Does anybody know (or have a link to) what the step settings are for a Large Ox with GT3 belts on TinyG v8 and how to set them? Maybe I missed it, but I didn’t see it here:
I have a large OX, but my belts are only GT2. My settings are here:
I imagine that the only thing that should change is the “travel per revolution” which will be 3mm x the number of teeth on your pulleys. Mine are set to 40mm because I have 20 tooth pulleys with 2mm pitch. The step angle will be dependant on the stepper.
Stupid G+. I refreshed but didn’t see this before making my “Bueller…” post. Thx @dhylands , I will take a look at this.
It looks like my travel/rev (same as yours) is 40mm, which appears to be the default settings (I didn’t change it). But, it looks like I have 20 tooth 6.35mm bore GT3 (taken from SMW3D.com’s pulleys page, which is the only GT3 they have, so I suspect that is mine). my motors are likely the same step angle and I also have the same microstep setting (1/8). So the question is, what is my real travel/rev? I’ll see what I can get from 3D printer calculators like the prusa calculator page.
20 teeth x 3mm would be 60mm travel/rev
Really? I was just about to say it looks like it is 26.67mm, according to:
Output:
Result 26.67 (steps/mm?)
Resolution 37.5micron
Teeth 20
Step angle 1.8°
Stepping 1/8th
Belt 3mm
Wait…duh. 200 steps per rev * 8 = 1600 steps per rev.
26.67 steps per mm. 1600 steps/26.67steps/mm = 59.99250093738283mm. So, yeah, it looks like you’re right: 60mm. Thanks @dhylands !
Not sure how that’s relevant. TinyG calculate steps/mm internally using the other data. You don’t need steps/mm (which is what that web page calculates). TinyG wants mm of travel per revolution.
60 mm travel per rev. 200 steps/rev 8 microstep / step gives 1600 steps per 60 mm, or 26.67 steps/mm (which agrees with the web site - but its not a number you need).
It looks like our comments collided mid-air. I was responding to the second to the last one 
No worries. But you’re right, I unnecessarily overcomplicated things.
20 teeth * 3mm belt pitch = 60mm/rev. Oh well, hindsight is 20/20.
Also set my z-axis to 8mm/rev (IIRC it was TR8*8). Now that seems nailed down, I can move on to why my darn z-axis seems to bog down and skip mid-way. Grrr…I probably need to loosen something.
Make sure your power management is set to 1 (always on) or 2 (in-cycle) for all of the axis. There was also a bug in 438.02 that was fixed in 440.14 that was turning off the z stepper even though power management was set to 2. See my blog post here: http://blog.davehylands.com/2015/04/ox-more-clamps-and-tinyg-firmware-issue.html
If you mean midway through min to max travel, then yeah - could be alignment or crap in the nut: http://blog.davehylands.com/2015/03/ox-build-part-3.html It could also be irregularity in the diameter of the leadscrew. I’d recommend disconnecting the stepper and trying it by hand all the way through the travel to see if you can feel any binding.
@SirGeekALot
James I have a large Ox with GT3 belt and I also run my travel at just under 60mm per rev. I think I need to make a minor adjustment as I just did a test and my square and circle dimensions were slightly under what they should have been. My $tr is at about 59.6 so maybe I need to adjust it closer to 60. As Dave mentioned on your Zaxis if the lead screw is not straight you can get some resistance in areas not straight. I have this issue too towards the lower portion of my Z travel. I just ordered a new lead screw to hopefully correct this. Openbuilds was having a sale this weekend on hardware, might be a good time to buy.
@Matt_Herrera that thought had crossed my mind. I’m busy this weekend, so I’m may not be able to take it apart to inspect the leadscrew for straightness for a few days.
@SirGeekALot hey I just setup my MEGA OX this weekend and yes its 60mm travel per rev. for x an y and for z its 8mm. Once you get your config dialed in can you let me know. I will put a “standard” ox config in the TinyG repo so people can just use that config. I would use mine but its rather larger than normal.
Check it out! Also if you are using the PWM spindle for your ox that @Brandon_Satterfield sells you need to move the jumper in the spindle controller to CP and use these settings:
$p1frq=5000
$p1csl=0
$p1csh=10000
$p1cpl=0
$p1cph=1
$p1pof=0
for your PWM settings.
Love G+.
I can never thank @dhylands enough for what he’s done for us OX people, always sound advice.
@Riley_Porter_ril3y that would be awesome to have a branch. I’ve wanted to make one for a while but will admit I’m not a github user, looks like a different language each time I visit a page. Would love to have an R7 and OX location, one day I’ll sit down and make myself learn this stuff. Really need a solid place to put all this information.
I’ve always called the OX a mechanical kit but so many choose TinyG it really could be standardized.
@SirGeekALot it looks like you’ve got your solution. It will vary slightly based on effective diameter. As @Matt_Herrera pointed out, and thank you as well for all your community contributions Matt, it’s extremely important to do actual cut test. I made a large post on here somewhere about how to do this, but alas my google foo is stinking as well.
I installed some limit / homing switches last night. I will share the config once its done. @Brandon_Satterfield its not really a branch but more like a hardware profile. Look at this… This is what we use:
So an OX and the R7 (when you get me the settings as I do not have one) will have their own hardware builds.
I would also suggest we post all info on TinyG and the OX / R7 on the TinyG github repo. Its free and anyone can edit it. @Brandon_Satterfield I think you should create an account. I create a quick page to help with the settings here for the OX.
its ugly but its just a start.
Sounds good I’ll create an account later today. Still looks confusing to me but will definably appreciated anyone’s feedback and hopefully get a nice set of base settings for everyone.
Is there a command to blast all of the settings in at once? That seems easier than doing a diff of this and current settings, and then manually setting the changed parameters.
I wrote a python script that does that. I’ve only tested it under linux. It’s here: https://github.com/dhylands/TinyG-Utils/tree/master/Config (the Config.py script). It can both save and restore complete configurations.