CNC foam cutter platform

[Andre Germain]

I've been musing about a CNC foam cutter for nearly two decades as I got tired of doing it the old way with paper templates slapped onto the side of foam blocks.

I recently ordered the following 4 axis stepper motor driver for 70$ and already have stepper motors. With simple kitchen cupboard bearing slides from Home Depot or Reno, it should be a snap to complete it. A nice winter project.

http://www.ebay.ca/itm/320903535790?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

To give you an idea of what these machines are, check this Google image search;

http://www.google.ca/search?q=cnc+foam+wire+cutter&hl=en&tbo=u&rls=com.microsoft:en-US&rlz=1I7GGLJ_en&tbm=isch&source=univ&sa=X&ei=2X7DULybEJSB0AHR1YHoAg&ved=0CGwQsAQ&biw=1461&bih=1200

Full machines are very expensive, upward of 2000$. I'll be out by less than 200$ for my contraption.

Anyone know of these CNC foam cutters?

[Andre Germain]

Using parts I had from my telescope building time some 20 years ago, and phenolic flight control cable pulleys from a Cessna Citation jet discarded in the refuse pile at CAE over 20 years ago [cockpit sliced off to make a simulator], I assembled a 4 axis foam cutter. It works well when driven by Mach3.

You can see the two twin axis units when I was testing the stepper motors with the eBay driver I received [they would normally be carefully set apart a good distance]. I used 16 tpi threaded rods as one doesn't need much speed when cutting foam and they're low cost. The vertical is a very good pair of ball sliders I had.

I'm now evaluating software that allows one to CAD wings, fuses and parts before I decide which one to buy. These are CNC Workbench, FoamWorks, Profili2 and DevCad.

Any one know where to get large blocks of EPS, EPP and EPO foam?

Stay tuned.

[loflyer2001]

Nice work.....There is a foam company in Terrasse Vaudreuil where a
friend had two large blocks of foam made. It was the core for a set
of floats for his ultralight aircraft. They are the company who made
all the large foam blocks used in the construction of Hwy 30
interchange.
Dont know the name but are easy to located. Drive west on Hwy 20 to
the Terrasse/cardinal Leger exit in Pincourt. Right turn over the tracks
to Terrasse Vaudreuil. Just after crossing the RR tracks, turn right and
after the first stop sign you will see the large brick building.

[Andre Germain]

Thanks for the tip!

I should have driven off with one of those blocks! :) NOT! they were BIG! I'll think about all that white foam when I drive through that interchange.

Cheers

[Xavier]

That's very interesting André.

Friends who were cutting foam wings a few years ago where getting it from Legerlite on the 40 I believe.

http://www.salespider.com/b-130781016/plastiques-legerlite-inc-les

[Andre Germain]

Thank you Xavier, duly noted.

As for the software I've chosen, for 50$ it is http://www.tjzoide.com/ that can do a complete aircraft (wings and fuselage) as well as drive the 4 axis CNC. Simple and nicely done.

I'm still waiting for 100 feet of nichrome wire from the USA. Priority mail, 14 days already, yet the stepper driver board got to my house in 7 days from Hong Kong. Until I get the wire, I can't cut foam (my old wires have so many kinks in them now).

Cheers

[dhamultun]

Nice work! A good cheap substitute for nichrome wire is mig welding wire. Here is an interesting video that shows a hand bow version. It discusses the power supply and wire etc...

http://youtu.be/beUvirvUUOw

[Sunfly]

I built my self a foam cutter few years ago.
The wire I found was available at Distributions aux Modelistes at that time.
My cutter is 54 " long and I used a Hammond 36 V transformer with a light dimmer.
I would say it works pretty well and gives a lot of margin to over heat.

Since that transfo has a center tap for an output of 18V -- my tests with 18 V
showed I needed more voltage for that length of wire.

[Andre Germain]

I completed the CNC and purchased TJZoid and cut a quick test wing. Pulled a high lift NACA airfoil in, added a top notch and inner spar and ran the machine. Pretty decent for a first try - I believe I have 30 years of foam cutting fun ahead of me!

I messed up the spar, but you get the point (TJZoid has a setting for wire lag and I had left it at default, should have put it to zero). The s/w can also do fuselage plugs as well as airfoils.

Had so much fun with the foam cutter CNC that I began another CNC project (now 10 years in waiting) on my KC-45 (http://www.kingcanada.com/Products.htm?CD=36&ID=21734) gear head mill (hence the extra photo - I still had to do the idler pulley for that one, where the black mark is - completed it a few hours later, works super well - will buy a Gecko 4 axis G540 and 500W 50V DC supply, using triple stacked Nema 23 steppers, 260 oz-in).

BTW Sunfly, I used to use an auto-transformer to vary the wire heat, but now I use a DC supply. I find that 0.016" nichrome cuts right at 1.7 amperes.

Cheers

[Andre Germain]

Nice work.....There is a foam company in Terrasse Vaudreuil where a
friend had two large blocks of foam made. It was the core for a set
of floats for his ultralight aircraft. They are the company who made
all the large foam blocks used in the construction of Hwy 30
interchange.
Dont know the name but are easy to located. Drive west on Hwy 20 to
the Terrasse/cardinal Leger exit in Pincourt. Right turn over the tracks
to Terrasse Vaudreuil. Just after crossing the RR tracks, turn right and
after the first stop sign you will see the large brick building.

Finally checked this place out, it's Polymos;

http://www.polymos.com/en/

[Andre Germain]

I completed the three axis CNC additions to my KC-45 (http://www.kingcanada.com/Products.htm?CD=36&ID=21734) mill. I got her a Gecko G540 (http://www.geckodrive.com/geckodrive-step-motor-drives/g540.html)drive with an eBay 50V 15A power supply (http://www.ebay.com/itm/DC-Power-Supply-48V-15A-36V-50V-720W-CNC-Servo-Step-Motor-Stepper-Driver-/321060294750?pt=LH_DefaultDomain_0&hash=item4ac0af505e) (overkill). The steppers are Moon Nema 23 with a belted gearing of 3:1, so plenty of torque. I set up Mach3 (http://www.machsupport.com/)properly (including backlash compensation) and then spent quite a while learning about CAD and CAM software. Been quite a lot of fun.

To test out my CNC mill and my skills at CAD and CAM, I used Cambam (http://www.cambam.info/) and milled the two parts shown below in wood (not going to waste precious aluminum!). Came out quite well for a first timer. The parts are random, not for any project, just to test out the system and my skills. Here's a very poor video of the first part being cut: https://www.youtube.com/watch?v=AwEAWjLhO-A

I can see this mill will figure prominently in my RC future, for making parts for my RPVs and such.

[dhamultun]

That is really cool stuff! Can't wait to see more creations off you mill.

[drgilo1973]

hello andre i have a plans for you to cut with the cnc for an rc concorde can u do it ,

[Andre Germain]

Hi,

about that Concorde project of yours, well, I haven't even begun any of mine! Those CNC foam and mill have been sitting around idly for months. My work and our new acquisition of a farm in Ontario is keeping me plenty busy. Gonna build me a runway on that property!

However, consider that a typical foam CNC project consumes 20 hours. You have to setup the CAM s/w with the shapes, quite lengthy, then set up the machine, a few test passes and then go at it for a few hours.

Chao

[Kevin Rochon]

Nice a farm, you can fly whenever, where about in Ontario?

[Andre Germain]

Dalkeith area.

[Kevin Rochon]

It's a little further than Ray's farm, how many acres do you have?