First, big thanks to @raess and others for undertaking this.
Before I add my experience and thoughts here couple of things I have to mention:
- I have "original"/"experimental" chassis from the shop and used the robot for one season already. Had some minor issues and repairs here and there, but in the end of the day it served the whole summer well
- I am fairly new to 3D printing. I got my CR-10 maybe 2 months ago.
- I have no experience in Fusion360 or anything like that
- I don't expect things to go smooth both because of my lack of experience in the subject and understanding that this is still ongoing project.
So, here it goes.
I've decided to give it a try and print the robot parts. There are couple of reasons why I like it:
- Rear wheel drive (there are some places in my lawn near the trees, where front wheeler can get stuck)
- Possibility to have 2 mower discs (single one just barely manages to maintain lawn running 2 x 3.5 hours / day for ~1000m^2 of grass).
- nice looks (why not
)
For printing I'm using Cura as slicer, PETG, micro-swiss full metal 0.6mm nozzle, 1.2mm walls (will try 1.8 for wheels), 20-50% octet infill
So far, I've got:
- Motor boxes and lids,
- mower boxes, holders and covers,
- chassis mounts
- battery box
- alu mounts
- PCB cover front and back
- Parts 4 and 11 (the frame for PCB box(?), which is not yet available in Thingiverse yet?)
- Part 3 (display holder on the back) and wheel arch (was part 1, but now gone from thingiverse, replaced by wheel parts)
As someone already mentioned, the wheel arch doesn't look sturdy enough and I broke it easily by trying to remove support material (it is somewhat harder to do that on with PETG).
Basically the area that holds wheel arch is ~35x7mm. Printing with 1.2mm shell is definitely not enough.
If the arch would connect to horinzontal plane throughout all length, it probably would be ok, as there wouldn't be much flex left.
I couldn't figure out reasonable way to print screen holder, because there will be supports necessary in places, where it is hard to remove then in case of PETG.
Trying to attach wheel arch to the screen holder didn't ended well either. I suspect that either the clearance is "just enough" and/or the support material (I printed it horizontally, thus support material had to fill the gap) wasn't removed to the extent required (I've tried my best) and natural PETG flex was not enough to handle.
Basically, I had problems sticking the parts together and then broke the display mount :|
Motor boxes print well without any supports. And connect using 36.5mm 2020 alu extrusion with 4 M4 bolts with T nuts and 3 additional M4 bolts with nuts.
2020 Alu extrusion mounts attach to the motor boxes with M4 bolts and nuts 8 for each mount.
These parts print and join fine. I've printed them at 1.2mm shell, but probably it would be worth to go with 1.8mm shell for motor boxes.
I don't have an idea how to close/attach the motor boxes lids later (wood screws?)
What I'd like to do, is to build a chassis that has basic necessary elements: PCB, battery, all motors.
What I still miss are:
- I don't know the length of the 2020 extrusions for the chassis (the long ones)
- STL's for front wheel holder (I guess that might chane later, but still that would allow me to test things) and PCB box.
Having these parts would allow me to "migrate" current mower parts to the new place and see what works and what not "in the field"
Currently started printing wheels. 1.8mm shell /w 50% infill. It is estimated to print ~1.5 days with these settings
One remark however. Because they have these cavities in the back side. They will be filled with the grass cuts pretty fast (by the opposite mower disk). I guess it would be best having flat surface on the back side of the wheels. Though, must admit, they look cool.
Hope that helps someone.
If you're interested seeing updates and/or pics of the build - let me know.
Also, if you have ideas for part print settings, orientation (to make it faster and less supports), let me know.
Cheers,
Romualdas
Before I add my experience and thoughts here couple of things I have to mention:
- I have "original"/"experimental" chassis from the shop and used the robot for one season already. Had some minor issues and repairs here and there, but in the end of the day it served the whole summer well
- I am fairly new to 3D printing. I got my CR-10 maybe 2 months ago.
- I have no experience in Fusion360 or anything like that
- I don't expect things to go smooth both because of my lack of experience in the subject and understanding that this is still ongoing project.
So, here it goes.
I've decided to give it a try and print the robot parts. There are couple of reasons why I like it:
- Rear wheel drive (there are some places in my lawn near the trees, where front wheeler can get stuck)
- Possibility to have 2 mower discs (single one just barely manages to maintain lawn running 2 x 3.5 hours / day for ~1000m^2 of grass).
- nice looks (why not
)For printing I'm using Cura as slicer, PETG, micro-swiss full metal 0.6mm nozzle, 1.2mm walls (will try 1.8 for wheels), 20-50% octet infill
So far, I've got:
- Motor boxes and lids,
- mower boxes, holders and covers,
- chassis mounts
- battery box
- alu mounts
- PCB cover front and back
- Parts 4 and 11 (the frame for PCB box(?), which is not yet available in Thingiverse yet?)
- Part 3 (display holder on the back) and wheel arch (was part 1, but now gone from thingiverse, replaced by wheel parts)
As someone already mentioned, the wheel arch doesn't look sturdy enough and I broke it easily by trying to remove support material (it is somewhat harder to do that on with PETG).
Basically the area that holds wheel arch is ~35x7mm. Printing with 1.2mm shell is definitely not enough.
If the arch would connect to horinzontal plane throughout all length, it probably would be ok, as there wouldn't be much flex left.
I couldn't figure out reasonable way to print screen holder, because there will be supports necessary in places, where it is hard to remove then in case of PETG.
Trying to attach wheel arch to the screen holder didn't ended well either. I suspect that either the clearance is "just enough" and/or the support material (I printed it horizontally, thus support material had to fill the gap) wasn't removed to the extent required (I've tried my best) and natural PETG flex was not enough to handle.
Basically, I had problems sticking the parts together and then broke the display mount :|
Motor boxes print well without any supports. And connect using 36.5mm 2020 alu extrusion with 4 M4 bolts with T nuts and 3 additional M4 bolts with nuts.
2020 Alu extrusion mounts attach to the motor boxes with M4 bolts and nuts 8 for each mount.
These parts print and join fine. I've printed them at 1.2mm shell, but probably it would be worth to go with 1.8mm shell for motor boxes.
I don't have an idea how to close/attach the motor boxes lids later (wood screws?)
What I'd like to do, is to build a chassis that has basic necessary elements: PCB, battery, all motors.
What I still miss are:
- I don't know the length of the 2020 extrusions for the chassis (the long ones)
- STL's for front wheel holder (I guess that might chane later, but still that would allow me to test things) and PCB box.
Having these parts would allow me to "migrate" current mower parts to the new place and see what works and what not "in the field"
Currently started printing wheels. 1.8mm shell /w 50% infill. It is estimated to print ~1.5 days with these settings
One remark however. Because they have these cavities in the back side. They will be filled with the grass cuts pretty fast (by the opposite mower disk). I guess it would be best having flat surface on the back side of the wheels. Though, must admit, they look cool.
Hope that helps someone.
If you're interested seeing updates and/or pics of the build - let me know.
Also, if you have ideas for part print settings, orientation (to make it faster and less supports), let me know.
Cheers,
Romualdas
