Cutting foam sheets... with a needle!

[dkj4linux]

I'm dying to learn to cut foam board, and am quickly learning how ignorant I am on CNC software, the toughest part is figuring out what I do and do not need to learn, software and such.

Rit,

Given you're pretty new to this, I'd highly recommend going as straight-forward and mainstream as you can. Don't try to get fancy or improve anything at this point... just get the simplest, most modest, machine running that you can. You'll learn a ton along the way and quickly determine what's important and what's not. Keep everything as simple as possible at this point -- KISS is king around here -- and there's a lot to learn. But don't be overwhelmed or beat your head against the wall for too long before seeking help.

Use this forum. Here is basically where the CNC-borne needle cutter was introduced to the RC community so you are in the right place. There are many CNC machines and needle cutters in the wild now and lots of talented, experienced folks are building and using them... and most are eager to help. But we need to know as much information as possible about what you are trying to do and how you plan to accomplish it to do that.

Ask questions and answer the ones you're asked. We're not trying to pry or embarrass you. We're trying to help... we were all new to this ourselves at one time. Information has to flow in both directions and the more detail provided the easier it will be to find solutions and get the assistance you need. Some info will concern the machines and software itself while some will concern you, your plan, your experience level and capabilities, and what tools/materials you have and are most comfortable working with.

Pictures are indeed worth a thousand words. As a 72 year-old retired engineer, I hate cellphones (the kids made me get it)... but I quickly discovered, and fell in love with, the camera functionality. With it, I document my work far better now than I ever did when doing this stuff professionally.

Finally, read and watch as much as you can. Google and Youtube are your best friends. I know this is a lengthy thread (and for that I apologize) but it is chock full of great info concerning the very stuff you are trying to do. Also, take a look at these FT articles by our own Jason (jhitesma) and Mark (moebeast)...

https://www.flitetest.com/articles/cutting-foam

https://www.flitetest.com/articles/build-your-own-cnc-foam-cutter

https://www.flitetest.com/articles/another-cnc-foam-board-cutter

Welcome aboard! Let's get started...

-- David

 

[Shurakair]

I'm using the template you shared in post #1447... is that the correct one?
-- David

David, I actually downloaded that file and used it just to make sure I was doing it the same way anyone else here would have to do it.

Don't forget to account for MPF being thicker than DTF.

Heh thanks for the tip. The plans I'm using were designed for 6mm Depron or MPF. So its all good.

Shur

 

[Rit]

I could go for a tutorial on how the Foamboard inkscape template works.

 

[dkj4linux]

I could go for a tutorial on how the Foamboard inkscape template works.

Unless Shur has written something up since and wants to chime in, read through post #1447 on page 73, and a few following posts, to get the gist of converting a PDF plan to gcode. Mark (moebeast) has apparently used a similar flow as well. There should also be plenty of tutorials out there on using Gcodetools. -- David

 

[Rit]

Yeh, I git the gist, and need some more info. I read #1447 and circumscribed #1447

 

[dkj4linux]

Outstanding, Shur. I checked my Inkscape version... 0.92.3. Loaded in your Foamboard template, imported sheet 1 of your FT_Explorer, and successfully generated a gcode file. Unsure of myself and my apparent success, I also simply opened sheet 1 and successfully created another gcode file. Now I'll have to actually try processing my own PDF file, ala your post 1447, and give it another shot.

Flushed with success... I apparently can't miss now!

Thanks, Shur!

-- David

 

[dkj4linux]

On a sad note, back in May, my fishing/flying/golfing buddy passed away suddenly. He was the second of my two best friends lost in the last 11 months. Thankfully, neither of these men experienced prolonged suffering and were actively engaging in the things they enjoyed most at the time of their passing. We'd all spent many great times together and they are both sorely missed.

On a brighter note... back when we were actively building and flying our foam RC planes, I'd built Henry a MPCNC-based needle cutter setup... and, with his passing, the family has given that machine back to me. Since I already had a needle cutter setup of my own, I've decided to scrap out his machine and rebuild/update it in a smaller form factor and suitable for light milling operations. i'd already purchased a Dewalt 660, way back when, for this very purpose.

I spent several days printing all the new parts on my Prusa I3 MK2S and have begun assembling a 29" x 29" footprint machine. I've put in on a 30" x 30" wooden base... 1" x 4" whitewood boards, Kreg-jigged together, in two layers and with overlapping corners. The machine is essentially complete, mechanically, and now needs to be belted and wired up. I could reuse the old motors, of course, but I've decided to wait on new steppers, with longer leads/connectors, and a series wiring harness from Ryan... just to try and do it up to current standards. Those parts are due to arrive Wednesday... thanks, Ryan!

The following photos document my progress to this point -- printing new parts, dismantling the old machine, and building up the new...



More to come later...

-- David

 

[ironkane]

Sorry for your loss David.
It's funny, I was thinking about what to do with my old MPCNC the other day and it finally occurred to me that my main problem was its size and if I reduced it enough, I could do the same thing. I like how you have yours made portable with that frame. What's the plan? A drop in MDF Waste Board? I'm really warming up to this idea.

 

[dkj4linux]

Sorry for your loss David.
It's funny, I was thinking about what to do with my old MPCNC the other day and it finally occurred to me that my main problem was its size and if I reduced it enough, I could do the same thing. I like how you have yours made portable with that frame. What's the plan? A drop in MDF Waste Board? I'm really warming up to this idea.

Thank you, Steve.

Yeah, an MDF panel, or a stack of panels, that fit inside the frame are my thinking there... and it's easily clamped to a larger panel or benchtop if desired. I really don't know yet just how much more area I'll lose when I hang the Dewalt on its mount but my intent is to be able to mill LowRider-sized panels (13"-14" or so) inside the frame. The frame could be enlarged and/or the legs biased to one side to let the end-mill reach further into the "home" corner if need be. The frame does allow for a bit of portability, however, and is easily and accurately made using a miter saw and Kreg jig. I've used it on the last several machines I've built -- mostly laser machines -- and feel it does sturdy it up quite a bit.

-- David

 

[dkj4linux]

I finished modding the Dewalt (removed the tool-free collar) and mounted it on the tool mount. Looks as though my concerns were unfounded... I easily have 17"-18" of usable work area inside the frame. Should be plenty for most things I envision doing

My new stepper motors have made it to the post office this morning... hoping in time for delivery today. I want the longer leads and connectors so that I can use the series wiring harness I'd already purchased from the V1engineering.com site. I'm trying to do this build as close as I can to the current MPCNC "standards"... -- David

 

[dkj4linux]

As hoped, mailman just delivered my new stepper motors. Also whipped up a stand for the new MPCNC… 28″ x 28″ and 30″ high.

 

[ftwingnut]

Hey everyone! I just wanted to pop in and say Hi! I haven't been on in a while, but have been actively cutting foam with my rig. I cut several planes that I built and took with me to FliteFest in Ohio last week. I also decided to take my CNC with me, and wouldn't you know, as I was cutting more foam at the festival, Mark (moebeast) happened to be walking by and heard it, so he stopped to chat. He is the one that had his machine at FF last year, and got me hooked on it, so I was able to thank him in person. My 3ft x 4ft table traveled well on it's side, strapped to the wall of my trailer. I used ratchet straps to secure the gantry from moving around, and I removed the Z axis so that it didn't stick out so far, taking up less room in the trailer.
Anyway, we had a great week, and I was able to recut some new parts when my planes had injuries. I also cut some planes for other people. Many, many people stopped by to ask questions and were amazed at how well it worked. I now have my needle cutter ESC powered from the D9 pins on my RAMPS board, so I can power it on with M106, set the speed, and let it go. Once the job is finished, the code includes an M107 to shut down the power, which turns off the needle. That way I can be focused on other things while it runs, and I know when I hear it turn off, the job is done. I haven't gotten the servo pins to work for controlling the speed yet, but that will come in time.

 

[dkj4linux]

Thanks for the update! I really admire you and Mark for spreading the good word of MPCNC and the needle cutter in such a practical way! Great work! -- David

 

[RAGII]

So I finally got my middle assembly on the MPCNC updated and am working on a new needle cutter. I decided to go with the welding tip this time instead of the inflation needle. How are you attaching the tip to the cutter body? What is the thread size on the welding tip (typically welding tip .035)

 

[jhitesma]

I just use a bit of 1/4" hardwood to mount it. I mount the hardwood to the 3D printed cutter with 2 M3 screws and nylocs, and drill a hole in the hardwood just slightly smaller than the mig tip. Then I just let the mig tip self-tap as I screw it in.

I actually have one "spare" mig tip I use just for that since I hold it in vice grips and it's kind of scratched up. Once the threads are cut I swap to a new "clean" tip just because it looks nicer. (And since you get so many in a pack...why not use a nice looking one!)

 

[RAGII]

Thanks Jason, I will give that a try. I did that method with the inflation needle cutter I had (mouse trap body design) but there were a few times the needle started in slanted. That was easy to straighten out, the mig tip not so much.

 

[RAGII]

Cool and rainy here so it is a perfect day to tinker in my work shop. I am finishing up my new needle cutter and decided why not upgrade my firmware at the same time. I have had trouble with the laser option and I believe the new firmware took care of the latency issues with LCD updates. The issue is it appears the pins configuration is in a different file than before and has more areas defining the fan pin. I have attached a capture with the defining areas highlighted. Which one do I change now (or just change all of them)?

 

[jhitesma]

Look near the top of configuration.h for a section like:

// The following define selects which electronics board you have.
// Please choose the name from boards.h that matches your setup
#ifndef MOTHERBOARD
#define MOTHERBOARD BOARD_RAMPS_14_EFB
#endif

In this case my file is defined as EFB so in the code you're looking at the first section would be the one that would apply.

EFB/EEF/EEB define how the outputs are assigned. E= Extruder, F = Fan, B = Bed.....

 

[RAGII]

Thanks Jason. Found that but now when I try to download I get the following:

According to the write up, pin 44 is what the fan needs to be re-mapped to.

 

[dkj4linux]

Thanks Jason. Found that but now when I try to download I get the following:

According to the write up, pin 44 is what the fan needs to be re-mapped to.
View attachment 110938

Rob,

A few lines above -- in the Heaters/Fans section of pins_RAMPS.h -- that's where to change the RAMPS_D9_PIN value from 9 to 44. The variable should still be called RAMPS_D9_PIN in the line you edited... it just has the new value

...
#ifndef RAMPS_D9_PIN
//#define RAMPS_D9_PIN 9
#define RAMPS_D9_PIN 44 //laser PWM - M106/M107
#endif
...

I usually just duplicate, edit, and then comment out the original line just in case I should ever want to go back.

-- David