CAD/CAM Two Questions

[ajmadison]

Micro-Mark recently announced a desktop Laser-engraver at $2K. Admittedly, I've priced out a system that is compatible with my Mac and not require expensive CAD software, but you'd have Micro-Mark's customer support behind this tool. But I've seen no discussion of it here.

Is $2K way too rich? I can see that. For those modelers that are going that route, have you found an on-line resource for your custom cut/engraved photo-etch projects that doesn't approach $2000 not including computer?

Maker-bot, as an example, is selling 3D printers in the $2K & change range. Also too expensive? From what I've seen, a desktop 3D printer can produce parts better than I can with a knife, ruler, & sheet styrene. I can make parts to 1mm resolution.

Admittedly, from my dabbling with RTV and resin casting, (oh heck, vac-u-forming before that) that the reproduction technology becomes the hobby, not the tool supporting the hobby. So, ignore the cost, is the learning curve steep enough to intimidate the early adopters?

Just curious what other scratch-builders are thinking.

[Johnnycrash]

Just curious what other scratch-builders are thinking.

As you said, in many cases, the tool becomes the hobby. So...

Unless you plan on a high volume for a particle tool, it's my opinion, you should simply out-source.

There are many money saving reasons for this. Sure, you can make the parts cheaper if you owned the tool, but you are also then responsible for the cost outlay, maintenance, and screw-ups. By out-sourcing, you get back the exact parts you need, with no waste, and just the cost of perfect parts. If they crew it up in anyway, it's their problem, and they pay for the mistake. Well, unless YOU screwed up the design of the part in the first place, of course.

That laser engraver... Might be JUST an engraver, and not a very good cutter. Different lasers, different power levels, and costs. Most of those will NOT cut metal of any kind. Lots of power needed for that. That MakerBot (or whatever) makes part less than hi-rez, material it uses are expensive, and you get a lot (s)crap parts until you figure it out. Doing your own PE is messy, uses dangerous chemicals, and again, lost of trial and error, leading to higher costs in the end.

We have several people here on this board that have such machines that will do most of this for you.

ParaGrafix and myself (MMI) do custom PE, myself and many others do resin casting, Shapways for your 3D printing, and several people (Laserfire Creations) with Laser Cutters.

I do this stuff for a living, and I have NO desire to have these machines in the shop (laser cutter & 3D printer). The cost to run, maintain, and learn to be proficient on, the space they take up, and so on... Build the file, send it off, get a part back I can use, and I can do other useful things while that's all happening.

[DaveVan]

I have a commercial 25 watt 12x18 laser.
I am into model railroad hobby too.....so I get more use from it than you might in the plastic model hobby although I did have a line of plastic model kits cut on the laser. $2K is a lot less than what I paid in 2002, but this is a full on commercial machine and 13+ years ago.
My machines accept input art in CorelDraw format only....so you may need to check what MM machine requires.......you may need to learn a new software too.

Paying to have things cut may work better.......but I will admit it's great to get an idea late Saturday night, draw it, cut it and work right away!! Hit me offline if you have Q's

[Disillusionist]

I've seen Micromark's laser. It's basically one of the "cheap" Chinese machines re-dressed with their name on it. Looking around on Ebay, there are practically identical units being sold for less than $800.

With lasers you generally get what you pay for, and even though $2k is indeed a lot of money, it isn't very much in the world of laser engravers. The biggest reason these units are so inexpensive is they employ cheap glass laser tubes as their beam source, rather than the metal rf tubes the professional machines use. The beam quality provided by the glass tubes suffers significantly compared to their metal counterparts. Couple this with cheap optics, and low quality stepper motors rather than servos, and the result is poor engraving quality, slow speeds, and inconsistent performance all the way around.

I would be very dubious of their "40 watt laser power" claims as well. Further down in the description they say it takes several passes to cut through 1/4" acrylic. Well, I have a 50 watt machine that cuts through 1/4" material like hot butter with one relatively fast pass. So something there doesn't quite add up.

Honestly, I would steer a very wide path around any of these machines, and I'm not just saying that because I do this sort of thing for a living. I've spoken to more than one person who's purchased similar machines and been very disappointed with the results. I suppose it might be ok for some very basic cutting tasks on thin materials like paper, or balsa wood, but I wouldn't really expect much more than than.

There are some decent Chinese units out there, but even though they're cheaper than their american made counterparts, they're still significantly more expensive than this little machine. Actually, I have a feeling that after Micromark sells a few of these, then starts getting complaints, this unit will be disappearing from their catalog relatively quickly.

[DonS]

I would love to buy/have a 3d printer but the resolution on all the ABS or PLA units is just too far from what I need for parts with any sort of detail. Some of the SLA machines offer high enough resolution, but the build envelope at hi-rez is often quite small. So I outsource.

[ajmadison]

I would love to buy/have a 3d printer but the resolution on all the ABS or PLA units is just too far from what I need for parts with any sort of detail. Some of the SLA machines offer high enough resolution, but the build envelope at hi-rez is often quite small. So I outsource.

Don, or anyone else could expand on this comment about ABS or PLA? I have thought through the laser engraver/cutter idea and am not going there. Meanwhile, MakerBot seems to be everywhere, including my nearest public library. Obviously I could try a couple of ideas there before plunking down thousands USD.

But I'm still researching 3D printers. I did the math, and discovered that the 100 micron layer thickness, is approximately the same as 5 thou sheet styrene, which I only use to produce detail parts. But what I didn't see in any of the example pieces at the public library was any fine details. Couple of 1 mm "eyes" in an octopus, but that's about it. On another forum I saw some complaints of the printer incorrectly producing fine ridged detail, like on a jet engine exhaust, but several responses indicated "mistakes" were made, so its possible. The comment about PLA & ABS suggests the printer material itself is incompatible with scratch building. I'm aware of the adhesive needs of ABS, and its primer needs.

But what are the issues with 3D printed parts and modeling? I got the impression that some modelers takes printed parts and runs them through RTV & resin casting process to produce parts.

[Kekker]

Since they're built up layer by layer, printed parts end up similar to the way a part would look if you cut out a bunch of layers of .005 and stacked them. Kind of like a topographic map made of cardboard layers. OK for really flat stuff, but on curves you would have a terraced effect that a lot of people find at best annoying. Then you have to fill and sand to get a smooth curve. Without damaging any fine details around or on the curve.

Higher resolution makes for smaller terraces, but higher costs.

That "upside-down, draw it upwards from the liquid" method that just came out looks promising. Maybe not complete elimination of the terraces, but at least getting them small enough to not bother too much.

That's my take, anyway.

Kev

[ashrond]

Hi ajmadison,
don't think we've spoken before, nice to meet ya!

I just wanted to weigh in here because you sent up a warning flag and I really think you need to think about it a bit.

I would STRONGLY recommend you invest in some CAD software and learning it BEFORE you consider buying either a laser engraver or 3d printer. even when you are creating models with some of the recent apps designed for quick and dirty 3d modeling on tablets and such, you will run into problems such as tolerance issues, mesh errors, and the like. When you know your CAD software it will be allot easier to avoid or address these issues. even when your sending your model off to a place like shapeways it will help to understand their model requirements on wall thicknesses print resolutions to address model or printing issues. you will also be able to create vastly more complex models with the proper software.

I mention all of this because I know more then a few people who have decided to invest in these machines without understanding that it is nothing like a desktop printer, and ended up either selling off the printer, or it just sat in disuse because they were unable to produce their own models.

I have 2x 3d printers myself at present, a stereo lithographic laser printer like a Form1 and I have a DLP printer. I got the laser to replace the DLP because the DLP doesn't do what I need from it and the software is COMPLETE ≠♀§#&@(§, and that makes allot of difference too.

I'm still learning the new machine and its quirks and that takes a bit, because none of these devices are perfect yet and require a degree of tinkering to get AND keep running correctly. which is something they don't tend to advertise on these types of devices. there mostly geared for the type of person who doesn't mind taking things apart and tweaking them or performing regular maintenance (not exactly plug n play just yet)

I have my sites set on a desktop laser engraver, something that can handle 8x11" sheets of styrene, but then again I'm also considering building it, so take that for what its worth.

point is, 3d printing and laser cutting are both ALLOT easier with the right software and know how.

just some thoughts on the matter, hope they are helpful.

[ajmadison]

Appreciate the advice folks.

My day job is software development, in the embedded environment, so I'm no stranger to stuff that almost works, needs to be tweaked, sometimes with a hand tool (wink) and trying again.

I've been interested in getting computers involved in my model making for about a decade. Though some 8 years ago, I was investigating Mesh Development, Free/Open CAD software, Pepakura, and the resulting paper models, with the idea, could I convert a Mesh into frames that I could cut out and use toward a scratchbuilt model.

So I'm no stranger to CAD software, and my comments about TurboCad 5 on the Mac cannot be posted on family friendly forums, like this one.

My initial 3D printer projects are relatively unambitious. Mostly detail parts that could be cut out from sheet styrene with a sharp knife and a ruler (if you had infinite amounts of patience). If you look at the top of the thread, I realize that these advanced modeling techniques can become the hobby. My very first foray into this area was a home made vac-former. It worked, and for 30 years ago, produced fairly detailed parts at the time. But I would need to wait 20 years before my scratchbuilding skills reached a point where such a tool might come in handy.

At the very least, I plan on watching the MakerBot tutorials (wish there was written material, but none I can find). Still need to understand the process of initial design through to developing the input data for the 3D printer before I go ahead with any purchase. That was one discovery that halted getting a laser engraver years ago, was not just the engraver, but needing a Windows machine to host the CAD I/F to the laser.

[DonS]

Sorry I didn't reply to this sooner....forgot I'd written something that should've been followed up on.

I strongly suggest you don't spend a dime on a printer until you've held in your hands a printed part from the printer in question of a 3D model you're familiar with. Pictures don't tell all....you need to see the output personally to best judge if it's what you want.

I'm currently working on a project that sounds like what you're talking about...making detailed parts in 3D, then producing RTV molds of the parts for resin casting. For me, the 3D modeling was not a problem and it sounds like you know something about that, also. After a lot of research, I found that no currently available printer under $5k could make the parts I needed....FDM printers could make larger pieces (i wanted at a 6" cube-sized build envelope) but with insufficient resolution. DLP-type printers offer fine detail but small build envelopes. So I outsource.

You mentioned 100 micron resolution....it sounds small, but man, I can tell you that's not even close to what would make an average modeler happy...not for detail parts. My parts were printed at 16 microns and still needed, in many cases, a lot of finishing work. Some parts came out better than others. As was written above, flat areas often came out great...curves had varying degrees of visible stair-stepping.

As you know, 3D printing technology is constantly evolving and doing so quickly. With that in mind, I'm not spending my money until a printer can make exactly what I want for a reasonable price. It'll get there. Until then, I'll focus on gettiing better at making 3D parts that will result in good prints...and have a service with state-of-the-art machines produce them.

[ajmadison]

Thanks for the information DonS.

As per my usual process for this kind of acquisition, I obsessively collect information until I get a full understanding of the technology. One of the most interesting conclusions, is that MakerBot's latest machine, an attempt to make 3D printing as simple as bringing home an inkjet has failed in that quest, and has serious issues, to the point where one is better off getting one of their previous generation machines, or a Chinese copy/clone, some of which are superior to the MakerBot machine. I am glad I obsessed over the available materials, I could today be the unhappy owner of a machine that does not represent the state of prosumer 3D printing.

Anyone following along, I strongly encourage reading the reviews and forums at 3dprintinggeeks.com and 3dhubs.com.

And yes 100 microns is very large compared to the better printers, many of which are capable of 20 micron layers. Yet, that is not the only relevant specification. The size of the extruder nozzle controls the dimensions in the X & Y planes. The smaller extruders are in the .35mm range, but there is substantial discussion that the smaller extruder causes headaches with clogging, lots of fine tuning the printer to permit faster prints without errors. If you can design your pieces with recessed lines rather than raised details, then you can work around the limitations of the extruder head, partially.

At this point, I am playing around with 3D CAD software, rhino for the mac is on sale until September 15.