I'm starting a new RepRap project. Any thoughts?

Hi everyone,

I've started designing a new printer, and though it is mostly just for fun I thought I would see if anyone is particularly interested. It goes in the opposite direction of most RepRaps I've seen and for good reason- It won't be terribly practical for too many people.

A little background- I am a mechanical engineer who does automation engineering, and I find the difference between here and the industrial world so interesting. We in the RepRap community do everything to save every dollar, and the difference between $10 and $50 is huge here, while there if something very minor costs a few hundred dollars extra, it isn't a big deal at all. I've built machines with a tenth the functionality and purpose of a reprap for many thousands of dollars, simply because it had to adhere to codes and last 20 years.

I have to add that the developers here have done an astounding job at keeping costs down while building an amazing machine. The longer I work in my field the more respect I gain for people like nophead and Prusa- they are truly amazing.


But what if I have the money for a Makerbot but want to do it myself? I would still like to stay in the ballpark of several hundred dollars, but with a couple hundred more than my $400 i3 I would like to build a printer that is more solid, easy on the eye, and will need a lot less maintenance over time. I also want to include many features not standard on most repraps or 3D printers in general. Though none of this is truly necessary, I have plenty of time, money, and space, but wouldn't buy a commercial printer. Here's what I'm looking at:

-Solid construction with no limitations on size and weight (to a degree of course)
-Clear heated enclosure or semi-enclosure
-Fume dispersment/filtering.
-All visible 3d-printed parts vapor treated if possible
-Enclosed, actively cooled electronics with relays powering everything. No current above signal level through ramps besides motors.
-No exposed wiring/motors
-High cooling abilities at the print head, from a frame mounted fan
-Automatic bed leveling
-AC powered bed, <30s time to 100C and 12"x12" (300mm)
-Bluetooth printing
-Built in Acetone vapor treating. It will have an out-of-view acetone "tank" and use custom pronterface buttons or an external interface to treat parts either as they lie on the bed after printing or manually later.
-Fire safety. I want to be able to start a print and go to work or to sleep, but wouldn't do that without some kind of automatic shutoff and preferably an integrated fire suppression system. Being a single enclosed unit I imagine a few small co2 canisters could fill it pretty quickly and put out any potential fires, but I will need to look into this more.

I either have implemented the above or have the ability to, but here are some more far-fetched ideas that won't make the cut without some extra help:

-Servos or linear motors instead of steppers. While steppers work, there is a reason they are very rarely used commercially and servos would be very nice.
-Wireless internet connection for remote monitoring- I'd like a text when my print is done. The new makerbot mobile interface seems mostly gimmicky, but a simple notification would be nice.

If you're interested, let me know what you think.

Use a welded exoskeleton/superstructure.
Use >=16mm ball profile linear bearings.
Sounds like you plan to only print with PLA, which isn't any good for structural components.
Given enough time acetone, or any solvent is probably going to destroy some thing, and it's a fire hazard.
Use a all metal hot end with water cooling.
Use a 32-bit ARM microcontroller ( LPC1768 Cortex-M3 or the newer M4 ).
Use FSR for bed leveling.
For high accuracy, and resolution make your own voice coil linear actuators, (some one showed some interest in this last week and is exploring it).
For fire safety you shouldn't leave it unattended, but if you do make a firebrick insulated steel plate (not sheet) enclosure with a lock, elevated and well away from any combustibles, e.g. acetone, curtains, etc, with automatic fire suppression, and don't use it in a building where other people have access.

Good luck keeping it under $700.00 usd

Thanks for the advice!

I know welded would be strongest, but with the frame I really don't need too much strength so I'll probably go with a 6061 & polycarbonate structure. I'd also like to keep within the RepRap concept and make it mill-able.

I'll probably use a laser or inductive prox sensor for the auto-leveling. FSR doesn't sound like it can do heat too well.

Where do you gather I only want to print with PLA? I plan on only printing with ABS actually.

Definitely an all metal hotend eventually- A J-head will work fine at first with the fan setup but eventually I'll go with a liquid system. My J-head has never jammed or caused any issues so I probably won't be motivated to change it until it does.

Acetone may eventually destroy something stored wrong, but an ounce or two in an Acetal tank could sit for a year without issues.

As far as fire safety goes, I'm not looking for OSHA approval, just peace of mind.

Yeah I'm probably kidding myself with the price tag, but I don't think I'll be too far off considering I have access to a mill and already have most of the electronics.
Does the RAMPS system have any limitations though, where an ARM controller would be necessary? I have no idea whether or not the arduino is a limiting factor, something I hadn't really considered. Thanks!

LASER, or Inductive prox sensor: based only on what I have read, I don't think that will work.

Here are all my links on FSR:

FSR Mount, Neoprene Rubber (not foam). This seems to have the proper flexibility and lack of compression. [www.thingiverse.com]
Autolevel with Force Sensing Resistors works better than expected [groups.google.com]
Auto-tuning FSR sensor signal cleanup with MCU for end-stop signal generation [groups.google.com]
Force Sensitive Resistors (FSRs), Graphite Foam Pressure Sensor [www.openmusiclabs.com]
Force Sensing Resistors (FSR) [reprap.org]
FSR Guide [www.openmusiclabs.com]
Pressure sensor Interlink FSR402 about 10 g - 10 kg [www.conrad.at]
WingTangWong/AutoTuningFSRTrigger [github.com]
Automatic tramming/leveling on a Replicator 2X [www.reddit.com] [groups.google.com]
UK website selling FSR. Seca4all on reprap. [www.mytechno3d.com]
Self Adjusting FSRs, Posted by JohnSL [forums.reprap.org]
Auto Adjust FSR End Stop Detector Posted by JohnSL  [trains.socha.com]
FSR Mount for 1.5x Mini Kossel 260mm Glass [www.thingiverse.com]
$7.95 + $4.77 shipping, Jameco Electronics, FORCE SENSING RESISTOR,0.5 INCH ,CIRCLE,1oz-22LB,FLEXIBLE [www.amazon.com]
Z-Probe Bed Leveling for SmoothieBoard [mauk.cc] [www.thingiverse.com]
DIY Force Sensitive Resistor (FSR) [www.instructables.com]