Welcome! Log In Create A New Profile


super beginner here

Posted by gardenmagic 
super beginner here
November 13, 2013 03:29AM
I have tons of questions to ask, but before I start picking every ones brains, I need to learn more basic info. any links to a thread that had all the general faqs, print sizes, print speed, parts list with estimated costs, etc etc...

I plan on building hundreds of 8" x 2" x 1/8" trays, so direction to something that would be capable to this would be great.

Re: super beginner here
November 13, 2013 04:18AM
What do you mean by

8" x 2" x 1/8" trays
do you mean something like this


Edited 1 time(s). Last edit at 11/13/2013 04:19AM by rogerclark.
Re: super beginner here
November 13, 2013 10:53AM
Not really. There is no "dish" to my trays. Imagine more of a flat sheet of plastic, with small ridges on underside for support. Either end well have holes for hanging apparatus. Tray itself will have 5 - 1.25" holes to hold little cups.
Re: super beginner here
November 13, 2013 01:02PM
Have you explored vacu-forming



Re: super beginner here
November 13, 2013 01:50PM
I've believe the best route for these would be either injection molding or stamping out of plastic sheets, but as both of those require thousand of dollars just for tooling, and a shop ( so paying for labor) to do, I've come to the conclusion that until this takes off, a 3D printer would be my best bet. Since I'm a tinkerer by nature and there are other part parts that I can make as well, owning a 3D printer would come in handy. I've looked into some of the sites that rent out the big industrial ones ($1000/mo) which I might be willing to do, but buying/ building one of these, then using it to build another, seems like the best option. Worst case, company flops, no sales, in out maybe $5k instead of $20k (a 10 run injection mold cost like $15)

my questions were more about the plastics, and maybe on rebuild of second printer, making a bigger tray.
A decent estimation of what I'm looking at spending to get one of the lager ones up and running, including printer, a pc capable of running software, the software needed.... pretty much assume I have nothing to start with. I would be interested in the kit, but have read that these need calibration, so wondered about how to go about that if I'm the one building it.

thanks again
Re: super beginner here
November 13, 2013 04:03PM
I'm not sure how strong your trays need to be, as extruded 3d printed objects are not as strong as injection moulded, but I think if you could increase the thickness a bit, they would probably be quite tough.

Re costs

Software is open source and is free. Modelling, I use Blender and Openscad, slicing I use Slic3r, printer control I use Pronterface
Pc. Anything less than 10 years old should be ok. Running windows, Xp or newer would probably be easiest, but you could use a free os like Ubuntu

Cheapest printer is probably a self build Mendel, but it will be challenging. More realistically buy a newer Mendel variant kit or Mendelmax kit, or something with similar geometry, and you probably need to budget up to $1000.

There are cheaper pre built units like Solidoodle, but if you intend to rebuild and make it bigger if it works, you may be better off building from a kit to get a better understanding of how a 3d printer works.
Re: super beginner here
November 13, 2013 04:36PM
Is there a reason for a Mendel over the prusa? It just happened to be the first one I researched.

So modeling I understand, slicing is???
Printer control I assume means exactly what it sounds like, sending the correct info to printer to be used to create model. Printers use standard usb connection?

what are the different types of plastics that can be used, what are their main structural differences? Ate any of the printers on here capable of doing metals? Maybe an attachment change out to work.

I am fully willing to build my own, as I enjoy that kind of stuff. Hopefully it is easy enough for someone that ifs only mechanically/ electrically trained.

What is the longest run unsupported a 3d printer can handle.
example, design a bridge, with 2 support pillars, 3" apart, can the printer then print the connecting bridge part?
I'll try and find a pic to attach to show what I mean. Am on a phone now so limited capabilities.
Re: super beginner here
November 13, 2013 04:54PM
I can answer some questions, but there are far more knowledgeable people on here than me ;-)

Most Reprap printers use Fused Deposition Printing [en.wikipedia.org]
where the printer lays down successive layers of plastic.

So you need to use a Slicer program to divide the 3D model into a series of flat slices.
The Slicer generally outputs GCODE commands, which tell the printer to move the print head, print bed and extruder in order to produce the print.
The printer runs software (firmware) that accepts GCODE and then converts the commands (e.g. commands to move the print head and extrude plastic), into the data that it sends to the motor controllers (part of the printer electronics), the motor controller then control the motors by applying the correct voltages (waveforms) to the motors.

Probably the most widely use reprap electronics is a Arduino Mega2560 board paired with RAMPS (1.4) controller

An example of this kit on eBay is [www.ebay.com.au]

(Note. I've no idea if this particular kit is any good, as quality of components varies)

But basically this is the electronics and motors that you'd need to build most repraps
Re: super beginner here
November 13, 2013 04:57PM
Re: Plastics etc

I think you are better off reading the info on the Wiki.

But main plastics are PLA, ABS and now Nylon. AFIK, PLA is harder but more brittle, ABS is not quite as hard as PLA and is a bit more flexible, which probably makes it better for real world applications, as its still quite strong.
I think Nylon is more flexible (but I've not printed with it, so I can't really give you first hand experience)

I normally use ABS for items that are not decorative.
Re: super beginner here
November 13, 2013 05:00PM
Re: Printing bridges

Generally, I'd say print them upside down. 3D printers can "bridge" gaps, but you have to limit the angle of overhang.

I successfully print pipe couplers of various sizes laid flat, so they have overhangs in both directions, ie outside and inside overhangs as the printer prints from the ground up.
Re: super beginner here
November 13, 2013 05:53PM
rogerclark you are the man, this is exactly what I was looking for, useful links to find out what questions I actually need ti be asking. Thank you.

As to the printing over gaps, I think a better representation of what I am trying to build would be a house.
If I were to print out a house, four walls, all attached in a square, with a base measuring 4" x 4" tallest point on a wall maybe 6". Would a printer be able to leave openings where the doors and Windows would be? just a blank square maybe 1x1 ?
Re: super beginner here
November 13, 2013 06:24PM
Re: Printing a house

No. You can't print the tops of the door and window frames without using "support material", unless you had round windows and doors (or some other non-rectangular shape)
i.e If the windows and had arches at the top it could be done.

The Slicer's have an option to create support material, which you then have to remove afterwards e.g. with a knife, but personally I find this time consuming and try to avoid printing things which need support material.

I have printed things where the 3D model has support material (snap off) items, and this has been OK, but I still prefer to design and print stuff that doesn't need it.

BTW. This limitation only applies to Fused Deposition Printing. The laser + powder, and laser + resin ones are totally different and don't have this limitation, but I'm not aware of any RapRaps that use this technology (thought it is possible that someone has done these types as Reprap)
Re: super beginner here
November 13, 2013 06:59PM
Vacu-forming requires:
a frame to hold plastic
a mold wood, clay, styrofoam
a vacuum box -- source of suck
a heating oven

>$100 ?
and time -- mount plastic, heating, forming, unmount plastic
over and over again

Cups could be integral
a punch for holes
a belt sander to grind away plastic to open holes

$2000 3D printer 1000Kgs of PLA/ABS
1000s hours watching printer
fixing prints
smoothing prints

No Asparagus for a long time???

confused smiley
Re: super beginner here
November 13, 2013 09:44PM

I agree. 3D printing is not the solution to everything.
Re: super beginner here
November 14, 2013 03:13PM
Once I get my printer configured I plan to do something similar. I'm working with composite materials, so slightly different than working with injection molding. I would suggest using the printer to print both sides of the mold with enough of a gap in-between for the printing surface to be coated with your mold release, then you can create a small inlet to inject your plastic. just keep in mind the temperature of the injected material and the melting temp of the printed mold. I see many benefits to using a 3d printer. You can have a database of your creations available whenever you want. When your molds get worn out, you can just print another one. if you need to change something it would be a lot easier than sending the new specs to a company.
Sorry, only registered users may post in this forum.

Click here to login