Teacup, Pronterface, Sfact... oh my!

So I have something that looks like a Prusa Mendle. And when I push print... by golly, my print head moves around and spits snot all over the table. It doesn't look like anything yet but "she's givin it all she's got Captain!"

I have Teacup, Pronterface and Sfact and loaded it all following the Youtube video... (I'll insert the credit and source here later). My head is buzzing from all of the searching, reading and confusion around making something more than an inconspicuous blob.

I need basics. I need a third grade teacher's explanation of the basics. No offense, but I keep reading explanations given by others on this forum and in many other places and the explanations often times need more explanations. The terminology is cryptic and like learning a new language. It would be extremely beneficial to the new person getting started to have a page they can go to where there is a graphic explanation of just what a "carve" is and many of the other terms used in setting up or tweaking the software to print well on their individual machine. Pictures with the words... just saying. :-)

So... right now I am looking for a basic understanding of just what happens when I push the print button on Pronterface. I've already loaded an stl... watched it gyrate through slices and a graphic has appeared on the screen.

I dont' know how to move the graphic to a particular location yet (or if it is possible in Pronterface).

So I press print and I am expecting a few things to happen. I think the printer head wants to know exactly where it is... so I expect it to move to the xyz home sensors first. Mine does not. It just starts printing gook on the table an inch below it.

I've run out of time.. I'll add more to this shortly... got to get to work.

Thank you for listening!

Ross

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You don't need a parachute to skydive. You only need a parachute to skydive twice.

[fabmetheus.crsndoo.com]

my advice: skeinforge (sfact) is your friend, get to know all the paramaters and try and learn some of the gcode commands, there is a G code PDF somewhere in the reprap wiki

Thank you Mlagana,

That was a great link. I'm all over it!

Is there a link like that for Pronterface?

Thank you,

Ross

Edited 1 time(s). Last edit at 12/07/2011 12:07PM by rossfree.

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You don't need a parachute to skydive. You only need a parachute to skydive twice.

I think pronterface/SFACT does not home in Gcode for each object. I always set my temp, wait for temps to stabilize, and home the bot before starting a print. If you want it to home before each print, you can put it in the start.gcode.

Thank you Bryan, I'll try that!

Ross

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You don't need a parachute to skydive. You only need a parachute to skydive twice.

In the shower today I had an epiphany! (That's where I do all my best thinking.)

All those settings in Sfact (Skeinforge) are for building the gcode file for building the part. Once the gcode file is made, changing those settings only affects the next stl file that I pull in. Is this correct???

Put another way... if I have a gcode file of a part and change settings in Sfact, it does not change the way the gcode file prints. I must re-skein the stl file (making another gcode part file) to see what affect my changes will have.

Is this correct???

Thank you!

Ross

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You don't need a parachute to skydive. You only need a parachute to skydive twice.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

Thanks for the thumbs-up Bob. I don't remember reading that did-bit anywhere. It's starting to come together in my head. Still a long way off from a pretty print but it's starting to look better.

Regards!

Ross

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You don't need a parachute to skydive. You only need a parachute to skydive twice.

Hi Ross,
I'm not the best to cover this, but I will take a stab at covering the basics.

The software toolchain is designed to take a 3d model in as a stl file, convert it to simple commands that the rep rap understands (gcode) and then spoon feed those commands a few at a time to the machine.

Things can be simple - replicatorg can take in a stl, handle the gcode comversion and then give it directly to the machine.

Things can be complicated - some people like different / better control over gcode creation, so they separate that part from the "feeding it to the machine" step Some people even have been working on an alternate version of stl files that can be directly converted to gcode.

I think the reason why there isn't a good straight-through explanation is because there are so many hardware and software choices. Replicatorg was the popular software a few months ago, now its pronterface. 2 years ago the prusa wasn't even out yet, now we are on v2 of it.

there is a picture on the toolchain page that shows the process pretty well. [reprap.org]

I hope I helped!

_Ross

[blog.tinyenormous.com]

Ross:

It is unclear to me whether you've done the extruder calibration on your machine or not. If not, you have to do this first and put the proper steps/mm value in your firmware's configuration file. I did not know that and my printer was spitting way too much plastic on my first attempts.

Regarding gcode, once a file is created no matter what changes you do to skeinforge it won't affect to your previously created gcode files, only the new ones, so won't be surprised if the changes do not show if printing an old gcode file.

misan

Thanks for the help ya'll... I appreciate all I can get.

I do understand about gcode files and that I have to re-write them when I make changes to Skeinforge. I didn't understand it earlier and that made much of what I did a waste of time. There really is a need for more simplified basics somewhere for the beginner. Such a barrage of information, and CHOICES right from the gate. Choosing machine model, firmware, software interfaces, skeining software, motors, heated tables or not, electronics, operating system to load up on... and then the settings! Lord... the settings! (and I DO recognize that it has gotten a lot better... wow!)

Some people are asking what size wire to use for stuff. I can't imagine the hair pulling those people must go through. I'm pretty knowlegable about the mechanics and electronics and such... the software side has been daunting.

But you good people keep me on the straight and narrow. Haven't gone over a cliff yet! Thanks!!!

I have 1.7 ABS filament and so all of my work is based on that. I love ABS... use it at work. Nice stuff. I've made a couple of nasty looking parts but the software and mechanics were working correctly and that was a big hurtle. My table is unfinished and nothing more than a sheet of Lexan and blue tape on it. My biggest problem thus far has been getting the ABS to stick to the tape reliably. You can't get off first base if your filament pops up and creates a molten ball of plastic under your extruder. So that's my first objective... get the stuff to stick.

I purchased a the MK2 heated circuit board and plan to finish my new heated bed design. Pictures attached:

I liked the three-point designs I saw by others. I'm using linear bearings and started by making a four point design. I also made a more secure clamp block for mounting the end stop sensor board... but it got in the way of full travel of the bed. So going to a three point bed solved a couple of issues. It gave me plenty of room for the end stop and it allows for simpler leveling of the bed. I also designed it to be as light as possible while still maintaining rigidity. The black tubes are carbon fiber cut from an arrow shaft (as in bow and arrow). They are very strong and light weight. I also clip the assembly to the belt. There are no side loads on the belt to push it out of the clip and it allows simple removal of the entire bed without tools. I just push the bearings out (3) and unclip the belt. I will also have to disconnect the heater / thermistor wires when I get that all assembled. But I like how it's comming out. I will assemble it all with screws and epoxy. The screws will allow me to align everything and hold it together while the epoxy allows a few minutes of adjustment before solidiying the frame. All of the parts print without any need of support material. Man... I love this 3d printing stuff!

So here's a question... Is getting the ABS to stick more related to temperature or proximity of the extruder nossle to the table?

Thanks all!

Ross

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You don't need a parachute to skydive. You only need a parachute to skydive twice.

Nice arrangement but how do you fasten the 3rd point to the middle of the side of the PCB?

I don't think ABS sticks to blue tape, that is for PLA and a cold bed.

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[www.hydraraptor.blogspot.com]

Ah Ha!. Ok... nix the blue tape! Got it.

It may not be elegant, but I plan to use silicone seal to attach the circuit board to the heads of the flat-head screws. Silicone remains flexible, takes the heat and is pretty strong in shear which is the only real forces it will see. I have a sheet of glass that I will clip on to the circuit board with the big paper clips as others have done. I made ABS thumb nuts to allow ease of adjustment.

I am aware of the bowing the circuit board has but hope that once it is turned on and up to temperature, the bowing will be consistant and will allow me to dial in flatness between the glass and extruder. We'll see. I think this is about as light weight a design as you can get and still have a full size bed and tight axial alignment. Kinda proud of it. :-) Can't wait to put it together this weekend.

So... does ABS stick to glass or do I have to use Kapton (polyimide) tape? Are there any other substrates of choice here?

Thank you!

Ross

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You don't need a parachute to skydive. You only need a parachute to skydive twice.

For ABS use PET tape on the glass, or Kapton tape, or get a GFK printing plate from Dr.-Ing. Philipp Schlautmann.
For PLA glass works great as long as it is squeaky clean.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

I just put together my new "Y" style linear bearing table support (cad pics above). It came out AWESOME! Epoxy is setting up right now. Then I'll attach the heated circuit board (MK2). Still have to cut down my glass top to fit. Can't wait to see this puppy in action! So light weight but strong!

Ok... I'll stop now. :-)

Ross

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You don't need a parachute to skydive. You only need a parachute to skydive twice.

Ross,

Look forward to seeing some pictures of your new "Y" table support. Nice and elegant style to it. I like the incorporated end stop in the bearing holder.

I've found that PLA sticks to glass most of the time, but some of the translucent PLA is hard to get to stick. For those I use a piece of glass that I frosted with a sand blaster. Gives just enough grip for the PLA to bond to while having enough sheen to break loose after printing.

Mike

Thanks Mike,

I've put things on hold while kids are home from school... will get back to it next week some time.

The "Y" table support works great! Easy to put on and take off. Easy to adjust the bed and room for the sensor. All of that works great. Now I'm piddling with the extruder again. I need to replace with a hinged extruder so I can get to it easier when it strips out. Bother! :-)

Ross

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You don't need a parachute to skydive. You only need a parachute to skydive twice.

I have a Botmill 3D printer.
I have been shown how to set up the latest version of python, Proterface, SFACT on my laptop and it appears to work well.
I have loaded an STL file and it looks good on the screen.
I have the temperature set and it is up to correct temp.
I set the head to home position, and it all travels to the left hand front corner and just clears the bed by 1 paper thickness.
I press print and the head checks the bed height and then goes to the centre of the bed.
It starts printing but the extruder does not extrude any PLA.
What settings in SFACT do I have to change
If I use the test extrude function It extrudes OK.
I have been using Repsnapper and everything works fine except for the quality of the print which may be my home made hot end.

You have to check (activate) Dimension before generating the gcode.

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

You want the extruder to home so that the first layer of filament is squished down and flat.