very strange delta Z axis issues

been working on my delta rostock printer for awhile using arduino and ramps 1.4, and things have been getting better and better until the z axis started to act up. first issue is that with repitier host, i cant seem to get the z feedrate to stick. i had a problem where the z was extremely slow when i was using manual control and homing, but printing was fine. i changed the z feedrate and that worked like magic, until i opened the program again the next day. the number that i changed was in the box and saved, but its still super slow. how can this have had an effect in the past when the option suddenly acts like its not even related? the second problem is that up until now ive been able to print (trying to calibrate the printer with z feedrate set to 100 is crippling) and now after having the issues with the homing again, the z axis has strange reactions to the manual control buttons. all else works, extruder, x/y control, but if i press ANY of the z buttons, the nozzle plunges to the plate and beyond. wtf is going on..... there have been a few times with my friends printrbot simple metal where it will not have had ANY changes made to it, and it will change how it homes without warning. no firmware changes, no internet connection, even used different computers and had it home the same "new" way. im getting frustrated that i will have everything pin-point accurate, then the printer decides to age in some way. had that unsolved mystery issue with both printers, homemade and whoever garage the simple metal is built in. the only hardware the things even have in common is the nema17's and linear bearrings. so my question is how can i finalize the delta printer so it stops changing on me when i get it set the way it should be, and how can i get it how it should be if the z axis wont respond correctly. this is not a simple problem like having the steppers wired backwards, or somthing like that. ive been looking for hours and the only thing google likes to bring up is the more common stuff. would love some concrete answers to why the printers will randomly decide to change homing tactics as well. i have been using the printer on the same computer until it had these issues, then changed the computer and used a fresh install of repitier host on a different windows version with no prior configuration, and its doing the exact same things. could it be the arduino or firmware etc? any help would be awesome.

there are 2 threads because my mouse sometimes clicks twice at once, and apparently you can accidentally double click the post button but dont get any easy option to delete it

You could work on the readability of your text above.

+1 on improving readability, try a few capital letters and paragraphs.

As for the printer issue if it sounds like electronics problems. Arduino clones and badly made ramps boards are everywhere. Some work, some don't. It might be worth trying a different controller and stepper drivers.

You don't say what firmware you are using but it won't be a firmware problem if the problem happens spontaneously/randomly and not repeatably.

Hope this helps.

Edited 2 time(s). Last edit at 12/07/2016 05:00AM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions