ERC TimSav - Cheap DIY CNC Foamboard Cutter

[luvmy40]

What I did to minimize the effect of bowed foam board was to use the foam board hold downs from thingiverse and glue 4"x4" squares of sacrificial foam board down at the corners of the cut bed and then at each clamp/hold down and 2 in the middle of the cut bed. Then make sure to put the foam board down with the bow down so the edges are higher than the middle. When you apply the hold down clamps, just tighten them enough to pull the bow out. It's not perfectly flat but it's much better.

 

[dgraviett]

forgot about that one. I looked at it but never made one. For length of the needle I usually just cut it just a bit lower than the mig tip then sharpen it with a wet stone. I have used a few different head designs but I am happy with mine as I also use my frame as a laser cutter/engraver and the head design allows me to change between the needle and laser quickly and also has less play in the cutter allowing for very good cuts. I have built 4 timsav's now, 2 as needle cutters and 2 as lasers (for friends). The green foam in the picture was a depron type foam with no paper but painted on one side. The needle cuts are pretty much perfect. I have also copied the needle holder for you. Too bad that your not on facebook, the ERC Timsav group has a lot of info on it from the last few years. Be aware that the FT plans now make it hard to convert for cutting.

Why are the FliteTest plans harder to convert?

 

[dgraviett]

My TimSav (link) has been sitting idle for a long time now. The head I designed starts off working really well, then quickly gains slop as the needle wears through the nozzle, and the whole thing has a small chance of wrecking itself while cutting if the wheels holding the tool plate come off. I've been trying to decide what I wanted to do with it since I am not that keen on going back to the CAD drawing board. I do a lot of my own custom DTFB designs though so it would be nice to have a tool that does something helpful though, so I am considering modding it to just be a plotter to draw my plans on the material.

The issue I'd want to resolve first though is dealing with the bowing of the DTFB. I'd previously addressed this with a DTFB vacuum table hooked to a shop vac, and that sort of worked ok, but the suction bits were relatively fragile and I didn't have anywhere to store them so they fell apart quickly. Has there been any innovation in this area? I thought maybe having the toolhead have a couple omniwheels or casters or even just a smooth stainless ball on it that just applied some weight to the DTFB under the toolhead would be enough to smoosh out any concavity of the material, or something along those lines.

I'd also like to point new users to the Inkscape mod I made long ago that allows 4 different depths of cut based solely on the color of the line in Inkscape instead of having to do multiple layers / runs with the cutter: Multicut Inkscake Extension (link)

Waiting on parts to come back in I thought I would learn the process of Inkscape. I copied your multi cut files into Inkscape and went to work on a plan. When I ran your multi cut I got a bunch of error and the Goode file was blank. So I just opened up a blank file and did some shapes and ran your multi cut and it worked no errors.

 

[luvmy40]

Why are the FliteTest plans harder to convert?

The newer plans are copy right protected. You can't ungroup and edit them. You have to copy over them manually in a second layer. It's doable but time consuming.

They had to start doing this because of some disreputable overseas companies marketing sub standard kits as Flite Test SBKs.

 

[dgraviett]

Waiting on parts to come back in I thought I would learn the process of Inkscape. I copied your multi cut files into Inkscape and went to work on a plan. When I ran your multi cut I got a bunch of error and the Goode file was blank. So I just opened up a blank file and did some shapes and ran your multi cut and it worked no errors. View attachment 233656

I think I figured it out. I didn’t regroup everything before running the multi cut.

 

[dgraviett]

I think I figured it out. I didn’t regroup everything before running the multi cut.

Nope I didn’t figure it out.

 

[luvmy40]

Nope I didn’t figure it out.

The multi cut is very color specific. What colors are you using in inkscape?

 

[dgraviett]

The multi cut is very color specific. What colors are youding in inkscape?

I used the Tiny Trainer plans cause they were simple to mess with. I deleted all wording and graphics and left just the black and red lines. I was wondering if the lines were not the right color and I was going to have to overlay the plans and redraw the whole thing. If it’s very color specific I will look through it maybe I left a reference line in there. Should I connect all the lines or leave them how they are? I know they are not connected to keep the pieces connected to the foam board and if i connect them then the pieces will be fully detached. Will that cause issues while the machine is cutting everything?

 

[dgraviett]

I used the Tiny Trainer plans cause they were simple to mess with. I deleted all wording and graphics and left just the black and red lines. I was wondering if the lines were not the right color and I was going to have to overlay the plans and redraw the whole thing. If it’s very color specific I will look through it maybe I left a reference line in there. Should I connect all the lines or leave them how they are? I know they are not connected to keep the pieces connected to the foam board and if i connect them then the pieces will be fully detached. Will that cause issues while the machine is cutting everything?

So I guess the colors used in the pdf are not 100% black and red. I deleted all red lines error, deleted all black lines error, added a layer and redrew the whole thing it worked.

 

[luvmy40]

I used the Tiny Trainer plans cause they were simple to mess with. I deleted all wording and graphics and left just the black and red lines. I was wondering if the lines were not the right color and I was going to have to overlay the plans and redraw the whole thing. If it’s very color specific I will look through it maybe I left a reference line in there. Should I connect all the lines or leave them how they are? I know they are not connected to keep the pieces connected to the foam board and if i connect them then the pieces will be fully detached. Will that cause issues while the machine is cutting everything?

I have only cut one set of plans with the multi cut extension so far. The mini scout. I honestly don't remember if I edited the FT PDF or if I drew a new set in layer 2. I did find that the "green" cut has to be "Lime Green' and not "Green" I haven'y used the blue cut yet. I plan to use the "blue" for the pen function when I get around to figuring the offsets and installing the pen on my cutter head.

 

[dgraviett]

I have only cut one set of plans with the multi cut extension so far. The mini scout. I honestly don't remember if I edited the FT PDF or if I drew a new set in layer 2. I did find that the "green" cut has to be "Lime Green' and not "Green" I haven'y used the blue cut yet. I plan to use the "blue" for the pen function when I get around to figuring the offsets and installing the pen on my cutter head.

That’s what I would like to figure out is the pen for drawing the reference lines. I looked at all the ones on Thingiverse and none of them tell you how to set it up.

 

[luvmy40]

That’s what I would like to figure out is the pen for drawing the reference lines. I looked at all the ones on Thingiverse and none of them tell you how to set it up.

Right now, I am just using a very shallow cut for the reference lines and some notes. I have a cutter assembly that provides a pen holder and the drive gear allows for a zero cut, no pen and a zero cut pen position. The pen is offset from the needle by a few millimmeters, which does mean that anything you would want to be pen scribed would have to be offset in the plans. Its completely doable. I just haven't done it yet.

 

[Edwardchew]

Hey Capnbry, I just try to bend/apply pressure to the board until it gets flat enough haha

 

[dgraviett]

forgot about that, yes I used a parts from a previous mod. Like I said, went through about 5-6 different designs I am a little ocd and was trying for the best cut I could get. I would also suggest the double wheel for the x axis https://www.thingiverse.com/thing:4603770

Do you have pics of this v mount gear assembled?

 

[Dudley1001]

View attachment 233802

 

[Dudley1001]

Here is the assembled cutter, ignore

the large nuts behind the vertical rail. I redid that piece with one that had the spacer block.

 

[dgraviett]

So the v mount gear assembly was from another build version. You just incorporated it into your v slide version and did away with the gear.

 

[Dudley1001]

Yes it was, I figured it fit so use it. It was glued to the blue plate then drilled for the wheel bolt. I think it the fact that the needle is on the centerline of the z rail keeps the drag from the cutting from flexing the cutter head too much.

 

[Ohio3D]

Here is the assembled cutter, ignore View attachment 233803 the large nuts behind the vertical rail. I redid that piece with one that had the spacer block.

What design is that cutter head? I keep seeing it but I haven't found the files / plans for it.

 

[Dudley1001]

https://www.thingiverse.com/thing:4785628