Also i wanted to stay more towards the hobbyist side of things SLS is exciting but its not likely to be available anytime soon. i need to find out more about the HP 3d printer and they are being mum about it. it seems to be a hybrid between the SLS style but using a liquid colorant binder with a plastic powder.

As for the software while important ii don't know it as well as i would like and if you are buying a printer the software is usually provided

Since you broach the subject of alternative printing technologies such as SLA, you might also want to include SLS.  It is after all the best printing technology for high quality models.  In fact due to it's high resolution accuracy, it's used almost exclusively for prototyping, and low run production.

Something else to consider is your usage of the word "resolution" as it applies to printing.  In many places you reference "low resolution" as it applies to the layer thickness. 

A 3D printer has basically 2 "resolutions".  One applies to its ability to move the printhead in the X & Y axis, the other applies to the layer thickness it's capable of producing.

Most printers are capable of X/Y resolutions of about 300dpi, which comes down to about 0.08mm.  The problem with the X/Y resolution is that it's hampered by the thickness of the extrusion.  This is where the nozzle size comes into play, or in the case of SLA printer the diameter of the laser beam.

The slicing software can take the extrusion thickness in consideration and inset the outer dimensions in order to produce a dimensionally accurate model.  Unfortunately very small details (those less than the extrusion thickness will always be lost).

You also mentioned Open Source vs. Closed Source.  Outside of the hardware, one of the most important parts of the 3D printing solutions is the software.  Some software like the Affinia software or the MakerBot software are closed source, and while they do provide an easy to use, all in one solution, they have very few options for customization or tweaking. 

There's software out there (like this printer that was intended for schools, don't remember its name), that won't even let you print your own objects, only stuff available from their web site or store.  That can be a real deal killer unless all you want to print is their trinkets.

Anyway, these are some of the things you need to revisit on your next revision, and clarify them, but for now I think a thorough proofreading is in order.

Good luck with your ebook.

IS this it?

http://www.amazon.com/So-You-Want-Buy-P … %27s+guide

over the next few weeks i'll re evaluate it and may make a few changes as the information changes some. I'd like to thank everyone who helped

closed source isn't always bad just more expensive in the long run.

I don't really go into a massive amount of detail about any one printer

i have editing i have to do but if anyone would like to proof read and offer suggestions send me an email.

- purchase price (obvious one, I know)
- - - purchase new, or used?
- - - customer service? (or lack there-of)
- build area
- - - heated bed vs non-heated
- - - enclosed vs open
- - - build volume (size)
- extruder options
- - - single extruder vs multiple extruders
- - - direct drive vs bowden
- filament choices
- - - proprietary spools/cartridges vs non-proprietary
- - - what types of filaments can be used? (PLA/ABS/other)
- ease of operation (learning curve)
- - - software requirements (and their learning curves)
- ease of repairs/upgrades when needed
- - - parts availability - not just purchased stuff either, but print-able stuff as well
- - - how handy is the person? are they willing to dive in & try fixing things?
- community help & support (Soliforum rocks!)

The other half (madkow007) did most of the researching, for several months, before finally pulling the trigger on a used SD4.
Why used? Cost savings for one, and near immediate availability (a few days for shipping vs a few months wait for it to be built & then shipped).

So we didn't get any kind of warranty. From what I have seen of SD, that is a complete nightmare anyway, so we didn't feel bad about making modifications right off. And no waiting for weeks on end for them to get things fixed and shipped back...

The longest this printer has been down was about a week while waiting on a replacement Rumba board when the USB crashed - otherwise it was maybe a day while making major modifications... it has been run nearly every day since it arrived back in mid February.

We have made multiple upgrades since February, including the Lawsy linear bearing carriages (best mod ever for an SD), a fan for the X motor, Rumba controller board, upgraded power supply, recently installed an E3D v6 hotend, and I have rebuilt the heated bed to get rid of the severely warped stock bed that was a constant issue for leveling (one of these days I will replace it with something better, but for now, it works).

For us, the used printer was a fairly good fit. We are both pretty handy at fixing things, and not afraid to dive in to something new. It has definitely been an adventure, but one that has been mostly fun and interesting. I like a challenge, and the SD4 has certainly been that! LOL

From the Australian perspective,  Must do's are as follows
1) find a great community for your printer. 90% of the people who will sell you a printer locally offer "servicing" that is the equivalent of bend over and think of England. Every single problem I've had with this machine, one of the guys on this forum has solved

2) Parts are a freaking pain to come by. even most 3d printer supplies wont stock what you need for a repair, with most suppliers only stocking whole units.  Consider E-baying some spare belts bearings and others from china before you experience a failure.  I discovered the Aussie parts shortage  when my acrylic head failed (in the damn middle of trying to print out my own mk5 Lawsey). Both the guys within a mile or so of my place who have 3d printing businesses had printers  sidelined due to lack of parts.

its more to help people ask themselves the questions of what they want, and actually need. I'm trying to give people a basic overview of the technology and i figure to update it as the technology goes forward.

For instance at microcenter this week i was told that microcenter is going to get a new type of printerit uses a resin that cures in the presence of oxygen so there is no hot end print head. Sounds good right? except it makes it more dependent on the printer company to supply the materials such as the resin and print heads. also think of all the things that could go wrong and i'm sure its going to be very closed technology.

So i'm explaining all the little things that people should use to make their decision, like why are davinci and some of the other printers in expensive. Telling them to figure out their needs so they can figure out the printer they want and explaining some of the main differences.

So far its only about 24 pages with illustrations and an appendix and glossary of terms.

I'd of course love other peoples input on what considerations they had in their decisions.