Some additional question insolation/calibtrate Z menu/Y axis course  

Re: Some additional question insolation/calibtrate Z menu/Y axis course

Hi Christophe

Calibrate Z moves the nozzle to 0.23mm above the glass without enabling the XY stepper motors, which enables you to move the extruder around the glass by hand to ensure the gap is constant by using the supplied card at various points.

The maximum Y axis is 197mm, I believe and that is based on the Y end-stop being positioned as far back as possible with it still activating. This position is determined by the right-hand rear linear Y bearing (when looking from the front of the printer); the left-hand linear Y bearing is what should activate the Y end-stop.

Heated bed insulation in OK, but not necessary. A thin cork tile is one of the best insulating materials and is quite cheap. When adding anything to the X and Y axis, be aware that any added mass may require lower acceleration values for the stepper motors.

Y frame position: the manual state 3 to 5 mm (from memory, but I may be wrong), but in any event, refer to my second paragraph.

Peter

Re: Some additional question insolation/calibtrate Z menu/Y axis course

Hi Peter.

Thanks for your feedbacks, really appreciated.

Ok for Z calibrating description, now it's perfectly clear !

Regarding Y axis, I do not get what you mean by "This position is determined by the right-hand rear linear Y bearing (when looking from the front of the printer)". For me the Y axis is moving from the position where the front right hand linear Y bearing is touching the front right Y corner, so when the Y carriage is as front as possible, and the position where the left hand Y bearing is touching the Y-stop, when the carriage is as back as possible. What do you mean about the right hand left bearing ?

Thanks for the tip regarding insulation, I will weigh the panel to check it, but for me it's pretty light.

For the last point, I think there is a misunderstanding, I was talking about the distance between the Z vertical frame and the back of the Y back corners, where the Y motor is located.

Re: Some additional question insolation/calibtrate Z menu/Y axis course

Christophe

To avoid confusion (and to make things easier for my simple mind to understand), one point at a time.

The Y axis chassis has 3 bearings; two on the right and one on the left (when looking from the front of the printer)

The Y axis end stop should be positioned on the left smooth rail near to the rear of the printer and should be activated by the single linear bearing on the left hand side, when the chassis is towards the rear.

In the position whereby the switch is activated by the bearing, the rearmost linear bearing on the right should be 3mm (1/8") away from the frame corner on the rear right of the printer. If you decrease this gap by 2mm, then you can just about get 200mm of Y-axis travel, assuming you make the relevant change to the firmware.

Peter

Re: Some additional question insolation/calibtrate Z menu/Y axis course

Christophe

I think I get your last point now. It's clearly stated in the manual (see step 4): http://manual.prusa3d.com/Guide/2.+Y+axis/40

Peter

Re: Some additional question insolation/calibtrate Z menu/Y axis course

Mmmh, I think both points are related, the position of the Y frame is probably a consequence of something wrong on my Y-axis.

In my case, what limits the movement to the rear of the Y-carriage is the motor touching the Y-belt holder, not the right rear linear bearing . I'll double check this evening, I'm not in front of my printer right now.

What amaze me is that I was really reading attentively the setup guide while building, but however I missed some obvious steps. I remember of this initial 80 mm, but due to issue with the Y belt holder, I tried various position then forgot.

Re: Some additional question insolation/calibtrate Z menu/Y axis course

Not sure they are related actually; the distance between the belt holder and the right rear bearing should be consistent on all printers and the 80mm gap between nuts would not affect that be it set to 60mm or 100mm (it would affect the available build area only). Is there a possibility that the belt holder is wrong way round? Or the chassis? Or the motor positioned incorrectly?

Check out step 30 of the same manual link:

"Check the gap on the dual bearing side of Y-carriage between bearing and Y-corner (should be around 2-5mm)"

Certainly, it's well worth checking in more detail.

Peter

Re: Some additional question insolation/calibtrate Z menu/Y axis course

Ok, I've done the double check.

In fact I was pretty close, it's just that my Y-stop was not adjusted after my last repositioning of the frame and the Y motor. My bad ! Now I have almost 198 mm course. I'm happy with that.

I did not take yet the time to weigh the isolation, I will do that latter.

Thanks for your feedback and your patient explanation !

Re: Some additional question insolation/calibtrate Z menu/Y axis course

Hi Christophe

Great news.

I am aware that for some guys, size matters. It is possible to stretch the Y axis by 6 to 8mm by moving the corner nuts apart a little and having a small gap at the end of the smooth Y rods. However, the Y axis movement is limited in firmware to 198mm, so to gain the 2mm, a firmware change is required.

Peter