I own a K8200 since october 2014.
Although i’ve had all kinds of trouble (and now and then still have) I like the machine.
Now, I want to build a second, larger printer from scratch. I want to use the controller, the stepper-motors and drivers, the extruder and the hot end
from a K8200, mostly because I’m familiar with this hardware. I’m not going to use the aluminium frame.
I’ve already made a design. In this design, I need 2 stepper motors for the z-axis.
Question : is it possible to connect two stepper motors to the same connection of the z-axis on the controller?
How much larger do you mean exactly by larger, since you are thinking about 2 steppermotors to drive the z-axis…
Greetz,
Deekay[/quote]
Well, the bed will be 60cm x 40cm, printheight : 50cm.
Goals :
I want to make it as easy as possible to maintain the printer. Every screw and bolt must be easy reachable.
Levelling the pad must be very easy. Levelling is manual.
It must be very stable, not shaking.
Speed is not very important (the standard speed of the K8200 is OK).
Since it’s going to be used for prototyping, nozzle 0.5 mm is OK. Don’t need a smaller nozzle.
I know I must face the following challenges :
Heating the bed.
Power for heating the bed.
Speed for heating the bed.
Settings in Repetier host.
Possible solutions for challenges :
Will use relays to switch the power for the heated bed
Will use separate power supply or supplies for the heated bed
How much larger do you mean exactly by larger, since you are thinking about 2 steppermotors to drive the z-axis…
Greetz,
Deekay[/quote]
Well, the bed will be 60cm x 40cm, printheight : 50cm.
Goals :
I want to make it as easy as possible to maintain the printer. Every screw and bolt must be easy reachable.
Levelling the pad must be very easy. Levelling is manual.
It must be very stable, not shaking.
Speed is not very important (the standard speed of the K8200 is OK).
Since it’s going to be used for prototyping, nozzle 0.5 mm is OK. Don’t need a smaller nozzle.
I know I must face the following challenges :
Heating the bed.
Power for heating the bed.
Speed for heating the bed.
Settings in Repetier host.
Possible solutions for challenges :
Will use relays to switch the power for the heated bed
Will use separate power supply or supplies for the heated bed[/quote]
I don’t think it’s a good idea to equip a machine that large with a moving bed.
You would need at least 120cm by 100cm inner movement space as well as linear guides.
Wich results in a really giant machine with really heavy moving bed.
Ive just modified an K8200 to print 400mm X 400mm X 370mm (Z)
Its huge, the base frame is nearly 1000 x 1000
ichbinsnur is correct about sizing, 400mm wide bed needs 400mm movement, so the frame has to be 800mm internal size plus allowance for the bearings etc
Ive got 4 8mm guide rods for the “Y” axis, but only 2 10mm rods for the “X”, but looking at the flex i think i will need 4 10mm rods in the end
I think that once ive fitted the glass top to the 4 off heated beds there might be a problem with the inertia generated by the mass of the carriage, potentially losing motor steps.
But ill address by slowing down the print and movement speeds
Ill post some pictures when i get a moment
All axes are driven by twin stepper motors
Its not fully wired up yet but will complete by end next week for trials.
[quote=“jan1959”]Ive just modified an K8200 to print 400mm X 400mm X 370mm (Z)
Its huge, the base frame is nearly 1000 x 1000
ichbinsnur is correct about sizing, 400mm wide bed needs 400mm movement, so the frame has to be 800mm internal size plus allowance for the bearings etc
Ive got 4 8mm guide rods for the “Y” axis, but only 2 10mm rods for the “X”, but looking at the flex i think i will need 4 10mm rods in the end
I think that once ive fitted the glass top to the 4 off heated beds there might be a problem with the inertia generated by the mass of the carriage, potentially losing motor steps.
But ill address by slowing down the print and movement speeds
Ill post some pictures when i get a moment
All axes are driven by twin stepper motors
Its not fully wired up yet but will complete by end next week for trials.[/quote]
Well, i’m currently thinking about a larger , more service friendly and upgradeable design too.
But i think for machines larger than 300mm square print area a fixed bed is the better choice.
[quote=“jan1959”]Ive just modified an K8200 to print 400mm X 400mm X 370mm (Z)
Its huge, the base frame is nearly 1000 x 1000
ichbinsnur is correct about sizing, 400mm wide bed needs 400mm movement, so the frame has to be 800mm internal size plus allowance for the bearings etc
Ive got 4 8mm guide rods for the “Y” axis, but only 2 10mm rods for the “X”, but looking at the flex i think i will need 4 10mm rods in the end
I think that once ive fitted the glass top to the 4 off heated beds there might be a problem with the inertia generated by the mass of the carriage, potentially losing motor steps.
But ill address by slowing down the print and movement speeds
Ill post some pictures when i get a moment
All axes are driven by twin stepper motors
Its not fully wired up yet but will complete by end next week for trials.[/quote]
I would really like to see some pics from your build
I completly agree that a moving bed so big will give inertia problems. In the past, I already had this problems with a 6mm thick glass on my current bed (21*21cm), so larger… no it’s not a good idea. Thats why I designed a fixed bed, and a moving printhead.
There are benefits to having a moving bed. I’d design a printer of this size with a fixed head, and moving bed. However, the bed should be driven with screws, not a belt.
Why? Mine would be a CNC mill, as well as a printer. A fixed head minimizes tooling problems.
[quote=“szeedijk”][quote=“geedee06”]Here are some pics of the design I made in Sketchup.
As you can see, my drawing skills are very basic, but you get the idea…
[/quote]
If this is basic drawing then I don’t know to call my “basic” drawing anymore ;)[/quote]
Thanks, but it’s really no big deal. I’m sure you can do the same to. Sketchup is really easy to learn.
It’s only in my opinion for what it’s worth, having one of the extruder axis (x or y) as a fixed rail/runner was a good idea. Once that was set up parallel and level the other axis had to be correct. That left the variable as the table. As this is a very slow moving part it could be over engineered to ensure it was both flat and level.
With your new design you have to engineer to ensure that both of the extruder support rails are aligned at all times. It seems to me that you are building in a problem when you need to keep alignment to less than 0.05mm at worst if you want good prints. Keep the new design but fix the two extruder rails and move the bed as you did before. A bit like this http://www.vertex3dprinter.eu/#home
As for your advisers, bear in mind the saying: Those who can, do. Those who can’t, teach.
The reason I changed to a fixed bed is because the bed is very heavy.
Consider :
the frame of the bed
4 heating elements 20x30 cm
a glass 7mm thick, 40x60 cm when I’m printing, or a MDF-board at the same size when I’m milling
the object itself I’m printing or milling.
Another, but not so important reason, is that the total height of the printer is +/- 180 cm. I’t difficult to work with it, when the bed is in the upper position.
Of course, the bed will be adjustable in height, in a way similar to the k8200.
Do you think there will be a problem because of the stepper at the left and the stepper at the right not going to move exactly the same?
