What stepper motor to use in heated chamber
I want to build a 3D printer with a heating chamber of around 90 °C with build area 200x200x200 mm. I have never build a CoreXY system, so my design is currently an XY system with moving X motor (mounted on Y). Since it has a heating chamber I can't use normal stepper motor (there's a way, but I have to provide forced air cooling like NASA did, or water cooling). Extruder is Bowden type. I have already sourced almost all components, but I'm stuck at choosing the motor.
I could find high temperature stepper motor in India (that's where I'm from), but it cost too much. I found one at the Visionminer website, they're the dealers for Intamsys printers, which has a chamber of 90 °C and they are providing replacement stepper motors as well.
Comparing the cost, the motor I found in India costs three times as above. Even with shipping I will save a lot. But one issue is they're not providing any details about torque and current rating. There's one image in the website and it says,
MOONS STEPPING MOTOR
I thought it might be a MOONS motor, so I contacted them, no reply so far. I tried to find the motor by part number, but failed. I tried mailing Visionminer as well.
Anyone have any idea which motor is this? or know any high temperature motors?
Also they use Gates belts, which is rated for 85 °C. How reliable will it be in 90 °C chamber?
Could you not place the motor outside the heated chamber, since it is a bowden setup?
@Mick, I can place the extruder motor outside. But what about X & Y? I will have to then consider CoreXY setup, and read it's is not very forgiving it terms of belt tension . Even with coreXY, I don't understand how to avoid motor getting affected by heater temperature
@FernandoBaltazar But normal motors only work at 50-60 degrees right? I want mine to work at 90 Degree max
The maximum temperature is 80°C but adding a cooler you can have it working below this value. Normally this can be achieved with a fan, just like cooling a CPU or an engine.
Watercooling is really easy, I would consider it. Get a GPU cooling block 40x40 mm and stick it to the SIDE of the stepper (not the rear) with double-sided heat conductive silicon tape (0.5 mm thickness), and put a zip tie for extra adhesion and tighten it well. Get an acquarium pump. Done. Also, don't forget that PVC wiring is rated up to 85 °C, so you cannot get above that unless you replace the wiring.
"Since it has a heating chamber I can't use normal stepper motor" Sure you can, the interior doesn't get all that warm unless you really seal it up tight, and that's not really needed. I have an enclosure around my 200x200x200 mm MIGBOT (early Prusa clone with direct drive extruder), printing PLA with 60 °C bed, the interior only gets a few degrees warmer. The motors can take a lot more heat than you think they can.
I have a couple pictures in this thread.
The front & back panels are 18x24 inch polycarbonate from Home Depot, I 3D printed the corner brackets, and added a couple of pieces of wood for some stiffness. The entire front hinges up. The top is 24x24 inch, and the back 6" hinges up to access the SD card that is on the display/control panel.
But what I'm trying to print is PEEK, and it requires around 80-90 Degree chamber, and most stepper motors are rated for an ambient temperature of 50 Degrees. And I'm really planning to seal the chamber using SS sheet. It's going to be something like Intamsys funmat HT. What is th biggest print, I mean duration that you run your printer at 60 Degrees??
The heating bed won`t over heat the chamber, normally the prints are 50-60°C for PLA and 80-90°C for ABS; but if you want to climate the chamber is a good idea but cool the motors with some fans or circulating water. I think this is cheaper that special motors. For the extruder I think will be a hard task since is the moving part, so the extruder need to be a remote extrusion driver. Or you need to change your chamber desing.
An alternative to finding steppers that can withstand the heat, you can consider not getting the heat near the steppers:
- Moving the steppers outside the heated build volume
With 2 extra pulleys per stepper you can get the steppers outside the build volume.
- Shield the motors from the heat by placing them in a cooler tunnel or behind a face plate/cover
You can also shield the steppers from the heat, e.g. the Ultimaker 3(E) the steppers are behind a cover.
Be aware that creating a 90 °C heat chamber, all the printed parts for the CoreXY need to be printed in a filament type that can withstand prolonged exposure to the temperature you want the chamber to be (or be made in metal). For the mentioned temperature this implies the use of some more exotic filament types, see e.g. this answer.
- Moving the steppers outside the heated build volume
Two things matter for the stepper motor: the insulation temperature and the Curie point of the magnet.
You probably aren't near the Curie point.
The critical temperature is the sum of the ambient plus the temperature rise from the drive power. In your case, I would try mounting the motor to a water cooled metal cold plate. Bring the lower temperature to the motor. Mount the full face of the motor to the plate with thermal compound.
Use a tiny pump to move water from a reservoir through the cold plate. For an example, check out the E3D Kracken.
It is possible to buy cheap high temperature steppers. E.g., you can buy LDO 180 °C winding steppers.
They can be used up to 135 °C without additional cooling and with reduced lifetime probably even higher.
You don't need to worry about the stepper for heating chamber since the direct drive uses a fan for cooling the motor area.
When I started to make my own printer I had the same question but in order to make me feel good and peace. I prefer to use a bowder extruder.
This bowden extruder comes in different sizes: Normal as picture shows above, small, and mini like the other that shows pre assembled below.
However the question should be different like, Can I print inside an oven? for this will address the question to other possibilities:
1.- Cover or shield the motor with some foil to avoid the heating
2.- Add a water cooling like CPU, so the water flows from outside to the motor to keep a low temperature.
3.- Add cooling fans, this ones should take te air from outside and tha air can be directed with a corrugated tube for the Extruder motor and the radiator. For the X, Y and Z motors can be a rigid tube.
This cooling fans won't affect the internal chamber temperature due the cooling process is punctual.
4.- Many electronics components are designed to work at 105°, so won't be affected in short terms, however the life of circutry will decrease a lot, since designs cover until 5 years at normal conditions so your printer can last up to 1.5 years.
I don't see a real reason to keep the printer isolated to high temperatures while the porpuse of this is to keep temperature variations from clime like winter and summer. In my case the print room has a normal temperature of 38°C on summers and -2°C on winter, so how can I print with the same quality on winter if the printer is so cold? ah, I need a chamber to keep that temperature of summer. then I made the chamber to acheive 38°C not the whole temperature of the bed print.
If I need to print ABS so I set the bed temperature to 80°C so the parts won´t get warped, due the temperature for adhesive for ABS is the correct; also this temperature won´t over heat the chamber at least near to 60°C, but can it be reduced extracting the heat with other fan. For this case is just only one or two fans.
The Idea to have the whole printer inside an oven will help to keep that 80°-95°C under control is good, but some times is hard to implement it due materials and its purposes are different and serviseable life will be too low.
So your chamber should include the printing area only or follow the recommendation as the picture above. Those photo was taken from the site industrial RepRap and also exposes som e features as i'm suggesting.
My extruder is bowden, same as you've shown E3D V6, with updated high temp parts. Plated Cu heater block + Nozzle, High temp heating coil and Thermocouple. Buy In my desigh X xis motor is moving one. I mean it's mounted on Y Similar to this image So it will be inside the chamber and I have to cool it somehow or looks for high temp motor
you need only a fan like the first image, no matter if your extruder are mounted on verticar or horizontal in the carrier. if you need extra cooling you can add a fan on th back of the stepper; I install this fans on Z axis when I have to print more than 36hrs because the motors can over heat. My local temperature is around 38°C and some times are near to 42°C in the print room.
I can add a fan to cool stepper motor and I have done that. In normal case it would work, but in a closed chamber the air is as hot as 90 degree. Even if I put a fan inside, it will blow this hot air in to the motor. I need atleast air as cool as atmospheric air
You understand that all of that equipment is going inside the heated chamber right?
I'm just going to come straight out and say it. If you can't design and build a Core XY system then you should not even attempt a heated build chamber.
The Stratasys 3D printers that have heated chambers use a H-Bot design (the predecessor of CoreXY), so as to keep everything out of the chamber. You can't use a regular hot end. You can't have fans on that hot end to keep it cool. You can't have the motors inside the chamber. You can barely have the filament in the chamber because it could get soft inside the tube.
Some of the answers state that motors can operate at high temps already. That is only true in ambient conditions. The heat that the coils of the motor generate is trying to escape to the outside of the motor. It it much hotter inside! Therefore if you raise the external environment's temp to 90 then the heat won't escape as quickly; and if it raises beyond the melt/burn temp then the motor will fail.
After that fails the PVC coating on the lead wires will fail, usually resorting in a short, which could destroy the stepper drivers.
Additionally, everything made of metal will expand. The ball bearings will expand, the rails will expand and the hot end will expand. The linear system could become tighter or looser; it could even warp depending on the type of steel. If it becomes looser, then there goes your ability to 3D print! You might end up needing to design and fabricate your parts so that they fit and work properly only when they are at the working temp.
EDIT: Here is what you need to build:
HIWIN linear guideways are capable of operating up 100 Degree Celsius with out reduction in life. There are wires whose temperature rating is 110 Degee or more, even the normal stepper motor cable tubing is rated 110 Degree Celsius. Stratasys has patent on it's build chamber design that's why no one else is using heat barrier as they are doing. Google Intamsys Funmat HT, perfect example hotend, fan, and motor inside the chamber. Depending on the filament I can turn the chamber heater ON or OFF or reduce temp
Then you need to add water cooling system for them.
Something like this:
Also, water cooled hotend would be a go ahead I guess.
Do you realize that water cooled hotends are very heavy in comparison and introduce a lot of torque on the print head by the flow of water?