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Apr 09, 2015, 04:21 PM
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Thread OP
Build Log

4-axis Arduino based CNC hot wire foam cutter


THIS IS NOW A HOWTO

4-axis cnc hot wire foam cutter test (2 min 38 sec)


Hardware:

- RepRap kit:
get it e.g. here: http://www.ebay.com/itm/SainSmart-Me...-/271253409360

- 4 x Nema 17 stepper motors

Software:

- Arduino 1.6.3

- 6 Axis CNC Demo Rumba - Thanks to Dan Royer from www.marginallyclever.com
Get it here: https://github.com/MarginallyClever/...Demo6AxisRumba

- GcodeSender - Thanks one more to Dan Royer from www.marginallyclever.com
Get it here: https://github.com/MarginallyClever/GcodeSender

- To generate the Gcode I use Profili Pro from Stefano Duranti
Buy it here: http://www.profili2.com/eng/prices.asp
Profili is good, because it can create the Gcode for the 4-axis cnc hot wire foam cutter.

- You can also get the Gcode in many other ways.


Original question

I need some advice on this.

  1. Is it good, bad, medium or directly off-the-road-crazy what I found?
  2. What is missing?
  3. Do I need more/other electronics?
  4. What kind of software will I need?
  5. Can I use my USB-port on my laptop to control it?

For a long time I have been reading about this subject in several fora, and now I took the decision to buy what I meant was reasonable to get at good beginning on my foamy CNC adventures. I am an RC plane hobbyist with a preference for big gliders and maybe DLG's, if my nice machine some day will cut the wings for me

I've bought some stuff today in the hope to build a 4-axis CNC hot wire foam cutter.

These are my parts:

1 x RAMPS 1.4
1 x MEGA 2560 R3
4 x A4988 driver
1 x USB kabel
4 x NEMA 17


The mechanical part is not my question. I know how to build the towers for the hot wire and I will control the hot wire separate from the CNC 4-axis electronics.
Last edited by Søren Vedel; Jun 21, 2015 at 09:57 AM.
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Apr 10, 2015, 03:46 AM
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the foam linx hardware is expensive!!!..have a look here.

http://www.rc-letmathe.de/CNC-Technik/CNC-Mechanik

.and the ramps 1.4 is not really suitable for a hot wire machine. Why? the software does not do 4 axis movement (3 .5 axis?) and the GRBL options such as this one https://github.com/LETARTARE need all 4 step and direction pins on one mega 2560 port (see the pins.h file in the arduino load module), which RAMPs hasn't.

Here is a mega schematic http://pighixxx.com/megapdf.pdf

and the arduino mega schematic http://www.elecfreaks.com/wiki/index...-Shield-10.jpg

These 2 show the incompatibility issue.

Also the Heater driver FETs on the Ramps board are not speced to the correct max voltage >24v requirement of hot wire cutter implementations. Here is a guide to hot wire volts/amps issues

http://hotwirefoamcutterinfo.com/_NiChromeData.html

hope this helps
Apr 10, 2015, 04:59 AM
Earth girls are easy!
RCWorks's Avatar
I don't like wood, MDF or folded sheet metal machines.

Wood had problems with humidity.
MDF is what it is and I have a sensitivity to what ever is holding it together.
Folded metal machines can be frustrating as far as getting them to move well.

There are better ways t go. I use aluminum plates and bearings for the linear sides. Everything glides with no friction.
Latest blog entry: Jonesy's mausoleum
Apr 10, 2015, 05:09 AM
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Thread OP
I agree totally but when I look here: http://reprap.org/wiki/RAMPS_1.4 it seems like I actually am able to control 5 independent stepper motors, according to the diagram below.

When it comes to the hot wire, my current plan is to control it as a separate unit. But if I can control it from my board in a more clever way, it would of course be great.

I also found this one in another thread here:
CNC4 (10 min 48 sec)


but this is not, what I want to do, but as I understand him, he uses also the same hardware more or less...
Apr 10, 2015, 07:15 AM
Registered User
Yep but if you look there are only 3 motion axes x,y and 2 zs and the others are extruders. The motion axes have acceleration planning and the extruders don't....

For a 4 axis foam cutter you need 4 motion axes(!)..and the Ramps solution only has 3.

as regards the heat control the FET only controls up to 12 v I think...depending on the length and type of the wire you may need 24-36 v at say up to 10 amps..so you probably need to change out the heater fets and some how turn off the Marlin firmwares heat routines ( including the safety checks it performs to prevent movement and extruding when under temp and aborting when over temp) and control the fet separately.

As I've mentioned GRBL does all these things, is mega compatible and can do 4 motion axes but needs all the step and direction controls to be on a single port..maybe explore the possibility of using the driver boards on a different shield?..maybe the GAUPs board? with the arduino mega ?
Apr 10, 2015, 07:17 AM
Registered User
Oh yep I forgot GRBL controls spindle speed (i.e. hot wire temp) using PWM linked to Spindle commands in the G code
Apr 10, 2015, 10:39 AM
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speedyb_tx's Avatar
I am in process of building one, using hardware/extrusions from openbuilds.
for the money it easily competes with the unit you have shown.
The opnebuilds extrusions are what I would consider "light" structurally. well compared to other extrusions I have from 8020 and the scrap yard.
I won't use it for the future (hopefull) cnc router build.

The new C-section from them is heavier. got two pieces "just cause" and decided I will use them for X axis.

BTW, At first I selected Nema 17, then changed my mind and got 23 size.

I also decided to get a Gecko 540. because just building and assembling the machine is enough work. not interested in doing arduino, etc. even though I am well versed in C and general controller "stuff". - Well enough to know I want to cut foam, not make it an electronics project.

I do not care for all the wood/mdf do it on a drill press ideas out there. Most people are not going to be able to make the parts accuratly enough. I bet for every one good build is 100 bad builds.
The foam cutter build is is also a stepping stone towards a CNC router that can handle aluminum.
Apr 10, 2015, 10:52 AM
Registered User
Thread OP
Quote:
Originally Posted by speedyb_tx
I am in process of building one, using hardware/extrusions from openbuilds.
for the money it easily competes with the unit you have shown.
I'm not sure if I understand you right about the "money". I have paid 113 USD in total for what you see on my list.

By the way! What specific project from openbuilds are you doing? Can you please provide me with a link?
Apr 10, 2015, 02:24 PM
Registered User
speedyb_tx's Avatar
the foamlinx cutter was the $$ item

no specific project - have only been gathering the basic parts needed.
I will make other parts - I am fortunate to have a Mill and lathe.

It will probably look like all the others out there...with minor differences.
I do not have anything drawn up yet, lol.
Apr 10, 2015, 03:41 PM
Registered User
speedyb_tx's Avatar
PS..
I am one who never saves $ by DIY... as opposed to those who do.
example....just ordered $100 worth of counterbore bits....
it is a never ending thing
Apr 11, 2015, 01:52 AM
Registered User

cnc stuff


i have made lots of cnc stuff and if you are not in to engineering than it can be hard and expensive

the RAMPS 1.4 Arduino
1 x MEGA 2560 R3
4 x A4988 driver
1 x USB kabel
4 x NEMA 17 are all designed for 3D printers having a X Y and two Z axis where you will need a X Y A B axis for a foam cuter just search ebay for 4 axis cnc there are lots of gear out there
http://www.ebay.co.uk/sch/i.html?_fr...c&_sacat=92074

i have the hobbycnc boards they are bulletproof and i have had no problems with them but you have to assemble then

as for the machine there are all sorts of cutters out there personally i do not like the tower with a spring tension wire i prefer the bow type
there are lots of stuff to see on the and read hear

http://www.cnczone.com/forums/parts-...44247-cnc.html

http://www.openbuilds.com/builds/lar...-printer.1768/

the openbuild and vslot system is a new concept in of the shelf meccano type assembly of liner motion machinery but it is expensive and shipping is not good and my last two orders came with some of the order missing but that did put it right and you have to have a plan or design thats works to build from

if you wont to design your machine then i am happy to help as many others her will also my bag is cad and engineering electronics not so good

software for wing cutting you have GMFC good and works with usb but i like DEVcadwing and profilpro2 but you will need mach3 or 4 to run it on your cuter
Last edited by dpot; Jan 08, 2019 at 11:21 AM.
Apr 11, 2015, 02:09 AM
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Ronys's Avatar
Quote:
Originally Posted by Søren Vedel
I also found this one in another thread here:
https://youtu.be/aco9OinN21I

but this is not, what I want to do, but as I understand him, he uses also the same hardware more or less...

Anyone can identify this software?
Thanks,
Apr 11, 2015, 04:47 AM
Registered User
Thread OP
Quote:
Originally Posted by Ronys
Anyone can identify this software?
Thanks,
Yes, he made the software himself.

https://www.rcgroups.com/forums/show....php?t=2149960
Apr 11, 2015, 06:37 AM
Registered User
Thread OP
Quote:
Originally Posted by dpot
http://www.openbuilds.com/builds/lar...-printer.1768/

if you wont to design your machine then i am happy to help as many others her will also my bag is cad and engineering electronics not so good

software for wing cutting you have GMFC good and works with usb but i like DEVcadwing and profilpro2 but you will need mach3 or 4 to run it on your cuter
Interesting to see your large format 3D printer. I nearly have all the components to make this one in stead of my 4-axis foam cutter


BUT!

I really do want to make a 4-axis foam cutter.

I understand that RAMPS 1.4 is the wrong tool, because it can only control 3 independent stepper motors, but what about the rest of my electronics?

1 x MEGA 2560 R3
4 x A4988 driver
1 x USB kabel
4 x NEMA 17

Can I buy something else to connect to what I have to control all 4-axis ?
Apr 11, 2015, 08:17 AM
Registered User
The issue really is mounting the stepper drivers. All the boards I've found mount directly on the mega and have 4 axis/ single port issues with Letartare's 4 axis mega GRBL.

May be best to buy a 4 axis stepper box with a parallel port and then wire the mega to it?. (e.g. http://www.ebay.co.uk/itm/4-Axis-Tb6...item51cdfc1be3)

And then use the stepper drivers you've got for a 3 d printer?

just a thought..


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