Re: My coreXY design is progressing to the build stage October 31, 2017 03:06PM |
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Re: My coreXY design is progressing to the build stage October 31, 2017 04:34PM |
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Re: My coreXY design is progressing to the build stage October 31, 2017 05:31PM |
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Re: My coreXY design is progressing to the build stage October 31, 2017 06:35PM |
Registered: 12 years ago Posts: 5,796 |
Re: My coreXY design is progressing to the build stage November 02, 2017 09:31PM |
Registered: 12 years ago Posts: 5,796 |
Re: My coreXY design is progressing to the build stage November 04, 2017 10:54PM |
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Re: My coreXY design is progressing to the build stage January 03, 2018 09:57AM |
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Re: My coreXY design is progressing to the build stage January 03, 2018 12:31PM |
Registered: 9 years ago Posts: 338 |
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the_digital_dentist
On a slightly different subject, I recently pulled a CPAP machine from the hack-rack at the makerspace. I disassembled it and pulled the blower out of it. It's about 90mm in diameter, and has a 20k rpm (max), 3 phase BLDC motor. I also recently had some PCBs made for the MCP8063 3 phase BLDC motor driver chip with PWM input. I'll be testing the blower as a print cooling fan in UMMD once I get a couple of the PCBs assembled.
The blower is sort of interesting- it has a nearly flat impeller that takes air in at it's center and flings it out along its periphery. It's in an enclosure that directs all that air flow out a single, round port that a CPAP hose fits over. The hose is very flexible and light weight, so the plan is to mount the blower on top of the printer and run the hose to the extruder carriage with a nozzle to blow on the print.
Re: My coreXY design is progressing to the build stage January 03, 2018 01:38PM |
Registered: 12 years ago Posts: 5,796 |
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NathanaelXYZ
@DigitalDentist,
Apologies if this is a silly question, but is differential thermal expansion between steel linear rails and the aluminum they are bolted to a concern? It seems to me that the higher expansion of the aluminum could put stress on the rails in a way that tends to make them bow concavely. Though perhaps this effect is too slight to cause any significant deflection.
Re: My coreXY design is progressing to the build stage January 03, 2018 02:23PM |
Registered: 12 years ago Posts: 5,796 |
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Qdeathstar
Did this work out? I'm not happy with my current design and the berdair is sort of fussy for me, I always gotta play with those small metal tubes...
Re: My coreXY design is progressing to the build stage January 03, 2018 11:16PM |
Registered: 12 years ago Posts: 5,796 |
Re: My coreXY design is progressing to the build stage January 05, 2018 11:35PM |
Registered: 12 years ago Posts: 5,796 |
Re: My coreXY design is progressing to the build stage January 07, 2018 01:34PM |
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Re: My coreXY design is progressing to the build stage January 07, 2018 02:16PM |
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Re: My coreXY design is progressing to the build stage January 09, 2018 01:04PM |
Registered: 9 years ago Posts: 338 |
Re: My coreXY design is progressing to the build stage January 09, 2018 01:57PM |
Registered: 12 years ago Posts: 5,796 |
Re: My coreXY design is progressing to the build stage January 10, 2018 06:26PM |
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Re: My coreXY design is progressing to the build stage January 10, 2018 07:02PM |
Registered: 12 years ago Posts: 5,796 |
Re: My coreXY design is progressing to the build stage January 12, 2018 01:30PM |
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Re: My coreXY design is progressing to the build stage January 14, 2018 08:12AM |
Registered: 7 years ago Posts: 128 |
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the_digital_dentist
Z axis redesign recap:
The Z axis started with a NEMA-23 motor directly driving the Z axis motion, but then the problem of bed-drop became very apparent, so I replaced the direct drive motor with a 30:1 Rino worm gear reducer this way:
Though it looks symmetrical, the path to the motor from each of the belt clamps on the bed support cross-bar are actually quite different. Testing indicated that it should perform just fine, but the asymmetry bothered me, so I redesigned to this:
I ordered a longer shaft for the worm gear reducer and a pair of 34 tooth pulleys and pillow blocks. I remade the Rino mount- much easier this way- just a couple small plates with a few relatively small holes. The switch with the roller on the lower left is the Z max limit switch- I couldn't find another one of the tiny ones in my junk box.
I'm waiting for a few parts to arrive then I'll drill the mounting holes for the pillow blocks and move the top pulleys into position. The printed parts will be done in the next day or so and ready to drop in the moment the rest of the stuff arrives.
Re: My coreXY design is progressing to the build stage January 14, 2018 09:08AM |
Registered: 12 years ago Posts: 5,796 |
Re: My coreXY design is progressing to the build stage January 14, 2018 09:30PM |
Registered: 12 years ago Posts: 5,796 |
Re: My coreXY design is progressing to the build stage January 15, 2018 03:37AM |
Registered: 9 years ago Posts: 5,232 |
Re: My coreXY design is progressing to the build stage January 15, 2018 05:45AM |
Registered: 9 years ago Posts: 601 |
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o_lampe
I'm a bit confused about the enclosure heater thing in general:
Say your enclosure is heated up by the print bed only. The environment temp would climb up to a certain level. It will reach this peak, because the bed heater will heat less and less, the higher the environment temp is.
Now you want to raise the environment temp even more, say +20°C. Wouldn't that in turn mess up the constant bed temperature we need?
IMHO, we'd have to set the priority to constant bed temp. How much higher can we heat up the enclosure without ruining the bed-temp PID settings?
Re: My coreXY design is progressing to the build stage January 15, 2018 10:10AM |
Registered: 12 years ago Posts: 5,796 |
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o_lampe
I'm a bit confused about the enclosure heater thing in general:
Say your enclosure is heated up by the print bed only. The environment temp would climb up to a certain level. It will reach this peak, because the bed heater will heat less and less, the higher the environment temp is.
Now you want to raise the environment temp even more, say +20°C. Wouldn't that in turn mess up the constant bed temperature we need?
IMHO, we'd have to set the priority to constant bed temp. How much higher can we heat up the enclosure without ruining the bed-temp PID settings?
Re: My coreXY design is progressing to the build stage January 16, 2018 04:11AM |
Registered: 9 years ago Posts: 5,232 |
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I think the root of your question is really "how good does the bed temperature regulation have to be?" If I run the bed's autotune in a room temperature environment and then heat the chamber will it cause the regulation to "fail"? I haven't tried running PID autotune on the bed with the warm enclosure. It seems to be working fine anyway, based on the temperatures I see reported by the controller board.
Re: My coreXY design is progressing to the build stage January 16, 2018 09:32AM |
Registered: 11 years ago Posts: 14,685 |
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o_lampe
Yes, I guess that was the reason of concern. I read horror stories about how bad a bed heater is in bang-bang mode, so I thought bed temp would be critical.
Re: My coreXY design is progressing to the build stage January 16, 2018 09:52AM |
Registered: 12 years ago Posts: 5,796 |
Re: My coreXY design is progressing to the build stage January 16, 2018 03:51PM |
Registered: 11 years ago Posts: 14,685 |
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the_digital_dentist
Do you think a total 1/2C variation in extruder temperature is going to cause a noticeable change in the print, especially something as pronounced as Z-banding?
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the_digital_dentist
I have run temperature tower prints on different filaments in 5C extruder temperature steps and it can be hard to see differences between adjacent temperature bands in the prints.
Re: My coreXY design is progressing to the build stage January 21, 2018 11:51PM |
Registered: 13 years ago Posts: 27 |