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View Full Version : What's needed for a 3d printer build??



Davek0974
13-02-2014, 10:54 AM
I have nearly finished building a small CNC plasma table, tests with a pen show it to be very accurate in it's movements and I was wondering what it would take to go to a 3D printer.

I have Mach3 up and running and the XYZ axes all seem very nicely tuned.

I guess it would obviously need a print head and psu but what else???


Thanks

EddyCurrent
13-02-2014, 11:34 AM
There's quite a bit of info if you search about the net, here's just 2

Converting a CNC Machine to a 3D Printer | powered by gnexlab (http://cnc2printer3d.wordpress.com/)
3D Printing on a CNC Router Mach3 Emc (http://www.rockcliffmachine.com/forum/showthread.php?586-3D-Printing-Mach3-Emc-on-a-CNC-Router)

Davek0974
13-02-2014, 02:44 PM
Thanks for that.

I'm amazed so far, seems like I just need a print head - 50, some 1.75mm filament - 25/kg, a psu for the heater plus controller - junk box items and kissslicer software - free.

Unless I have missed something out, it appears that's about it for a bolt-on conversion????

Clive S
13-02-2014, 03:36 PM
Thanks for that.

I'm amazed so far, seems like I just need a print head - 50, some 1.75mm filament - 25/kg, a psu for the heater plus controller - junk box items and kissslicer software - free.

Unless I have missed something out, it appears that's about it for a bolt-on conversion????

And a heated bed if you are using ABS. It is not as simple as it seems like what surface will you be printing on etc. why not have a look here RepRap Forums (http://forums.reprap.org/) ..Clive

EddyCurrent
13-02-2014, 03:37 PM
I'm interested in this myself so looking forward to seeing your conversion.
One thing that might stand in the way is the Z axis travel, it might need a new lighter weight Z added that has a good travel, of course then you are restricted by the gantry height.

Davek0974
13-02-2014, 04:04 PM
Heated bed is no problem, I have junk-box kit that will cover that easily for a bed around 200x250mm.

I realise Z travel is a factor, if I pull the floating head off, I have 100mm to play with which for what I currently have in mind is plenty.

My Z travel is 0.01mm per step without micro-stepping which seems to be well in the ballpark of what others are using. Cant find much regarding the XY travel resolution yet but I have a strong feeling this machine will be ideal.

Interesting stuff

Neale
13-02-2014, 07:03 PM
I built a 3D printer a couple of years ago, before I built the CNC router. I'd got the bug...
Positioning accuracy doesn't have to be that great to get usable results although as with all such things, better accuracy and machine stiffness shows up in finished surface quality. Hot end is fairly easy to make if you have access to fairly simple machining facilities, or you can just buy one, but you will need an extruder to drive the filament through the hot end. There are a number of standard designs, most intended to be printed themselves.
I wonder if you will be able to get away with your current controller, though. One key aspect of 3D fused-filament printing is that you need to very accurately control filament extrusion rate with XY movement and I don't think that that's something Mach3 or LinuxCNC will know how to do. Most people use dedicated controller hardware based on the Arduino such as the Sanguinololu and running software like Sprinter. There's lots more to be discovered at reprap.org, and the forums for specific questions.
Probably easiest to use the CNC router to build one of the later design printers, tempting though "just swap spindle for extruder" might be!

Davek0974
13-02-2014, 07:48 PM
It's hardly worth making a head, there are 0.3mm extruders complete on eBay for less than 50.

there does seem to be a way forwards with mach3 as there are several bolt on type builders using their large CNC routers for 3d work just by slapping the extruder next to the router.

there is some slicing software "kiss slicer" that seems to have a direct connection to mach3 via its code creation so maybe it can be done easily, I really don't want to get into arduino et al just yet.

keeping on with the research...

Neale
13-02-2014, 10:24 PM
I'm not a Mach3 user, so I'm pretty out of touch with what it can do over and above the basics. From what I read, though, it's interesting that there seem to be more add-ons for a piece of commercial software than for something open-source like LinuxCNC. 3D printing is a pretty obvious area to extend it.
For me, the interesting bit of the printer was building the thing, and just buying bits would have taken all the fun out of it! But then, I've just designed and built a microprocessor temperature controller for an old soldering iron I rescued from a skip, when I could have gone out and bought one from Maplin for, relatively speaking, peanuts. I used my 3D printer to make bits for the router, and I'm now thinking about a new and improved printer that I could build now I have the router available - or maybe I just need to build the mk2 router first and do a better job... I know I could build a seriously good extruder with CNC machining available!
Be interesting to see what you discover in your researches, and where the crossover points between additive and subtractive machining are these days.

Davek0974
14-02-2014, 11:07 AM
Hmm, it seems that it really is that easy!

There is this head on the 'bay -
0.3mm Nozzle Extruder Print Head for RepRap 3D Printer Feed ABS 1.75mm UK STOCK | eBay (http://www.ebay.co.uk/itm/201024549965?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649)

Will need an old ATX psu for the 12v heater supply probably.

And the temp control will have to be manual in that it is not controlled by the CNC, simple PID controllers, one for a bed and one for the hot end.

Fans will also be manual control.

Great software is found in "Slic3r" a very smart bit of open source coding, that takes .stl files and converts them into code suitable for Mach3 systems, I have tested this today and the code generated makes sense and can be read easily so my Mach3 setup should have no issues digesting it.

I will need to add another drive board for my unused "A" axis, this feeds the filament out. Will possibly need another psu but as the head only has a very small motor, I might try using the "Z" axis output on my existing psu.

That seems to be about it, the rest is just a learning curve in tweaking settings to get it all to play ball.

Need to decide to go for PLA or ABS filament too, ABS seems a bit cheaper.

Slic3r also has a great help manual as well.

FatFreddie
14-02-2014, 11:32 AM
PLA doesn't produce fumes - with ABS you need some ventilation.

For PLA a dilute solution of PVA applied to the glass bed helps it to stick and the parts come off quite easily when the bed cools.

Operating in a warm environment helps minimise warping.

If you are printing fine detail or small objects a cooling fan helps - it should be turned on after the first layer has been deposited.

Be prepared for some experimenting....

Davek0974
14-02-2014, 12:06 PM
Excellent, thanks for that info.

Will switch direction to PLA to start with.

I take it that the PVA is applied and allowed to dry first on the glass?

I will need to upgrade the stepper on the head as my drivers can only go down to 1.5A and the teeny little motors supplied only run 0.84A, luckily motors are cheap and standard Nema17's

Neale
14-02-2014, 01:33 PM
I use Slic3r as well, it's a good piece of code. Also runs on Windows and Ubuntu so I can use it for printing indoors from a laptop and in the garage using my LinuxCNC machine, in conjunction with Pronterface for printer control.
The extruder stepper needs next to no current so should be fine off the ATX psu.
PLA is a good starting point but I would disagree that you need to mess about with PVA, etc, on the bed. I use a heated bed running at about 60C and don't have any problems. However, the top layer of my bed is a glass trivet from a local discount shop which has a ground finish. Getting the "squish" of the first layer on the bed is critical so you need the bed to be level to, maybe, better than 0.05mm so the layer is uniform across the piece. The bed gets cleaned with a quick wipe with acetone between prints to make sure it's grease-free.
Don't need PID for the bed as the temp isn't that critical and there's lots of thermal inertia but PID on the hot end is really useful. I reckon that I need to hold the temp to within 2-3C and without PID that's difficult. Took a little while to tune the PID parameters but I seldom see the temp move by more than a degree or so during a print. I built my favourite hot end with about 24W of heater power so about 2A on 12V. I think the heated bed (about 200x200) takes about 120W off the same 12V supply as the rest.
Just my experience, though - there are as many religious debates in the 3D printing world as, say, the Mach3/LinuxCNC world!

FatFreddie
14-02-2014, 09:20 PM
I used clean glass at first and it was a bit hit and miss - I would think the frosting is an improvement.

The PVA is quite dilute (5:1), applied with a tissue and will dry while the bed heats up. It lasts for several prints and I find it easier than cleaning the glass each time.

I agree with the bed flatness - I use a DTI gauge to make sure it's flat.

Neale
14-02-2014, 09:31 PM
The other side of my heatproof glass was plain and didn't work too well; I flipped it over and used the ground surface and it's very good. If you can find someone with a sandblaster I gather it is trivial to lightly frost the surface.

Davek0974
14-02-2014, 09:34 PM
Great, makes sense too, should be able to find frosted glass somewhere.

njhussey
15-02-2014, 11:09 AM
Could you not get some glass etching solution and frost the glass that way?

Neale
15-02-2014, 12:02 PM
Yes - it just depends on whether you have access to a glass frosting solution or happen to know a glass-worker with sand-blasting kit! Although in my case, the heatproof glass I bought just needed little plastic feet scraped off and it was ready to go. Very minor problem is that there is a pattern of narrow unfrosted lines in the otherwise frosted surface which comes out on the printed parts, but there's enough frosted to ensure good adhesion while printing. What's not obvious is that you have to do a lot of playing around with print speeds, extrusion rates, layer heights, hot end temp, etc, before you start getting halfways-decent prints. There are a lot of interdependent parameters to be played with, maybe even more than for CNC routing. Very satisfying when you get there, though.

Davek0974
15-02-2014, 03:37 PM
Twiddling software settings is the easy bit I think, once the mechanics and electronics are fixed, the rest is just fine tuning as with many DIY subjects.

having a good forum is a big help.

njhussey
15-02-2014, 06:38 PM
I was getting all excited (sad I know!) about adding a 3D print head to my router (when I finish it...) and then I remembered that I'll be mounting it nearly vertically....doh! Ok so I'll have to make a second CNC machine :)

Clive S
15-02-2014, 07:21 PM
I was getting all excited (sad I know!) about adding a 3D print head to my router (when I finish it...) and then I remembered that I'll be mounting it nearly vertically....doh! Ok so I'll have to make a second CNC machine :)

You can use a 3d printer upside down if you want. ,,Clive

Davek0974
15-02-2014, 07:48 PM
I was getting all excited (sad I know!) about adding a 3D print head to my router (when I finish it...) and then I remembered that I'll be mounting it nearly vertically....doh! Ok so I'll have to make a second CNC machine :)

Im no expert as I haven't even hot the bits yet but I'd be fairly certain a 3d printer does not care about orientation due to the extremely small clearances involved. It's not like inkjet where the ink flies through an air gap, the plastic extruded is sort of smeared onto the work as the gap is only around 0.4 to 0.1mm, I'm aiming for 0.2 to 0.1mm layer height on mine.

njhussey
15-02-2014, 08:08 PM
I just thought it would have to be flat as I've not seen one in any other orientation?

Clive S
15-02-2014, 08:11 PM
I just thought it would have to be flat as I've not seen one in any other orientation?

Bukito 3D Printer Works On the Go, Upside Down - Tom's Guide (http://www.tomsguide.com/us/bukito-3d-printer-maker-faire,news-17592.html) ..Clive

irving2008
18-02-2014, 08:33 AM
Talking of 3D printers, slightly OT, but CostCo Watford are selling the Cube 3D printer, 5" cube work area, for ~825+vat.

Pointy
18-02-2014, 11:49 AM
I would actually interested in this if I thought my 3020 machine was suitable.

Regards,

Les

EddyCurrent
18-02-2014, 11:54 AM
Talking of 3D printers, slightly OT, but CostCo Watford are selling the Cube 3D printer, 5" cube work area, for ~825+vat.

At least delivery is free but +5% if not a member.

Costco UK - Cubify 3D Printer, Silver (http://www.costco.co.uk/view/product/uk_catalog/cos_11,cos_11.1,cos_11.1.2/160430)