ERC TimSav - Cheap DIY CNC Foamboard Cutter

[Lance Nordby]

The machine managed to get through three each of the first sheet. Now on the second sheet it's having a lot of issues with getting all the way through the job without stopping or trying to run out of bounds.

All the arcs are converted into splines and that helped but it's still choking on that invalid ID:33.

I think I've averaged about 10 trial runs for each successful sheet so far. It's getting old. Is anyone else trying to go from a 3D model to dxf to gcode? Or is everyone drawing in Inkscape?

The machine cuts great when the software works.

 

[Matagami Designs]

The machine managed to get through three each of the first sheet. Now on the second sheet it's having a lot of issues with getting all the way through the job without stopping or trying to run out of bounds.

All the arcs are converted into splines and that helped but it's still choking on that invalid ID:33.

I think I've averaged about 10 trial runs for each successful sheet so far. It's getting old. Is anyone else trying to go from a 3D model to dxf to gcode? Or is everyone drawing in Inkscape?

The machine cuts great when the software works.

If you share your .dxf I will take a look and see if I find any issues.

 

[Keno]

All is well, Something is going to heated up and smoke.

 

[Lance Nordby]

Please, have a look-see Matagami.

It seems the more things I try, the worse it gets. On the last try the servo never moved.

 

[Matagami Designs]

Please, have a look-see Matagami.

It seems the more things I try, the worse it gets. On the last try the servo never moved.

So here is what i have noticed.

There are a bunch of splines in the .dxf i am not sure if GRBL will support that? I have never had any luck with them anyhow. What i meant about poly-lines is just a bunch of small simple line segments connected together to make a curve. Atthached is an example from the P-38 .dxf i have. I went ahead and processed your code anyway and it looks like the .dxf2gcode is turning these into polylines anyhow but with an extremely loose tolerance. I used this when i make my code if its an arc or a spline i convert to a polyline with about .03-.06" tolerance. With lines that small you will never notice its not a complete curve.

I still find it odd that its pulling id code 33 on a straight line but i think this would go away if there are no splines or arcs that the .dxf2gcode is trying to process? Another thing you could try is to use this and only do 2 decimal from your gcode but i think you will still end up with poorly converted splines.
https://riaupart.com/index.php/gcode_decimal_converter

I also noticed in your attached bit of gcode the command m3 s900 which im not sure what the program will do with? Normally that is a m3 s90. Is this why the servo never moved?

If you haven't already joined the facebook group for the timsav i would suggest going there next. There are plenty of helpful people there as well that know much more about this stuff than me.

Good luck.

 

[Lance Nordby]

Thanks Matagami. I've been mulling over what you said for a while.

Most of the parts are flattened lofted sheet metal CAD files so it's almost all splines. That just falls out of the design methodology used to create the 3D model assembly.

I have yet to figure out how to convert splines to polylines.

I've tried exporting as a pdf and bringing it into Inkspace but haven't figured out to make a path like Edward does it. Nothing happens when I pick either object to path or stroke to path and trigger the grbl extension. It seems like it should work but no satisfaction.

I suppose I'm pushing the boundaries of what CAD and CAM programs can do but then again it is 2020 and pretty soon we will be able to send men (and women) to the moon again so you would think this would be possible. I wonder how SpaceX derived the cut files for the gores on the nose of the Starships.

 

[Matagami Designs]

Thanks Matagami. I've been mulling over what you said for a while.

Most of the parts are flattened lofted sheet metal CAD files so it's almost all splines. That just falls out of the design methodology used to create the 3D model assembly.

I have yet to figure out how to convert splines to polylines.

I've tried exporting as a pdf and bringing it into Inkspace but haven't figured out to make a path like Edward does it. Nothing happens when I pick either object to path or stroke to path and trigger the grbl extension. It seems like it should work but no satisfaction.

I suppose I'm pushing the boundaries of what CAD and CAM programs can do but then again it is 2020 and pretty soon we will be able to send men (and women) to the moon again so you would think this would be possible. I wonder how SpaceX derived the cut files for the gores on the nose of the Starships.

If your trying to get the inkscape extension to work with nothing happening you might want to make sure any antivirus software isnt stopping it. Ask me how I know.

 

[Lance Nordby]

I got a pdf through inkscape to work. Sort of. The job hangs up at about 10% and just quits. One odd thing is that the z axis goes up and down at the end of every line segment. Wastes a lot of time but maybe it would cut better. It's at one of these unnecessary z moves where it stops.

I've come to realize after going through this thread and the facebook page that I am once again marching to a different drummer and no one else is dealing with spline laden files from 3D CAD. They seem to be having good luck using fusion 360 but I don't want to learn yet again another program to do this. My brain is full of software program crap and it's overflowing. Reminding me of the polylines dredged up ancient memories of working with Autobad 20 years ago. I thought those days were behind me.

I've been trying to figure out the best work around for this situation. I need to sit down and write out a summary of the three or four methodologies tried so far.

 

[Matagami Designs]

I got a pdf through inkscape to work. Sort of. The job hangs up at about 10% and just quits. One odd thing is that the z axis goes up and down at the end of every line segment. Wastes a lot of time but maybe it would cut better. It's at one of these unnecessary z moves where it stops.

I've come to realize after going through this thread and the facebook page that I am once again marching to a different drummer and no one else is dealing with spline laden files from 3D CAD. They seem to be having good luck using fusion 360 but I don't want to learn yet again another program to do this. My brain is full of software program crap and it's overflowing. Reminding me of the polylines dredged up ancient memories of working with Autobad 20 years ago. I thought those days were behind me.

I've been trying to figure out the best work around for this situation. I need to sit down and write out a summary of the three or four methodologies tried so far.

Unnecessary movements drive me crazy this is why I dont use g code that I dont generate myself. I think there are a few updates to the inkscape add-in that solves some of this that is on the facebook group but I am happy with my methods so far. When I design I start at the bottom and work my way up so never really have issues with splines. I'm not really sure the best way to convert to polylines but when I have to I just segment a spline and redraw myself. Would be handy to have a macro for this but haven't found one and it would take me too long to develop one myself.

Good luck!

 

[Lance Nordby]

Yeah, I'm thinking I'm going to have to sort of trace all the parts by hand some way.

I just talked to a friend that knows Fusion360. We decided I would send him a file to import into F360 where he could use the gcode export function and he could send it back to me. We'll see if that works.

 

[SavageX89]

My ERC TimeSav is up and running! Time to make all the planes!!!

 

[The Hangar]

My ERC TimeSav is up and running! Time to make all the planes!!!

Woohoo! Mine should be up soon, as soon as I get the 3D printed parts from @Grifflyer

 

[Grifflyer]

Woohoo! Mine should be up soon, as soon as I get the 3D printed parts from @Grifflyer

What makes you think I'm printing stuff for you

 

[SP0NZ]

My kit made it to New York. We'll see how long it takes to get to Wisconsin from there. Most of my parts are printed. Still need to order rails. What is the best place to get those?

 

[dkj4linux]

Openbuilds is where I got mine. Good folks, there.

 

[Guy S.]

Openbuilds is where I got mine. Good folks, there.

Ordered mine from openbuilds. Shipped fast and got them in a few days from the order date.

 

[SP0NZ]

My kit arrived on June 24. Still have some parts to print and I still need to order my rails. Starting a new job on Monday so this build may take a long time to get done. Pretty excited to get started though.

 

[chris398mx]

My kit arrived on June 24. Still have some parts to print and I still need to order my rails. Starting a new job on Monday so, this build may take a long time to get done. Pretty excited to get started though.

Good Luck on the new Job!!

 

[varg]

Aww man, bummer about the kits no longer being sold. Looks like I'm going to have to piece one together when I get to it. Lost track of this and never ordered the kit. Will probably wait for things to settle down a bit before doing so, to wait for prices and shipping times to stabilize. Maybe next year. It's going to be a busy 5 months.

 

[kevbospr]

So my kit arrived in late June, It has been assembled, tested and calibrated and seems to work very well, except I am struggling with needle breakage right at the flex point near the top of the two rows of bearings that guide the needle down into the MIG tip. I can get through a single sheet on a needle, but never two in a row. the "PING!" noise the needle makes is exhilarating, but I could do with hearing it a lot less frequently. Interestingly, the parts list calls for .6mm wire, but the pre-made needles I received were at most .4mm (still look to be 304 stainless). I bought a spool of 20 gauge steel wire that measures .58mm and it will not fit between the bearing guides. I am running the cutter motor at 8500-8900 rpm, the needle has been sharpened quite well using a Dremel and fine grinding wheel. When the needle is in one piece, my cuts are pretty sharp and clean, although I noticed some fine alignment issues that look like they're due to slop in the Z-axis motor plate. I am considering building this: ERC TimSav ball bearing head

I would really welcome advice on both diagnosis and what needle material I should be using (if this has been discussed earlier, I apologize; I read through the thread as best I could, along with Cutting foam sheets... with a needle!, but i Could easily have missed it since there is an absolute trove of information there. I took the advice posted earlier and have been running the JTech Inkscape plugin and am impressed; it is no more difficult to use than GRBL but more flexible and up-to-date.

FWIW, I found that importing the plans into a CAD program, converting all the spline curves to closed polylines and fixing the teeny, tiny mismatches and poor intersections that importing brings along make for quick work in Inkscape, without excessive Z-Axis changes and clean joinery. Importing as a DXF seems to keep things tight, and allows me to completely rearrange plan sheets to minimize waste.