I thought I would setup a CNC foam cutters thread.

I have a CNC foam cutter from FoamLinx and am still in the tweaking stages. I imagine there are other CNC cutters on EZone who want to share information.

I have still a few things to iron out but the main issue is the need for speed.

My first question for the thread:

What software do you use to generate your .dat files and what software do you use for cutting?

Henry
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New Canadian E-Tailer
www.zebrahobby.ca

http://groups.yahoo.com/group/CNCFoamcutters/
This is a group about foam cutters, I have a Foamlinx cutter also but I haven't had a chance to mess with it yet. From what I read cutting anything other than a wing profile can be a bit tricky which is what I want to do, as soon as I have some time I will figure it out. The software uses percentages of the length for thickness. Anyone here convert dxf to dat ?

I have joined that Yahoo group and there is great information there.

I have been using Profscan to do the conversion. You can find it on Gilles Muller site:

http://gm.cnc.free.fr/index_en.html

Take a look at Litcut. Its a "visualization" tool but I haven't had a chance to get it to work.

It took me about 4 hours to setup the Foamlinx machine. Currently I have it tweaked to go at 1.5 mm/sec on the X axis.

I'm working with Tal to see if I can tweak it a bit so I can better cut swept wings. Another fellow on the Yahoo site upgraded the motors and board but I'm seeing if I can just upgrade the power supply.

Henry
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New Canadian E-Tailer
www.zebrahobby.ca

I have Profscan and Scan 2 Dat software, the S2Dat seems to work well in Autocad I have messed around with it but haven't cut anything with it yet.

I custom built my machine but am using FoamLinx hardware, stepper motors, controller card, power supplies etc. If your machine has 1/4"-20 threads 1.5mm per sec is about all your going to get. If you change your screw threads to comething coarser like 3/8"-16 you'll pick up some speed. No, you can't just increase the voltage going to the motors unless you put some power resistors in line with the coils of the motors.

I use a program called CreatDat to creat almost all of my dat files from My AutoCad drawings. It's not perfect but it's the best I've used to dat. Here is the link to the free download. http://213.97.27.39/aero/cnc_bcn/cnc_bcn.html. Good Luck

John Boren

Thanks for your info John.

When you say to change the screw threads to 3/8"-16, do you have to change the lead screw as well?

I'm looking to at least double the speed as I'm cutting some cores with "moderate" sweepback and am having problems with temperature. Speeding up the cut will definitely help.

I just tried some Iconel wire and it does work much better than the wire supplied with my kit from Foamlinx. I think I saw a thread where the wire was fishing lead.

I've sent a few emails to Tal and his next generation of cutters will be faster and he is working with me to help me get my speed up. He is intent on making me happy and I'd like to recognize his efforts.

Looks like I'm going to go with higher voltage and upgraded motors.

Anyone intersted in going into a group buy for Iconel wire? The forum on Yahoo has done it.

Henry
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New Canadian E-Tailer
www.zebrahobby.ca

Maybe I'm using the wrong words. The long 1/4-20" threaded rod you currently have that powers the X and Y Rails and the drive nuts can be changed to a lower pitch threaded rod. Now, I'm not sure how hard this will be on the FoamLinx machine, or if it's possible at all. If you go from 20 threads per inch down to 10 threads per inch you will double the speed of the machine. If you then up the voltage and use resistors you will gain another 20% or so. I may upgrade my power supply and add the resistors but as soon as Tal has his new board ready, I'm going to put that bad boy in my machine and waste foam even faster then I am now. My garbage man must hat me. If you need any help generating good dat files you can send me the Acad file and I will see what I can do. Tal is in deed a good guy to deal with.

boren@megsinet.net

John Boren

John,
You are using the right terminology, its just I'm not familiar with it although I'm picking it up fast.

Tal contacted me and I too will be testing his new board. If the motor upgrade gives me 20%-25% improvement, thats all I'm looking for.

Looking at the leadscrew, it looks like I'd have to mill it to use the coarser threaded rod. Would be nice for Tal to offer as an upgrade as I would pay for the upgrade.

One other thing I'm trying to stabilize is the vertical axis. With the plastic bushing, there is a bit of play. Just thinking on how I would eliminate any movement. Do you notice this as well?

Henry
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New Canadian E-Tailer
www.zebrahobby.ca

I am only using his board, motors and power supplies. I designed and built my own machine using precission linear rails for both the X and Y axis. I have about $700.00 invested in it and a good hundred hours of labor but I hope it is a different league then Tal's machine even though I'm sure his is fine. I have No play what so ever in may rails. I've been having a ball cutting just about anything I can think of. I really like it when modelers come over to the house and I show them what the machine can do. If you would like to see something I cut with my machine you can take a look at the Foamie section of this group. Go down until you see a post called Fight Master Foam Flying Wing.

Good Luck with your machine, and have fun making small pieces of foam out of big pieces.

John Boren

I'm not new to CNC, but I am to CNC foam cutting. I'm currently building a modified version of the "Rustica" machine. So far, I've asemble most of my major framework bits, and will start putting them together this weekend. I'm using some hefty aluminum channel for the main support rails, with 1" OD Aluminum tube for the roller guides. I know it's overkill, but too much stiffness never hurt anyone, right? It's what was easily found at the scrapyard in enough quantity to do the job.

I still need to procure steppers, bearings, threaded rod, and a control board, as well as all the little fastening-type thingies. I'm having fun just working out the cutter - I can't imagine what fun I'll have once it's built!

FlightofSong,

Here are some sites that have been useful for me:

HobbyCNC http://www.hobbycnc.com/
McMaster-Carr http://www.mcmaster.com/
FoamLinx http://www.foamlinx.com/

I'm in the process of upgrading my board and steppers from FoamLinx. A number of CNC hobbyists also recommend HobbyCNC gear.

Henry
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Canadian E-Tailer
www.zebrahobby.ca

Henry,

tell me what motors you are using, the volts and amps, etc. you will be able to go almost double the speed with the right power resistors and power supply.

I don't have a foam cutter, but I have a cnc mill and can go over 40 inches a minute on 27 volts with 5 volt motors.

I wrote a resistor calculator program for calculating current limiting resistors for steppermotors. Download it here: www.e-zflight.com/files/stepcalc102.zip

Eric

Eric,
40 inches per minute...that translates into almost 17 mm/sec. Over 10 times faster than my 1.5 mm/sec.

Unfortunately, I have the controller and steppers boxed up and am waiting for Tal's, Foamlinx.com, shipment to come in to Calgary.

I'd be happy with 3 - 5 mm/sec. I'm hoping the new steppers and controller can get me there.

I'm in the process of understanding how the steppers and controllers work. I may try to boost the performance if its easy to upgrade the power and resisters.

Thanks...Henry
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Canadian E-Tailer
www.zebrahobby.ca

For lots of cnc info go here: www.cnczone.com

Eric

Eric,
Whats the effect on driving the steppers at higher voltage? Is there a decrease in life, more jitter, etc?

Henry
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Canadian E-Tailer
www.zebrahobby.ca