Cura for Chocolate - Needs review :-)

[burhop 14]

Hi all.

 

For a fun side project, I got a LuckyBot Food extruder for my Creality Ender 3 Pro.  It required an old version of Cura, "some pre-Gcode" to run, and a lot of tuning. Yuck!!!🤢

 

So I created a small Hackaday.io project to create some proper Cura printer, extruder, and material profiles.  This is my first machine configuration for Cura so recommendations or suggestions on what I should change are welcome.  If you have a LuckyBot, some testing would be appreciated too. 

 

https://hackaday.io/project/187144-food-printing-with-luckybot

 

The actual config files are on github: 

 

https://github.com/burhop/cura-luckybot

 

 

 

[burhop 14]

Creating a tuned Cura profile is harder than it seems!

[burhop 14]

My wife is accessorizing my prints.

[GregValiant 1,455]

@burhop you rat...you sucked me in on this one.

Here is what's in the box.  It's very well packed and the parts look good.  I'll start playing with it later tonight after the wife is asleep (in case I have to break in to her chocolate stash!).

 

[GregValiant 1,455]

A minor update:

I have the hardware in place and @burhop's definitions installed.  It all looks good.  I have to make a chocolate run to the store.

[burhop 14]

@GregValiant  Any problems?   Honestly, you may be the first tester for my profiles.  If you tweak anything, let me know what works 🙂

 

I'm also keeping a table of my material 🍫.

 

https://docs.google.com/spreadsheets/d/1nOycKwzfE2wTM-pcfwQJhniCNGCOwwhmAR6NsiA-WdE/edit#gid=0

[GregValiant 1,455]

All the chocolate in the house has nuts in it.  I'm guessing they won't pass through a .84 nozzle.  At some point I'll get off my butt and get some proper Hershey's nuggets.

I did a dry run of a simple vase and all the motion looked good.  My printer is also an Ender 3 Pro so everything went together as it should.  The wiring is sort of festooned over the machine.  That will need to be addressed.

I did make some changes to the start up gcode.  I don't know that "#" is a proper comment character.  I changed them to semi-colons.

I added the M302 S175 and M92 S97 to the Ending Gcode.  M302 self-resets anyway and I figured if I set the Esteps back to my normal setting after every print it wouldn't hurt anything.

[GregValiant 1,455]

1. There was nothing in any of the videos I watched that said "Do not use a double boiler to melt milk chocolate because it will never get firm again."
2. It is a bit of a messy operation.
3. It is a bit of a messy operation.  (just in case anyone missed #2)
4. Mechanically and software-wise it seems to be fine.
5. The lead on the aluminum plunger doesn't want to fit into the silicone seal.  The result (admittedly after only one attempt) is that the silicone piece cocked.  There will be some rework there.
6. A huge plus is that scrap material is really good on ice cream.

I'm putting the printer back to plastic for a bit so I can print a stand to hold the plastic containers vertical.  Filling them was the biggest part of the mess.  Then I'll give it another go.

[burhop 14]

Well, 1. is a user error... like thinking ABS stored in humid environment should still print just fine years later. Definitely time to learn about tempering 😂

 

2. Yes. Someone needs to come up with some proper maintenance tools. I have figured out there is some cooking paper that after you cut the end off to fit on the build plate, leaves enough to lay under nozzle when it is just sitting there.

 

3. Seriously.  Biggest issue.

 

5. Have you mastered the stopper removal yet?  I spent 5 minutes the first time 😂

 

6. It can also create some awesome sculptures!  Tiny little stalagmites under the nozzle form between prints. 

 

Some other plusses:

 

1. You have good chance of convincing your spouse it is a cooking device and letting you keep your 3D printer in the kitchen (although I think my wife is on to me)

 

2. Sustainability -  Working with renewable resources.  Even the scrap is reusable!

 

3. Particles in the air are not a big problem, unless you have a lot of kids and they smell the chocolate.

 

 

[GregValiant 1,455]

St. Paula the Patient took one look at the machine and stated "If I see chocolate all over the den that thing is going into the garage".  I have been warned.  I dared not bring up what the kitchen looked like after her last batch of fudge brownies.

Back to #1.  It never occurred to me to just put a little tin cup on the build surface of the printer and warm it up to 28 or 30°C.  Duuh!!!

One video stated that "melting chocolate" has a higher melting point and was unsuitable.  I think I'll go there for an experiment.

The results are in on this test:  Stalagmites are tastier than Stalactites.  Gravity may be involved.

I've been printing with plastic the last day or so.  The bag of Hershey's Nuggets needs a better hiding spot.  My supplies are dwindling.

 

[burhop 14]

I've been using hot tap water and my wife's cooking thermometer to pre warm the chocolate. Water at 33 C works well. 

 

BTW, I've updated all the profiles and released Beta 0.4 in Github.  It tweaks the gcode to what you mentioned above as well as setting the default layer size to 0.5.  So, nothing that will really help you but maybe it will give the next person a head start.

 

https://hackaday.io/project/187144-food-printing-with-luckybot

 

[GregValiant 1,455]

I've been dealing with the aftermath of hurricane Ian.  It's been a rough few days.

Power came back up yesterday.  Only two gas stations in town are open and the lines are about 3 hours long and peoples tempers are getting short.

Virtually all gas stations have large canopies over the pumps and virtually all of them are smashed to one degree or another.  It may be a while before more open up as I'm sure customers would not be happy if a 200kilo chunk of metal was to come down on their head.

Winds here got up to 105mph.  We were doing pretty good until the wind came around and started coming from straight out of the north.  That was bad.

So extruding chocolate hasn't been a high priority and was in fact impossible with the generator running.  Once again, the supply of Hershey Nuggets has dwindled and may even have fallen below "extrudable" levels.

[burhop 14]

My wife and I graduated HS in Tampa  many years ago so we know the hassle 😞.  I'm just glad you all didn't float away.  The Luckybot would make a terrible oar.

 

 

[GregValiant 1,455]

Today I made another attempt to get this thing to make chocolate prints.

• The chocolate doesn't get hard fast enough.  Everything is just a pool and walls collapse.
• The extrusion rate is inconsistent.  A lot of air printing is going on.  I think the retraction needs work.  I wish the material tube would fit into the machine with the silicone plunger already in place on the ram.  The ram slides in and out of the silicone and eventually the silicone piece gets cocked in the tube.  It's a non-positive displacement situation.

Some of this may be user error, but the "won't get firm" thing is really annoying.  I'm making puddles instead of prints.

[GregValiant 1,455]

I gave it another chance today.  Cooling is a major issue.  The chocolate won't firm up at an ambient temp of 25°C (78F).

I was using the dismounted hot end fan for cooling.  It just isn't enough.  I think a 5015 sucking air across a bowl of ice will be required.

Single wall prints were OK until about 6mm tall.  At 8 to 10mm they collapse as the soft chocolate won't support the weight.  I haven't tried more than single wall because the greater mass will just mean more thermal inertia and without better cooling I have serious doubts.

 

A bed cooled by ice water may be an alternative.  An aquarium pump may work and it would be easier than trying to duct cool air to a 5015 that is moving with the print head (or even hard mounted off to the side).

 

On the plus side, the scrap remains good (but gooey).

 

So far this thing is a bust.  My original comment about it being nice looking remains true.  I have a nice looking boat anchor too.  The difference is that the boat anchor is good at it's job.

[PizzaBoot 0]

Has anyone found a good way of cooling extruded chocolate? We are not using the Luckybot, we are using a discontinued prototype from 3Drag (https://store.open-electronics.org/index.php?_route_=3DCHOCO).

At my university we took an old industrial robot and turned it into a 3D printer. PLA works fine for its purpose, but chocolate is too dependent on room temperature to cool down in time for the next layer.

 

The attached picture shows some of our results. Only one print turned out really good.

[GregValiant 1,455]

I did not.  I tried using a fan, but it wasn't enough cooling.

I was thinking that if the fan intake was ducted to draw air across ice and then blow that cold air at the extrusion that it might have a better chance of hardening.  In the end I decided to cut my losses and I gave up.

Considering what I paid for the LuckyBot, I am really disappointed with the results.

[PizzaBoot 0]

Alright. Maybe we'll find a way that might work for you as well.

[angie25 0]

Hello! I recentally just got a luckybot, but I'm having trouble using it. I've preheating the chocolate and run the for Luckybot gcode file, but everytime I go to execute a print file, the extruder doesn't move at all and the printing stays at 0%. Can anyone help me out with this? 

[GregValiant 1,455]

Did it all wire up correctly?  The unit itself is fine.  Well made and complete.  It just made a mess.

 

It's been a while since I played with it.  Something did happen at the beginning and it wouldn't extrude but I seem to recall I made a simple change and it worked.  It has to be closed and up to temperature and the steps/mm need to be correct.  You also have to disable the "Cold Extrusion Preventer".

I found the config files if you want them.

The startup gcode has to include:

M302 S0 ; Turn off Cold Extrusion Preventer.

M92 E750 ; set the Esteps/mm

[angie25 0]

Hi! Sorry for the delayed response, I've been playing around with it and I still can't figure it out. I was able to get one file to work, the one on the Luckybot website where I just straight downloaded a gcode file. But anything else I slice myself off of Cura won't work. 

 

I'm new to 3D printing and I've just been trying to learn about it. For the startup gcode, should I copy and paste it into the printer settings or into the gcode-file? Also, does it matter where I copy and paste it? How do I disable "Cold Extrusion Preventer"? Is it apart of the startup code?

[GregValiant 1,455]

I'll look around to see if I can find the files.  I'm on a new computer since I played with the chocolate extruder and I'm not sure where the files are.  I'll get back.

 

Edit:

OK here are the files I have.  The instructions are in the ReadMe file.  Good luck.

My problem seemed to center on the fact that the chocolate wouldn't firm up on the build plate.  My next attempt was going to involve inventing some sort of system to suck air across a dishpan full of ice, get it to the intake of my layer blower, and blow it at the extruded chocolate.  That seemed easier than buying a refrigerator to print in.

At some point I'll probably revisit the thing, but right now I'm still mad at it.

 

 

Ender3LuckyBotProfiles.zip

Edited December 4, 2023 by GregValiant

[angie25 0]

It worked!! Thank you so much. 

 

Now another problem I've run into is that the chocolate stops extruding at certain points until I hold the down arrow down for the stopper to push down onto the chocolate. Do you know of anyway to solve this? I don't want to be in the room the whole time watching the print and pushing it down when needed.

[angie25 0]

Also, for some reason it is only printing some of my file. The remaining time is normal and then halfway through, the remaining time changes to like 1/3 of the time and ends early.

[GregValiant 1,455]

That second comment about only printing a partial gcode might be because of bad sectors in the SD card.  You could try reformatting it.  I have had to do that every few months.

You first comment about "extrusion stops" might also be related.  I found the hardware to be pretty nice and my printer works well.  I just couldn't print anything more than 3 or 4 layers tall as the prints would collapse from their own weight.