Adjusting Tower Rotation with Alpha A/B/C in EEPROM?

[MSURunner]

http://www.youtube.com/watch?v=qrrO0elG ... e=youtu.be

Here's the quick first draft video of the calibration process I went through. I forgot to mention that when using the calibration tool, you want to leave it still attached to the printer bed, do not simply toss it up there as I do in the video for demonstration sake only. Anyhow, it should get someone pretty close without having to do a ton of guess and check, but there is still some print, examine, adjust, print again involved, particularly once you get to the bed level guide.

[Eaglezsoar]

http://www.youtube.com/watch?v=qrrO0elG ... e=youtu.be

Here's the quick first draft video of the calibration process I went through. I forgot to mention that when using the calibration tool, you want to leave it still attached to the printer bed, do not simply toss it up there as I do in the video for demonstration sake only. Anyhow, it should get someone pretty close without having to do a ton of guess and check, but there is still some print, examine, adjust, print again involved, particularly once you get to the bed level guide.

Thanks for the video. Now I am beginning to understand.

[geneb]

Excellent work!

Thanks!

g.

[enggmaug]

your way of measuring actual parameters to fill in Repetier totally makes sense.
It's exactly how things should be....

But I must be a moron, my machine won't work with those settings.

I've been trying to calibrate my machine for so long, I think I'll just wait until I receive the height comparator I ordered to do it my way.

Too bad I won't be printing in few days, but hey, it has been 10 days I spend at least 1 hour after work to calibrate, without success. I kinda wish I never decided to resquare these towers. It used to print not too bad before that.

[Eaglezsoar]

your way of measuring actual parameters to fill in Repetier totally makes sense.
It's exactly how things should be....

But I must be a moron, my machine won't work with those settings.

I've been trying to calibrate my machine for so long, I think I'll just wait until I receive the height comparator I ordered to do it my way.

Too bad I won't be printing in few days, but hey, it has been 10 days I spend at least 1 hour after work to calibrate, without success. I kinda wish I never decided to resquare these towers. It used to print not too bad before that.

Could you describe the height comparator you purchased?

[neurascenic]

Wonder if my laser rangefinder would work? Though, it is more of an architectural scale, so probably not precise enough.

[MSURunner]

Wonder if my laser rangefinder would work? Though, it is more of an architectural scale, so probably not precise enough.

Unless it can get within .5mm I would say no...

[neurascenic]

Yea, think it is more like 1.5 mm But I shall check just out of curiosity.

Thanks!

[enggmaug]

Could you describe the height comparator you purchased?

It looks like the one in the picture I already put here : [img]http://img.directindustry.com/images_di ... 081773.jpg[/img]

But I'm still due to receive it.

[Eaglezsoar]

Now I understand, the words height comparator threw me a curve. I call those dial indicators that why I got confused.
But it doesn't take a whole lot to confuse me.

[enggmaug]

Well, I may have used the wrong word.
English is not my mother tongue, but I found links in google when I searched for "height comparators" , so I assumed it was the english name for it.

Dial indicator sounds good to me too... just that I did not search that one yet

Anyway, the main thing is that I finally got understood... as it does not occur so often.

[Eaglezsoar]

Well, I may have used the wrong word.
English is not my mother tongue, but I found links in google when I searched for "height comparators" , so I assumed it was the english name for it.

Dial indicator sounds good to me too... just that I did not search that one yet

Anyway, the main thing is that I finally got understood... as it does not occur so often.

No problem, I also learned a new term - height comparator. Makes sense to me now that I saw the picture.
English may not be your mother tongue but I would not have known if you didn't tell me. If I tried to communicate
using your mother tongue it would be nothing but gibberish because I don't have any idea how to speak or write in
anything but English. Your English skills are excellent.

[enggmaug]

haha, you'll make me blush.

By the way, off topic, but have you seen a STL file of a dial indicator/height comparator mount for the RMax ?

I found many, just not for the RMax. Sounds like I'll have to design one myself.

[Eaglezsoar]

haha, you'll make me blush.

By the way, off topic, but have you seen a STL file of a dial indicator/height comparator mount for the RMax ?

I found many, just not for the RMax. Sounds like I'll have to design one myself.

Here you go:

Dial Indicator Mount Rostock.stl

(1.03 MiB) Downloaded 272 times

[enggmaug]

Thanks a lot !!


you are full of resources ! (I guess it was not on thingiverse, or I would have found it...)

From this point, with this tool, I'll have 2 approaches.

First, make an excell sheet that would give parameters to modify in order to be better calibrated from a given number of measurments on the plate (Probably 7, but maybe more...)

Second, if the calibration is still not perfect, make a post slicing python script that would translate GCode in order to adapt the movements to the machine geometry, given a number of height measurments. (mapping and interpolation)

Before I do all that, I'd like to know if I am the only one who did not manage to calibrate my machine following the instructions in the indeed very good video posted before ?

[Eaglezsoar]

Thanks a lot !!


you are full of resources ! (I guess it was not on thingiverse, or I would have found it...)

From this point, with this tool, I'll have 2 approaches.

First, make an excell sheet that would give parameters to modify in order to be better calibrated from a given number of measurments on the plate (Probably 7, but maybe more...)

Second, if the calibration is still not perfect, make a post slicing python script that would translate GCode in order to adapt the movements to the machine geometry, given a number of height measurments. (mapping and interpolation)

Before I do all that, I'd like to know if I am the only one who did not manage to calibrate my machine following the instructions in the indeed very good video posted before ?

You are welcome and it is not on Thingiverse, I guess the author did not want you know who to have it.
You are not the only one concerning the video, the instructions in the assembly guide is the best way to calibrate your machine. Geneb devoted a lot of time creating those instructions.

[enggmaug]

About my machine, I have apparently been too confident in myself...

I carefully squared the towers towards the center of the plate with the clamps on... but stuppidly assumed the clamps would keep the towers square on the sides... I somehow feel ashamed for myself.

I just lost one week of evenings trying to calibrate on that pisa tower...

Now, I re squared another time.... I should be able to print soon, if my wife doesn't complain too much.... (I wish I could print myself a new one)

I'll try again the instructions from the video and let you know how it goes.

[Eaglezsoar]

Good luck on that calibration and if you figure out how to print a new one please send me a PM, I could use that information!

[enggmaug]

I managed to better calibrate the printer, and I cant print small objects again. I used the directions on the video, just not using the printed part.

I'm still waiting for the comparator / dial indicator to fine tune my calibration. It should be here soon now.

[MSURunner]

I managed to better calibrate the printer, and I cant print small objects again. I used the directions on the video, just not using the printed part.

I'm still waiting for the comparator / dial indicator to fine tune my calibration. It should be here soon now.

The purpose of the printed part is to get a better understanding of the difference between the top and bottom of the printer. I use it to average between the bottom measured difference (more accurately measured) and the top approximately measured difference and tweak as necessary. It sounds like there's been enough of the community views on the view to determine what works/doesn't work as far as explaining the process. Any feedback would be appreciated and I can re-shoot it in a more finalized state. Otherwise, if it works or is largely ineffective in getting people closer to printing, I'll just leave it there/remove it.

[enggmaug]

To measure the difference between the top and bottom, I pin pointed the bottom center as you shown on the vid, and measured the distance to each tower.

Then Homed the printer, and measured the distance to each tower, using squares to do it properly.

I then substracted one from the other to get the difference.

I did not quite get why do you need to print the part you gave the link for... ? How does it make it easier ?

If you bring in the size of a printed part in your calculation, and that printed part is from a not yet calibrated printer... I don't get how it could make things easier or more accurate ?

[MSURunner]

The printed part simply offsets the center of the printer the distance of half the aluminum extrusions so that a more precise tool can be used. You could simply pin the center and measure to the belt with a square and then add half (or in my case half minus the 2 mm the center appears to be inset), but I felt it was easier to get a consistent measure with the calibration part.

[lordbinky]

I liked how the printed part aligned with the edge of the extrusion making it a straightforward measurement.

The flaw I found in my use of it was that the print varied in dimensions slightly throughout adjustments. The inaccuracy from that variance seemed to be larger than the inaccuracy I got from measuring between the tower and print head dots on paper with the back of my long calipers. I could measure and correct it each time, but along with that step and the time printing I preferred to get more iterations in a set amount of time.

Then I got distracted by exporting my eeprom settings and then just changing settings trying to get a feel for the corrections.

[enggmaug]

The printed part simply offsets the center of the printer the distance of half the aluminum extrusions so that a more precise tool can be used. You could simply pin the center and measure to the belt with a square and then add half (or in my case half minus the 2 mm the center appears to be inset), but I felt it was easier to get a consistent measure with the calibration part.

The minus 2mm is another thing I didn't get from your video : The position of the belt does not influence in how the cheapskates move imho.

And I don't see why you need to measure to the center of the tower, since you'll substract measurments anyway, you could measure from the flat in side of the tower to the center. If you substract the top/bottom measurments, you'll substract the half width of the tower...

So there are some parts I quite don't get in what you do, but for most of the rest it's a great video and I thank you for it : it helped me understand what were really tower rotation and delta radius.

And putting parameters knowing what you do rather than just changing random numbers is really gratifying.

[lordbinky]

From what I understood, and it ended up being similar for me, was the tensioner at the top wasn't directly centered over the extrusion. So you're not taking a measurement to either belt, but the midpoint between them. Which would be the equivalent to the center of a rod setup.