Custom 3d Printer

[amitppatel2003]

I am new to this board, I am currently building a custom 3d printer. I am thinking about a HBot/CoreXY layout, but had some questions. I am wanting to have a 14 by 14 build area, but am wondering is how much space do I need to keep around the build area, so i can figure out what size my printer frame should be. Any help is greatly appreciated!

[curious aardvark]

single extruder or double ?

[MiniMadRyan]

I typically layout the rough design of my extruder centred to the build volume of the printer. I then design my gantry and other components around that, and then lastly the frame. This also gives you a good idea of where motors, rails etc will end up, and allow you to choose how/what you want to build the frame.

Frankly, through a dozen designs or so already, designing a printer around a frame/set size just leads to too many compromises in the actual bits that matter. Design a good solid gantry and bed first, and worry about the frame and foot print later

[amitppatel2003]

I typically layout the rough design of my extruder centred to the build volume of the printer. I then design my gantry and other components around that, and then lastly the frame. This also gives you a good idea of where motors, rails etc will end up, and allow you to choose how/what you want to build the frame.

Frankly, through a dozen designs or so already, designing a printer around a frame/set size just leads to too many compromises in the actual bits that matter. Design a good solid gantry and bed first, and worry about the frame and foot print later

I was going to start with a single extruder then expand to two. -- what is the main different with using one or two.

I am very new with this so i am not really sure where to start at, could you please explain some more, I know i am going to use v-slot for the rails.

[MiniMadRyan]

The primary difference between a single extruder and dual, is that it basically doubles the size of your extruder platform. Because the hot ends are no longer completely centred over the bed, you typically lose a bit of build volume. Simply, you typically lose the length of your extruder carriage, so if your print volume was 10" and your extruder carriage was 2" in length between hot ends, then typically your build volume is 8".

You also need to be careful about the free space you have on either side of the bed, and or the free space between the bed and z-rods etc. You typically want to have an amount of free space between the bed and uprights that is half that or slightly more than that of the width of your extruder carriage. Without that, your carriage could interfere with the uprights and not travel to the full extents of your bed

[LambdaFF]

I was going to start with a single extruder then expand to two. -- what is the main different with using one or two.

Hi,
As explained above, unless you go for very specific hotends that combine filaments, you need 2 hot ends and that means that whatever distance is between the 2 will automatially be deduced in the print space ... unless you take allowances for it in your gantry design.

Typically, that is what killed for me the ORD SOlutions printer : Yes, it has 5 extruders, but the 5 are so far away from each other and the frame has not taken it into account so if you want to use all 5 you are restricted to a cube in the center that is 30% smaller than the print cube expanded from the bed... (look at their Kickstanter for the rova 3D, it is one of the last updates before closing starting the project).

[amitppatel2003]

I am still a little confused i apologize, but it does make some sense to me i wanted to have at least 2 so i can print with different colors, most builds i have seen usually just have one but i with my build i want to keep in mind i would like to upgrade and expand the printer if need be

[LambdaFF]

If you look at printers that have more than one extruder (Hyrel, printrbot metal plus, ...), they are usually spaced horizontally. Say you have 4, all separated by 5 cm (2 inches), then if the left hot end wants to print on the right border of the printbed, that means the 4th hot end is 15cm (6 inches) out of the printbed to the right. Which means that your total travel must be : printbed width + 2 times 15cm !

To avoid this issue, ORD solutions had an idea, they spaced their 5 hot ends on X and Y as a square. That means you loose less travel on one axis, but you loose on 2 axis instead. A kind of trade-off.

See their explanation here : https://www.kickstarter.com/projects...d/posts/920926

See what I mean ?

That is why people are try to develop hotends that take in multiple filaments : that actually solves a few issues (levelling a printbed with several hotends is more difficult).
To see what I mean look at this : https://www.kickstarter.com/projects...ti-color-3d-pr
The issue of that however is that all filaments go through the same hot end, meaning you need filaments that all need the same temps. Which is not the case if you are looking for support material usually.

[amitppatel2003]

If you look at printers that have more than one extruder (Hyrel, printrbot metal plus, ...), they are usually spaced horizontally. Say you have 4, all separated by 5 cm (2 inches), then if the left hot end wants to print on the right border of the printbed, that means the 4th hot end is 15cm (6 inches) out of the printbed to the right. Which means that your total travel must be : printbed width + 2 times 15cm !

To avoid this issue, ORD solutions had an idea, they spaced their 5 hot ends on X and Y as a square. That means you loose less travel on one axis, but you loose on 2 axis instead. A kind of trade-off.

See their explanation here : https://www.kickstarter.com/projects...d/posts/920926

See what I mean ?

That is why people are try to develop hotends that take in multiple filaments : that actually solves a few issues (levelling a printbed with several hotends is more difficult).
To see what I mean look at this : https://www.kickstarter.com/projects...ti-color-3d-pr
The issue of that however is that all filaments go through the same hot end, meaning you need filaments that all need the same temps. Which is not the case if you are looking for support material usually.

Thank you that makes sense now, now i have to decide how many extruders i want