Make a CNC Hot Wire Foam Cutter from parts available at your local hardware store

Make a CNC Hot Wire Foam Cutter from parts available at your local hardware store like HomeDepot . This machine can be used to cut wings for RC planes, surfboards, crown molding, packaging foam and lots more

The original design was built in order to cut RC wings (even tapered wings - where one side is different then the other side)

Polystyrene (EPS and XPS) will cut using a hot wire - other foams - like polyurethane should only be cut with a blade or saw.

When cutting, be careful !!! - wire will get hot, and some people may be allergic to the EPS fumes - always work in a well ventilated area.

Step 1: Over View

Most parts can be found in your local hardware store, like Home Depot..
The first prototype was made out of wood, but didn't look "professional" enough, so I decided to go with a more robust design made of steel.

The design can be modified to almost any size. Keep in mind that for longer travel you will need a longer lead screw.
The problem with a long lead screw is that because it its own mass, it will "wobble" in higher speeds.
One way to overcome this problem is to move to a larger diameter lead screw.
Another way is to move to a chain or belt driven design. Belt driven machines are usually 8' and longer but require the use of micro-stepping. An example of a machine larger then 8 foot would be a surfboard foam cutter.
Some surfboards are up to 12 feet in length, the only way to cut these boards would be a belt driven or chain driven mechanism
I will try to cover this topic in the future with a sample machine and pictures...

We started out building a machine to cut wing cores, but soon after we discovered a huge interest in the machine for other industries - like moldings, architectures, surfboards, Logos, props, packaging Willow Sills, Casings, Wainscoat , Fascia, Crown, Parapets, Wallcaps, Pediments, Quatrefoils, Columns

www.8linx.com

Comments

[burnerjack01]

interesting design. Very clean. one question though: What gauge/size wire did you finalize the design with? My instinct is to go with heavy gauge to minimize/eliminate breakage but will I lose resolution?

[Kinnishian]

In the instructables, you mentioned "click here for more information" about the abrasive wire type of cutters. There is no hyper link, though. Do you have any suggestions for more info about abrasive wire cutters?

[AJMansfield]

ACME threads are much better then UTS threads when the threads will be used for moving parts, not just permanent or semi-permanent assembly. ACME threads are more wear-resistant and contamination-tolerant than their UTS counterparts. The reason UTS is good is that they don't migrate out of their holes as much; ACME threaded screws need to be re-tightened far more frequently.

[etopsirhc]

idk about ACME , if they make the screws the same quality as their rockets i'll pass

[AJMansfield]

ACME isn't even a company. Or at least its not one particular company; there are many companies that call themselves Acme [fill in the blank]. Just look at  this wikipedia page.

[etopsirhc]

*facepalm* joke post taken too seriously D=
haven't you ever seen the roadrunner and coyote cartoons?

[AJMansfield]

I know, but a lot of people actually do think that there is some ACME giganticonglomeracorp somewhere.

[Kinnishian]

Does anyone have tips for breaking wire? I put together a simple foam cutter for making precise width rectangular prisms, but I find the wire breaks even at a slow pace after several runs. I'm thinking perhaps the problem is that I am using Constantan wire, which is some blend of copper and nickel, in similar proportions to how Nichrome is nickel and chrome. I'll try it out with nichrome, but in theory I think Constantan should have similar high temperature strength.

This is a wonderful instructable! I hope the company gets some sales, the machines you guys have looks great.

[lordduckx]

Thats fantastic!

About how much did this all cost? I'm really interested in replicating it

[JKJ1961]

I'm curious about that myself.

[ultratuga]

Amazing. One friend of mine is doing all this mannualy. This will be may gift to him. Thanks .
Credito Pessoal

[rapidprototyping]

cut four foam circles for this

[rapidprototyping]

I see your plane parts and they look smooth . I have idea cut circles for savanious wind turbines. making four circles three or four feet in diameter should be no problem. next rout a couple flat bottomed s shapes into the discs use adhesives gorilla glue ,silicone to adhere the pieces together. My first HAWT was plywood and aluminum flanged pipe cut in half the foam is lighter and after assembly could be coated with polymers or powder coated with some coating to make it a uv resistant and possibly after further rounding over or stream lining. I hope adventually some one will do this challenge project. the cnc plasma could easly cut steel parts to support the foam at each disc attach it to the shafting fabricate bearing supports ect

[isurfwater]

Does anyone have a FREE design for one with a chain drive?

[Light_Lab]

Pure Polystyrene foam contains no nitrogen so it is impossible for it to produce cyanide without additional compounds. Polyurethane foam does contain nitrogen and carbon so it can (and does) produce cyanide during thermal decomposition. All wire cutting though produces dangerous fumes and adequate ventilation is mandatory.
An excellent idea is to use an old vacuum cleaner to collect the fumes and  exhaust through a wet filter.
I have hot wire cut PU foam but it requires a much higher temperature and a much slower cutting rate.  It is extremely corrosive of the cutting wire and produces ugly charred patches. I would not recommend it.

[slattermatter]

 Hey thank you for this tut.  

I want to make one like this except it will be 6' long and 3' tall.  I have heard if the key screw is to long it will shake at speed.  If I use a key screw that is a 2 start or 4 start the screw will turn slower minimizing the 6' key screw shaking, right.

Do people use over 1 start with hot wire foam cutters?

[tbarnea]

At 6' long you should use a 3/4-6 ACME screw or even a 1" ACME screw.
Anything longer you will need to go for a chain or belt design

[slattermatter]

 What would the difference be if i used 3/4-5 ACME or 3/4-10 ACME.  I know my motors would spin half as far to move the same distance, and they will be spinning slower to move the same distance... but is there any other drawback/positives  that I don't know about?

[tbarnea]

Correct - at 3/4-5 your motors will turn 5 turnes and advance 1"

[slattermatter]

 Why do people always use ACME 10 TPI with foam cutters? all most every application I can find thats what they use.

[mrubenb]

 Very nice work.

[crunchie1000]

i am going to make a similar design to this one and i was wondering if i could use threaded rods as an alternative to the lead rods as it will be cheaper. any advice? has anybody done anything similar?

Thanks

[tbarnea]

you can get ACME screws at www.use-enco.com
we use them on our machines www.foamlinx.com

 

[WoR]

yes it would be cheaper, but it would you would have alot of backlash. The quality would most likely not be good at all. ACME rod is not that expensive, especially in the grand scheme of things when your building a cnc machine.

i guess to better answer your question, could you - yes, would you be happy with the results - most likely not. Hope that helps

[Loonytech]

Haha! GO FOR IT !! And thnx for this one. Fantastic work.

[Andy S.]

Is there any one willing to build this CNC Cutter for me I am in northern California willing to travel any were in California looking to cut 4X8 blocks of foam to make crown molding, Thanks

[tbarnea]

Hi there
We are in northen CA - www.foamlinx.com

 

[frmco]

Im a model maker and have cut wings from foam befor for a quicki 500 racing. and other types and all you need to cut a wing is  couple of templets cut from formica and treight edge with music wire attached and powerd by 9V battery or 12 will do too then use weights attached to the streight edge with fishing line and set up the cut, easier than all of these mombo jumbo. LOL

[vicsrc]

has anyone built this cutter? how did you connect the horizontal axis to drive the vertical tower?

[big8]

From what I've seen so far, the cutter uses 4 independant motors. If these were arranged like a pen plotter it would free up at least one motor to use for a "Z" axis. A hot wire, in the form of a soldering iron tip could then vaporise the foam into 3D shapes. Obviously, some preforming would be needed. However, I'm new to foam cutting and about to embark on such a project, so if anyone can see a fault with this please shout before I get to far into it. Would appreciate some help with the electrical/software interfaces to.

[macrumpton]

The problem is that a soldering iron is not quite hot enough to really vaporize foam. it will melt the foam, but it creates a gooey buildup on the iron that makes a mess when it blobs off. I am thinking that if you had a fairly high power laser that would be hotter and you could use short pulses to control the depth that it would melt/vaporize.

[big8]

Hi macumpton, ( like to know about name) My reference to a soldering iron was just a figure of speech. I agree a suitable laser may work and would have many other and better uses but is a little complex a setup and rather expensive for many. Don't really know enough but would like to know where to get one at a reasonable price if you can let me know. I was referring to a small loop of ordinary resistance wire like Nichrome V that can be made hot enough to do the job. Rotate it if necessary. Changing the subject I have discovered two rather good sources of slideways to use as axes. Secondhand drawing board slides and a cross country skiing machine. There must be many other gadgets out there, that can be used also. I got both lots for less than £10. They needed a little modifying to restrict unwanted lateral movements but have turned out very well and removed the prime cost components.

[LWJCarroll]

FYI...to my knowledge cutting Polyurethane foam with a hot wire produces cyanide gas... (hence the warning) while polystyrene doesn't.......Rgds .Laurie

[macrumpton]

I took a metal casting course where we made shapes out of styrofoam and packed them in a metal box full of sand. When you poured the hot aluminum onto the styrofoam it evaporated leaving a hollow space in the shape of the foam. This process would pick up a surprising amount of detail, right down to the wrinkles on the masking tape that you put on the foam. We were told to never do this without the ventilation blowers being on full blast because the polystyrene released small amounts of cyanide when it vaporized.

[kinggato]

nice

[welgemoedr]

i cant wait!

[twrecks]

I love this concept - and the price seems right. NEMA23 bi/uni/polar motors can be had for for $12.95 ea at www.mpja.com. Just the thing for cheap R/C airplane fun. I plan to build the stepper control board myself. Also some folks on ebay are selling ACME rod machined down with delrin nuts for <$30 if that makes a performance difference - does it really matter? I would like 0.010" accuracy. Has anyone here (or posted elsewhere) besides the author built one yet? I really want to make one. It looks like some of the steps are not described - ie on the X slides, how is the drive nut attached to the carriage? It seems to me that the method used on the uprights (rivets) would interfere with the mount of the upright to the carriage. Also, how are the threaded rod end mounts made - that part is not mentioned or show clearly. It occurs to me that a 1/4"ID flange bearing should work there nicely I think - again I see em cheap on ebay. Also, can the Y motors be top mounted to lower the cutting height w/o added too much weight to the top and causing instability? Are limit switches needed or desired? How does one set the home position w/o them? Is there another forum that folks are talking about this machine? Tim

[twrecks]

I came across some 1/4-20 "T" nuts with flange at Lowes (stock #137342), in the drawers next to the threaded rods. This is a blind nut with 3 "brad" holes in the flange, which takes a 4-40 tap well - for a $1.04 it seems to make a decent traveler, no metal lathing required to mount it. I think the outside of it would take 5/16 thread OK too (0.304" D). Still working on the end holder.

[sgt_rock]

clearly i'm missing something. what cuts the foam?

[twrecks]

the hot wire...