Upgraded to metric rods

Contact Robo3D. They can probably send you a new coupler.

 

Good idea. Im not going to bother them with that as I bent it ... note to self better allen wrenches!

I measured them and ordered some.
Specs are 5 x 8 mm 25mm length.

 

I seem to be having the same problem Cmckinney, I've done the switch over to 8mm, 1.25 pitch metric rods and then printed a second calibration angle which was coming out a little shorter than the original which I expected. So I went to change the default z axis steps in the new Marlin_3_14_14 firmware

From:
#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,2267.72,723.38}
To:
#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,3200,723.38}


Now it seems if I use the 3200 value I cannot home my Z axis. No idea why

 

Thanks for the correction Ziggy, just realised earlier in the thread the rod pitch was 1mm rather than 1.25mm.

Unfortunately even with the adjusted z step if I attempt to home the z axis the stepper motors seem to lock up and hum. If I go back to the default or lower than the default z axis step of 2267.72 it homes fine.

Any ideas why that could be happening?

 

I have a bunch of black nylon nuts (M8x1.25) if anyone needs some. The greatest thing about these nuts is they fit perfectly in the X axis carriage, no sanding needed and it has zero play.

 

I currently use brass nuts. Works as well.

 

Ta Ziggy, I'll have a play with the pots settings after work tonight. I do however find it strange I can move the Z axis up or down through cura/repetier but homing causes only the Z axis steppers to freak out.

As Matthias mentioned I also switched to brass nuts, which fit correctly without shaving, but I will see if i can steal some of SoLong's nuts

 

That's odd, Jerry sent me some firmware that has these settings:

#define DEFAULT_AXIS_STEPS_PER_UNIT {80.69,80.69,2560,747.626}

 

#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,2267.72,723.38} is the default in Marlin 3_14_14 firmware

I think I have an older copy of the Marlin 2/4/14 firmware saved at home where the default was the settings Jerry sent you, minus the 2560 z step setting.

 

I have a dedicated hard drive just for Arduino/ATmel/PIC firmware, I always keep old versions. The 2/14 firmware has these settings:

#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,2267.72,723.38}

They must have refined the steps since the 3/14 firmware I guess, all the files in the firmware Jerry sent me were created on 4/1/2014 at ~10:13 AM. If anyone wants me to post the full firmware zip I will in case there are other changes as well.

 

I have just fitted metric rods M8 x 1.25 and printed a rather short looking 15 mm cube, I knew this would be the case and am now looking how to address this but per this post there seems to be a lot of confusion as to what the settings should be so to all the people who are using metric rods successfully what are the recommended settings that actually work ?

 

I live in San Diego and am actually heading over to R3D headquarters today to sit down with Jerry and hammer out the correct settings and get this working. I will report back once that happens.

 

cheers, I wait in anticipation

 

incidentally even though the Z height is now incorrect the print has a much better quality to it, the striping is less and I am hoping a new coupler to replace my eccentric one will help even more but the overall appearance of the sides seems a lot tighter and neater, it may just me but hey its me that counts in terms of what I am printing

 

There are calculators for the steps of there. I think I used one for a Prusa, but it doesn't really matter.
I believe 80,80,2560 are the right ones.
Don't have a link handy, just ask google ;-)

 

Just put this in the shoutbox for Deadwood: http://calculator.josefprusa.cz/. The defaults look right for the M8x1.25 rod.