The 3D Printer Thread

[Woz]

PLA is the easiest material to work with. Print temp is quite low 190-210 c, virtually no shrinkage and if you've prep'ed your build plate right (I use cheap hairspray) then no warping.

ABS is harder to use. Print Temp 200-220 c, high shrinkage and warps. So you need to resize your model to offset the shrinking and to reduce the warping you need a Heated Build Plate (HBP) and an enclosed print area (this can be just a box over your printer) the keep the build area warm. Some people even use small heaters (or cheap hairdryers) to heat up the build area.

Nylon needs very high temps to print 250 - 270c. This is too hot for most printers without modification. You can get low temp stuff 225c but it's expensive and is still near the max temp of most printers-

Just pulled this off a Wanhao forum - "I would highly encourage you to upgrade to an aluminum carriage for printing Nylon.
As a note to Wanhao Duplicator 4 owners just seeing this message, the stock extruder contains PTFE liners and is NOT recommened for printing Nylon in a stock configuration.
Nylon typically requires higher extrusion temperatures 245-265C to get proper layer bonds. It just so happens that PTFE breaks down and may produce poison gas at those temps.
Again, in general, I cannot in good faith tell anyone it's OK to set a stock Wanhao Duplicator 4 or 4X extruder above 230C.
The reason again for upgrading to an aluminum carriage is that the hot end enventually heats up the plastic carriage. Over time, it can warp and deform when using elevated extruder temps associated with printing Nylon and other high temp plastics.
For D4 and D4X owners, I highly encourage you to also upgrade the entire hot end assembly for high temp printing. "


Any material that contains particles that don't melt like wood effect, glow in the dark, carbon fibre will wear out the nozzle quicker. They print just like PLA or ABS depending on the material.

If you think that you may print in ABS then it's better to get a printer with an Heat Build Plate to start with (you can always build your own enclosure later on).

I've done all my printing in PLA but I'm going to try ABS some time. It's like a dark art to master but if I get the hang of it it'll mean I can print out stronger suspension parts.

[wibblywobbly]

Thanks Woz, I have been all over the web, and never saw the info on nylon and heat before. The hairspray trick seems to be a common one, along with a heated sugar water mix, and Pritt sticks.

Still leaning towards the Smartrap, can get a new modified one fully built with auto levelling for bargain prices, and all open source/upgradeable too.

[RobW]

Out of interest what type of CAD is used? Sketch & extrude or the older style "bottom up"? Do they still use stl for the printer?

[Woz]

I use Openscad but any 3d software that saves as STL will do. The STL is then sliced and saved as a .x3g file (or .s3g for older printers).

[CHRISTOPOPPIN]

In terms of "choosing" a printer, it's down to what you intend to do.

If you're up for some DIY and pretty much, limitless expansion, go with a RepRap - the Prusa I3 is by far the most solid from them all (in my experiances, that is).
You can buy them in kit form or ready built.

The joy of a RepRap is that you can make it whatever you like, theoretically it could be any size you want if you go down the scratch build route.

As for plastic compatibilities, it really depends again on what you want. ABS and PLA are still by far the most common thermoplastics for printing, though i've seen some more *exhotic* materials used, but can't remember off the top of my head right now.

As far as electronics go, I've not seen any major improvement in quality when comparing between a RAMPS 1.4 board to a RUMBA board, both pretty closely related boards. I think it's more of a "addon" to replace a RAMPS 1.4 board with a RUMBA since it supports 3 extruders.

Needless to say, I *personally* wouldn't go with a commercial model of printer - Replicator, Ultimaker, etc. But i wouldn't hold me to this! They look like well developed machines, with a very high price tag in all, but without the facility for upgrades and a more "sustainable" approach is a bit of a deal breaker for me. But if you're looking for something that can just be taken out of the box and set up, and you're good to go, then that's more ideal - less faffing about!

Another option, if you're based in the UK, is THREEDY. They make a more expensive model (£800-£1000~) of RepRap which takes the more Replicator design and merges the RepRap-ness into it.
I met these guys in London earlier in the year and they had a few of these running on the stand they had. (Model Engineering Exhibition?) Can be found here: http://threedyprinters.com/

All in all, depends what you need! Not fussed on build volume? A RepRap! Prusa I3 is your best bet. Need something quick? A commerical model.
A good place to start for more technical info is the RepRap wiki, shows comparason and list of suppliers by region too.
http://reprap.org/wiki/Main_Page

[RobW]

I use Openscad but any 3d software that saves as STL will do. The STL is then sliced and saved as a .x3g file (or .s3g for older printers).

OK, thanks. We just need the scanners to be easily accessible & stl based CAD tools and we're sorted!

[CHRISTOPOPPIN]

I use Openscad but any 3d software that saves as STL will do. The STL is then sliced and saved as a .x3g file (or .s3g for older printers).

OK, thanks. We just need the scanners to be easily accessible & stl based CAD tools and we're sorted!

Autodesk's 3DSmax can export to STL, and so can AutoCAD(I think..?)

EDIT: To add on to that note!

Scanner wise, Autodesk does do some software for it. 123D Catch (I think it's called), you use a camera to take photos of the object from all directions, then import into the software for it to make a 3d model of it. Then it's just a case of exporting to .STL.

[wibblywobbly]

Just ordered the SmartRap kit for £289 inc postage. Its not much more than a half decent tank would cost, and in kit form just like a tank too.

My brothers place can cut and polish the rods, and after all of the tanks that I have built over the years, I don't foresee any probs with soldering etc.

I reckon I will have it finished by Christmas??

Design software? OpenScad works, as Woz knows my first test was ok and I had never used it before (though for some obscure reason I left one extrusion 0.5mm too long). Luckily it doesn't show when fitted to the Kodiak.

RobG

[RobW]

Autodesk's 3DSmax can export to STL, and so can AutoCAD(I think..?)

EDIT: To add on to that note!

Scanner wise, Autodesk does do some software for it. 123D Catch (I think it's called), you use a camera to take photos of the object from all directions, then import into the software for it to make a 3d model of it. Then it's just a case of exporting to .STL.

Thanks. I was actually thinking of the reverse engineering side of things to allow scanned objects to be turned into NURBS based CAD for dimensioning & machining. Although scanning & making a 1/16 Churchill or Mk IV could work from a 1/35 kit?

Am a long way off either - will be 2-3 years before I rebuild the garage!

[Swamprat33]

Hi all, I guess this is something for WOZ in particular.

I also do 28mm WW2 wargaming and for this I use 1/56 scale armour.

I am wanting to 'make' a Crusader 111 AA tank. The tank hull is available, and i have one on order.
I was planning on scratch building the AA turret which houses 2 x 20mm cannon.

I have a set of plans and it looks fairly straight forward but i'm now wondering if someone could knock one out on a 3d printer.
Is it Possible to make one from scaled plans, or easier to replicate an existing part.
Can you also say, scan a 1/72 scaled item and then increase size to 1/56 and then print?

I am aware of some aspects of 3d printing and would love to understand better, but not sure if i can justify the expense and time needed for another toy.

Your advice would be much appreciated.

Cheers

Tim