Prints are too tall

calabus · Post by **calabus** » Sat Mar 21, 2015 12:28 pm

I am just now getting my calibration dialed in and printed a few calibration cubes. I was looking for problems such as warping, bridges, layer adhesion and such but never really looked at the overall cubes. Once I measured them they are about 2mm too tall. I have a layer height of .2mm So where am I going wring here? Where should I look for the issue?

teoman · Post by **teoman** » Sat Mar 21, 2015 12:34 pm

And the other dimensions?

calabus · Post by **calabus** » Sat Mar 21, 2015 1:14 pm

They seem consistent, but not accurate. My 25mmx25mm hollow cube is coming out about 26.4mm wide on all sides, but almost 29mm height.

*edit
Here is the cube file if that matters
http://www.thingiverse.com/thing:5011

Polygonhell · Post by **Polygonhell** » Sat Mar 21, 2015 1:49 pm

If the height is incorrect, you have a bad setting in the firmware, most likely Steps per mm for X/Y/Z.
That setting needs to be calculated from the pulley tooth count and the fact you are using GT2 belts.
The correct setting for an Early V1 Max is 53.333333 steps per mm
The correct setting for Late V1 and all V2 Max's is 80 (I think - assuming they use a 20 tooth pulley still)

calabus · Post by **calabus** » Sat Mar 21, 2015 2:01 pm

Polygonhell wrote:If the height is incorrect, you have a bad setting in the firmware, most likely Steps per mm for X/Y/Z.
That setting needs to be calculated from the pulley tooth count and the fact you are using GT2 belts.
The correct setting for an Early V1 Max is 53.333333 steps per mm
The correct setting for Late V1 and all V2 Max's is 80 (I think - assuming they use a 20 tooth pulley still)

In Repetier I pulled up the firmware settings and Steps Per mm are 92.650 I don't recall setting that manually, but it's possible I did and just forgot. Is this where I should be looking and not in configuration.h? I'm not really sure what version of the V1 I have. What should I look for to distinguish between the early and late V1?

IMBoring25 · Post by **IMBoring25** » Sat Mar 21, 2015 2:33 pm

That makes sense for your machine having an 80 nominal.

92.650 steps/mm / 80 steps/mm = 1.158.

29 mm / 25 mm = 1.16.

16% too many steps, 16% too-tall parts. Not looking like a coincidence.

calabus · Post by **calabus** » Sat Mar 21, 2015 2:44 pm

IMBoring25 wrote:That makes sense for your machine having an 80 nominal.

92.650 steps/mm / 80 steps/mm = 1.158.

29 mm / 25 mm = 1.16.

16% too many steps, 16% too-tall parts. Not looking like a coincidence.

Solid math there. So I set the Steps to 80 and tried to run the cube print again. The print starts about 3 inches above the bed. I guess I now need to run through the entire calibration process again or can I just reset Z height?

IMBoring25 · Post by **IMBoring25** » Sat Mar 21, 2015 3:45 pm

I thought about putting that in the previous post, but I'm still kind of new to the delta math. That may be a full cal. If everything was perfectly square the endstops would still be in the right places, but everything may not be perfectly square. With the distances being different it may take a different delta radius too.

techstorage · Post by **techstorage** » Sat Mar 21, 2015 4:24 pm

I think 92.650 is the setting you were to make for the Extruder stepper motor. It has been a few months now so I could be mistaken.

calabus · Post by **calabus** » Sat Mar 21, 2015 5:07 pm

Setting the Steps to 80 and resetting Z height and changing firmware to match the new number results in a new cube about 23.75mm square at the base. It's still printing, but the height will probably be too high as the rest of my runs. Maybe bad slicer settings and firmware settings?

*print finished and I have 25mm height and 23.3mm width.

Earthbound · Post by **Earthbound** » Sat Mar 21, 2015 7:00 pm

Dimensional accuracy in Z-axis of print confirms that the tower steps per mm is now correct. And yes, the 92.650 number is the default(?) for EZstruder steps/mm.
Undersized X and Y axis on print suggests that something needs mechanical adjustment (belts, cheapskates, u-joints).

I don't recall if Gene explained it in the manual or not, but the 80 value for tower steps is based on:
20 tooth pulley driving a GT2 belt (which has 2mm pitch) so each turn of the pulley equals 40mm of travel. Stepper motors turn 1.8 degrees per full step (200 full steps per revolution) and the V2 uses RAMBo in 1/16 microstepping mode so there are 3200 microsteps for each turn of the stepper motor. 3200 steps for 40mm travel = 80.

Polygonhell · Post by **Polygonhell** » Sat Mar 21, 2015 7:02 pm

What's your arm length set to in the firmware?
Should be 269mm unless you have some sort of DIY arms.

calabus · Post by **calabus** » Sun Mar 22, 2015 8:15 am

Polygonhell wrote:What's your arm length set to in the firmware?
Should be 269mm unless you have some sort of DIY arms.

Yep it is set to 269mm. I have attached my EPROM file if that helps.

RobertPhoenix · Post by **RobertPhoenix** » Tue Mar 24, 2015 6:53 pm

I am using the MatterControl software which I downloaded just this weekend together with the settings from SeeMeCNC

I am having exactly the same problem. I printed the PEEK fan shroud and it was nowhere near the right size. I used Sketchup to design a 25 mm cube and printed that.

The height is 28.9 mm and each side is about 26.15.

I checked the Steps per mm and I also had a setting of 92.65. I've now changed it to 80 and I'm about to do a new calibration and test.

Seems like the bad value is in the configuration file when you download the Rostock MAX V2 version of MatterControl. I'll let everyone know the result of the next print !

RobertPhoenix · Post by **RobertPhoenix** » Tue Mar 24, 2015 9:20 pm

I ran my test piece after changing steps to 80. Now I am amazed at how accurate the piece is

Height 25.01, 25.11
Sides 25.18, 24.97, 24.92, 24.99

calabus · Post by **calabus** » Thu Mar 26, 2015 6:13 pm

RobertPhoenix wrote:I ran my test piece after changing steps to 80. Now I am amazed at how accurate the piece is

Height 25.01, 25.11
Sides 25.18, 24.97, 24.92, 24.99

That's awesome! Wish I could find out where my settings are off. Has to be maybe bed size or printable size? What are yours? Maybe I can compare.

zerjuuk · Post by **zerjuuk** » Wed Apr 01, 2015 9:18 pm

I was having the same issue with the steps. Changing the steps fixed the height, but now the X, and Y are too small.
I used the calibration cube that was in mattercontrol, it should be 20x20x10mm. The Height is 10.08 , that is great, but now the X and Y are 18.22, and 18.26.
The arms length is 269, and I'm printing ABS with a 0.35 nozzle. The first layer at 0.32, and the others at 0.15.

KAS · Post by **KAS** » Wed Apr 01, 2015 9:24 pm

Your nozzle is .35 and your first layer is .32? Maybe try bringing that down a bit and run everything at .20 and see how it goes?

edit: well maybe not, your Z isnt that out of whack. It just seems like your laying the filament on the glass vs giving a good squish for adhesion.

zerjuuk · Post by **zerjuuk** » Thu Apr 02, 2015 1:01 am

KAS wrote:Your nozzle is .35 and your first layer is .32? Maybe try bringing that down a bit and run everything at .20 and see how it goes?

edit: well maybe not, your Z isnt that out of whack. It just seems like your laying the filament on the glass vs giving a good squish for adhesion.

That's the only way I could get the ABS to stick to the kapton tape. Any thinner and nothing sticks, I'm running the bed at 110, and the nozzle at 238.

Edit: I didn't do a calibration test after fixing the steps, I just redid the Z = 0. After that the parts started printing out good.

calabus · Post by **calabus** » Sat Apr 04, 2015 1:13 pm

zerjuuk wrote:I was having the same issue with the steps. Changing the steps fixed the height, but now the X, and Y are too small.
I used the calibration cube that was in mattercontrol, it should be 20x20x10mm. The Height is 10.08 , that is great, but now the X and Y are 18.22, and 18.26.
The arms length is 269, and I'm printing ABS with a 0.35 nozzle. The first layer at 0.32, and the others at 0.15.

I'm still stuck with the issue as well. My Z is 24.99 but the rest are about 23.37 Not really sure where to go from here. I was thinking of decreasing the arm length number by 1 and see if that changes anything at all. I'm printing a 25x25x25 hollow cube

**Edit

I adjusted my rod length down from 269 to 264 which increased the X Y print size to about half the difference of what it should be which is 24.2 Now setting length to 260 and will see if that actually gets this sucker dialed in! Hopefully my Z height remains accurate...which it should.

calabus · Post by **calabus** » Sun Apr 05, 2015 10:13 am

Adjusting rod length is the way to go I guess. I'm getting pretty close the 25mm target. Another adjustment or two and I think it will be darn near perfect.

*edit
After doing some reading it looks like the same results can be had by adjusting the Printable Radius. Mine is set to 138 (not sure where I got that number) and the normal radius should be about 129 or 130. So if I set it to 130 and put the rod length back to the default of 269 it seems like I will be back where I started with prints that are too wide. Or am I thinking this out wrong?

KAS · Post by **KAS** » Sun Apr 05, 2015 4:42 pm

hmm, from my understanding some of those setting may in fact get your desired target in the middle of the bed, although around the perimeter could be a different story.

Once you get that middle setting were you want it. Do a final test and place 6 cubes around the bed at X/Y/Z and between each tower. See if those changes mess with anything towards the outside.

http://boim.com/DeltaUtil/CalDoc/Calibration.html

Post by **Eaglezsoar** » Sun Apr 05, 2015 5:20 pm

See this thread.
http://forum.seemecnc.com/viewtopic.php?f=37&t=2318

calabus · Post by **calabus** » Mon Apr 13, 2015 8:33 am

I went through the linked threads and saw nothing there that I have not already tried or checked. All my settings in EEPROM and software are correct (20 tooth and steps). The only thing off was the print area. I took a few days away from printing and decided last night to just set everything to default (arm length and print area). Ran through the entire calibration process again and now the prints seem to be accurate. So essentially the only thing that changed was print area.... I think. I've made so many adjustments I might have lost track of some other change I made, but I don't think so. Now I just need to make backups of my Repetier settings just in case.

Post by **Eaglezsoar** » Mon Apr 13, 2015 12:48 pm

calabus wrote:I went through the linked threads and saw nothing there that I have not already tried or checked. All my settings in EEPROM and software are correct (20 tooth and steps). The only thing off was the print area. I took a few days away from printing and decided last night to just set everything to default (arm length and print area). Ran through the entire calibration process again and now the prints seem to be accurate. So essentially the only thing that changed was print area.... I think. I've made so many adjustments I might have lost track of some other change I made, but I don't think so. Now I just need to make backups of my Repetier settings just in case.

Keeping track of the changes is difficult, I went through the same thing.
Changed a lot of settings without documenting the changes then forgot what I had changed, I think that we all got hit with that one some time or another.
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