3D printing with PETG filament can produce strong, glossy parts with good chemical resistance. However, getting the best results requires dialing in the right settings – especially the heated print bed temperature. An optimal bed temp helps PETG parts stick during printing and prevents warping or splitting.
So what is the perfect bed temperature for PETG 3D printing? Most sources recommend 70-90°C for the heated print bed when using PETG filament. Lower temperatures around 60-70°C may also work if printing smaller parts with good initial adhesion. Higher bed temps above 90°C can improve adhesion but increase the risk of oozing or other defects.
In this comprehensive guide, we’ll explain the basics of 3D printing with PETG and discuss optimal bed temperature settings. You’ll learn PETG’s characteristics, how bed temperature affects print quality, troubleshooting adhesion issues, and top tips for success. With the right bed temp dialed in, you can get great results with this versatile and durable printing material.
An Introduction to PETG 3D Printing Filament
PETG is a popular filament choice for fused deposition modeling (FDM) 3D printing. The material has several advantages:
- Strength – PETG is durable and impact-resistant. Printed parts are tougher than PLA.
- Temperature resistance – PETG can withstand temperatures up to 70-80°C. It holds up better than PLA in hot environments.
- Chemical resistance – PETG has good resistance to many household chemicals and won’t degrade as quickly as other materials.
- UV stability – PETG maintains color and mechanical properties when exposed to sunlight. It won’t become brittle like PLA.
- Easy to print – PETG extrudes smoothly and has good layer adhesion. Minimal warping or splitting compared to other materials.
PETG does have some drawbacks. It’s more prone to stringing than PLA, can be brittle when thin, and has a glossy surface finish that shows layer lines clearly. Still, with the right print settings dialed in, PETG’s advantages make it a top choice for functional parts and prototypes.
How Heated Bed Temperature Affects PETG Printing
The heated print bed temperature is one of the most crucial settings for success with PETG 3D printing. PETG can be sensitive to temperature changes. The bed temperature affects:
- Adhesion – Heated beds improve adhesion during printing so the first layer sticks and parts don’t detach. PETG beds need 60-90°C for good stick.
- Warping – Higher temperatures reduce warping and splitting by keeping the part evenly heated as layers are deposited.
- Accuracy – Consistent temperatures limit shrinkage and deformation that alter dimensions.
- Surface finish – The right temp smooths out bubbles and layer transitions for better looking prints.
- Low bed temps can reduce adhesion, while excessive heat causes oozing, stringing and other defects. Finding the optimal balance is key.
Recommended Heated Bed Temperatures for PETG
Most PETG filament manufacturers recommend a heated bed temperature of 70-90°C for optimal print adhesion and to limit warping. However, acceptable results can be achieved from 60-100°C depending on other factors:
- Smaller parts – Prints with a small surface area touching the bed can stick at lower temps of 60-70°C.
- Larger parts – Larger surface area needing more adhesion does better at 80-90°C.
- Enclosures – Enclosed printers hold heat better so can use lower bed temps.
- Drafts – Open printers exposed to cool air drafts need higher temps up to 100°C.
- Bed material – Non-stick surfaces like PEI allow good adhesion at lower temps around 70°C.
- First layer height – Thicker first layers up to 0.3mm help with 60-70°C beds.
Start with a bed temperature of 80°C, then adjust in 5-10 degree increments to find the best results. Also make sure your bed can safely reach and maintain higher PETG temperatures.
Bed Leveling and Initial Layer Settings
An evenly leveled, well-trammed print bed helps parts stick regardless of print material. Here are some first layer tips:
- Level with a heated bed – PETG can soften and distort when hot, so always level when heated to printing temperature.
- Use a raft – A raft acts as an interface between the part and bed to improve bottom surface quality. Useful for delicate PETG parts.
- Thicker first layer – Increase initial layer height to 0.3mm for better squish and adhesion to the bed.
- Slower first layer – 30mm/s or less gives heated PETG more time to bond to the bed before hardening.
- Closer nozzle – A 0.2mm first layer nozzle gap smears the PETG more, improving stick.
Take the time to get leveling and first layer settings dialed in. It will pay off with better bottom finishes and prevent popped-off parts.
Bed Surfaces for PETG 3D Printing
The build platform surface material impacts PETG’s bed adhesion. Here are some popular options:
- PEI sheets – PEI provides excellent PETG adhesion at lower bed temperatures around 70°C. It’s durable and can withstand repeated hot removals.
- BuildTak – PETG sticks well to textured BuildTak surfaces. Its foam construction helps moderate print temperatures.
- Glass – With the right temps and glue stick, plain glass can work. Borosilicate glass handles repeated heating better than standard glass.
- Flexible steel sheets – Spring steel sheets with PEI or powder coating work well. The flexibility helps release large PETG parts after printing.
Avoid ABS/PVC sheets, as PETG can bond too strongly to these plastics. Kapton tape also does not adhere well to PETG without gluestick orBLue tape helps but can leave residue.
Troubleshooting PETG Not Sticking to the Bed
Even with optimal settings, PETG may still not adhere well to the print bed. Here are some common solutions:
Increase bed temperature – Try 85-90°C if small parts aren’t sticking at 70°C. Higher temperatures provide better adhesion.
Use glue stick – A thin glue stick coating gives extra stick, especially on bare glass. Apply evenly and recoat for each print.
Rough up smooth PEI – Smooth PEI can repel PETG plastic. Lightly sanding it with fine grit paper improves grip.
Lower fan speeds – High cooling fans can rapidly cool and warp PETG edges before fusing to the bed. Slow them down for better adhesion.
Switch surface material – Glass, Garolite, Kapton may not grip well. Try PEI for the best PETG stick.
Clean the bed – Dust, oils and contaminants reduce adhesion. Clean with isopropyl alcohol between prints.
If these tips don’t resolve sticking issues, try a brim or raft to increase surface contact. Slowing print speeds can also help.
Signs of Excessive Heated Bed Temperatures
While heating the bed improves PETG sticking, too high of a temperature causes other print defects:
- Oozing and stringing – Hotter beds increase PETG oozing, creating messy strings and blobs.
- Elephant’s foot – Base layers squish out with high bed heat, causing elephants foot bulge.
- Warping and detachment – Parts can release or deform due to uneven shrinking forces at extreme temps.
- Discoloration – High heat degrades PETG over time, causing yellowing.
Start with a standard PETG bed temperature, then increase only as needed for adhesion. Exceeding 90°C risks more issues than it resolves. Slow parts cooling can also reduce oozing and bottom bulging.
Cooling Fan Settings for Optimal PETG Prints
In addition to bed temperatures, cooling fans hugely influence PETG print results. PETG needs gentler cooling than PLA:
- Lower speeds – 30-50% fan speeds are recommended. High airflow can warp PETG layers before fusing.
- Later start – Delay fan activation until after the first few layers for better adhesion.
- No cooling for small layers – Disable fans for the first 0.2mm of height to avoid cracking thin areas.
- Gyroid infill – Gyroid infill patterns minimize wispy strands that are vulnerable to overcooling.
- Slower print speeds – Reduced speeds give layers more time to harden before the next one deposits.
With the right balance of cooling, PETG overhangs and bridges print cleanly without sagging. Slow things down to prevent layer shrinkage and splitting.
Enclosures for Draft-Free PETG Printing
PETG can be sensitive to ambient temperature fluctuations that cause uneven cooling and warping. Printing in an enclosure helps:
- Acrylic or plastic – DIY enclosures keep ambient temps stable. Plastic filters UV better than glass.
- Heated chamber – An actively heated chamber minimizes cooling gradients even better.
- Insulation – Insulating the printer with ceramic fiberboard helps maintain chamber heat.
- Electronics outside – Locate control boards outside heated chambers to prevent electronics damage.
Enclosures allow lower bed temps of 60-70°C while retaining excellent adhesion. They also reduce stringing, allow faster cooling, and produce clearer prints.
PETG Bed Temperature Troubleshooting Guide
Use this handy PETG bed temperature troubleshooting guide to identify and resolve common issues:
| Problem | Potential Causes | Solutions |
|---|---|---|
| Parts not sticking to bed | Bed level too low Cooling fans too high | Re-level bed Increase bed temp Reduce fan speeds |
| Elephant’s foot | Bed temp too high First layer too squished | Lower bed temp Raise nozzle, lower layer height |
| Oozing and stringing | Too high bed temp | Reduce bed temp to 70-80°C |
| Warping and cracking | Uneven cooling Low bed temp | Use enclosure Increase bed temp |
| Weak thin-walled parts | Fast cooling of thin sections | Slow print speed, reduce fan speed |
| PETG degrading over time | High heated bed | Lower bed temp, or use Borosilicate glass |
PETG Bed Temperature – The Key Points
PETG 3D printing produces great looking and functional prints when you dial in the right settings. Getting the heated bed temperature correct is crucial for this filament. Here are the key takeaways:
- Use 70-90°C heated bed temps for optimal PETG adhesion and to prevent warping.
- Small parts may stick at 60-70°C. Larger prints need 80-90°C for proper adhesion.
- Level the bed when hot and use thicker first layers for maximum stick.
- PEI, BuildTak, and glass offer the best PETG bed adhesion.
- Increase bed temps incrementally if parts aren’t sticking enough.
- Avoid excessive temps over 90°C that risk oozing, elephant’s foot, and yellowing.
- Enclose the printer and reduce fan speeds to prevent uneven cooling and layer splitting.
With the right heated bed temperature dialed in, PETG is an easy-to-print filament that produces strong and durable prints perfect for functional parts. Use this guide to get your bed pre-heating at just the right temp for PETG success.
