Free 3D CAD software....

Free 3D CAD software....

Joined: August 14th, 2004, 2:44 am

October 15th, 2008, 1:31 am #1

Google has it's own free 3D CAD software for download.... http://sketchup.google.com

Haven't played with it enough to see what it can/can't do, but hey.... the price is right.



A pic from their user gallery...



Enjoy.

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Joined: May 12th, 2005, 1:57 am

October 15th, 2008, 1:54 am #2

I am about ready for the cnc mill project to get going again so this might come in handy soon.....peace...

Pete Matos
865-363-9218
Matospeter@charter.net
Safe Journey Space Fans, Wherever you are....
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Joined: January 7th, 2007, 1:03 am

October 15th, 2008, 8:33 pm #3

What size mill are you going to be using? Have you decided which drivers and software you will be using yet/ IE Gecko Drives and MACH Mill etc?

I have a small Sherline CNC mill and use AutoCAD for some design as well as Rhino but most of my g-code is produced using FeatureCAM and I drive the mill with MACH.

With such a small setup I was able to get by with a Xylotex board for 3 axis motion since I do not require high torque steppers.

I need to get my mill straightened out since my X azis backlash nut started to act up. Since the hurricane haven't had much time but with it getting darker sooner I will be back out in the shop more over the winter.

Also have a CNC gantry router under construction with the Z and Y axis pretty much ready to go just need to figure out what I will do for the X. Right now I have 70" long linear rails but I am thinking they are to long and maybe not stiff enough for the task. Still a long way to go on it but linear motion and CNC control is super fun, when it works


Dee
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Joined: May 12th, 2005, 1:57 am

October 16th, 2008, 12:16 am #4

I just wrote a long post detailing my conversion plans and all about my lathemaster mill I am using and when I posted it network 54 somehow lost it and I am kinda pissed right now. But yeah I am planning on converting a mill and I am insanely jealous that you have one running right now. nice going ya jerk!! haha just kidding of course....peace

Pete Matos
865-363-9218
Matospeter@charter.net
Safe Journey Space Fans, Wherever you are....
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Joined: February 16th, 2007, 8:51 am

October 16th, 2008, 4:09 am #5

What size mill are you going to be using? Have you decided which drivers and software you will be using yet/ IE Gecko Drives and MACH Mill etc?

I have a small Sherline CNC mill and use AutoCAD for some design as well as Rhino but most of my g-code is produced using FeatureCAM and I drive the mill with MACH.

With such a small setup I was able to get by with a Xylotex board for 3 axis motion since I do not require high torque steppers.

I need to get my mill straightened out since my X azis backlash nut started to act up. Since the hurricane haven't had much time but with it getting darker sooner I will be back out in the shop more over the winter.

Also have a CNC gantry router under construction with the Z and Y axis pretty much ready to go just need to figure out what I will do for the X. Right now I have 70" long linear rails but I am thinking they are to long and maybe not stiff enough for the task. Still a long way to go on it but linear motion and CNC control is super fun, when it works


Dee
I want to build up a CNC mill. I haven't used a mill since high school metal shop!
I can use all the help/advice I can get.

So far I have bought...

The harbor freight mini mill
DRO's with reader kit
A 42 or 52 piece clamping kit
Some end mills
Collet holder with 4 collets

I do have autocad for design.

I want to be able to use the mill manually still after the conversion.

I was thinking I may use Mach3 as the software to run the mill.

This is similar to the set up I am trying to put together.
http://www.fignoggle.com/plans/index.htm

Here is a link to how this fella did his. Using an ancient computer running dos!
http://home.cinci.rr.com/hardball/CNC.htm

How would you guy's go about it?

Thanks,
Jason


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Joined: January 7th, 2007, 1:03 am

October 16th, 2008, 4:18 pm #6

Sourcing all the parts yourself and making sure everything is compatible can save you a lot of money over a pre-designed kit to upgrade to CNC.

There are so many variables in the design that you will have to determine what you want to do and how much you want to spend. If you have some wiring skills and understand the mechanics of linear motion, stepper torque versus RPMs etc cobbling together a machine should not be that difficult. The best part of building the machine up this way is that when something craps out you will know how ot fix it since you will be intimately involved with it's creation.

What size stepper motors do you plan to use? Which driver do you plan to use. The driver will be the determining factor in what you should be looking at for your steppers and the power supply to run things.

Have you been to CNCzone.com ? They have lots of people building machines using the same mill you have and I am sure you could get lots of details about what others have found works or does not cut it.

As for being able to use it manually that will depend on getting dual shaft motors for each axis. This can be good if you have resonance issues as the handwheels will act as a vibration dampener. It also increase the swing load inertia put on your motors which can be a negative depending on the motors and power supplied to them.

With CNC even if you do not have the handwheels installed you can still "manually machine" with the CNC setup by using simple one line code inputs or with simple jogging of the machine.

I suggest checking out CNCzone and look under the benchtop mill section where you will find lots of info about others setups and be able to ask them any questions you have related to your mill.

MACH is a very good choice for control software. It is very powerful and has lots of online support as well. I just switched to it from Turbo CNC under DOS. Got it all setup and configured then my X axis backlash nuts started to act up and I haven't had a chance to get back to it yet.

Are you familiar with G&M codes as of now? Back in college when I was taking CAD/CAM classes we were always made to code one program by hand for each one we did in the CAM program. This was only for the 1st course and after that everything was done in CAM. The point being that knowing how to read and troubleshoot the code itself is a very big plus because you will have times when the CAM program says everything if fine and looks good then when you go to cut the piece your machine goes crazy. Being able to look at the code and see whats happening and what you need to modify to get it to do what you want is critical.



Dee


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Joined: January 7th, 2007, 1:03 am

October 16th, 2008, 4:34 pm #7

I just wrote a long post detailing my conversion plans and all about my lathemaster mill I am using and when I posted it network 54 somehow lost it and I am kinda pissed right now. But yeah I am planning on converting a mill and I am insanely jealous that you have one running right now. nice going ya jerk!! haha just kidding of course....peace

Pete Matos
865-363-9218
Matospeter@charter.net
Safe Journey Space Fans, Wherever you are....
If you get the chance just write up an abridged version of your plans as I would like to know what you have in mind. From what I have read the Lathemaster machines are well suited for conversion to CNC. The guy who sells them is just around the corner from me actually. If I ever go that route I may use one of them myself.

Have you ever run CNC machines before?

Oh and don't be jealous about my little mill. It is really a toy but very capable if kept within it's limits. Plus I need to work on it to get it running still yet. Had recently upgraded the spindle motor and then the X axis acts up. Always something.

Even after having used Fadal 40/20 machine centers and Cinncinati Millicron Lathes I am still amazed and in awe when using CNC, it is just to cool.



Dee
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Joined: February 16th, 2007, 8:51 am

October 16th, 2008, 7:07 pm #8

Sourcing all the parts yourself and making sure everything is compatible can save you a lot of money over a pre-designed kit to upgrade to CNC.

There are so many variables in the design that you will have to determine what you want to do and how much you want to spend. If you have some wiring skills and understand the mechanics of linear motion, stepper torque versus RPMs etc cobbling together a machine should not be that difficult. The best part of building the machine up this way is that when something craps out you will know how ot fix it since you will be intimately involved with it's creation.

What size stepper motors do you plan to use? Which driver do you plan to use. The driver will be the determining factor in what you should be looking at for your steppers and the power supply to run things.

Have you been to CNCzone.com ? They have lots of people building machines using the same mill you have and I am sure you could get lots of details about what others have found works or does not cut it.

As for being able to use it manually that will depend on getting dual shaft motors for each axis. This can be good if you have resonance issues as the handwheels will act as a vibration dampener. It also increase the swing load inertia put on your motors which can be a negative depending on the motors and power supplied to them.

With CNC even if you do not have the handwheels installed you can still "manually machine" with the CNC setup by using simple one line code inputs or with simple jogging of the machine.

I suggest checking out CNCzone and look under the benchtop mill section where you will find lots of info about others setups and be able to ask them any questions you have related to your mill.

MACH is a very good choice for control software. It is very powerful and has lots of online support as well. I just switched to it from Turbo CNC under DOS. Got it all setup and configured then my X axis backlash nuts started to act up and I haven't had a chance to get back to it yet.

Are you familiar with G&M codes as of now? Back in college when I was taking CAD/CAM classes we were always made to code one program by hand for each one we did in the CAM program. This was only for the 1st course and after that everything was done in CAM. The point being that knowing how to read and troubleshoot the code itself is a very big plus because you will have times when the CAM program says everything if fine and looks good then when you go to cut the piece your machine goes crazy. Being able to look at the code and see whats happening and what you need to modify to get it to do what you want is critical.



Dee

I am pretty proficient in electronics. I own and know how to use my oscilloscope.

I don't know what size stepper motors I plan to use. Any advice/recommendations on this subject (bearing in mind that I still want the hand wheels on)?

Driver? Are we talking computer driver here to control the motors? I thought the software handled that. Please explain.

I haven't, but will definitely check out the CNCzone site.

GM code is something I am not at all familiar with. I will research about it.

Overall I am a pretty quick learner,good with computers, and am mechanically inclined. I am just new to this.
I only started getting this kit together a few days ago. The mill and the rest of the stuff has not even arrived yet.

Thanks for you help!

Jason

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Joined: January 7th, 2007, 1:03 am

October 16th, 2008, 10:37 pm #9

On the tool side you have a Mill for example that has either Stepper motors or Servo motors attached to each axis you intend to control via the CNC.

So for each axis you will need one driver. When I speak of a driver I am talking about hardware the takes the G code being sent to it by the computer Controller software and turns it into step and pulse directions which then in turn power the motors and give them the info they need to travel however far they need to go in the right direction.

My setup is one PCB board with 3 axis control chips. Some have 4 axis or more on a single board and others are each just single axis drives.

When you draw the part in AutoCAD for example, you will save it into a format like .stl, IGES, .dxf or whatever your CAM software can import. You then import this drawing into your CAM software. At this point you can start to define the cuts you want to make based on the lines of the drawing. This is called creating tool paths. Once you have created all the cuts and holes etc you plan for this setup you select the correct Post Processor to match your hardware that will then use all the information you have given and generate the actual G&M Code output. You must use a post processor that can create the code in the correct format for the hardware you are running. There are MANY different post processors and sometimes you have to customize one yourself.

This is the code you would load into MACH which is the controller and then run to make the cuts on the mill.

It is all a bit confusing I know and each person is likely to have their own way of doing things that suits their systems best. MACH is a program that you can use to run the code and also create some code as well. For some people this is all they require. Many people like myself prefer a seperate CAM program to generate the code that we then send to MACH for the cutting.

You can do CNC milling with a notepad file by hand it is really not that hard for basic 2D work but forget 3D by hand or even lettering, IIRC a C has around 72 arc segments in it alone thats a lot of calculating and trig to draw a C, so its best to let the software do things. But as I mention you need to be able to read the code to trouble shoot. With my setup I do not have a custom post processor for my hardware so I use the post that most closely matches my requirements and then just go into notepad manually and remove the parts that I don't need and the part (usually) will run fine. But there is no way I could do that without knowing what I am looking at in the code.

So much to learn. As for handwheels you just need to make sure your motors have dual spindles so you can mount them on the outside thats about it. As for motor size I would think some 282 oz holding torque steppers for that size mill would be about right. Take into account when you think power though that with steppers unlike servos as the power increases the speed the torque drops out. So the lower the speed to more torque up to 282 oz will be applied.

Your very broad in your scope right now I would suggest starting at the beginning and making yourself more knowledgable about each part and how they interact. You will learn a lot and save yourself a lot of hassle and cash. You have the mill coming so look at motors, couplers, drive units such as Gecko and Xylotex ( I have a xylotex and while the lowest in power ability it is very good for the money) Gecko is the cadillac drive many people use but you have to get each axis seperate and they cost a bit more but they are able to drive larger motors etc.

Hope this jumble of words helps you some. If you can narrow your questions down more specifically I can probably give you more precise answers.

Here is a pictoral idea of what happens.

1st Your draw your part in CAD. This case a Chicken



Then you save it to import into you CAM..In here you tell it what tools you will use and give it all the details speeds, feeds, depth of cuts, stepover etc etc etc...



Then you save the Code as a .nc or .cnc file etc for your controller to run. In this case its a screen shot from a Ram I was testing since I just started to use MACH and tune my mill I made test cuts in wood.


Then you fire up the mill and go from something like this...


To something like this...


Then you have come full circle.. And it is cool and very addictive!!!



Hope that helps shine some light on the steps as they come and go to make a cut.







Dee
Last edited by Bowman26 on October 16th, 2008, 11:27 pm, edited 1 time in total.
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Joined: February 16th, 2007, 8:51 am

October 16th, 2008, 11:25 pm #10

First things first...
Would you show me a pic or schematic of your pcb?
Do you run yours with the wheels on the mill still?

What part of the computer does the mill hook into. The gpu?
Ah I see the pcb board hooks into a pci? slot in the computer?

Like this?



I sincerely thank you for taking the time to answer my stupid questions. Sorry to be a pest!

Jason

Last edited by Ballistixx on October 16th, 2008, 11:32 pm, edited 1 time in total.
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