Delta vs Cartesian

[MorganTH]

Hi all.

I used to works on cartesian printers but i'm thinking to get a personnal 3D printers and i m thinking of getting a Delta one ( The rostock v2 seems to be a good choise ) but i don t understand well what are the advantages and the disadvantages of the Delta.

Can you give me your feedback when you use both technologies ?

Morgan

[Jimustanguitar]

Hey Morgan!

Delta machines can move more quickly than the axes of a cartesian machine, so they're more 'nimble' on fast prints. There's also less weight moving around while you print, many cartesians move the whole extruder for X and the whole print bed for Y, and that's a tad clunky compared to traditional machinery. Delta machines like this can also be scaled easily since the frame is the linear rail, increasing your ZHeight is as easy as installing longer extrusions (and wiring, belts, etc to match).

The Rostocks are very hackable, you'll understand them intimately after assembling one, and the user community is great.

[MorganTH]

I heard the argument of the speed but can you give me an approximative speed for ABS ? I was sure that the problem of the print speed depends on the capacity of the plastic to stick on the bed/other layer. I understand that less weight moving egal less inertia and probably better print this way but i don t understand why big brand like 3DSystems, Stratasys didn develop this printing technology if this get so much advantages.

Thanks for your answer.

[geneb]

It's not that a delta can extrude plastic faster than a cartesian - it can't. What it can do a LOT faster is those rapid travel moves when it's NOT extruding plastic. That's where the delta beats the cartesian in print speed.

Because the effector/hot end assembly has such a low mass, it won't over-shoot the destination point when traveling at a high speed.

Another benefit is that while you're printing on a delta, it's not moving your part all over the place like most cartesian printers do.

g.

[MorganTH]

Okay I see. Thanks for your answer about the benefits of this kind of printers.

Morgan

[gchristopher]

One underrated advantage of the Max is the quality of the instruction manual. A developer friend described the manual as "the best piece of open-source work I've ever seen."

Two main disadvantages of a delta are that it requires a Bowden tube (which has never created a problem for me because I haven't wanted to print flexible filaments much), and that it's a pretty large machine. This was once inconvenient when I wanted to transport the printer to show it off.

In terms of sub-$1000 printer kits, having done builds of both a Prusa i3 (from nwreprap, who provide very good instructional videos) and a Rostock Max V2, the Rostock was far easier to get put together and tuned, mostly because of the laser-cut and injection-molded parts. I'd lean away from choosing a reprap as a first project for most people without lots of mechanical experience.

That said, home 3d printing is rapidly changing and at any given moment, there might be a new, nicer low-cost option? A coworker just bought a Max V2 a few weeks ago and is really enjoying leisurely assembling it.

It looks like the main development recently has been wider availability of inexpensive kits from China? I bet some of those are adequate mechanically, but they usually come with a cheap Melzi board, and I'm sure they'll have a much lower level of instructions and community support. (Sorry if this reply was beyond the scope of the question.)

[geneb]

Wow. Thanks.

I was going to put a Dino reference in the 4th Ed., but I had to throw JJ under a bus instead.

g.

[Xenocrates]

Another reason for 3D systems and stratsys to not develop the delta is that they don't really have competition on the industrial scale. There is no reason to innovate, especially as delta systems require more bearing surfaces (the arm ends, linear rails, and the belt driver/idler, versus just rails and belt or leadscrew), more complex firmware and controllers ( many CNC machines at the 250K price point still use less than one gig of memory for onboard programs) It's not proven tech, nor is it especially backwards compatable, so most shops won't pick it up, when the machines they sell are so very expensive.

Industrial machines are very clever and nice. but they are simple and dumb in many ways. Take a look inside a Haas simulator if you can, they use exactly the same electronics as the machines of the same era. Still PATA, only one USB controller (two internal ports though, for redundancy), and they use the same video connection as they have since the CRT days in many ways. This is a big thing with almost all industrial tools. They use what works, what's installed, and what people are trained on. For example, in the shop on campus we have an AT box running windows 2K, to talk to a robot so it can have a floppy drive. The newest bot takes PCMIA cards, and was bought only about 3 years ago. You want the best tech, you go either to hobbyist's, or to research labs. SeemeCNC does damned good on the printer design side. The mods of the community step it up. The electronics could be better, but right now is a preview of what I would call a great time to upgrade, what with the RAMBO successor supposedly in development, the V2 smoothie confirmed, and the next Replicape coming along. Sure, you've got great options now, but there are potentially even better ones if you wait just a bit.

[MorganTH]

Wow. Both answer give me more that I want. The bowden tube is not a problem for me, i m used to work with it. And the inconvinient of the large machine is not an huge one.

I m looking for a personnal printer but in the same time i m looking for some nice professional delta printers ( but my boss don t understand too the advantages of this kind of printers. )

So if I understand well, the main advantage is the community, the mod and the flexibility of the printer.

And yes Xenocrates but why i don t understand is why no one tried to create industrial delta printer. Nor a big brand but maybe an innovante brand. I must admite that now my knowledge of technology is more or less equal to my english level : correct but far far to be fantastic. And I tried to work both. But I understand your exemple with the CRT and the Haas simulator. This can explain the problem of the delta printers. People are trained with cartesian, so ( like my boss) it s not easily to swap to an other technology.

One more time, the best way to understand this is to take a Delta tried to play with it and compare both results.

And a last question, as we get a lot of " classic " 3D printers ( mono, double or triple extruder, big capacity, heating chamber, etc ), we re looking to a really polyvalent machine. We re looking at the Z Morph 2.0 because of the multi head which allow to use a laser toolhead and a milling and engraving toolhead. Did a delta machine exists, which allow us to engrave some metal pieces or to transform your printer in a mini CNC ?

[geneb]

The problem with multi-function machines like that is that you end up with a machine that doesn't do any one job very well.

A delta configuration printer isn't suitable at all to a tool head that would put side-load on the effector platform. However, I've seen a few people here swap the hot end for a semiconductor laser with cool results.

g.

[MorganTH]

Yes. As I said, we get a lot of functionnal printers and the " printing " capacity of the machine is not what we looks for. I consider that multifuction mean " medium to all, good to nothink " and that this will not be as functionnal as a full 3D printer or a full engraving laser. In the best case we ll get a little " toolbox " with a lot of think to help us to be less dependant to our subcontractor ( not sure it s the good word, someone from an other brand which do things we can't do ), in the worse case we get a medium quality printer for our little parts.

I ll take a look at the way they swap the hot end for a laser.

[gchristopher]

I was going to put a Dino reference in the 4th Ed., but I had to throw JJ under a bus instead.

g.

Haha, that's hilarious that you were even considering it!

[geneb]

I should probably stick something in there along the lines of, "This kit is so easy to build, even a pair of stuffed Dinosaurs could do it!"

g.