What The DfAM?

[fergazz 60]

On 6/22/2018 at 12:44 PM, Nicolinux said:

 

Yes, I have created a Crossfit Rack step which breaks when stepped on. So far it takes around 100kg but I'd like to know if other infill types would make it stiffer. I have also added a second version which has a small notch. My idea was that it should help spread the load on the flat part.

 

 

 

Which infill did you use for that?

As far as I know triangular is the strongest. I also saw a video with a lot of strech testing and the best results where using 50% infill (stronger than 100%) and a lots of perimeters, around 5 or 6. Don't know if the forces applyed will match with this case but I will try to find this test in youtube

 

Edit: I found it... CNC Kitchen video.  Also, keep in mind to print hotter (You should know about it but it can help someone else)... it will looks worse but will increse strenght. Also avoid PLA cause it's rigid but don't bend to much. Maybe nylon should be the best option for this apllication? 

 

Edited June 29, 2018 by fergazz
video link

[JCD 28]

Have you try to make a hole in your model up to the flat part and insert a big screw inside ?

 

 

[fergazz 60]

On 6/29/2018 at 3:42 PM, fergazz said:

 

Which infill did you use for that?

As far as I know triangular is the strongest. I also saw a video with a lot of strech testing and the best results where using 50% infill (stronger than 100%) and a lots of perimeters, around 5 or 6. Don't know if the forces applyed will match with this case but I will try to find this test in youtube

 

Edit: I found it... CNC Kitchen video.  Also, keep in mind to print hotter (You should know about it but it can help someone else)... it will looks worse but will increse strenght. Also avoid PLA cause it's rigid but don't bend to much. Maybe nylon should be the best option for this apllication? 

 

 

Of course that this is a software solution, not a design solution ?

[Nicolinux 288]

@fergazz I am using 75% triangular infill. But still, I think there is too much stress at on the flat part. I have added a small "notch" to help spread the load but so far I am just tinkering with it and going by gut feeling. I fear I do need to get into Fusion360 and try the Fea analysis...

 

@JCD hehe, nice idea. Don't know if it would hold because there is still plastic in between the screw and the hole in the rack where this object is inserted into, but it is worth a try.

[owen 19]

16 hours ago, Nicolinux said:

@fergazz I am using 75% triangular infill. But still, I think there is too much stress at on the flat part. I have added a small "notch" to help spread the load but so far I am just tinkering with it and going by gut feeling. I fear I do need to get into Fusion360 and try the Fea analysis...

 

@JCD hehe, nice idea. Don't know if it would hold because there is still plastic in between the screw and the hole in the rack where this object is inserted into, but it is worth a try.

 

Maybe make a part like this printed on the side will give give more strength by the direction of the print lines

 

 

and make a foot plate to go on top which you would print on the front facing side to give good strength

 

 

 

[Nicolinux 288]

Another good idea - damn I should have asked people who are smarter than I am - before I started printing tons of iterations ?

[bespoketailor 1]

This is very beautiful story you have made