Surfaces ............................................................................................................ 6
Contact with Fluid..................................................................................................... 6
Contact with Powder ................................................................................................ 7
Foreseeable Misuse ............................................................................................................ 7
Safety-Related Guards............................................................................................. 7
Restricted Access..................................................................................................... 7
Lack of Training........................................................................................................ 8
Special Conditions for Different User Groups...................................................................... 8
Residual Risks..................................................................................................................... 8
Fluid Hazards ........................................................................................................... 9
Powder Hazards....................................................................................................... 9

H350 User Guide
Page vi
Location of Safety Symbols .................................................................................... 10
Renewal of Safety Symbols.................................................................................... 11
Use of Personal Protective Equipment .............................................................................. 11
Overview of Printer Safety Functions ................................................................................ 11
Test of Safety Functions......................................................................................... 13
Emergency stop...................................................................................................... 13
Restart after Emergency Stop ................................................................................ 14
Emergency Situations........................................................................................................ 14
2 Printer Setup.................................................................. 15
General Information ..................................................................................... 15
Weight and Dimensions..................................................................................................... 15
Stratasys Required Additional Equipment ......................................................................... 15
Basic Setup.................................................................................................. 16
Environmental Conditions.................................................................................................. 16
Printer Temperature and Humidity ......................................................................... 16
Powder Storage and Preparation ........................................................................... 16
Moving the Printer........................................................................................ 17
Identifying Your Printer....................................................................................................... 18
Making the Network Connection........................................................................................ 19
Back Panel Connections.................................................................................................... 20
Connecting to a Local Area Network (LAN) ....................................................................... 21
Installing and Connecting the H350 3D Printer to the GrabCad Print Server 23
GrabCAD Print Server Software ........................................................................................ 23
Setting the Printer’s Date and Time ............................................................. 23
Updating the Controller Software Version.................................................... 23
Installing the H350 Job Preparation Software.............................................. 24
Installing and Connecting the H350 3D Printer to the GrabCad Print Client ..................... 24
Installing the Stratasys H350 Build Processor................................................................... 24
Stratasys H350 Build Processor Installation Procedure ......................................... 25
Adding the H350 Build Processor to Materialise™ Magics™................................. 31
Stratasys H350 Build Processor Configuration ...................................................... 35

H350 User Guide
Page vii
Stratasys Online Resources ........................................................................ 39
Stratasys Academy ............................................................................................................ 40
Stratasys Support Center .................................................................................................. 40
Stratasys Academy YouTube Channel............................................................................... 41
GrabCAD Community ........................................................................................................ 42
3 System Components ..................................................... 43
Printer Overview .......................................................................................... 43
Access Doors and Panels.................................................................................................. 43
Lid........................................................................................................................... 45
Powder container inlet access door........................................................................ 45
HAF and Waste cartridge access door................................................................... 45
Right side panel...................................................................................................... 45
Top cover................................................................................................................ 45
Rear panels: ........................................................................................................... 46
Interface Panel................................................................................................................... 46
Touchscreen User Interface ................................................................................... 46
Power Button .......................................................................................................... 47
USB Port................................................................................................................. 47
Processing Chamber Components.............................................................. 47
Lower Processing Chamber Components ......................................................................... 47
Distribution Sled ..................................................................................................... 47
Print Sled ................................................................................................................ 47
Dosing Blade .......................................................................................................... 48
Build Plate .............................................................................................................. 48
Overflow ................................................................................................................. 48
Upper Processing Chamber Components ......................................................................... 49
Overhead heaters................................................................................................... 49
Vortex bell with thermal camera window ................................................................ 49
Spotlights................................................................................................................ 49
Air vents.................................................................................................................. 50
Modeling Materials....................................................................................... 50
Materials Used .................................................................................................................. 50

H350 User Guide
Page viii
Powder ................................................................................................................... 51
High Absorption Fluid ............................................................................................. 51
Printing Overview ................................................................................................... 51
Reports .............................................................................................................................. 51
Software....................................................................................................... 52
Printer Software ................................................................................................................. 52
Build Preparation Using GrabCAD Print for H350 ............................................................. 52
Build Preparation Using Materialise™ Magics™ ............................................................... 52
Opening the software ............................................................................................. 53
Loading a scene ..................................................................................................... 54
Importing a part ...................................................................................................... 56
Translation and Rotation ........................................................................................ 57
Rescaling................................................................................................................ 60
Duplication.............................................................................................................. 60
Cross Sectional view. ............................................................................................. 62
Hollowing ................................................................................................................ 64
Collision Detection.................................................................................................. 65
3D Nesting.............................................................................................................. 68
Sinter box ............................................................................................................... 71
Dimensions............................................................................................................. 73
Fix Wizard............................................................................................................... 74
Submitting a Job..................................................................................................... 77
4 User Interface ................................................................ 79
Overview...................................................................................................... 79
Loading a Build Job File .................................................................................................... 80
Deleting a Build Job File .................................................................................................... 81
Viewing Build Job Information ........................................................................................... 82
Live Data Screens .................................................................................................. 83
Owner Web Interface ................................................................................... 85
Accessing the owner web interface ................................................................................... 85
Owner web interface.......................................................................................................... 87
Overview screen..................................................................................................... 88

H350 User Guide
Page ix
Live Data screen..................................................................................................... 89
Live Data Screens .................................................................................................. 90
Configuration menu ................................................................................................ 91
Build file library ....................................................................................................... 94
Build job history ...................................................................................................... 95
Event log................................................................................................................. 95
System info............................................................................................................. 96
Software updates.................................................................................................... 96
Browse files ............................................................................................................ 97
5 Operating the Printer ................................................... 101
Workflow .................................................................................................... 101
Basic User Operations ............................................................................... 101
Powering ON the Printer.................................................................................................. 101
Reactivating a Dormant Printer ............................................................................ 104
Powering OFF the Printer ................................................................................................ 105
Accessing Printer Folders .......................................................................... 106
Loading Material ........................................................................................ 106
Load Material Cartridges ................................................................................................. 106
Unloading and Replacing a Cartridge............................................................................... 111
Refilling Powder............................................................................................................... 112
Preparing the Powder Mixture .............................................................................. 114
Loading the Printer with Powder........................................................................... 114
Basic Job Build Tasks ................................................................................ 120
Starting a Build Job (Select From List) ............................................................................ 120
Starting a Build Job (Previously Used) ............................................................................ 127
Removing a Build....................................................................................... 128
Prepare the Stratasys H trolley and build removal box.................................................... 130
Placing the build removal box on the printer.................................................................... 133
Remove the Build Using the Wizard ................................................................................ 140
Remove the Build Removal Box From the Printer ........................................................... 145
Cooldown......................................................................................................................... 147

H350 User Guide
Page x
Post-Processing Considerations................................................................ 148
Depowdering the Build..................................................................................................... 148
Powder Reuse ................................................................................................................. 149
Bead Blasting the Build.................................................................................................... 149
Automated Bead Blasting ..................................................................................... 149
Manual Bead Blasting........................................................................................... 150
Build Warnings................................................................................................................. 151
Aborting a Build ............................................................................................................... 151
Abort safely........................................................................................................... 152
Force abort ........................................................................................................... 152
Next steps............................................................................................................. 152
6 Calibration and Adjustments........................................ 154
Load Cell Calibration.................................................................................. 154
HAF Load Cell Calibration ............................................................................................... 157
Waste Load Cell Calibration ............................................................................................ 158
Test Load Cell Calibration................................................................................................ 160
7 Maintenance ................................................................ 162
Updating Controller Software..................................................................... 162
Procedure ............................................................................................................. 163
Printhead User Maintenance ........................................................................................... 169
Maintenance Schedule .............................................................................. 170
Post-Build Maintenance............................................................................. 171
Cleaning the Printer Using the Cleaning Wizard ............................................................. 171
Printer clean wizard .............................................................................................. 172
Cleaning the Distribution Sled .............................................................................. 178
Vacuum Cleaning the Distribution Sled with Covers Removed............................ 184
Cleaning the Distribution Roller ............................................................................ 185
Cleaning the Print Sled......................................................................................... 197
Cleaning the Print Sled Protection Strips ............................................................. 200
Cleaning the Printheads: Full Black Image Test .............................................................. 210
Procedure ............................................................................................................. 211

H350 User Guide
Page xi
Full Test Image Print ........................................................................................................ 213
Procedure ............................................................................................................. 214
Cleaning Infrared (IR) Lamps #1, #2, and #3 .................................................................. 217
Preparation ........................................................................................................... 218
Cleaning IR Lamps #1 and #2 .............................................................................. 219
Cleaning IR lamp #3 ............................................................................................. 221
Every 40 Build Cycle Maintenance ............................................................ 224
Cleaning the Extraction Outlet ......................................................................................... 224
Required Tools ..................................................................................................... 224
Procedure ............................................................................................................. 225
Cleaning the Front Sled Guide ........................................................................................ 228
Required Tools ..................................................................................................... 229
Procedure ............................................................................................................. 229
As-Needed Maintenance ........................................................................... 233
Cleaning the Vortex bell and the thermal camera window (lens)..................................... 233
Cleaning the Touchscreen Display .................................................................................. 236
Cleaning Blocked Nozzles on the Printhead Cleaning Module........................................ 237
Additional Areas Requiring Cleaning ............................................................................... 239
Clean the Powder System ............................................................................................... 242
Test Powder Distribution .................................................................................................. 246
Customer Replaceable Units ..................................................................... 249
Replacing Spot Light Bulb ............................................................................................... 249
Required Tools ..................................................................................................... 249
Procedure ............................................................................................................. 250
Replacing the Sled Protection Strips ............................................................................... 250
Required Tools ..................................................................................................... 251
Procedure ............................................................................................................. 251
8 Troubleshooting ........................................................... 256
Getting Help............................................................................................... 256
Fault Codes................................................................................................ 256
Warnings and Errors .................................................................................. 266
FMS Fill pump timeout..................................................................................................... 266

H350 User Guide
Page xii
Background information........................................................................................ 266
9 Supplementary Info...................................................... 268
Declaration of Conformity .......................................................................... 268
Dismantling, Disabling and Scrapping ....................................................... 268
Special Risk Reduction Measures ................................................................................... 268
Personal protective equipment ............................................................................. 268
Sequence or Chronology for Decommissioning .............................................................. 269
Disassembly ......................................................................................................... 269
Disposal, Destruction and Recycling .................................................................... 270
Regulatory and Environmental Information................................................ 270
EMC Class A Warning...................................................................................................... 270
FCC Statements (U.S.A.) ................................................................................................ 271
Canada Electromagnetic compatibility (EMC) ................................................................. 271
Normes de Sécurité (Canada).............................................................................. 271
DOC Statement (Canada) .................................................................................... 271
MSDS (Material Safety Data Sheet) ................................................................................ 271
Disposal of Waste Equipment by Users in Private Households in the European Union.. 272

Intended Use
Page 1
© Copyright 2022 Stratasys. All rights reserved.
1 SERVICE AND SUPPORT
This chapter provides information on service and support for the H350™ SAF™ Selective
Absorption Fusion™ Powered 3D printer as well as safety information and safety label
locations.
Intended Use
Intended use for this printer is 3D printing. The H350 SAF Selective Absorption Fusion
Powered 3D Printer uses two materials to create parts: High Yield Stratasys PA11 powder and
High Absorption Fluid.
Reasonably Misuse
Any actions not complying with the directions contained within this guide will be considered a
way to reasonably misuse the H350 SAF Selective Absorption Fusion Powered 3D Printer.
Objective
The objective fulfilled by this user guide is to ensure the correct use of the printer, including
operation, handling, cleaning, maintenance, dismantling and scrapping.
The user guide is an integral part of the printer, providing the user the required information
needed for correct and safe use.
If changes are made to the printer, the user guide and the risk assessment must be reviewed
and corrected, if necessary.
Reading Instructions
The user guide has been prepared in accordance with the Machinery Directive 2006/42/EC
and EN ISO 20607 – Safety of machinery – Instruction handbook – General drafting principles
and is the manufacturer’s original user guide for the printer.
The user guide provides the user with the information necessary for the safe and efficient use
of the printer during the life cycle of the printer. General safety instructions and conditions are
described in a single chapter.
The instructions are for all users of the printer, where content is subdivided according to the
user's function and use of the printer. Safety-related information and instructions appear at
specific printer related tasks or as general information for all users.

Knowledge
Page 2
© Copyright 2022 Stratasys. All rights reserved.
Knowledge
It is the responsibility of the employer (the printer owner) to ensure that all users who are to
operate, maintain, or disassemble the printer, have read the user guide or at least the parts
relevant to their tasks.
In addition, everyone who has to operate or maintain the printer has a duty to search for all
relevant information in the user guide.
Availability
The user guide must be kept in a place known to the staff, where it is easily accessible to
relevant users.
Symbols Used
Symbols are used to highlight information, references and warnings of hazards during printer
use or when performing specific tasks.
The following symbols are defined:
Symbol Symbol Meaning
Attention
Attention required.
Indicates required action, for establishment of safe working conditions or use.
Reference to documentation
Refer to relevant information in this or other manual or safety data sheet.
Information aimed at operators
Indicates chapters, information, etc. targeted, but not limited, to operators.
Warning:
Indicates a potentially hazardous situation which, if not avoided, may result in
injury or death.
Warnings and Cautions precede the paragraph to which they pertain.
Caution:
Indicates a situation which, if not avoided, could result in damage to equipment.
Warnings and Cautions precede the paragraph to which they pertain.

Nameplate
Page 3
© Copyright 2022 Stratasys. All rights reserved.
Safety markings and pictograms are used to warn and/or inform different user groups. Their
meaning are interpreted as follows:
Nameplate
Abbreviations
Note:
Indicates additional information relative to the current topic.
Notes follow the relative paragraph.
Geometric
Shape Meaning Safety Color
Contrast
Color
Graphical
Symbol Color
Use Case
Example
Warning
signs Yellow Black Black
Symbol Symbol Meaning
Abbreviation Full Name
E-Stop Emergency Stop

User Groups and Qualifications Operator
Page 4
© Copyright 2022 Stratasys. All rights reserved.
User Groups and Qualifications
Users of the printer must identify themselves with a user group. These are divided according to
their user interface and tasks related to the use of the printer throughout the life cycle of the
printer. The information and instructions in the user guide are divided according to user groups,
and are symbolized by the use of symbols, see below.
Operator
Tasks, instructions, etc. addressed to operators are symbolized by:
Operators are people whom:
• Physically use the printer and/or its control system during normal operation.
• Such as operating the printer and its controls.
• Use the printer under management and with the consent of the owner of the printer.
• Are able to make general adjustments, rearrangement, etc.
Operator Requirements and Qualifications
Operators must be trained/instructed in the use of the printer based on the following
requirements:
• Must have read and understood the user guide as well as any attached instructions, safety
instructions, etc.
• Gain knowledge of the printer’s functions and safety conditions. This may be achieved by
employee-by-employee training, or by reading the user guide as well as any attached
instructions, safety instructions, etc.
• Trained and/or instructed in the use, handling, etc. of the printer.
• Gain knowledge of the location of emergency stops and safety equipment.
FMS Fluid Management System
GUI Graphical User Interface
HMI Human-Machine-Interface
HPC Head Personality Card
MD Machinery Directive (2006/42/EC)
XPM Xaar Print Manager
Abbreviation Full Name

Service Operator
Page 5
© Copyright 2022 Stratasys. All rights reserved.
Before starting or servicing the printer, operators must be informed of all installed safety
measures. See “Overview of Printer Safety Functions” (page 11).
Before commencing maintenance work on the printer, maintenance personnel must be
instructed in safety conditions around the printer. An experienced colleague must train new
personnel.
Service
If you have a problem with your printer that is not covered in this guide, please contact
Stratasys Customer Support. Contact information is available from the Stratasys website at:
https://support.stratasys.com/en/contact-us.
When calling in for service, always have your printer’s software version (see “Updating
Controller Software” (page 162)) and hardware serial number available (see “Identifying Your
Printer” (page 18)).
Software Support
If you have a software problem that is not covered in this guide, please contact Stratasys
Customer Support. Contact information is available from the Stratasys website at: https://
support.stratasys.com/en/contact-us.
When calling in for service, always have your printer’s software version (see “Updating
Controller Software” (page 162)) and printer serial number available (see “Identifying Your
Printer” (page 18)).
User Guide Terms
Warning:
Improper maintenance can be dangerous, and in the worst-case lead to death!
Term Definition
Build The completed parts and the used powder which functions as
support material.
Build chamber The area in the printer where the build is created.
Build envelope The available area where the build may be created as
delineated by the H350 build processor software.
Build plate The metal plate which forms the bottom of the build chamber
and descends along the Z-axis during the build process.
Build removal box This is used to remove the completed build from the printer.
H350 build processor The software which slices the parts into layers.

Safety Instructions Hazardous Situations During Intended Use
Page 6
© Copyright 2022 Stratasys. All rights reserved.
Safety Instructions
The printer may only be used as intended. If the printer is used for another purpose or changes
are made to the design, the supplier does not guarantee the safety of the printer
Hazardous Situations During Intended Use
Hot Surfaces
Contact with Fluid
HAF™ high absorption fluid The fluid which is jetted on to the powder surface to enable
fusion of the powder when irradiated by a fusing lamp.
Layer The 100µm layer of powder which is distributed with each pass
of the distribution sled.
Powder retrieval station The machine used to collect used powder.
Virgin powder The fresh, unused powder used by the printer.
Term Definition
Symbols Meaning and Actions
Danger of Hot Surfaces!
During operation, the surfaces of the printer become hot and can cause burns or
discomfort when directly touched.
Exercise care when performing maintenance on or near hot printer surfaces.
If hot surfaces are to be accessed, or work near hot surfaces is required, the
following personal protective equipment must be used:
Wear Heat-Resistant Protective Gloves
Wear heat-resistant protective gloves where it is necessary to handle hot items
or surfaces.
Warning: Eye Contact Hazard
Various printer fluids in the tubes is subject to pressure and is hazardous if it
touches the eyes. Do not continue before putting on protective eyewear and
draining the fluid from the printer.
Warning: Skin Contact Hazard
Various printer fluids can cause skin irritation after prolonged contact. Do not
continue before putting on protective gloves.

Safety Instructions Foreseeable Misuse
Page 7
© Copyright 2022 Stratasys. All rights reserved.
Contact with Powder
Foreseeable Misuse
Safety-Related Guards
Restricted Access
Warning: Inhalation Hazard
Inhalation of airborne particles could result in serious respiratory injury. Do not
continue before putting on a dust mask that complies with local regulations.
Warning: Eye Contact Hazard
HAF in the tubes is subject to pressure and is hazardous if it touches the eyes. Do
not continue before putting on protective eyewear and draining the fluid from the
printer.
Warning: Skin Contact Hazard
HAF can cause skin irritation after prolonged contact. Do not continue before
putting on protective gloves.
Warning: Serious Damage can Occur in Case of Missing or Defective
Guards
Direct contact with the moving parts of the printer can result in serious injury or death
when within the guards of the printer.
The printer is equipped with safety related guards to prevent access to dangerous
areas on the printer. Bypassing, dismantling or neglecting guards can lead to serious
injury or death.
Before starting the printer, the operator must inspect the printer for visible defects that
affect safety during operation.
Warning: Printer Surfaces May Not be Used as Access Ways, as This May
Lead to Falls Resulting in Injury
It is not permitted to use the printer's surfaces as an access path unless designed for
such.
• Do not stand or climb on the printer, etc.
• Do not use the printer's surfaces as storage, workspaces or similar.

Safety Instructions Special Conditions for Different User Groups
Page 8
© Copyright 2022 Stratasys. All rights reserved.
Lack of Training
Special Conditions for Different User Groups
The printer owner may only hand over work on the printer to persons who are familiar with the
basic regulations on occupational safety and accident prevention, and are instructed in the
handling of the printer.
Only trained or instructed personnel may use the printer. Determine staff qualifications and
responsibilities for operation, preparation, maintenance and repair. Regularly check that the
personnel work in a safety and hazard-aware manner in accordance with the instruction
handbook.
Personnel under the age of 18 must not operate the printer.
Residual Risks
The following residual risks have been identified for the printer:
Warning: Lack of Knowledge of the Printer and its Safety Conditions can
Lead to Irreversible Injury
Do not use the printer until you have received the necessary training and instruction
in the use and service of the printer. Uncertainty about the safe and efficient use of
the printer must not occur.
Suppliers of components may make stricter requirements, for age and qualifications.
Symbols Meaning and Actions
Danger of Electric Shock!
The printer contains dangerous voltage levels. Contact with dangerous voltages
can result in serious injury or death.
1. Disconnect the supply through the supply disconnecting device.
2. Verify that the printer is in a de-energized state before starting maintenance.
3. Electrical related work may only be carried out by a trained expert or
instructed person.
Danger of Hot Surfaces!
Contact with hot surfaces can cause burns or discomfort when touched directly.
1. Power down the printer.
2. Wait until the hot surfaces of the printer have cooled below 60°C, or use
protective gloves.