DIYDrones - CNC Project

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DIYDrones - CNC Project

Well, it originated as a blog, and has grown into a DIYDrones attempt at creating a CNC machine.

This group is set up so that we can organize the activity.

For background, the original blog is located here:

http://diydrones.com/profiles/blogs/cnc-stuff

Location: Cyber Space
Members: 178
Latest Activity: Sep 27, 2018

Discussion Forum

Progress on the Harp Fabricator

Started by Monroe King. Last reply by Monroe King Sep 29, 2017. 40 Replies

Continue

Need some help with the following for my designs. Telemetry, GPS, barometric leveling, altitude hold

Started by Bill Schonfelder Nov 10, 2015. 0 Replies

I have been using kk2.1 boards upgraded with stevis 1.9 firmware.The highest motor I have used is 800 kv with 30 amp simonk flashed firmware.I have created new styles of power distribution boards for…Continue

New CNC website

Started by John Hestness. Last reply by Ruwan Jan 26, 2014. 1 Reply

I found a CNC related website that seems like a good fit for the DIYdrones culture.  http://www.openbuilds.comContinue

Brainstorming Specifications.

Started by Ellison Chan. Last reply by chewdonkey Nov 27, 2013. 278 Replies

Setting this discussion up to gather up and brainstorm ideas.LIST OF EQUIPMENT AND MATERIALS UNDER CONSIDERATION:Motors/Controllers:…Continue

Comment Wall

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Comment by Gary McCray on May 26, 2013 at 6:35pm

Hi Monroe,

Wow, you really are a rocket scientist.

I followed here from a comment you made about the Disrupter Blog.

I am a member of the Planet CNC forum although I haven't been to active of late.

http://www.planet-cnc.com/index.php?page=home

But I do think they have the right idea, there board takes (and loads G codes directly to internal memory and then takes responsibility for executing them).

Back at the PC it just shows progress and lets you step in if you need to interfere, completely off loads the PC of the real time tasks.

Which Windows machines are seriously bad at anyway.

I am positive this is the right way to go, and now they have a potential for 6 axis drive, but I still think their a little light on the microcontroller end.

By the way I'd really like to use brushless servos myself, AC or DC, they are just so not a consumer product at any level, and at least the Chinese have made really decent steppers affordable.

And with decent microstepping and encoders for in the loop feedback they can do a decent (if somewhat slow) job.

Unfortunately, the drive part of the equation looks like the most affordable part, balls screws not so much.

I still favor linear ball guideways and I have several projects I built on Hiwin Linear Guideway here: http://www.hiwin.com/html/lg/

But they do have limitations, if you can keep them clean and lubricated and don't apply too much force they can maintain reasonable tolerance and last a really long time.

Basically OK for high speed machining aluminum, wood and plastic, but definitely need to keep your feed rate down with steel.

Work better with a high speed spindle and not too much force on the feed.

The biggest problem whole thing is that half the stuff you need is reasonably priced and at least fairly easy to find, the other half not so much.

Still, I look forward to digging back into this and may pick up one of the Planet CNC boards to retrofit to my old(ish) Aluminum extrusion, ball screw and linear ball bushing machine.

If any of you know of any other CNC boards that work like the Planet CNC USB ones and are affordable by mere human beings, I would like to know about them.

Actually seems like a good candidate for an open source, open hardware project, maybe even Kickstarter.

Comment by Gary McCray on May 26, 2013 at 4:06pm

Hi All,

Just joined this group, but I have my own machine built with aluminum extrusions, linear ball bushings, ball screws and steppers and controllers similar to what you are using.

It is running on Mach 3.

I actually set it aside, because of the complete inadequacy of running directly out of a Windows (or worse legacy DOS) environment.

At one time I even had a Bridgeport Explorer 3 Axis CNC, but trying to maintain and operate an out of date CNC machine is an exercise in futility and frustration.

Windows is NOT a real time operating system and DOS is so far back its a bottleneck at this point.

I came to the conclusion that you really needed to have an intelligent dedicated controller running the hardware and that it could have a very nice interface to a windows machine for human interaction.

Some of these are already being made and the fact is almost all are a product of the Arduino community.

Aside from getting a suitably rigid and precise "machine" the real challenge is in producing a competent "microcontroller" to do all of the actual work so you can just use the Windows (Mac, whatever) to provide the nice screen and control interface to the person.

The problem with using wood in these things is that it is not dimensionally stable and warps and moves in response to humidity or just aging.

The trouble with aluminum is that it expands and contracts in relation to normal temperatures.

Steel (iron) is the preferred medium, but it is heavy and can require expensive castings.

Ball screws are the preferred motion device, but they are expensive and do not suffer contamination well, same for linear ball bushings.

Basically, steppers are pretty cheap, here is a great reference for some very nice ones: http://www.stepperonline.com/index.html

And if you want feedback, steppers and optical encoders are still a lot cheaper and easier to interface than servos.

I am actually in the process of revisiting this whole endeavor to see what might be reasonable now. 

Comment by R. D. Starwalt on May 9, 2013 at 4:39am

The Momus build is moving into what I call the 'much work, little progress seen' stage.  The torsion box construction is super rigid but unlike a metal, wood surfaces require finishing for visual appeal and to protect it from cutting fluids, spilled coffee, cold beverage condensation, etc. I am in the fill, sand, refill, repeat mode. Some builders have just slapped paint on it and moved on but my personal standards won't allow me to do that.

Here is a shot (also posted on CNC Zone) with the electronics chassis test fit into their locations in the base and the covers just sitting in their general location. The front cover will be hinged to the back cover and will flip up to access the cutting tool and the work piece.The back cover is not in position but slid back and resting on some bar clamps to allow me access for finish work on the front. The back cover will be attached to the base. Lighting will be installed inside the back cover to allow you to watch. Plexiglass/Lexan windows will be installed in the big hole in front and the trapezoid holes on either side of the front cover. 

The more I work with Bondo, the more I appreciate the stuff. The working time is very short.

The Gecko G540 driver supports 4 stepper motors and two relays. I have the two relays and their separate power supply mounted in the same chassis as the Gecko with an Estop slap switch. The rear chassis holds the motor power supply and the AC power interface.

Bob has released ver 2.1 of the plans set

Check it out at MomusCNC.

-=Doug

Comment by Rob_Lefebvre on April 5, 2013 at 10:09am

Yay, Monroe is back!

Comment by R. D. Starwalt on April 5, 2013 at 10:02am

Thanks Monroe. One benefit of the Momus is that *IF* I want to try servo based motion control, I just swap out the motors with that type.

This build is with 380 oz/in steppers and a Gecko540 4 axis driver. My idea is to make a 4th axis assembly much later to allow aluminum tube rotation for all-side cutting.

-=Doug


Moderator
Comment by Ruwan on April 4, 2013 at 1:26pm

Great to see you back, Monroe!
I'm still hoping to build a CNC machine, although my interest on a 3D printer head took a different route [1]

:-).

[1] http://www.kickstarter.com/projects/1650950769/rigidbot-3d-printer

Comment by R. D. Starwalt on April 4, 2013 at 5:15am

Hello Monroe! Good to see you back.

-=Doug

Comment by R. D. Starwalt on March 9, 2013 at 8:10am

There has been no update on Bob's webpage about the print head. He has been somewhat quiet on the CNCZone webpage (they are completely reworking that site at this time).

Yesterday I bought the 3/4" plywood for the base assembly and spent several hours rough cutting the parts for it. Today that work will continue.

When running, I there are several plans for printheads online so if Bob is slow to publish his efforts, there are always others to try.

The router can be removed from the Z axis rail and the print head bolted on. Filament feed, power etc..that will have to be worked out.

First things first. Get the machine built and aligned.

-=Doug


Moderator
Comment by Ruwan on March 8, 2013 at 11:31am

Thanks @RD, great to see your update. BTW, did they finish R&D on 3d printing head?

Comment by R. D. Starwalt on March 7, 2013 at 5:54pm

Just to keep some motion (pun intended) going on this thread/group..

99.99% of the metal work is completed on my build of the Momus V2.

What you see below is the Y gantry with the Z axis. The unit is laying on its 'back' on a bench jig I cobbled together until I can get the base of the unit constructed.

Below is how the gantry will be oriented when in the base and riding on the X rails.

The base will be constructed of 3/4 inch cabinet grade plywood.

It is a stress-box construction, very rigid with integrated cover to control the mess of chips and dust. The X rails and drive motor will be mounted on the base. The Y gantry (with Z attached) will lock into the X rails.

Stepper motors will be employed on this unit. The planned controller is the Gecko G540.

I am maintaining a worksheet of the costs and will share with this group and the CNC Zone group for the Momus when done.

Yesterday I loaded a PC with Ubuntu and LinuxCNC EMC software. That will be a new adventure in itself.

-=Doug

 

 
 
 
 

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