Heated chamber? Why?
Some may ask why a heated chamber. I have my reasons, one being that I like to print large objects in ABS and I like how you can process ABS with acetone and use ABS goop (Acetone/ABS mix) as a glue if necessary.
The second reason is purely as an engineering practice. I like a challenge.
- Heat the chamber duh!
- NO PLA parts whatsoever they will deform in these temperatures. ABS parts are necessary here or even metal parts if you can find them.
- A large power domain, I could have gone simple with a 120v bulb as a heat source and called it a day. Would have cost me ~$5USD tops. I did not want to do this as I do not like mains power inside my printer. I use a server PSU rated in the ~1300W range for a reason.
- A real thermostat with finite control is a good thing to have.
- One automotive ceramic heater with built in blower. (get ceramic heaters as the cheaper stuff is a fire hazard, they use elements like hair dryers)
- Wiring, plan on replacing the ceramic heater wires with heavier gauge wires for efficiency sake as well as reducing the fire risk.
- Insulation, I cannot stress this enough. Hindsight being 2020 I could have done a better job with insulation. Plan on at least a 10mm or ½ foam with aluminum foil cover for this.
Do not underestimate the power used.
- The whole reason I am writing this post is because someone on the forum was asking about heated chambers. They underestimate the power used by these 3d printers once they are built.
- Quick math shows my printer uses 400w/hour while running with a peak power consumption in the 500W range. This is out of socket measurement. The result figuring in 8 hours a day working is 3.2kw/hours. Figure in 360 days of use and you have 1152kw/hours to pay for. My rates are in the $0.19 range with delivery charges being in the $0.24 range. This printer will consume $495.36 worth of power in a year estimating only running it for 8 hours a day average. This is staggering, the better you insulate the lower the w/h average will be.
Experience is critical
- The printer will need some tweaking to get it to run right under heated chamber conditions.
- 40c range is fine for smaller than 100mm cubed objects.
- No heated chamber is necessary when you run smaller than 50mm cubed objects.
- 55c seems to be the sweet spot for larger objects 150mm+
- You can use ambient printer air to cool the hot end, no need for external air.
- Ideally you add a mixing fan to the printer to reduce the temperature gradient.
- Let the heated chamber stay for 5-10min after the print is done.
- Let cool 10 min at least before removing objects.
- A filter on a blower fan to act as an evacuation fan is good but not necessary.
- A nice door with as few leaks as possible is essential.
Depends on your view point. For me it’s worth every penny and more. My horn speakers came out beautifully with a heated chamber. I could even back down on the nozzle temp without reducing bonding and increasing surface finish.
I can only think of two downsides.
- Engineering a proper solution takes time - Power consumption went up by 30% on my machine. $$$$