DIY high soulder CNC with cad model.
24 Jun 2021 06:16 #212784
by oficinerobotica
DIY high soulder CNC with cad model. was created by oficinerobotica
Hi to all, how's it going?
This is my first post here on the forum, I'm still a total noob regarding both LinuxCNC and cnc in general so please be patient with me. I'm slowly getting there. By looking at some forum posts around here I'm feeling like a dwarf in the middle of titans.
Anyway, to the point. As I'm kind of involved with the FreeCAD developers and community, this project was started as a test bench file for the modelling and assembly capabilities of the cad software. (for credibility points, the hexapod model on the splash screen of version 0.19 is one of my models).
Some screenshots of the cad model inside freecad
Allot of the design decisions for this machine were driven by cost. I tried to get the best bang for the buck pretty much everywhere as this is a hobby project. Some design and material choices will make the hair rise on people around here that work with micron tolerances. My excuse is that I still have to buy a proper micrometer. It is all a learning experience.
The frame is out of 50x50 or 50x100 aluminum extrusion that I was lucky enough to recover from some dismissed industrial machines. The aluminum extrusions were reinforced with 5mm cold rolled steel bolted to the frame. These reinforcements were cuted and driled by hand with allot sweat and tears. None the less I think they came out pretty good.
After learning that cold rolled steel is tough to work with by hand I decided to laser cut some of the components that were missing.
And this is the X axis after a bit of work
This is my first post here on the forum, I'm still a total noob regarding both LinuxCNC and cnc in general so please be patient with me. I'm slowly getting there. By looking at some forum posts around here I'm feeling like a dwarf in the middle of titans.
Anyway, to the point. As I'm kind of involved with the FreeCAD developers and community, this project was started as a test bench file for the modelling and assembly capabilities of the cad software. (for credibility points, the hexapod model on the splash screen of version 0.19 is one of my models).
Some screenshots of the cad model inside freecad
Allot of the design decisions for this machine were driven by cost. I tried to get the best bang for the buck pretty much everywhere as this is a hobby project. Some design and material choices will make the hair rise on people around here that work with micron tolerances. My excuse is that I still have to buy a proper micrometer. It is all a learning experience.
The frame is out of 50x50 or 50x100 aluminum extrusion that I was lucky enough to recover from some dismissed industrial machines. The aluminum extrusions were reinforced with 5mm cold rolled steel bolted to the frame. These reinforcements were cuted and driled by hand with allot sweat and tears. None the less I think they came out pretty good.
After learning that cold rolled steel is tough to work with by hand I decided to laser cut some of the components that were missing.
And this is the X axis after a bit of work
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24 Jun 2021 06:49 #212786
by oficinerobotica
The machine electronics choice is Mesa7i96 Etherenet card coupled with cheapo closed loop nema 23 steppers from AliExpress (they seem to work allot better than expected tough). I had a really hard time wiring them because I NEED TO PAY ATTENTION TO WHAT I AM DOING. While testing the first motor and after loosing countless hours on the internets thinking I have wired wrong the mesa card or the encoders I realized that i have inverted one of the coils wires. These motors are pretty much plug and play. With that solved i went ahead and wired the tandem Y axis too
As previously stated, allot of the design decisions for this machine were driven by cost. One of those decisions was to use trapezoidal screws instead of higher quality ball screws. The design is made so that thees can be added at a later time.
Now for the problem: the trapezoidal screws are not strait. It seems they arrived curved and this is a HUGE problem. Now I don't want to wait for another set of screws and I'm pretty sure that misalignments, wrong design choices or wrong parts will happen again in the future. If the build doesn't continue I will never know where the problems are.
The intention is to buy precision ball screws at a later moment and modify the machine accordingly. Lukly that will be easily done but at the moment I decided it is time to spend no more money on this type of motion and to self fabricate the trapezoidal nuts in Teflon.
Replied by oficinerobotica on topic DIY high soulder CNC with cad model.
The machine electronics choice is Mesa7i96 Etherenet card coupled with cheapo closed loop nema 23 steppers from AliExpress (they seem to work allot better than expected tough). I had a really hard time wiring them because I NEED TO PAY ATTENTION TO WHAT I AM DOING. While testing the first motor and after loosing countless hours on the internets thinking I have wired wrong the mesa card or the encoders I realized that i have inverted one of the coils wires. These motors are pretty much plug and play. With that solved i went ahead and wired the tandem Y axis too
As previously stated, allot of the design decisions for this machine were driven by cost. One of those decisions was to use trapezoidal screws instead of higher quality ball screws. The design is made so that thees can be added at a later time.
Now for the problem: the trapezoidal screws are not strait. It seems they arrived curved and this is a HUGE problem. Now I don't want to wait for another set of screws and I'm pretty sure that misalignments, wrong design choices or wrong parts will happen again in the future. If the build doesn't continue I will never know where the problems are.
The intention is to buy precision ball screws at a later moment and modify the machine accordingly. Lukly that will be easily done but at the moment I decided it is time to spend no more money on this type of motion and to self fabricate the trapezoidal nuts in Teflon.
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24 Jun 2021 08:00 - 24 Jun 2021 09:31 #212793
by oficinerobotica
With the awareness that I will need to swap the motion with higher quality screws , I fabricated my self some teflon bearing holders in order to finally see some motion.
And low and behold we have motion. This is where my LinuxCNC adventure is starting.
Motor test video link
X axis motion video link
Now for the cad model. I will create a GitHUB repo where all the files will be uploaded and updated based on the modifications done down the road. As this project was spawned from the FreeCAD development road , there is a series of tutorials on how to model the thing and this is the first part:
CNC FreeCAD tutorial video link
Of course, all the files will be under a CC license, all in the spirit of open source.
Replied by oficinerobotica on topic DIY high soulder CNC with cad model.
With the awareness that I will need to swap the motion with higher quality screws , I fabricated my self some teflon bearing holders in order to finally see some motion.
And low and behold we have motion. This is where my LinuxCNC adventure is starting.
Motor test video link
X axis motion video link
Now for the cad model. I will create a GitHUB repo where all the files will be uploaded and updated based on the modifications done down the road. As this project was spawned from the FreeCAD development road , there is a series of tutorials on how to model the thing and this is the first part:
CNC FreeCAD tutorial video link
Of course, all the files will be under a CC license, all in the spirit of open source.
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