Posts made by superpotatofudge

So I've had other work related things keeping from the ability to work on this problem much for a while. I did however during that time manage to print some new belt tensioner options that work very well. I now have consistent belt tension on all three belts and it is easily adjustable. Right now each is set to ~1lbs 3oz measured at 1" deflection from the tower at the halfway point from top to bottom of the tower.

I've checked the alignment of the towers once again and somehow they're farther off now than they were before. At this point I'm guessing attributed to environmental changes. It goes down to 18C in that room overnight, but during the day with people it runs around 22-24C. Also moisture has gone from 70%RH to 47%RH in the last month. So as of now the towers are very close to 90degrees to the bed. As in I can't slip a sheet of paper in between the square and the tower, but I can see a bit of a gap.

Measurements between the towers at the top and bottom were taken with a 6" caliper using the head to tail methods so they are not absolute measure, but simply relative between each tower. The X-Y bottom: 80.97, top 81.04. Y-Z bottom: 80.13, top: 80.93. Y-Z bottom: 80.24, top: 81.11.

(all measuring etc done with bed@60C)
This is this morning G32 with S-1 before adjustments with 0 offset in the bed.g
Bed probe heights: 0.103 -0.007 0.162 -0.007 -0.057 0.151 0.015 -0.022 0.115 0.020 0.010 0.039 0.011 0.117 0.062 -0.020, mean 0.043, deviation from mean 0.065

I just reran through the "Adding trigger height to bed.g" steps and calculated all the offsets and placed them in my bed.g.
Bed probe heights: -0.017 0.161 0.475 0.368 0.028 0.006 -0.258 -0.232 -0.142 -0.032 0.165 0.191 -0.004 -0.035 -0.136 -0.008, mean 0.033, deviation from mean 0.193

Then G32 with S6 x3
Calibrated 6 factors using 16 points, deviation before 0.197 after 0.052
Calibrated 6 factors using 16 points, deviation before 0.055 after 0.055
Calibrated 6 factors using 16 points, deviation before 0.051 after 0.051

Then I switch back to no offsets (because it was better before) and I get worse results for S-1
Bed probe heights: 0.174 0.022 0.355 0.301 0.210 -0.024 -0.090 0.017 0.015 0.004 0.263 0.186 0.048 0.001 -0.097 -0.128, mean 0.079, deviation from mean 0.144
S6
Calibrated 6 factors using 16 points, deviation before 0.168 after 0.072

Cycled power, now no offsets S-1
Bed probe heights: 0.099 -0.003 0.342 0.339 0.235 0.176 -0.002 -0.070 0.040 0.004 0.126 0.211 0.123 0.101 -0.010 0.009, mean 0.107, deviation from mean 0.121

S6 x2
Calibrated 6 factors using 16 points, deviation before 0.160 after 0.054
Calibrated 6 factors using 16 points, deviation before 0.055 after 0.055

M665
Diagonal 311.755, delta radius 146.204, homed height 360.718, bed radius 140.0, X 0.102°, Y -0.139°, Z 0.000°
M666
Endstop adjustments X-0.18 Y-0.20 Z0.38, tilt X0.27% Y0.19%

And printing a 75mm diameter single layer test disk comes out pretty bad looking still.

I have no clue what else to adjust, what else to modify etc. I've locked everything down mechanically that I can possibly think of and is possible with the melamine frame.

@number40fan:

I'll even add, if I can't get it to work, I'll pay to ship it back to you. Or I could load it up with a couple pounds of tannerite and dispose of it properly.

ROFL the tannerite idea has occurred to me SEVERAL times over the last two years!!

@number40fan:

If you live in the states, I'll pay shipping to take the one you have at home off of your hands to give a go at it. If I can get it to work, you can have it back for the price of my shipping cost plus whatever to get it back to you.

Heh, yep I do and that's mighty tempting! The more I read about Rostocks and their seeming random issues the less I have motivation to tackle it. I've been out of work the last few days sick so I haven't been able to get any more measuring done on the one at work unfortunately.

I just read another thread about calibration and I'm getting the feeling that much longer arms are needed to make anything work right. And the spring tension between arms also being an issue up for debate as to whether it works better or worse. It just seems like there isn't any clear answers when dealing with Rostocks. Yet I see quite a few people getting absolutely fantastic prints out of them…makes me confused.

Great….

Yup the older style CF rods used Traxxas ball ends and used rubber tubing bands to keep tension for that reason..I have that setup on my machine at home that I can't get right either and I've given up on basically. So either both ball end styles are amiss or... idk?

The ball ends are the now standard SeeMeCNC injection molded type. They don't have much play, I have to put some decent effort into poking at the effector to get movement.
https://www.seemecnc.com/collections/parts-accessories/products/replacement-ball-joints

And they came with the Trick Laser effector and mount
http://tricklaser.com/Aluminum-ball-joint-platform-with-Groove-Mount-PLAT-ALU-BJ-32GM.htm

I didn't know they had an odd flatted part on them from the pictures or I would have been suspect of their ability from the get go. However, I cannot believe that SeeMeCNC sells SO many printers with this setup and so many people having more than decent success with them if these balls are the problem.

Bed shift?? I really doubt it. NOBODY was around the machine and it's held in place…it could only possibly rotate around center if it moved at all due to the bed fasteners being at each of the towers. These are the holders I am using for the bed. I couldn't stand the clips because they force the bed to curve to fit the bow in the PCB heater. Which ALWAYS humps in the middle and causes problems. I've tried everything I can find to flatten said heater to no avail. These clips with the TR aluminum heat spreader plate on the PCB allow the glass to sort of float at the edges and reduce the overall affect of that curve.
https://www.thingiverse.com/thing:974489

@number40fan:

There you are….took me a bit to find this thread again. Do you have a way to measure the width of the diagonal arms near the carriages and at the effector? Reading above, someone in the "shop" has a large caliper. Might have them check the uprights/tower spacing, if you could. Place a flat bar on the inside from tower X to Z and measure how far away Y is. Do this for all three towers at the bottom, middle and top. There has to be something seriously wrong to have your calibration disk to come out like that.

One last thing, can you post a picture of how you have your Z-probe mounted?

Another fun print has been added that clearly failed horribly! No clue what happened there with the massive shifting.

I can measure diagonal arm width, I have standard 6" calipers. However, that almost seems moot since the width likely changes a bit since the SeeMeCNC ball ends aren't exactly round and looks to me like the arms would shift a bit during operation.

And yup I asked them to check that tower distance also, so they SHOULD have. However I can check that again.

I also posted a few more pics to that same imgur link. The terrible print and the mount for the IR sensor.

Here's images of the 40x40x2 block. And a 75mm diameter 0.2mm high calibration disk.
http://imgur.com/a/1iV34

@number40fan:

Did you save the results before printing?

After running auto calibration and before doing anything else, run the bed mesh compensation and see what your bed map looks like.

Don't forget that you can calibrate the steps of each motor too. Find an accurate way to measure the movement of the X, Y and Z carriages. Command 100mm movement and measure actual movement.

I'm going to post pictures in a bit if I can get a chance. I haven't done any mesh compensation yet, I'll look at that tomorrow I guess.

I'm not horribly concerned about the steps/mm thing. Those measurements are pretty darn close and could just be shrinkage of materials. I won't worry about perfect dimensions until I get the rest sorted out. Simply being able to print a good looking object is the primary concern right now. So far everything I've printed looks horrid with wavy walls and banding.

@number40fan:

Any progress today?

Sort of …it's printing. Which is better than it was before. Sadly I've now also experienced some interesting heat creep type problems which I never had before...so I'm trying to understand what changed that as the only hot end related changes were to a PT100 and the all brass heat block, which I'd have thought would reduce such type of problems.

This morning I run G32 and here's the results, bed @60C, nozzle@ 200C :
Calibrated 8 factors using 16 points, deviation before 0.089 after 0.043
Calibrated 8 factors using 16 points, deviation before 0.047 after 0.043
Calibrated 8 factors using 16 points, deviation before 0.048 after 0.039

So I'm thinking that's looking pretty good now. I fire off an XYZ calibration cube print and it looks terrible!
First layer is still doing exactly the same thing I've been seeing for weeks now. Toward the right side of the machine (between Z and Y tower and around to the front) the first layer prints SUPER thin, just measured 0.07 and the left side between X and Z towers is 0.19 or 0.17 depending on how far forward or aft it is measured.

The 'cube' is supposed to be 40x40x20 and I'm measuring ~39.16x39.14x19.91.

This is still with NO H offsets in the bed.g. Just the 8 factor calibration

@dc42:

You can use a nozzle contact Z probe, such as the one we've just started selling (https://www.duet3d.com/DeltaSmartEffector) or a piezo probe, to avoid the problem of trigger height changes caused by effector tilt. But whatever causes effector tilt causes other geometrical issues too.

I'm frankly not sure I'm willing to spend MORE money on the same machine. Every time there's a new fangled thing that is supposed to make it better and awesome all I ever get is a headache and marginal improvement if any. $500+ extra into it and I'm still no better off than the original machine with manual calibration mixed with some formula and guesswork. If the readings I've posted above are finally right and I can get some prints I will be truly amazed!

What say you about the automatic arm length calculations here? Everywhere I read that I shouldn't, but that 8 and 9 factor FINALLY shows decent results.

@Eddiie:

Grumble. It seems calibrating a delta is never complete.
My effector tilts a little bit too. It sucks but I think the bigger the radius, the worse the tilt on the outter edge. So, smaller radius means no tilt. There is some math out there to calculate the radius based on many angles and variables but no doubt it is a labor of love it seems. My Prusa clone printer is so darn reliable, thank god I got that to use while I toy with my Delta.

I'd LOVE to see 3 IR probes, one for each tower! I think that is the only way…

How is your dimensional accuracy?

Ha no kidding. One of my Rostocks at home is still in the same pile of parts it was almost 2 years ago because I basically gave up on it. I was never able to reliably print anything larger than 100mm circle. And even that was not great. Anything under that and it was flawless beautiful prints. Also note that a Rostock was my very first 3D printer….over four years ago!

Dimensional accuracy on the machine in question is undetermined...I haven't even been able to get a solid print out of it since I started this maddening upgrade process last month. Tomorrow when I get back to the office I can load up filament and test with the results I was able to get yesterday operating it remotely.

@number40fan:

Increased the rod length quite a bit. I know David (DC42) says not to let it calibrate rod length if you know the exact length, but if it helps with calibration, I can't see why not. Your 9 factor proved that. You can save the results with M500 if you wish and when you get back to the machine, see what happens with a print. When I had massive effector tilt, it had to do with rod spacing. It was a cheap DIY delta that had a 3mm difference between the top and bottom widths of the diagonal arms.

Yup, I haven't measured the rods myself other than a quick guess with a decent ruler as I don't have a jig for proper center to center right now. And everything I read basically said "DON'T DO IT" to using the automatic rod adjustments. So that's the first time I've used the autocal with rod adjustment. Each of the rods came to me with 300.15 written on them and I'd assume that since TR uses a jig for manufacturing them…they might actually be exact. I'm not sure what to believe on that front now.

@number40fan:

Can you run M665 and M666 to see what the results were?

M665
Diagonal 311.755, delta radius 145.957, homed height 360.711, bed radius 140.0, X 0.295°, Y -0.288°, Z 0.000°
M666
Endstop adjustments X-0.53 Y0.27 Z0.26, tilt X0.17% Y0.23%

@dc42:

You could also try 8 factor calibration in case there is some bed tilt.

Is there a particular pattern to the height errors? For example, high spots between pairs of towers?

Did you run auto calibration a couple of times before doing those 4 runs in report-only mode?

Ok, so I finally got to doing it remotely today, so I haven't/can't do anything physical to adjust anything until Monday. But I was able to run a 9 factor:
Calibrated 9 factors using 16 points, deviation before 0.047 after 0.043
Calibrated 9 factors using 16 points, deviation before 0.043 after 0.043

Followed by S-1 report:
Bed probe heights: 0.028 -0.083 0.088 -0.024 -0.042 0.059 -0.005 -0.039 0.061 0.026 -0.002 0.052 -0.036 0.034 0.010 0.003, mean 0.008, deviation from mean 0.044

9 again:
Calibrated 9 factors using 16 points, deviation before 0.044 after 0.040
Calibrated 9 factors using 16 points, deviation before 0.048 after 0.043

8 factor:
Calibrated 8 factors using 16 points, deviation before 0.047 after 0.045
Calibrated 8 factors using 16 points, deviation before 0.047 after 0.044

And then I started getting "G32
Error: G-Code buffer '$s' length overflow"

So that's where I'm at now. Looks a load better than it did!

@number40fan:

You don't have to save the results, but what happens when you try a 9 point factor?

Haven't tried that yet. Will likely have to wait until Monday when I get back to the office.

@dc42:

Whatever is causing the tilt will be causing geometrical inaccuracies too, and also causing the relative heights of the IR sensor and the nozzle to change - which causes the trigger height of the IRT sensor (relative to the tip of the nozzle) to change. You can compensate for the variation of trigger height using H parameters on the G30 commands in bed,g, although measuring all the trigger heights is tedious. It's better to fix the geometrical issue that is causing the tilt. See https://duet3d.com/wiki/Calibrating_a_delta_printer#Make_sure_your_build_is_accurate for common causes.

Yup I'd prefer to fix the mechanical geometry. I've also done the H value offsets before by doing that tedious sampling. It didn't seem to help and barely reduced the error…or somehow I managed to do it wrong. And since I don't have all the high dollar tools, the machinist guys in the shop took it out and put their fancy run-out dial indicators on the towers and used some rather expensive 1m long calipers and gave it back to me and said it was square as could be with the flexing melamine frame. However, I didn't have them measure the rods. I simply trusted that TR makes them accurate since they use a jig. Bad assumption?

I've also read that guide and looked at the carriages, the ball ends..etc. At this point IF there is something out of alignment I'm sure not seeing it or have no way to verify it. I'm leaning toward the ball ends being the issue, but can't say exactly how or why.

So to start with I've been toying with this for several weeks, been quite busy at work so I caused myself problems early on by trying to move too fast through the write-ups and missing stuff!

The machine is a Rostock Max V2 melamine frame. It has an E3D v6 mounted with the Trick Laser aluminum effector and mount combo. Arms are Trick Laser CF labeled 300.15mm with red ball cup ends using the supplied (rather stiff) springs for tension. Carriages are SeeMeCNC injection molded. The heated bed PCB is the original, the build surface is original glass that has been painted matte black on the back per my readings here and Dave's write-up about using his IR leveling sensor.

Original mechanical end stop switches were flipped around so the metal lever no longer causes variance in activation. The screws now strike directly at the plunger.

Belt tension has been set using a digital gauge measured at 12" up from the base top plate with the belt at 1" of deflection from the tower so I know they are all within 0.05oz of each other.

The effector DOES tilt ever so slightly as noted by a cheap bullseye level. Not accurate enough to give me specific degrees, but quite clear there is a bit of movement.

I've even swapped out the TR tension springs for lesser power springs several times downgrading until the springs were so weak they couldn't hold the effector to the arms.

Current bed.g setup for 16 points, 6 factor.
Here are the results of four runs of G32 w/S-1

Bed probe heights: 0.004 -0.177 0.045 0.057 -0.374 -0.276 -0.034 -0.512 -0.465 -0.148 -0.112 -0.035 -0.238 -0.162 -0.285 -0.233, mean -0.184, deviation from mean 0.167

Bed probe heights: -0.009 -0.189 0.045 0.044 -0.374 -0.263 -0.021 -0.500 -0.465 -0.161 -0.112 -0.035 -0.226 -0.137 -0.272 -0.220, mean -0.181, deviation from mean 0.163

Bed probe heights: -0.009 -0.202 0.020 0.032 -0.374 -0.238 0.016 -0.475 -0.452 -0.148 -0.112 -0.035 -0.213 -0.112 -0.272 -0.220, mean -0.175, deviation from mean 0.158

Bed probe heights: -0.021 -0.214 0.020 0.032 -0.361 -0.226 0.016 -0.475 -0.465 -0.161 -0.125 -0.048 -0.213 -0.112 -0.272 -0.220, mean -0.178, deviation from mean 0.156

Help me see what I'm not seeing!

Well I just ran
Room temp bed G32
Bed probe heights: 0.345 -0.136 0.308 0.302 -0.233 -0.201 -0.018 -0.385 -0.098 -0.021 0.223 0.127 -0.085 -0.134 -0.135 -0.095, mean -0.015, deviation from mean 0.208

60C bed G32
Bed probe heights: 0.495 0.039 0.471 0.477 -0.095 -0.076 0.132 -0.260 0.015 0.091 0.335 0.227 0.053 -0.047 -0.035 -0.008, mean 0.113, deviation from mean 0.219

So that doesn't look great. And I just noticed that the X carriage seems to have a lot more friction and resistance to movement than the other two carriages. I didn't notice before I guess because the belt tension was so much higher than the other belts. Now it is quite obvious so…off to figure out why it is significantly worse.

@Whitewolf:

@superpotatofudge:

So Whitewolf, why are you using such a drastic Z steps/mm??

I've recalibrated my extruder steps/mm and now I'm bang on to 100mm, minus flex/takeup inside the Bowden tube as there is some internal slop. I'm still not using pressure advance, but my prints look like absolute crap.

Somehow suddenly square corners aren't square. And by that I mean they aren't 90 degrees anymore. And my bed still seems high on the right side. I thought autocalibration was supposed to handle that leveling.

Z step per mm will be drastically different for every machine…. I have a 1.25 pitch leadscrew direct driven 400 is as fast as i can get it before it stalls... DC said his can only do 100 based on his configuration.

Not sure what is causing the rounded corners... are you sure pressure advance is off both in config.g and config override as well as start g code in your slicer

Ahhh ok, for some reason I thought you were also running a Rostock so I was like..whaaaat? That's why it didn't make sense to me.

Pressure advance definitely disabled in config.g and doesn't even exist in config-override.g. The odd thing about the square issue is that the outside corners are fine. I've put my machinist squares on them and they're basically perfect 90. As well as an FDM plastic 90 can be anyhow. It's just the inside corners on a hollow square column that made me notice in the first place.

I just checked belt tension and the X tower has almost 2oz more tension than the others, with Z being lightest of all of three. I have no clue how much tension differential could be playing a part, but my other Rostocks I all have within .5oz of each other. Not sure what happened to this one to make it this far off, but I'll rectify that shortly.

So Whitewolf, why are you using such a drastic Z steps/mm??

I've recalibrated my extruder steps/mm and now I'm bang on to 100mm, minus flex/takeup inside the Bowden tube as there is some internal slop. I'm still not using pressure advance, but my prints look like absolute crap.

Somehow suddenly square corners aren't square. And by that I mean they aren't 90 degrees anymore. And my bed still seems high on the right side. I thought autocalibration was supposed to handle that leveling.

Thanks for the input!! I'll look into the Capricorn PTFE. The only downer there is the lack of translucency for the ultra slick variety. But I suppose it is a worthwhile trade for being extra slick for long runs. So far I haven't had any issues with needing a clip, I always keep pressure on the tube when I push it in and use my fingernail to pull up on the built in clips and then double check from time to time that the tube has no play. Thus far I still haven't had a single instance of there being slop since I started that method.

Looking at your settings I see some rather glaring differences to what I've gleaned for the Rostock!
How do you get that Z2560 for M92 steps/mm?? That's crazy… most of my settings were either pulled from my RAMBo EEPROM or from mhackney's Duet config.

Currently I have:
M92 X80 Y80 Z80 E92.65

My motor currents are based on the same 1 amp used with the RAMBo for the Automation Tech steppers.
M906 X1000 Y1000 Z1000 E800 I30
Acceleration is based on what was used on RAMBo and what I've seen from others on the SeeMeCNC forum
M201 X1850 Y1850 Z1850 E6500
Max speeds taken from previous firmware
M203 X21000 Y21000 Z21000 E6000
Jerk taken from previous firmware and not increased based on mhackney and others on SeeMeCNC forum settings
M566 X2100 Y2100 Z2100 E1200

I had pressure advance set, but I thought it may be causing problems since I've never used it before. So I commented it out to work on later.

As for extrusion calibration... 99.443 is the average extrusion amount. So I'm pretty happy with that, but could be a little better. And my steps/mm for the extruder are 92.65.