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Re: Removing vertical lines on prints - 9 years ago

Quoteo_lampe I wonder, if we can stretch the discussion to investigate extruder drive gear diameter and it's teeth count. At least in my imagination the extrusion quality has an impact in surface quality as well. But you can't change it, just by changing layer height. I see an ( again academic ) difference between a classic 40 tooth MK8 drive gear and a similar 41 teeth gear. ( again prime number

by nebbian - Delta Machines

Re: Removing vertical lines on prints - 9 years ago

QuoteDjDemonD Print one? I presume it would be a 16t pulley with 2.01127124375 mm spacing. You're a devious, clever man. Of course, you'd have to stretch the belts quite a bit, but it certainly seems possible... You've got me thinking now, you bugger!!!

by nebbian - Delta Machines

Re: Double sided/passthrough bowden connector? - 9 years ago

I drill mine out as well, as Srek says you have to be a bit careful. They are made of brass, which does tend to grab the drill bit. A drill press can help to ensure you don't go too far.

by nebbian - General

Re: Removing vertical lines on prints - 9 years ago

QuoteDjDemonD No problems, what is your analysis of them? The microdelta shows your classic non-modded-driver tree ring pattern. Mod them and it will be vastly reduced. Of course, it's only a problem if you decide to print close to multiples of 0.16mm layer height, and really, why would you? One thing I'm starting to realise is that 16 tooth motor pulleys are superior to 20 tooth pulleys on d

by nebbian - Delta Machines

Re: Removing vertical lines on prints - 9 years ago

Legend! Many thanks for doing those prints, much appreciated. Edit: Just listened to that recording, wow I've never heard something sound like that before. Surreal!

by nebbian - Delta Machines

Re: Small, light, effective fan shrouds for popular hotend designs - 9 years ago

Those fans are great, aren't they? Try printing this duct in ABS or PETG and see how it goes. It should click straight onto those 30mm sunon fans, once you click off the existing face plate. I've been using a similar design for a few months on my mini, and think it works quite well.

by nebbian - General

Re: Removing vertical lines on prints - 9 years ago

Thanks for those cubes DJ. You won't see any tree rings if you use 16 tooth pulleys and 0.202 layer height. Try a cube at 0.161 layer height on your microdelta, I'm betting that you'll see some tree rings. Also, the one result I'm really interested in is seeing a cube from your XL at 0.161 layer height. It would be best if you set the drivers to 16 uSteps, no interpolation for this test.

by nebbian - Delta Machines

Re: E3D-v6 hotend has poor design for printing 3mm PLA using Bowden extruder? - 9 years ago

I've been doing similar experiments. The problem I see is that if the soft PLA is retracted back into the heat break, then it can expand on the next unretract and jam against the walls of the metal heat break. Others have used polishing techniques such as this one: to make the plastic less likely to stick. One design that works really well for me is to drill out the heat break till almost ri

by nebbian - General

Re: Removing vertical lines on prints - 9 years ago

QuoteDjDemonD I'll try to get few cubes printed on the micro delta now its back together after failed attempt to use tmc2100s, now back using A4988s so testing the rosc mod should be quite doable. It's still running off good old ramps. Good stuff DJ, looking forward to seeing them. I'd also really like to see two cubes from a delta that runs on a duet wifi/ethernet, if anyone has one going. If

by nebbian - Delta Machines

Re: Extruder advance - 9 years ago

I was having some issues with retraction, so did a hack to disable this when retracting/unretracting. It seems to be working well now, but I'm keen to do a better fix for retraction. I'm keen to see if anyone else wants to try it out. To enable, send: M572 S0.1 Values from 0.05 to 0.15 seem to be in the right zone for my delta with a short bowden using PLA.

by nebbian - Smoothie

Re: Removing vertical lines on prints - 9 years ago

Quotepaboman very interesting, will try that numbers on my smoothie. did you noticed any improvement using anything beyond a4988 ? Yep, the print quality I found, in order from worst to best: Stock DRV8825 - worst Stock A4988 Modded DRV8825 Stock SD6128 Modded A4988 Modded SD6128 Stock TMC2100 - best, although it has issues with torque

by nebbian - Delta Machines

Extruder advance - 9 years ago

Here's where I'm up to with extruder advance in Smoothie: I've gotten a proof of concept setup working, just using a simple algorithm that just modifies the number of steps on acceleration and deceleration of the extruder. Here I've changed the advance value on the fly a couple of times, to show the effect that advance has. These cubes were printed at 100 mm/s, with an acceleration value o

by nebbian - Smoothie

Re: Testing the effects of microstepping and segmentation on print quality - 9 years ago

I've posted my findings in this thread: Hopefully it helps someone.

by nebbian - Delta Machines

Re: Removing vertical lines on prints - 9 years ago

In conclusion: If you have lines on your prints, the easiest thing to do is to adjust your layer height. Use the following table: If your steps/mm is a multiple (or very close to): 80 / 160 : Use layer heights of 0.0809, 0.1618, or 0.3236 100/200 : Use layer heights of 0.1294, 0.2589, 0.3883 The next thing to do is to mod your drivers to go into the one decay mode at all times. Switching

by nebbian - Delta Machines

Re: Removing vertical lines on prints - 9 years ago

What’s all this got to do with segments then? In fact… not much. I started this investigation thinking that the vertical lines were to do with segments. It turns out that segments are surprisingly difficult to isolate. The only way I could get segments to show up was to use: RAMPS board running Repetier TMC2100 drivers running at 16 usteps interpolated to 256 microsteps You might think th

by nebbian - Delta Machines

Re: Removing vertical lines on prints - 9 years ago

The golden ratio To evenly distribute our artefacts, we can choose a layer height that is our step period, times the golden ratio. In my case, this is a layer height of 0.1618 mm. Let’s try it, with three cubes. I’ve chosen stepper drivers that accentuate the steps, to make it more obvious what’s going on. Here we have three cubes, printed (top to bottom) at: 0.1618 layer height (the g

by nebbian - Delta Machines

Re: Removing vertical lines on prints - 9 years ago

So what’s this got to do with layer height then? Remember back to when we discussed how deltas are different to cartesians, in that the Z height of a particular tower also affected the X/Y plane? Well, let’s go into this in a bit more depth, now that we know that it was full steps (not microsteps) that we’re interested in. Imagine that we put the effector right in the middle of the front fac

by nebbian - Delta Machines

Re: Removing vertical lines on prints - 9 years ago

Microstepping OK, so now we know why that U shape might be happening, let’s change the shape by changing the microstepping on our drivers. After all, if we double the number of steps per mm, we should get more of those U shapes if we double the microstepping, right? Three cubes, printed using smoothie, at varying levels of microstepping It turns out that there isn’t any real visible differen

by nebbian - Delta Machines

Re: Removing vertical lines on prints - 9 years ago

How deltas work, and why they are different to cartesian printers You already know that deltas have three towers, and you move the carriages around in very specific ways to move the effector to where it should go. No surprises there. But there is a hidden issue that only applies to deltas, and that relates to how the Z height, and X/Y planes interact. If you watch the Z carriage as your prin

by nebbian - Delta Machines

Removing vertical lines on prints - 9 years ago

Removing vertical lines from prints or "How I learned to stop worrying about segments" So you’ve got a delta printer that puts some lines on your prints like this, and you’d like to get rid of those lines? Read on. Before you do anything else, I want you to try the following experiment. It’s worth it, trust me. Take this STL file, and slice it with the following settings: Spiral vase mode

by nebbian - Delta Machines

Re: Stepper direction on Delta's - 9 years ago

When I was running Marlin, my config had this: #define INVERT_X_DIR false // DELTA does not invert #define INVERT_Y_DIR false #define INVERT_Z_DIR false which is opposite to yours. So I'd say that it's fine to adjust this value.

by nebbian - Delta Machines

Re: Piezoelectric disks for Z contact detect and bed levelling - 9 years ago

QuoteDjDemonD Thanks. Is there a higher resolution schematic available? That one is really hard to read.

by nebbian - General

Re: Piezoelectric disks for Z contact detect and bed levelling - 9 years ago

Regarding how accurate it needs to be, I find that a change of 0.04 mm is visible in the first layer. It can be the difference between layer lines not quite right, and layer lines perfect. If your sensor is repeatable to less than half that value, then you should be golden. So that works out to roughly 0.02mm. JamesK says 20 to 30 microns, which is pretty much what I've found through experime

by nebbian - General

Re: How to build a printer for detailed work? ie parts needed - 9 years ago

Quotenewbob MPCNC design will make a pretty slow 3d printer. Based on my little experience and a lot of research I'd recommend corexy or delta (using rails) based designs. Forget about deltas if you want accuracy. Or put it this way, the time you spend on a delta to get it accurate to within 0.1mm all over the bed would get to to 0.05 on a cartesian style machine. (I have 2 deltas) They are

by nebbian - General

Re: Ooze/Stringing issues that can destroy prints - 9 years ago

What's your Z hop set to? I find that 0.2mm z hop, a wipe, and fast travel speeds combat this nicely.

by nebbian - Delta Machines

Re: Re-arm, connection drops after G31 - 9 years ago

All working fine for me, have done at most a 1 hr print but no freezes since the code fix was posted (a week or so ago).

by nebbian - Controllers

Re: Testing the effects of microstepping and segmentation on print quality - 9 years ago

QuoteGroupB you have to mod them ? dont you just have to turn the decay pot to go fast or mix ... Got a decay pot on my thb6128 Mine had solder jumper pads. A pot might be easier, but the pads are pretty easy to understand and use. Same same I think. If you've turned the pot to fast, then I think we're both in the same mode

by nebbian - Delta Machines

Re: Testing the effects of microstepping and segmentation on print quality - 9 years ago

Quoteo_lampe Quote I'm starting to really wonder why no drivers ever seem to be in the best mode by default. Why should we always have to mod them??? The best mode is a quiet stepper for some of us ( running and/or holding), others prefer the best torque. Mixed decay is a compromise. My SD6128's were quieter, and more accurate after modding.

by nebbian - Delta Machines

Re: Testing the effects of microstepping and segmentation on print quality - 9 years ago

Good stuff Hercek. Here's some more data from a user on facebook with an MKS SBase (32 bit board, 8825 drivers) Left print is printed at 0.202 layer height, right print is at 0.161. From this I can see: 1) That he's using 20 tooth pulleys, so his steps/mm value is 80 or 160 2) That his drivers are not in the best decay mode For him to get better prints, he should print at one of the follow

by nebbian - Delta Machines

Re: Problems in calibrating the extruder - 9 years ago

You have eeprom enabled, so it's reading the values from eeprom, not your config file. Send M501 to see your current settings. Then, send M92 E96 to adjust, and M500 to save to EEPROM. If asking for 1mm always gives you 50mm of filament movement, then you might have forgotten to set your microstepping jumpers underneath the extruder driver.

by nebbian - Delta Machines