Questions about Cut2D

[johntech]

I am looking at building a rotary coal dumper for my model railroad. Here is a link to what I am trying to build. http://www.metso.com/miningandconstruct ... le/RCD.pdf

My question is, will I be able to draw the end pieces, as shown in the link above, with Cut2d and be able to draw the "ribs" to make it look like it was put together in sections?

I have downloaded the demo and can draw the circle and the cut-out in the center where the train runs through, but can I draw the "ribs" with Cut2D or do I have to use Cut3D? Could I then take that same piece I milled out and flip it over, design gear teeth in Cut2D then mill that out on the back side?

I'm sure I will have more questions before I buy

Thank you

John

[RoutnAbout]

John,
Cut2d is capable of creating all of the shapes as well as toolpaths to machine the parts.
The draw back is that Cut2d doesn't have all nice features as Vcarve Pro or Aspire.
The main drawback is creating a single line or arc. What you will have to do is to draw a square or rectangle and then use Node editing to break down the rectangle into a line. Now you can grab the line and put it where you want it.
You'll have to jump through some hoops to do it. But it Will Do it.

You'll also be able to create the track of gears along the curve also. But again you'll have use the node editing tools to shape the tooth/cog of the gear.

Cut3D will only create toolpaths for a 3D file, you can not do any design or editing in Cut3D.
There is a wealth of knowledge and help here on the forum, so if you decide to get cut2d and attempt that make that dumper, there are several guys around here that can help answer your drawing questions.
Hope this helps.

[JimG]

My question is, will I be able to draw the end pieces, as shown in the link above, with Cut2d and be able to draw the "ribs" to make it look like it was put together in sections?

John,

For complex shapes like the end pieces, it's much easier to draw them in a 2D CAD package then export them as DXF file into Cut2D and use Cut2D to produce the GCode for all the different levels and shapes required to get the 3D shaping. The drawing tools in Cut2D are very basic and take a lot of time to use if you want to do more than very basic shapes. You've got to find out how to use pockets and profiles and that can take some time to get to know how Cut2D works. The 3D previews in Cut2D are accurate so you can experiment within Cut2D before you put your GCode anywhere near a milling machine.

You don't need to spend any money on a 2D CAD package - you can download something like http://www.3ds.com/products/draftsight/ ... raftsight/ for free and it's as good as AutoCAD LT.

I've been cutting panelled coach sides for model railway coaches. I've attached a picture and all the different panels and profiles to five different levels have been cut from GCode out of Cut2D from a DXF file from a 2D CAD package. You've just got to mess around with the software and find out what it can do. I reckon you can do the circular ends for the wagon tippler with the ribs and gear teeth out of Cut2D.

Jim.

[johntech]

My question is, will I be able to draw the end pieces, as shown in the link above, with Cut2d and be able to draw the "ribs" to make it look like it was put together in sections?

John,

For complex shapes like the end pieces, it's much easier to draw them in a 2D CAD package then export them as DXF file into Cut2D and use Cut2D to produce the GCode for all the different levels and shapes required to get the 3D shaping. The drawing tools in Cut2D are very basic and take a lot of time to use if you want to do more than very basic shapes. You've got to find out how to use pockets and profiles and that can take some time to get to know how Cut2D works. The 3D previews in Cut2D are accurate so you can experiment within Cut2D before you put your GCode anywhere near a milling machine.

You don't need to spend any money on a 2D CAD package - you can download something like http://www.3ds.com/products/draftsight/ ... raftsight/ for free and it's as good as AutoCAD LT.

I've been cutting panelled coach sides for model railway coaches. I've attached a picture and all the different panels and profiles to five different levels have been cut from GCode out of Cut2D from a DXF file from a 2D CAD package. You've just got to mess around with the software and find out what it can do. I reckon you can do the circular ends for the wagon tippler with the ribs and gear teeth out of Cut2D.

Jim.

Hello Jim

Thank you for the assistance! I have d/l'ed the free cad program and am very excited to finally get started on this project. I know I will have to read the manual but do you have any tips on creating the pockets as shown in you picture? Thank you again

John

[JimG]

Thank you for the assistance! I have d/l'ed the free cad program and am very excited to finally get started on this project. I know I will have to read the manual but do you have any tips on creating the pockets as shown in you picture? Thank you again

John,

I've done a quick example based on your model requirements. I've drawn up a sort of representative tippler end in 2D in Draftsight which I attach - nothing deadly accurate to prototype, but with enough features to show you what is possible. When you are drawing in 2D for Cut2D try and get all your vectors joined where they need to be. In Draftsight that means either drawing with polylines or using trims, fillets, extends, etc to make sure that the lines actually join. Cut2D will only generate code for profiles and pockets if the vectors in the shapes are joined. Cut2D does have tools to join open vectors but it's a lot easier to make the vector joints in 2D before going into Cut2D. The drawing was exported from Draftsight as a R12 DXF file and imported into Cut2D. Version R12 of DXF is generally reckoned to be the safest to use - in later versions, AutoCAD added extra features which are not understood by some programs.

I've also attached a file of what is possible in Cut2D from that 2D drawing - this is using Cut2D's preview facility. All the cutting has been done with profiles or pockets on a piece of 10mm thick material. The centre squarish hole is a pocket cut right through the material. The inner and outer circles are selected and a pocket 3mm deep is cut to provide the face of the edges of the pockets. The twelve pocket shapes between the two circles are cut with a 2mm cutter to a depth of 2mm. A profile cut of 2mm deep is done round the outer circle with a 5mm cutter then a profile cut of 5mm deep is made round the tooth outlines with a 1.5mm cutter, which cuts the teeth completely through the material. The black bits in the corner are waste. For speed you should also cut the centre hole as a profile and leave a big chunk of waste in the middle - I've only cut it as a pocket to make things clearer.

You will find that you can do a lot of fiddling and changing to find the best way of cutting things. When it comes to putting your GCode on a mill, you might find that it can take, literally, days to cut your piece. So you try to get the time down by using as large a cutter as you can to get rid of material quicker, and do tool changes during the milling process, only moving down to the smaller cutters when you absolutely have to. Cut2D lets you save all the code files using the same cutter as one large file so you can save all your code in files by cutter size, which means you can cut all the parts using one cutter, then change cutter and cut all the parts for the next cutter, and so on. Sometimes you have to split the cutting differently but you can save the code in other ways to files to do it another way.

It's also quicker to cut profiles than pockets, so if you are cutting a hole in a piece, cut a profile and chuck the bit of waste left in the middle.

As I said earlier, the 3D preview in Cut2d is pretty good for assessing what is happening but I use Mach3 to do the CNC control and I usually load the code and run Mach3 offline to make sure that the cutter isn't going to plough where it shouldn't.

Jim.

[johntech]

Hi Jim

Thank you for pointing me in the right direction with the drafting program. I have downloaded it and am working through the tutorials learning how to use it. I can hardly wait to start working on the rotary dumper end pieces. Maybe I can finely get this thing drawn and cut out!!

john

[John S]

John,
As well as the manual for Draftsight there are loads of video's on YouTube showing how to use this program.

He's a good starter page.

http://www.youtube.com/results?search_q ... Draftsight+

[johntech]

Thank you John S. for the links! I will be watching them all !!

Once I get that program down then I can move over to Cut2D and start making actual parts.

You guys are the best!!

John

[johntech]

Hi Jim

Have have managed to work my way through the tutorial and this is the end piece that I have drawn up. Now I just have to figure out how to get it over into Cut2D so I can see what it will look like in 3D.

john

[JimG]

Hi Jim

Have have managed to work my way through the tutorial and this is the end piece that I have drawn up. Now I just have to figure out how to get it over into Cut2D so I can see what it will look like in 3D.

John,

To get it out of Draftsight, do a File/Save As/ and in the "Save As Type" drop down selection, choose "R12 ASCII Drawing (.dxf)". That will output a text file which Cut2D should import. Watch out that you are workign in teh same units in both Draftsight and Cut2D - i.e. either millimetres or inches.

Just looking at your drawing, remember that you cannot get square internal corners since you are using a circular tool of a finite diameter. So you can use a very small diameter mill and get a small fillet in a corner. But watch out since, in practice, the cutting part of very small mills is quite short in length and the shank is of much larger diameter, so there is a definite limit to how deep you can cut with a small mill before the shank taper starts fouing the work piece. Whoever supplies your milling cutters should give details of how long the cutting flutes are and that will be about as deep as you can go without fouing anything.

And once you get onto the milling table, you have to watch out for any holding clamping you use - i.e. setting safe distances for the mill to retract when moving so that it doesn't hit any clamps. I get away with holding material on my table using double sided tape since I'm cutting styrene or acrylic and the feeds and speeds are quite light - so I don't have to worry about clamps, etc.

Jim.

[johntech]

Thanks for the info Jim! Yes I realize that I won't get square corners but I will be cutting 1/2 PVC for the final piece using a 1/8" bit so that will work out ok for me. Just getting this far is a real delight!! I have put in "bridges" in the center piece and at various places around the outside to keep things together when cutting. I figure several screws on the inside piece should do well. Now I just have to purchase Cut2D and I should be able to put this all to the test.

Thanks again

John

[JimG]

Thanks for the info Jim! Yes I realize that I won't get square corners but I will be cutting 1/2 PVC for the final piece using a 1/8" bit so that will work out ok for me. Just getting this far is a real delight!! I have put in "bridges" in the center piece and at various places around the outside to keep things together when cutting. I figure several screws on the inside piece should do well. Now I just have to purchase Cut2D and I should be able to put this all to the test.

John,

If you are cutting plastics, go for carbide bits rather than HSS. The HSS tends to run hot and give poor results on plastics while the carbide bits run cool and give no problems. I've been cutting styrene and acrylic with carbide and have had no problems with cut quality.

Jim.

[johntech]

Hi Jim

Really getting used to using DraftSight. Here is a side pannel I threw together in about 45 minutes today

Thanks again for all your help!!

John