z-gap inconsistent ?

[CubeX 3D Printman]

It seems my z-gap keeps changing, even if I don't change anything, just go back to the z-gap check.

I set the z-gap, save it and select z-gap again and it is different? Tried homing inbetween, but does not seem better.

I just set the z-gap, save it and then print and hope it is ok. Most of the time its ok, but not always.

[amf]

Hmm, this seems like something to dig into and get figured out.  I will look at mine tomorrow.  When you say you go "back to the z-gap check" ... what exactly are you referring to (i.e. are you referring to the setting on the display, or are you referring to what your sensing with the feeler gauge)?

[CubeX 3D Printman]

Thanks,

I ment when I select the z-gap button on the display again, to check the gap again, repeatatly with no other change.

 

thanks,

Rick

[J.Andre.]

Hmmm....

I haven't seen that Rick, but i've also never tried it.  i'll try to give it a go next time.

I've got a little 4 hour build going right now.

[Curtis]

I have the same issue, I've printed about 5 prints (just got my CubeX) and every time I have to reset the z-gap.  If I don't the nozzle digs into the bed every time.. does anyone know if there's an upgrade that fixes this?  Wouldn't that seem like something that would be saved?

[J.Andre.]

Hey Curtis,

well... because you remove the plate every time you remove a print, i think that's why you need to reset the z-gap everytime you print -- in case there is a .01" change in the position of the z axis.

so everytime you print, you should first check the z-gap.

.

Doing that, i've never had the jet tip dig into the plate.

.

Congrats on your new Cubex!  

I hope you're getting some cool prints out of it!

.

Cheers!

    --J.Andre.

[msenos...@gmail.com]

Same thing happens to me. I just check the zgap consistently. However, last time i printed something happened. The Cube made a weird noise near the end of a print, My near perfect print came out messy at the top. Im not sure its a filament error or the zgapchanges suddenly.

[CubeX 3D Printman]

msenosiaindi,

The z-gap only affects the initial layer start.

 

Before each print, I hit the home button, clean left over filament off the jets (so it does not affect z-gap checking).

Then hit the z-gap button and check/adjust z-gap. then print. - seems to work that way.

 

Can you post a picture of part with the messy top. It could be a cartridge problem. I had that happen too. The spool inside the cartridge can bind up.

Try to pull some more filament out of the cartridge and see if it pulls out easy.

 

I pulled my problem cartridge apart, at the chip end (contacts) first to not brake it in half (as andre suggested - thank you), then unwound a bunch of it and rewound back up. I put the spool on an external holder and stuck the empty cartridge cover with chip in place back into the system. The cardboard spool sitting on a round post, turns easier and I can keep an eye on it. So far ok.

 

Rick

[amf]

Rick,
   I see what you mean.  I set my Z-gap (I use a 0.1 mm feeler gauge), and then save my settings for that Z height.  The carriage moves back to the Home position and the screen returns to the top level menu.  Now, if I press the button for Z-gap again, the carriage moves over to the center position for measuring the Z-gap and the screen shows that the machine correctly remembers the Z height I just set.  However, if I put my 0.1 mm feeler gauge in, it's not the same gap.  I can repeat this 5 or 6 times and the feeler gauge is always telling that the gap is either a little bigger or a little smaller than 0.1 mm.

   I guess this is just a limitation of the machine.  What do you think?

-amf

On Sunday, June 16, 2013 7:44:24 PM UTC-7, amf wrote:

[CubeX 3D Printman]

amf,

Thank you for checking that.

I think the magnetic distance sensor is not that repeatable / accurate (can vary with temperature etc), but it seems to work if you check / adjust the z-gap right before starting the print.

I think once you set/save that z-gap value, it uses the motor step count to move into position for the print start.The repeatablility of the sensor is therefore not as critical?

 

Rick

[amf]

When you say "check/adjust the Z-gap right before starting the print" ... do you mean using the Z-gap menu item to set the Z height?  (Or are you just foregoing that menu item and moving the platform to the right place with the Move command just before starting the print  ... or something like that?)

[CubeX 3D Printman]

Yes, using the Z-gap menu.

[amf]

I don't quite follow what you're saying.  If you set the Z-gap, and then start a print, the printing procedure starts with a Homing trajectory, so it obviously takes a Z-sensor reading during the Homing.

If the Z-gap checking is not repeatable when you press Z-gap several times in a row, why should it have the "correct" Z-gap when you start a print?

-amf

[CubeX 3D Printman]

Yes you are probably right. My thought was that after setting the z-gap it would just keep track of the step count and start the print at a certain step count. But since it seems to rehome again before printing, my theory is wrong.

At least it seems to be ok when checking/adjusting the z-gap using the menu right before the print.

 

Rick

[norsac]

I have the same issue, that the Z-Gap changes every time it goes back to home... Some prints its close, and others its off by a mm.

[Peter Gregory]

I thought it was just me having issues with z-gap.

I reset the z-gap each print but it still is off.

I usually abort a print and reset the gap about 2 times before I get a good first layer.

I'll try the newest firmware as soon as I get my printer operational again.

I'm still waiting for a tracking number for replacement parts to fix the X axis belt.

[stefan...@gmail.com]

On Sunday, June 16, 2013 10:24:25 PM UTC-4, CubeX 3D Printman wrote:

I've noticed this as well. Also, we had problems with z-axis inconsistencies because the z-screw was slipping in the coupling to the z motor. This caused all kinds of problems. I think it is fixed now, but still have some inconsistencies.

[forema...@aol.com]

I'm having the same issue and I notice it moves on certain prints.
depending on how many times the bed skips and jumps on a print this is what causes the Z gap to change, so just get use to checking it before a new print.
Prints that don't require the bed to jump while printing will maintain Z gap. On a jumping bed print it will require setting Z gap again.

[forema...@aol.com]

[Tony Shulthise]

The CubeX printer uses a non contact Hall Effect sensor that senses a magnet in the build platform frame to set the Z offset.  Unfortunately, that sensor is not precise enough for the way its being used.  Most printers use a standard mechanical switch that touches something on the z-axis frame to sense z-home.  The mechanical switches are much more precise.

Also, the z axis frame and magnetic mounting design are such that just a small bump to the frame can cause the z offset to change.  I would imagine someone has posted an improved design for the entire CubeX z-axis by now.  I'd suggest searching for such and making some mods to make your printer much more enjoyable to use.  

Even better, buy a different printer.  If you look at the MakerGear M2 Google Group board you won't see a long string of issues like you do here.  I owned a CubeX Duo for a while and I hated it.  I bought a Lulzbot TAZ and it was much better but still not what I was looking for.  I finally bought a MakerGear M2 and its been what I hoped a 3D printer would be.  So much more reliable and quality printing.  It brought the joy back to printing after I almost gave it up due to the CubeX hassles.

The CubeX could be a very good printer if switched to using a different slicing program that doesn't require the 400% price markup cartridges and that gives much better control.  I think Kisslicer and Simplify 3D have ways to run on a CubeX now.  A few mechanical mods would go a long way toward making the printer enjoyable to use also.

Good luck,

Tony

On Sunday, June 16, 2013 10:24:25 PM UTC-4, CubeX 3D Printman wrote:

[dan.para...@gmail.com]

I'm suprised this hasn't been mentioned.
The Cubex 3d printing blog over at blogspot (google it, first hit) has a step by step how-to guide to relocating the z-sensor. Turns out if you move it from inside the bed to the z-rail, it is far more accurate and holds the correct gap indefinitely.
Confirmed by multiple users.
I haven't done it but I should, my gap also shows inconsistent results

[paulca...@gmail.com]

Guys - contact Cubify. I had the same problem and they sent me modification details (you have to move a fan).

Hope this helps,

Paul

[bikejunky98]

Relocating the sensor works better because it allows you to keep the fan, which is needed if you are printing PLA

[Rodney Wells]

It will always change. The magnetic field is just not that constant over time give changes in the temp and so on. change it to Optical breaker type like the Rep rap use.

I did my CubeX and never recalibrated it again.   

[Rodney Wells]

Looks like this.   This is the best,  I have tried ever thing to stabilise the magnetic one.     

[Peter Gregory]

I've had good results with magnetic sensors using the following process:

Home the bed - this will raise the bed if it is lowered, lower the bed if it is raised.
Home the bed again - this will first lower the bed until the sensor deactivates, then raise it to a known location.

Execute the two home method before setting the Z-gap or starting a print.
If the bed homes by raising upward, it will end at a different location than when it homes by lowering the bed.
Since the Z-gap executes by expecting the bed to be at a known location, the two home method is more accurate.

[Gary Muir (GRM Products)]

Just an FY... we offer a Z sensor relocation kit for $24.95 + freight and have sold hundreds of these worldwide. For more information you can take a look at the heated bed install video which shows the sensor kit installation toward the end.

Install video is on the home page.

http://www.grmproducts.com/

[james-willia...@charter.net]

Hi Rodney,

Nice job. I'd like to do the same since I'd like to get away from the mechanical switches. So questions that could save me some R&D are:

1. Did you modify the main board or were you able to make this mod using the as is factory board?

2. If you used the factory electronics for the mod, then do you recall what Slotted Optical Switch you used?

3. Did you bother to draw up a schematic? I'm interested in how you powered up the diode.

One thing the Cubex designers forgot to think about in addition to the drawbacks you listed is that people can potentially have powerful magnets in their shops. Just a little 12 mm X 50 mm N48 NIB magnet can influence one of those reed switches from 1 to 2 meters away.

[Rodney Wells]

to answer your question . Could i send you my optical conversion.  Its new modification and i just got the boards back from the manufacturing,

I believe this is a good idea as i have never had to worry about z Inconstancy  again.   I will send it to you it for Free, and help you fit it to your machine by correspondence on the forum.     Just give an Honest valuation of it  on the forum. Its kind of a beta test for hardware lol  I have worked on this for some time  I think it would solve your problem.

I will send you my kit ready to fit. no cost to you .    

[james-willia...@charter.net]

WOW! Really! That would be really cool of you! Yes, I’d be glad to install it and give an honest review.

I have a Cubex Trio. I am using the KISS slicer with third party filament. I'll PM you my shipping address.

James

[Rodney Wells]

Theses are early prototype photos I am still writing up the how to PDF. So this will get me off my butt and get it done.  

[james-willia...@charter.net]

Nice work! Looks like you have a lot of time involved with this. I sent a PM to your Business address since I couldn't find a way to do it for Google Groups or Google+.

How are PMs sent on here? Is there even a way to do that? I've never used Google+ and Google Groups before other than to post a comment or two a few times over the years.

[Rodney Wells]

All post come directly to my email box.  I just been interstate visiting family. was an emergency dash,  so i never got back to the forum.

send me your address to hydro...@bigpond.com  .   

[james-willia...@charter.net]

Hi Rodney,

I just resent the message to your address. Seams to be some kind of email weirdness happening, but it will eventually work I think.

I don't know why I'm being so cautious about posting my shipping address since anyone can find out anything they want about me with the long arm of search engines! HAHAHA! :D It's one of the drawbacks of being online for decades.

I guess I'm just old fashion I guess. :)

[robertr...@gmail.com]

On Saturday, September 27, 2014 11:23:24 PM UTC+1, Rodney Wells wrote:
> Theses are early prototype photos I am still writing up the how to PDF. So this will get me off my butt and get it done.   On Sunday, 28 September 2014 08:16:12 UTC+10, james-willia...@charter.net wrote: WOW!  Really!  That would be really cool of you!  Yes, I’d be glad to install it and give an honest review. I have a Cubex Trio.  I am using the KISS slicer with third party filament.  I'll PM you my shipping address. James

Hi, I have been having this problem for some time and tried out the relocation kit which still does not solve the problem. Have you taken your optical solution further to a point it could be purchased or do you have any further details? I can sort out the physical side by its the electronics that I am not sure about. Can you help. Robert (UK England).

[Giovanni]

Hi Robert,

the optical solution is here :

http://www.cubexupgrade.com/produit/z-stopper/

[afel...@gmail.com]

Rodney, 

Did you ever complete instructions for adding the optical sensor?

Thanks,

Tony

[mnade...@gmail.com]

Just so everyone knows when having z gap issues it could be the rod connector/extender.  the motor to jack screw extender/connector is made out of plastic, not metal even though they colored it to look like anodized aluminum.  this part was broken on mine when I opened the box and I was having z gap problems from the beginning and did not know it was cracked.  You cant see the cracks, they are hard to see and the set screws will not tighten and the jack screw slips.  I have replace mine with a rod extender made out of metal.  I no longer have z gap issues.  BTW that horrible noise you are hearing could be the motor spinning and the rod extender slipping.  My jack screw was scratched up really bad where the set screws were positioned.