ERC TimSav - Cheap DIY CNC Foamboard Cutter

[Airkaos]

Still very interested to see what you come up with regarding the laser plugin. I looked up the plugin and was thinking of trying it out. Will have to do some fiddling to figure out commands for the different depths.

I came up with a similar approach with 4 layers in Inkscape: orig, full, score, and mark. Was going to do a quick video.

Please do, and let us know when you post it, am sure we all would love to see what you guys come up with

 

[dkj4linux]

Still very interested to see what you come up with regarding the laser plugin. I looked up the plugin and was thinking of trying it out. Will have to do some fiddling to figure out commands for the different depths.

I came up with a similar approach with 4 layers in Inkscape: orig, full, score, and mark. Was going to do a quick video.

Check it out... here.

I've worked through this procedure a few times but it certainly isn't "bulletproof". I'd love to see what you've come up with... and I'm sure a video would be very helpful for a lot of folks. Hopefully we're not too far apart...

 

[dutchmonkey]

Still very interested to see what you come up with regarding the laser plugin. I looked up the plugin and was thinking of trying it out. Will have to do some fiddling to figure out commands for the different depths.

I came up with a similar approach with 4 layers in Inkscape: orig, full, score, and mark. Was going to do a quick video.

Yes share please

 

[jpot1]

Check it out... here.

I've worked through this procedure a few times but it certainly isn't "bulletproof". I'd love to see what you've come up with... and I'm sure a video would be very helpful for a lot of folks. Hopefully we're not too far apart...

Spot on. You take it a step further than I did with the black inner/outer setup. I was redrawing the full red lines rather than connecting endpoints. Need to give that a try. Thx!

 

[FoamyDM]

@FoamyDM - you NEED this!

Sorely!
I have a couple dumb questions.
1. what material do you need the base to be?
2. How do you keep the cutting still/pinned down during the process?
3. When you are done how easy is it to move the finished cut board without loosing your cutouts? (I would like to work on a feed system to print like a SLOW xerox.)

Unrelated, is @Edwardchew do you have a printable template to cut the 3d printed pieces from 1/8" or 1/4" MDF or acrylic?

 

[Edwardchew]

Looks like an interesting board David. I just wish it had a second servo output so there's no need for the servo tester. I love being able to control the cutter from gcode on my setup - really tempted to build one of Eric's even though I have my MPCNC - but I want to come up with a compact board that will still let me control the cutter RPM from gcode. Though I'd also like to stick with something like RAMPS that can use an LCD screen and run untethered without a pi to feed GRBL. But RAMPS feels like overkill

I'm kind of surprised you haven't hacked the Z to use a little 28BYJ servo with a printed screw setup like you've played with before

Actually you can. I simply Y the servo signal to the ESC lead, it works! the pwm value happen to give just the right amount of RPM, it would run quieter as those "lift up" also translate to motor off.

But i didn't introduce that due to safety reason. As the motor would spin up as soon as you send in any M3 Sxxx, unless there's additional switch for motor on off.

Shoot ment to ask - @Edwardchew - what substrate should I be looking at?

Huh what is "Substrate"?

What David just said. I haven't used it myself but Edwards setup looks like by far the best option for those who want something that just works and don't want to tinker.

Please don't let guys like me and David who enjoy the tinkering scare you away if that's you, Edward had standardized and documented a great solution for those who don't want to tinker.

Yeap. Everything is figured out, though took a long time. Developed to be as simple as possible to build, with criteria like low cost, compact(foldable) since I myself fly too many planes too.

 

[Edwardchew]

Sorely!
I have a couple dumb questions.
1. what material do you need the base to be?
2. How do you keep the cutting still/pinned down during the process?
3. When you are done how easy is it to move the finished cut board without loosing your cutouts? (I would like to work on a feed system to print like a SLOW xerox.)

Unrelated, is @Edwardchew do you have a printable template to cut the 3d printed pieces from 1/8" or 1/4" MDF or acrylic?

For 1, 2, 3
Watching the intro video will clear your question

Those template are for me to monetize the Ultimate KIT. LOL

 

[FoamyDM]

@Edwardchew Thank you. I have watched nearly all the videos. GREAT job them. They are exactly what I need to get it working. The instructions appear to be very clear.
- I just finished the rest.

my confusion was the 3d model shows a ply base material. We will be using DTFB, which gets taped down.

How long does it tend to last before replacing?
Can I take the finished product out without having the cut parts fall out?

 

[AIRFORGE]

@Edwardchew
Can I take the finished product out without having the cut parts fall out?

That's what I was wondering. Can "tabs" be used to hold pieces in place, or is there a protocol for cutting the score, and reference lines before making the full perimeter cuts.

 

[Michael9865]

That's what I was wondering. Can "tabs" be used to hold pieces in place, or is there a protocol for cutting the the score, and reference lines before making the full perimeter cuts.

You want to cut/mark score and reference lines first before through cuts. Sometimes with my needle cutter the parts fall out other times they stay in. Depends on rpm and speed of movement.

 

[dutchmonkey]

@Edwardchew i just came across this on inkscape could this be the problem with running .92?
Since Inkscape 0.92, my drawings are just a quarter of their original size when I open them with program XYZ
With Inkscape version 0.92, native units for the standard template changed from px to mm. To help integrate this change, some new options are available in Document Properties > Page tab > Page Size > Scale. Some non-standard-conforming external programs and some Inkscape extensions cannot yet deal with this change, and require px as the unit that is used in the SVG code.
If you would like to use px for native units in a new project, there is a special template available at File menu > New from template > default px. To make this your standard template, please see the FAQ item about templates.
If you need to change the standard units in an existing document, to use it with programs (some plotter/cutter software or external SVG viewers, some Inkscape extensions) that expect a certain unit (usually px) in the SVG code :

1. Make a backup of your document, because the following scaling can have unexpected side effects.
2. Change Documents Properties > Page tab > Display Units to px. (Note this is Display Units at the very top of the dialog, not the units for Custom Page Size, which is a little bit below.)
3. If you do this when there already is a drawing in your document, the objects' sizes will change in the next step. Please make a note of their size now (select all, copy width and height values), if you want to keep their size.
4. Set Document Properties > Page tab > Page Size > Scale > Scale x to 1.0.
5. Go back to Display Units and change to your desired unit, if it is different from px. (This will change the Scale value again, but now it's changed to the required (by the external program) value.
6. If you need to resize objects now, select them all and apply the old size.

For a detailed, technical explanation of unit handling, please see this wiki page.

 

[dkj4linux]

@dutchmonkey I really must chime in here... I have been using Inkscape 0.92 and JTech's laser plugin to process PDFs and generate gcode, for both laser and needle-cutter, for a couple of years without issue. I use "mm" units and my machines produce properly-sized output. I've just written up and posted the basic procedure I've been using and provide "landscape" and "portrait" templates for both A1 and DTFB (20" x 30") for convenience ... and they can be found here. There were indeed issues when Inkscape's internal DPI representation changed from 90 DPI to 96 DPI with the 0.92 version but those issues have largely been resolved.

For those faithfully following Edward's procedures and are happy using Inkscape 0.91... please continue to do so. For those really wanting to use Inkscape 0.92, please check out my procedure referenced above to see that you can work safely in "mm" (or "inch") units and see properly-scaled output from your machine. I don't provide "inch" templates... but there's nothing keeping you from loading a metric one and changing the units and saving it as a new template; i.e. there's nothing to be afraid of, using Inkscape 0.92.

-- David

 

[dutchmonkey]

@dutchmonkey I really must chime in here... I have been using Inkscape 0.92 and JTech's laser plugin to process PDFs and generate gcode, for both laser and needle-cutter, for a couple of years without issue. I use "mm" units and my machines produce properly-sized output. I've just written up and posted the basic procedure I've been using and provided landscape and portrait templates for both A1 and DTFB (20" x 30") for convenience ... and they can be found here. There were indeed issues when Inkscape's internal DPI representation changed from 90 DPI to 96 DPI with the 0.92 version but those issues have largely been resolved.

For those faithfully following Edward's procedures and Inkscape 0.91... please continue to do so. For those really wanting to use Inkscape 0.92, please check out my procedure referenced above to see that you can work safely in "mm" (or "inch") units and see properly-scaled output from your machine. I don't provide "inch" templates... but there's nothing keeping you from loading a metric one and changing the units and saving it as a new template; i.e. there's nothing to be afraid of with using Inkscape 0.92.

-- David

i did see that but did not put two and two together thanks for pointing it out to me. once i get my kit i will have to try it before i remove .92

 

[dehager]

I have all of the parts printed and I have my extrusions, now just waiting on the component kit from Edward to be delivered.

During setup and calibration I didn't see any mention on setting the V-Ref on the A4988 Stepper Motor Drivers. I am assuming the values below based on Edwards spreadsheet and links to suppliers. Is anyone confirming the driver voltages during their build?

- VREF = Rated motor current x 8 x Rsense
- VREF = 1.70 x 8 x 0.05
- VREF = 0.672
- VREF with a 10% safety margin = 0.6

 

[dkj4linux]

I have all of the parts printed and I have my extrusions, now just waiting on the component kit from Edward to be delivered.

During setup and calibration I didn't see any mention on setting the V-Ref on the A4988 Stepper Motor Drivers. I am assuming the values below based on Edwards spreadsheet and links to suppliers. Is anyone confirming the driver voltages during there build?

- VREF = Rated motor current x 8 x Rsense
- VREF = 1.70 x 8 x 0.05
- VREF = 0.672
- VREF with a 10% safety margin = 0.6

That's about right... a touchy adjustment it is, I usually shoot for about 0.7 volts.

 

[jpot1]

So everything is together and tested out. First real cut was a wing for the FT Goblin. Score cuts looked fine. However the full cuts seem offset on the Y axis. Using a feed rate of 1400mm/min. Unfortunately do not know the needle rpm as I'm still waiting for my tachometer to arrive. Below is the result. You can obviously see the shift when cutting the full cuts both along the right side of the wing as well as the curved piece. Also pretty obvious in the wire cut out area.

I previously had my Y axis belt a bit too tight and the machine was making a lot of noise/straining. Perhaps I loosened it too much. Below is a picture of the belt along the Y axis with a gap that can be seen so it is not centered in the channel. Need to tighten and try again? Slow down feed rate? Both?

 

[dkj4linux]

Definitely looks like skipped steps on Y axis. Certainly can happen if belt is too loose. Might check grub screws on motor pulley(s) as well... also adjust them so belt runs in center of channel without rubbing. Slowing down usually helps... can't begin to tell you how many problems have been fixed when the tach arrived...

 

[Jonny360]

I have been looking for some kinda foam cutting cnc for awhile and this pushed me over the edge. Just placed my order. Amazing job! I've watched about half the videos posted so far and you cover everything in great detail. I'm very excited to get going on this project. One question, what is everyone printing the parts from? I have some PETG on hand but its been causing me some issues, for this would PLA work. Or would PLA work for a few parts and just a few that need to be PETG?

 

[rockyboy]

I used PLA on my CNC machine and it's still going strong a couple years later

 

[AIRFORGE]

Are there pdf plans for the printed parts?
I've had a cnc router for several years, now, which I also use to cut foam board and I would like to cut the ERC TimSav printed parts, if that's possible. Has anyone else done that?