Z axis problems

Hi,

First of all, I have a Mendel printer with RAMPS 1.4, my current Z axis is the old style with the belt that drives both threaded rods underneath the printer. I plan to upgrade to the dual motors mounted up top as soon as I can make some semi accurate prints. I am using repetier with repetiers firmware which I believe is a modified version of sprinter.

I'm currently having problems with my Z axis as the title states. Here's a little story and my current deductions to go along with it.

With the help of a friend, we managed to get my printer finally going. We did a test print of a 20mm cube and without doing any precise calibration, it managed to be printed within .5mm tolerance on all sides. Not bad for a first print. However when I went home, I did not save the marlin corrections to my current marlin firmware on my computer. When I came home I went to edit an end stop location, uploaded it to my arduino mega board with RAMPS 1.4 and successfully wiped it back to a standard blank marlin firmware state with an edited end stop variable.... Whoops. So I decided to go down a different path. Previously we did it with marlin on pronterface. Which was good and worked well until I wiped it, but I found it a rather un-user friendly experience to begin with.

I liked the look of repetier gui better so I went with that, I also used this to generate the firmware for arduino [www.repetier.com]
It appears to be a modified sprinter instead of firmware, but I managed to configure it almost perfectly in less than a 1/16th of the time. I like the EEPROM features which from my understanding allows the repetier host software to configure most printer settings without having to go through the code and upload and all that jazz. Please correct me if I'm wrong.

Previously I had my printer set up and working but all the axis's where somewhat backwards and I was having min and max endstop configuring problems. With repetier I no longer have these problems and the left button makes it go left, the end stops manage to stop the axis's in the correct direction and it always homes to the end stops. So I'm loving the repetier solution over all apart from my problem Z axis.

So anyhow, hopefully that gives whoever is reading this insight into how I got to where I am now.

At the moment the Z axis is incredibly slow, sounds like its missing steps and doesn't respond to any changes to steps, units, acceleration of feed rate settings.

In the previous marlin configuration we had the Z axis flying, it would go from home to max within 8 seconds. It also ran very smoothly. I also tried swapping out for my spare stepper motor drivers and stepper motor itself to diagnose if I had faulty hardware. This seems to be a software related issue.

If pictures are needed I can upload some of the specific parts that need to be inspected. It's probably a simple solution like some sort of acceleration limiting factor pre determined by the firmware to protect other printers from catastrophically destroying themselves if an endstop failed. Any insight is welcomed.

Thanks

I think Marlin is better than sprinter. And In my opinion Marlin is an evolution of sprinter.

Maybe it takes some time to set up, but it doesn't compare to the time you waste later on with sprinter.

Why don't you just put Marlin on it again? It only takes about 5 minutes to set up anyway?

list your printer type and model as well as upload a copy of your configuration.h

Quote
jamesdanielv
list your printer type and model as well as upload a copy of your configuration.h

He has a Mendel. It has one motor, gears, and a belt for the z-axis. Since he already has that, I think he's better off staying with it than moving the motor(s) to the top. There are other things in the Mendel that can be improved before that: The y and x carriage for instance. Since it worked with another firmware before, I agree that it likely to be a configuration.h problem.

also since you are using repetier host, look at the printer settings and make sure feed rate is set appropriately fo x,y and z. I would start out with 2000 for x/y and 100 for z. this is lower than normal and should be possible.

as for pictures: please show a picture of the entire machine,a picture of the underside that shows the entire z axis belt system on both sides, and a picture of the entire x carriage.

likely the step counts per mm need adjusting in firmware.

Edited 2 time(s). Last edit at 01/21/2014 01:07PM by jamesdanielv.