3d to CNC

[ukracer]

I think I know the answer sort of. But would like an official confirmation.
I have an STL.that I use to print amitem started on here by a member ( think it might have been @Screwdriver ) I think the files was modified by a guy swarmitized I think it was called. He essentially made the parameters adjustable I think.

Anyway its resided on my micro SD card for some time now.
The printed items worked well but some muppet (insert buyer) decided to save money buy ordering cheaper roofing felt that I cut into squares.
It's thicker and less flexible.
Anyway I need to have a conversation with them but for now it's taking its toll on my tool. I am wondering if a CNC version would last better.

I will post files up later but for now how do I get a files to CMC?

 

[mike os]

Convert to stp / step format

The machine shop will be able to deal with it from there

 

[MattH]

Knowing a bit about the background here mate, I don’t really think CNC is the answer.

You have a manual setup for cutting these squares, if you need more power then get more power.

Create a belt driven slide for the cutter and stick a power drill on the end.

No need for full numerical control.

 

[ukracer]

Knowing a bit about the background here mate, I don’t really think CNC is the answer.

You have a manual setup for cutting these squares, if you need more power then get more power.

Create a belt driven slide for the cutter and stick a power drill on the end.

No need for full numerical control.

Ah sorry Mate I might have misled you.

I am not wanting to cut the felt with a CNC just replace the 3D printed Stanley blade holder with CNC produced aluminum one.



The blue one has done about 10000 squares. So it's not beyond me to print a few more out and change them when needed. I printed the red one in about 2 hours. A sensible person would just do that anyway.

But I have a small CNC that I purchased 2 years ago and its never been used, but I finally got it all connected up with UCCNC and thought it might be a good project to start with.
(Typical me) lol

Don't really need it but want it. (Just because)

 

[ukracer]

Convert to stp / step format

The machine shop will be able to deal with it from there

Ah but......its me that will be the machine shop.

 

[ukracer]

I have to do another 18 rolls tomorrow so I will video a short bit to give people a laugh.

 

[Dev]

Depends on your CNC software but making a dxf of the top face features might work. You can do that in fusion 360, it takes a few steps but is pretty straight forward.

 

[Misterg]

I have an STL.

I have a small CNC

I can't remember - do you also use Fusion360?

If so, you should* be able to import the STL as a mesh (on the mesh tab, rather than solid), work on it and then turn it into a solid body. After that, you can use the Fusion CAM to generate G code for your CNC.

*If everything run smoothly. It depends on the quality of the STL. Fusion seems to be a bit picky, and doesn't handle large meshes well (IMHO). It does have various tools for fixing the things it complains about so you might be OK without resorting to the likes of Blender.

(Ping me the STL file if you want me to have a go for you.)

 

[Agroshield]

I printed the red one in about 2 hours.

But I have a small CNC that I purchased 2 years ago and its never been used

For something that small and simple, put the orange one on a sheet of paper, draw round it and measure with a ruler. Then use a 2D CAD progam to draw the main outline, the three slots and the pocket for the blade. Ideally save as three separate files. What you have there is not 3D at all, more like 2 1/2D - 2D with a thickness.

By the time you faff around converting the STL, you could have the dxfs you need.

If you CNC it from solid, you would clamp down your oversize piece of aluminium plate (if you can buy in the right thickness, or make the part to suit the thickness you have, that saves decking it off) such that the clamps do not cover the slots. Orient the machine so two of the slots are over a T-slot. Use the first dxf to mill the three slots. Reclamp through two of those slots and remove the original clamps. Use the second dxf to cut the outline of the part. Use the third dxf to cut the blade pocket.

If you are smart, you make two at a time as that uses a rectangular piece of material more efficiently.

Note that you will have to change the blade pocket in the subtractively-manufactured item. There is no milling cutter in the world that will make the sharp internal corners that the 3DP version has. You need to put a circular relief in each of the corners that is fractionally bigger than the diameter of the cutter you will use.

---

A really stupid way to get want you want is to run the G-code file through a simulator. At some point above the initial layer, the path the nozzle traces will be the outline of the part. At a leter point in the file, the path will include the blade pocket. You extract those lines from the file and reverse them into a dxf.

 

[Dev]

to be fair you could probably rough it out with a bandsaw and grinder and only need a mill for the slots.

 

[Agroshield]

to be fair you could probably rough it out with a bandsaw and grinder and only need a mill for the slots.

That is true, but if he wants to learn CNC milling, that is a really good shape to start with. It is simple enough to cut with a single 6mm endmill. You'd learn an awful lot making that: clamping/fixturing, cutting strategies, zero-setting, profile cutting, pocket cutting, not breaking cutters by driving them through your clamps (clearance planes), not milling into the machine's table, not breaking cutters when a part you have cut off jumps into the cutter (holding tabs), swarf clearance, workflow of going from dxf to finished part, how to mill into a corner (see above).

It is very educational to make the same part in three ways: 3DP, hacksaw from plate, CNC mill and see what is common to the methods and what is not.

 

[Misterg]

If so, you should* be able to import the STL as a mesh (on the mesh tab, rather than solid), work on it and then turn it into a solid body.

Actually, don't do that if you want to learn CNC milling / CAM: re-draw it so that you are assured of having perfectly plane, orthogonal surfaces (other wise, you could give yourself enormous headaches in the CAM side that would make the learning curve almost vertical!)

(Sorry to quote my own post, but past the editing deadline.)

 

[ukracer]

Depends on your CNC software but making a dxf of the top face features might work. You can do that in fusion 360, it takes a few steps but is pretty straight forward.

UCCNC is the software. But I also have free fusion version. Time is not an issue to not having rapids will not be a problem.

 

[ukracer]

to be fair you could probably rough it out with a bandsaw and grinder and only need a mill for the slots.

I have a bridgport so it would be fairly easy to make it on that to be honest. But as I have the CNC never used its more because I "want to make it with it.

Just to be clear for @Agroshield it's a CNC router not a vertical one with slots in the bed.

 

[ukracer]

For something that small and simple, put the orange one on a sheet of paper, draw round it and measure with a ruler. Then use a 2D CAD progam to draw the main outline, the three slots and the pocket for the blade. Ideally save as three separate files. What you have there is not 3D at all, more like 2 1/2D - 2D with a thickness.

By the time you faff around converting the STL, you could have the dxfs you need.

If you CNC it from solid, you would clamp down your oversize piece of aluminium plate (if you can buy in the right thickness, or make the part to suit the thickness you have, that saves decking it off) such that the clamps do not cover the slots. Orient the machine so two of the slots are over a T-slot. Use the first dxf to mill the three slots. Reclamp through two of those slots and remove the original clamps. Use the second dxf to cut the outline of the part. Use the third dxf to cut the blade pocket.

If you are smart, you make two at a time as that uses a rectangular piece of material more efficiently.

Note that you will have to change the blade pocket in the subtractively-manufactured item. There is no milling cutter in the world that will make the sharp internal corners that the 3DP version has. You need to put a circular relief in each of the corners that is fractionally bigger than the diameter of the cutter you will use.

---

A really stupid way to get want you want is to run the G-code file through a simulator. At some point above the initial layer, the path the nozzle traces will be the outline of the part. At a leter point in the file, the path will include the blade pocket. You extract those lines from the file and reverse them into a dxf.

Thanks for taking the time for the detailed reply. I am happy that I understood enough to understand most of it.

Like 3D printing and Laser engraving it's daunting till you get into it the first time.

 

[ukracer]

I can't remember - do you also use Fusion360?

If so, you should* be able to import the STL as a mesh (on the mesh tab, rather than solid), work on it and then turn it into a solid body. After that, you can use the Fusion CAM to generate G code for your CNC.

*If everything run smoothly. It depends on the quality of the STL. Fusion seems to be a bit picky, and doesn't handle large meshes well (IMHO). It does have various tools for fixing the things it complains about so you might be OK without resorting to the likes of Blender.

(Ping me the STL file if you want me to have a go for you.)

Just out of interest to see how you get on.

Dropbox

www.dropbox.com

 

[m_c]

You really want the original design file.
You can work from an STL, but for simple parts like this, it just unnecessarily complicates the process.

The Gcode file isn't much use. I'm sure you could reverse engineer the g-code file, but it will be far from ideal.

 

[ukracer]

Note that you will have to change the blade pocket in the subtractively-manufactured item. There is no milling cutter in the world that will make the sharp internal corners that the 3DP version has. You need to put a circular relief in each of the corners that is fractionally bigger than the diameter of the cutter you will use.

---

Yes I was concerned about the blade section.
It also has a tag for the blade on the opposite side to the photo of the red one. This one shows it better.

 

[mike os]

Ah but......its me that will be the machine shop.

So you import the step into your cnc interpreter to get the g code in the correct format for your machine and off you go

 

[Maker]

I can't get my head around this, what does the knife holder go in, and why do you want ten thousand felt squares?