My first attempt at a CNC foamcutter, built on a major budget with no special tools. All I had to work with was a Jig saw and a couple of Drills. I used shelves and hardware from Home Depot, Acme 1/2x10 Lead screws, Delrin ballnuts and Vexta motors from eBay. Controller is an original Foamlinx board that I bought used for $60.00, it even came with 2 1/2 AHATB heat controllers from HobbyCNC(have gotten those to work yet). A friend leant me a MONSTER Lab grade PS for the bow (variable DC 2-30V at 0-15A, thing must be 75lbs!).

Looking forward to producing some nice plane for myself and friends, perhaps even kit some for sale.

Sleedo

Well done. Looks a fairly clean build. Interesting to see you using double draw slides. Saw someone else doing something similar on a router.
Paul

Thank You, did my best without a proper workshop. Next one will be even nicer.

Sleedo

Well done Sleedo,
Looks like a very simple and effective machine. Good Cutting.

Bud

hey sleedo have you done any full wing cores yet?

I noticed you had some airfoil shapes blanked out.

If so could you post a couple of pictures? I was kinda curious what a home made CNC wire cutter was capable of.

thanks

Sure, here are some of the planes that have been made from my cores. I didn't make the wing for the boat but I am currently working with the designer of the vessel on an 1/8 scale model of it to do some testing and development on.

here's a couple o' more, with a shot of a nice set of cores ready to be prepped for bagging and the root of the wingeron wings for my Sig Samurai.

those are sweet man!

how long of a learning curve was it to get your machine cutting like you wanted?

And where do you get your foam? ep I pressume?

Learning curve was fairly steep and I ramped up within a week of cutting everyday for a few hours at least. Important to get a good software package and stick with it, very confusing to switch around. I settled on GMFC PE, works well and very good support. Wasted a lot of foam too, mostly Dow 250 from home depot. I also use EPP which I have gotten from many sources, it's far more expensive so I practise with the pink stuff.

how much did the "GMFC PE" software cost? and where did you get it?

here's a link to their page, you can get demo and learn to use it before you buy. It was 45euros, about $60.
http://gm.cnc.free.fr/en/index.html

thanks for sharing. great pic's.

After you cut the foam, what is normally used to finish the foam product? is it just paint? latex? fiber glass? just curious to know.
Thanks

A variety of composite methods are used, from packing tape to vacuum bagged carbon and kevlar skins. Depends on the application, I mostly build slope sailplanes so they need to be durable and rigid so they get a carbon spar with fiberglass reinforced packing tape sub-covering and a heat shrink outer skin.

Thanks, I would like to learn more about the different methods used.
Do you know of a web site that explains these concepts further? Or perhaps a few good books?
Thanks again

Hello Sleedo,

Can you post the parts you used and maybe some more closer detailed pictures. If you bought stuff from Home Depot, can you list the part #'s please. I think there are a few of us that would like to build one. I picked up 4 stepper motors in the last few days. I am now looking at the driver boards, so If you could make a shopping list per say, I will be shopping this week! :cheers:

Bill

Wow, it's been nearly a year since I set this system up and it's just getting attention now. I'm excited that my work has been appreciated by you guys and I would like to express my appreciation for all of the folks that I got my info from. I think I will have a really hard time remembering every-where and one that I gleaned an idea from but I will try to help out with the big stuff.

First off, trubleshtr, look here for info on a good method for finishing EPP wings, works well for EPS too but there may be better methods for rigid foam;
read here from post #67 http://www.rcgroups.com/forums/showthread.php?t=628341&page=5
Here's another link from my same friend as he explains the method in more depth; http://www.rcgroups.com/forums/showthread.php?t=525688
Bookmark RC Groups, if you are into RC planes you cannot find a better source of continuous information flowing about all related subjects.

Micro Rotors, do yourself a favor and buy a kit from Dave at HobbyCNC: http://www.hobbycnc.com/4aupcwhc.php he offers great support and his product works, flatout the best investment I made. I tried a crappy used board and I wasted alot of time and a little money, wish I went with Dave from the start.

The rest of the parts are fairly off the shelf, literally, the bases are 8x36" shelves. the upright gantries are 8x24" and I cut an 8x16 in half for the bases. There are 3 pairs of drawer slides, I forget the dimension but it shouldn't be hard to figure out the lengths needed. Some various corner brackets and L and T brackets. The lead screws and nuts were specially purchased. The screws were bought from Enco, here's my order info:
Model No. Description Qty. Price Ext. Price
408-0200 1/2-10 X 3' ACME THREADED ROD 1 $4.59 $4.59
408-0220 1/2-10 6'LENGTH ACME THREADED ROD 1 $6.99 $6.99
As you can see, they weren't expensive. The flanged nut were bought on ebay for $12.00 for 4 but I can't find them now, may have to work something out for those. The motor mounts are tool hangers, like you'd hang a broom in the garage on, from HD. Let me post some new pics and you guys can let me know what else you want to know.

Can You Use Mach Software To Cut ?
If Yes, What Other Conversion Software To G-code From A Dfx File ?

Mach software will work the motors but to get the ability to run 2 x axis motors at different rates for a tapered wing might prove challenging.

Can You Use Mach Software To Cut ?
If Yes, What Other Conversion Software To G-code From A Dfx File ?
I have used GMFC, Jedicut and Foamlinx so far, I am only interested in cutting wings and fuses at this point so I have not tried any other types of software.

I have used GMFC, Jedicut and Foamlinx so far, I am only interested in cutting wings and fuses at this point so I have not tried any other types of software.

Sleedo,

Out of those, which one did you like the best? And if you would, could you give the pros and cons between them? I am looking for some software for my foam cutter.

Thanks
Bill

MR, currently I am using GMFC exclusively. I tried the others, I even used Jedicut for a few months but GMFC has many more features. Of course it is not free like Jedi but the value was there for me. There is a trial version with full functions so I suggest you try them and see which works for you before you make the investment. I would not waste your time on Foamlinx. I would have a hard time describing the differences as it has been a while since I used anything but GMFC and once you learn the nuances of one package you really won't want to switch.

Download them, try them out and feel free to ask me any questions, it would be easier to address specifics than the entire packages.

Sleedo

Sleedo,

What version of GMFC are you running?

Bill

I've been trying to figure out to use Foamworks. 30days trial version at www.foamwork.com

But the problem i've been running into is the conversion process. I use a Cad software to draw and save as DXF file and so far, nothing ever converted right. Mach converting to G-code looks all funky, and foamwork freezes.

I a attaching the file here see if anyone else can help me convert it.

G-code and .Dat file for foamworks cutting.

PE, I really liked Pro and was running on W2k but too expensive for me. I like how you can cut two cores, top to top, in one operation with Pro. In PE you have to cust one side, flip the foam (trying to line them up) and cut the other side.

I have a bunch of accuglide slides that are very close tolerance slides. If anybody is interested in a few of these, e-mail me and maybe we can work out something. (haroldj@alphacomm.net). I have a pretty good assortment of lengths. I hope this doesn't swamp me with requests, but these are better than normal drawer slides.

Anyone have the English Documentation for GMFC PE .. the link on the sites seems to be broken,

So far looks like PE will run on Windows 2000 but need a separate driver,
is that right..

here is the English help file. The help says that cutting does not work under 2000 in GMFCPE. I used the demo of Pro on my laptop that ran W2K, I picked up an old system for free that has W98 on it and that's what I use now for cutting.

Thanks Sleedo,

I got thing working yesterday .. well at least moving, and did a dry run with no foam and hot wire.. it moves :-)

but so far I've stumbled on setting the steps\ inch.. well in this package looks like they set steps per rev and the size of the lead screw..

so far they don’t seem to match up...

I have a lead screw that turn 12 rev/in and 200 steps per so 2400 steps per rev..

I'm coming up short.. :-(

The values they show in the configuration help file.. are

M6 6 mm 1
M8 8 mm 1.25
M10 10 mm 1.50
M12 12 mm 1.75

I don’t follow there method to calculate .. steps per\in..

the lead screw is 3/8 thick.. but how does that matter.. if I could have a 1/2 in thick lead screw.. and will have ( 12 turns \in also )

hmm am I making this more complicated that in has to be..?

this was a snap to set up on my 3 axis machines.. :-)

you're close, what you are confused by is the difference in how SAE threads are described vs Metric. Here is my understanding, one revolution of a metric screw will advance the lead as follows: M6 6 mm 1, M8 8 mm 1.25, M10 10 mm 1.50, M12 12 mm 1.75 . What you need to worry about with an SAE thread is that you have 12 threads per inch, an inch is 25.4mm, so in 12 revolutions your lead travels 25.4mm. Therefore one revolution = 25.4/12 or 2.117mm. Plug that # into your GMFC "Screw thread" field to start then follow the instructions to tune your table. A few full trips the length of the table will tell you how close you are and you can adjust for the error.

Clear as mud? ;)

sweet.. thanks that perfectly clear now.. I'll try that ..

Sleedo.. thanks for the advise before.. it worked perfectly..

have another q for you..

the help doc says.. that GMFC will import arc's circles.. and split them into
2mm segments.. but I cant seem to get that to happen..

all I get is a strait line where the arc.. or circle should be.. :-(

I attached a few fix.. maybe it will help explain my point..

any advise..

hey,

I got around the problem..

I want to set up my own spars .. in the *.dxf..

but GMFC does a good job once .. I figure out how to use it..

would still be nice to know why.. it does not import arcs.. or circles..

Here a pic of a the first few cuts..

congrats! those look fantastic for a first effort!!! I'd be embarassed to show you what my first cuts looked like ;)

I'm finding out that.. Symmetrical wings are definitely but easier to cut..

the lighting holes or spars.. for example. if the wing has to extreme of a sweep back.. looks like its not such a good Idea...

so far I've just cut some small wings..

10.75" root .. 5.5" tip.. the thickness goes from 1.25" to .5 " ..
maybe it would be better .. for larger wings...

had to remove the lightning holes for the Tapered wings .. looks like the geometry caused the tip’s to be out of sink with the root cord.. and so GMFC would not cut it..

There is still a lot of little thing a I cant really make sense of..

For some reason if the values are.. 101.10000 ( I get a “Enter Positive Integer” pop up)

Looks like some mathematic error on the program side ..so I round up.. and the pop ups go away..

Also the “reverse table layout” hmm while it seems to reverse or invert the block in the cut panel screen it .. still cuts moving forward I was expecting that to be reversed also..

Sleedo thanks for the complement but I did cut a lot of scrap in the “test cut mode “ to make sure the speed and heat where in the ball park..

Here are some pic the firs wing set..

For some reason if the values are.. 101.10000 ( I get a “Enter Positive Integer” pop up)

Integer means WHOLE number or NO decimals.

This is why rounding works.

Thank,

Man how much have I forgotten since..
I've been out of school..

:-(

How do you set the configuration in GMFC program ? I have a regular 3-axis cnc board that i'm using on my foam cutter. GMFC does not seem to pick up this board. Any manual configurations like Foamworks?

I think its a combination of two things..

on my 3 axis machines I have a Xylotex board,
one is 3 motor setup .. the other is a 4 motor set up using,

TurboCNC and Mach2 .. those programs don’t seem to care if the control board is powered on they just run..

I noticed on my foam cutter GMFC will not run unless the control board is powered on the board is a HobbyCNC unit.

so I think the GMFC is looking for a signal that its powered on, maybe even that each step is taking place... ( but don’t “” me on that.. )

Mostly I just followed instructions on how to wire up each board.. and it all worked :-)

Venomx999,

What is the 3 axis configuration look like for foam is it the same …
Did you just replace the router ..with a heating element ?

Hmmm..

In GMFC the pin direction and Step pins are all under Windows Device Manager, But for me I did not have to change anything the defaults here good..

Not sure if any of this helps you..

Sleedo,

Where did you get the little plastic fitting that goes on the shaft of your steppers? I like the plastic hose coupling, but I will need that little plastic part to make it work.

Thanks,
Steve

The plastic fittings on the stepper shaft came from my local hardware store, I truly don't remember what they were intended for but they were just the right OD and ID for my needs. I drilled and tapped them from the side to mount a setscrew. Sorry I don't have any more detail.

EB