MK8 Hot End - is this correct or defective?

[chase]

Hi,

I just finished building my i3 Pro B. And it runs great.
Included with it is the stock assembled MK8 like this one:

http://www.geeetech.com/assembled-mk8-e ... p-857.html

In doing my wiring a tad better I turned the hot end around so the wires exit tree hot end to the right if facing the printer.

What I noticed is now, when I position the carrier at X+200 the nozzle is off the glass on the X axis.

Prior to turning the hot end, it was fine.

In taking a closer look, the hole on the top of the hot end is not centered to the bottom hole where the nozzle is.

Further more, after my very first print (yes! It prints! Hurray I built it right!) I thought I had a clog. I took the nozzle off and tried to feed some filament through the hot end. It wouldn't go. It pushed out the plastic tube inside off the hot end which has a crook/kink/double bend in it to line up the top and bottom holes in the hot end. It's not clogged... it's the bend and the fact the hikes don't line up that are making it difficult to push filament through. It'll feed through but it takes some force.

From watching the MK8 build video, I don't think it's correct.They shouldn't be off center from each other and there shouldn't be a bend or kink in the tube in the hot end. And pictures show the holes or nozzle and threaded extrusion tube lined up.

But I want to ask first... Is it suppose to be like mine or should they be centered with each other.

If centered, then that explains why my nozzle is now going past the glass on the hot bed at +200 on the X axis.

tia,
- chase -

[William]

Hi,

I just finished building my i3 Pro B. And it runs great.
Included with it is the stock assembled MK8 like this one:

http://www.geeetech.com/assembled-mk8-e ... p-857.html

In doing my wiring a tad better I turned the hot end around so the wires exit tree hot end to the right if facing the printer.

What I noticed is now, when I position the carrier at X+200 the nozzle is off the glass on the X axis.

Prior to turning the hot end, it was fine.

In taking a closer look, the hole on the top of the hot end is not centered to the bottom hole where the nozzle is.

Further more, after my very first print (yes! It prints! Hurray I built it right!) I thought I had a clog. I took the nozzle off and tried to feed some filament through the hot end. It wouldn't go. It pushed out the plastic tube inside off the hot end which has a crook/kink/double bend in it to line up the top and bottom holes in the hot end. It's not clogged... it's the bend and the fact the hikes don't line up that are making it difficult to push filament through. It'll feed through but it takes some force.

From watching the MK8 build video, I don't think it's correct.They shouldn't be off center from each other and there shouldn't be a bend or kink in the tube in the hot end. And pictures show the holes or nozzle and threaded extrusion tube lined up.

But I want to ask first... Is it suppose to be like mine or should they be centered with each other.

If centered, then that explains why my nozzle is now going past the glass on the hot bed at +200 on the X axis.

tia,
- chase -

Hi，
Could you plz show me your issue with a video or some pics?I'm not sure if i have got your points...
Regards

[chase]

[quote="William" ]
Hi，
Could you plz show me your issue with a video or some pics?I'm not sure if i have got your points...
Regards[/quote]

Sure thing William.
I'll have to do take some tomorrow when I have time to take it apart again.

Here's a pic of the wiring just after I finished the build though I don't know if that'll help illustrate what I mean.

[chase]

Hey William,

I didn't get a chance to take it apart this week-end, but will.

I think this may be two issues not one. I'm not sure. But in looking the assembled head over including the hot end. No matter which way I have the wires face coming out of the hot end it shouldn't matter. It shouldn't change the nozzle location point. But... on mine it seems to be making a difference.

These couple pics might help -

looking at the hot end facing from the front of the printer you can see the tube and nozzle line up...

Facing the printer the tube and nozzle are in line.

IMG_20160723_220551.jpg (250.16 KiB) Viewed 9727 times

But in this image from the side - you can see the nozzle doesn't line up.

From the side the tube and nozzle don't line up - the nozzle is super close to the edge of the aluminum hot end block.

IMG_20160723_220401.jpg (269.61 KiB) Viewed 9727 times

I drew the white line in to show what is happening inside, in since I didn't take it apart. (it's a bit of a pain to undo it all to remove it)
And the tube inside the hot end is doing the same. I have the 1.75 tube - from the top there isn't a Teflon tube inside the threaded tube. Just a 2mm hole in the threaded rod going into the hot end. They had a pic of it on the Geeetech site - I can't find it now.

I will take it apart and take some more pics.

To show what is going on on the X axis here's a pic.

[

X axis at 0 and 200mm

pixlr_20160724191052616.jpg (247.38 KiB) Viewed 9727 times

The X can't go any further than the stop - I'd have to cut off part of the X axis carrier to have it go further.
And at +200mm it's off the glass and over the bed retainer screw head as you can see.
It's off by about 5mm on both sides.

Just looking at it - it doesn't look like that's how the hot end should be. But I don't know...
But it isn't lining up - nor giving me 200 by two hundred mill.?

While I'm at it - here's the Y axis at 0 and +200m as well. It's off too.
- How do I correct the Y axis as well?

Y axis is off as you can see.

pixlr_20160724190402223.jpg (195.61 KiB) Viewed 9727 times

And the hot end - Will Geeetech send a replacement that is drilled straight from tube to nozzle?

Thanx
- chase -

PS sorry about the pic quality. I hope they'll suffice.

[William]

Hey William,

I didn't get a chance to take it apart this week-end, but will.

I think this may be two issues not one. I'm not sure. But in looking the assembled head over including the hot end. No matter which way I have the wires face coming out of the hot end it shouldn't matter. It shouldn't change the nozzle location point. But... on mine it seems to be making a difference.

These couple pics might help -

looking at the hot end facing from the front of the printer you can see the tube and nozzle line up...

IMG_20160723_220551.jpg

But in this image from the side - you can see the nozzle doesn't line up.

IMG_20160723_220401.jpg

I drew the white line in to show what is happening inside, in since I didn't take it apart. (it's a bit of a pain to undo it all to remove it)
And the tube inside the hot end is doing the same. I have the 1.75 tube - from the top there isn't a Teflon tube inside the threaded tube. Just a 2mm hole in the threaded rod going into the hot end. They had a pic of it on the Geeetech site - I can't find it now.

I will take it apart and take some more pics.

To show what is going on on the X axis here's a pic.

[

pixlr_20160724191052616.jpg

The X can't go any further than the stop - I'd have to cut off part of the X axis carrier to have it go further.
And at +200mm it's off the glass and over the bed retainer screw head as you can see.
It's off by about 5mm on both sides.

Just looking at it - it doesn't look like that's how the hot end should be. But I don't know...
But it isn't lining up - nor giving me 200 by two hundred mill.?

While I'm at it - here's the Y axis at 0 and +200m as well. It's off too.
- How do I correct the Y axis as well?

pixlr_20160724190402223.jpg

And the hot end - Will Geeetech send a replacement that is drilled straight from tube to nozzle?

Thanx
- chase -

PS sorry about the pic quality. I hope they'll suffice.

Hi,
1.For the X and Y axis,i think it's normal that there is a little deviation,cuz you just need adjust the glass bed a little then it will work fine.Look at the pics,the glass is too left and too front.
2.About the bend,i think you can take the extruder apart and uninstall the extruder fan to let me see how it bends,and which exact part do you think is bend?In my opinion,firstly you'd better check if there are some installation problems on extruder like the throat tube,the heat block...
Regards

[chase]

Hi,
1.For the X and Y axis,i think it's normal that there is a little deviation,cuz you just need adjust the glass bed a little then it will work fine.Look at the pics,the glass is too left and too front.
2.About the bend,i think you can take the extruder apart and uninstall the extruder fan to let me see how it bends,and which exact part do you think is bend?In my opinion,firstly you'd better check if there are some installation problems on extruder like the throat tube,the heat block...
Regards

Hey William,

Don't look at the glass, look art the lines on the heat board.

The glass cannot move over a screw head on the X axis.
The bed itself can't be moved over in any direction.

The lines of the bed, is what the nozzle should be lined up with. The lines on the bed are 200mmx200mm and where the heating elements are etched in the board.

The nozzle is clearly off the bed on the Y axis @ 200mm.
It's clearly to far into the bed on the Y axis @ 0mm.
Moving the glass off the bed doesn't fix this or come close to a resolve..

On the X axis the nozzle is clearly positioned over the cap screw head @ 200mm. The supplied glass goes past those cap screws on both ends. It can't be moved over even if you wanted to.

I want it to be correct. I want as advertised a 200x200 work area.
The X axis home position can't be changed mechanically without cutting off part of the carrier by 5mm.

Being off on an axis by half a mm is one thing, being off by half a centimeter and more on the Y axis is another.

Currently, if I have a print that calls for 195 on the X and 187 on the Y I can't print it due to these offsets in the current position on the X and Y.

Moving the glass out of the central heat area isn't a fix or a solution. The bed markings are laid out for a reason. That's where the heating element border is.

If it's normal for Geeetech printers to be off this much, I'll keep that in mind for future purchases.

In the mean time, and to find a solution for the printer art hand. Can this be corrected in the software? At least on the Y axis?

Do you know if the all metal upgrade correct these issues on the X and Y axis?

I did take the nozzle off and apparently there is a nylon tube in the bottom end of the feed tube. Looking art the tube now after I reassembled it. The nylon tube no longer shows a bend at the end.

When I turned it around and reassembled the tube/heat block assembly to the extruder assembly it must have tightened up the tube at the heater block closing a gap.
When I heated it up it must have taken the bend out.
That's all I can figure.

The hole for the tube/nozzle is definitely drilled at an angle in the heat block though. Center to the hole is off by 3+mm on the top and bottom. Ie if the center of the hole on the top of the heater block is 10mm where the tube goes, The center to the hole where the nozzle goes is less than 7mm.

It will print but the nozzle end is at an angle to the heat bed due to the angle the hole was drilled at.

At least there's no bend that I can see anymore. I just need a new heat block that's drilled correctly. Hopefully tech support will send one that's drilled right and that will correct that.

- chase -

[chase]

Hey William -

I thought about my last post - I realize I may have come off a little brash. Please don't take offense to my statements.
I know you are trying to help. And I may be a little overly frustrated at a few things which. So my verbiage may have been a little strong.


In researching a possible fix to the X and Y alignment issue, I'm seeing thorough out the forums and videos posts, as you stated it has been a long standing issue about the X and Y axis not aligning properly.

Geeetech should have come up with solutions long ago for the X and Y issue but since they didn't - I did.
Once implemented both the X and Y alignment will be fixed. Who knows - maybe I'll sell it as an upgrade!

Anyway - Enough said about it.

I really just wanted to thank you for your help thus far.

I'll guarantee - by the time I'm done - my i3 Pro B/C will be the best most precise 3D printer out there! lol

Thanx again for the help,

chase