Let's Make Robots!

The Beast CNC machine II

For now it draws the shapes provided, eventually it should cut them too - actually does do cutting now :D

Hi all,

 As OddBot suggested on my blog I have created a robot page for this thing. I will update this page with more pictures schematics, code and video as soon as I have some time on my hands. 

 

Ok yahoo gaved in :D Added the video. Warning: It is long and boring :P


13 June 2009 - First cut

Here is a quick preview:

first cutFirst cut yey :D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

And a closeup:

 p1050868.jpg

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ok engraving video added, its is 10 minutes long just skip forward when you get bored :D  Not yet used to this editor, the video is up ahead.

 

And the outcome below:

 

p1050877.jpgNot perfect but hey it is home made :D

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


14 Jun 2009 - Square test

As probably Myc expected (and I kind of did) the square test reveals the following:

 

Bad:
- I have to take the X axis apart and fix the play in it before attempting cutting a square again :)

- While at it I will check the other 2 as well

- not sure about why the straight corners come out rounded on the inside

- Right now the square is a pretty arty approximation of a square see below:D 

 

p1050879.jpg

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Good:

- Motors do take the load pretty well and do not loose steps

- Z axis can handle the weight of the Dremel tool without problems

- software and electronics do their job pretty well now.

- hoy mate it does do cut :D

- yey my work was not for nothing after all :D

- for a badly built prototype it works pretty well 

 

What now?

a) take the thing apart, put it back toghether, hope it works better

b) take the thing apart, put it in the parts box, forget the mess

c)  take the thing apart, try fixing the wrongs here and there

d) take a break, start thinking wildly, draw designs, make a 3d model, etc., etc., for a Beast V2 with a better design which ensures lesser things going wrong when building it 

I'm oscillating right now between c) and d) or both, so if I do c) and get better results, parts for d) might come out of the machine. 

 

Oh yeah forgot one thing: 

The posibility of an extruding head for plastics, just got my hands on nichrome wire from a friend, will play at some point with that too. It would work with the current thing pretty nice because there are virtually no friction effects as with cutting.


Update 16 Jun 2009 - Fixing axis play .... right

So the good news is that the X axis is fixed, virtually no play except for the nut play which is not really fixable.

The bad news is that the Z axis design is flawed, I should have gone with four bearings instead  of three on each side. This leads to a very flimsy Z axis :( time for redoing some bearing mounts on the Z axis ... bleah

 


Update 17 Jun 2009 - Z-axis ... kind of fixed

 

Still some play there due to general flimsiness ... my Z axis design kind of sucks there :/

Time to strap on the Dremel on it again and do the square .... probably tomorrow morning (daughter fell at sleep)...

 

 

 


Ubdate 18 - Square Test II - The return of the Beast

 

Without further intro:

 Square evolution

Square evolution 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

And closer:

Squarer square

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

So clearly an improvement  here ... diagonals are not equal but that I think is due to the Dremel being strapped on :)

 

 


Update 20 Jun 2009: Got real end mill bit - and the end of fixing axes 

 

Ok so dremel does not provide nice end mill bits here but Proxxon does :D 

I have been wandering around Bucharest looking for materials suitable for the new improved design and found out that:

- usually in the stores you buy mdf you can also get it cut for free (they have nice machines too)

- Dremel supplies suck in Romania but Proxxon rules :D (wish I had known that before I bought a Dremel)

So I got a box with 3 very nice Proxxon end mills with cutting bits of 1, 2 and 3 mm (which surprise ! have 3 mm diameter shaft and work with dremels just fine) :

51d-cNctFdL._SS500_.jpg

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 And a small test reveals that they do cut like a hot knife trough butter :D

 And some scrap mdf from other cut for a very low sum, and the new rails I'm going to use. 

And after waisting all afternoon on fixing the Z -axis I'm giving up: I shall build new, better, improved Y and Z axis, I'm happy with the X though, I think I 'll keep that one.

Stay tuned ... more to come ...

 


23 Jun 2009 - The Beast is dead, long live Valkyrie 

Ok I'm done with the Beast, it proved that it can be done. Sadly and annoyingly the Beast had a pretty rough time getting build and the mistakes I've done punished me. Since Y and Z axis would have required me to rebuild almost all of it and I got tired of rebuilding it, I have decided to move on to a new and better design inspired from the same initial source buildyourcnc.com. That guy obviously hit the same obstacles and decided to take a different rails approach which is alot easyer to build.

 

He is using v-grooved bearings to slide onto the tracks, since I do not have those I just improvised ;) 

More to come soon .. probably in a new robot page.

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Man you are seriously making me  think building one of these things, even if my electronics knowledge is basic.  

    what kind of files can you print? are they bitmaps or vector based drawings?

   it would be awesome if you kept sharing all your hadr work so we can learn from your mistakes :D 

This is actually my first machine ... it is long gone, it evolved into the Valkyrie see here:http://letsmakerobots.com/node/9006

The machine works by interpreting G-CODE sent trough the serial connection, so as long as the design can be converted to G-CODE you will be able to use it. 

For my tests I used Inkscape to draw SVG files and the exported them to G-CODE with a plugin. Then after editing the G-CODE to fix some bugs from the exporter I send it to the machine  using a small python script.

For more info see the Valkyrie page, it is more up to date.  You might also want to check John_NY's machine, he is very active about it :) here: http://letsmakerobots.com/node/12713

As far as I'm concerned I'm still working on it, very slow progress though, I have virtually no time to work on it.

If you intend to build a similar one, prepare yourself with a lot of patience and proper tools, I'll try to help if needed.

 Thanks! I'm reading your valkyrie now, thanks for the link to buildyoucnc.com  also.  I want to build one similar to yours because I already have dremel tool, and I want it to be compact.
can you make a picture in paint, or gimp etc., and make the beast II cut out all the black or yellow(ar any single color) lines??
But why?

AWESOME!

you could make a 2D-3D printer, if you used some kind of injection instead of that dremel

then..   you could make a picrure of, lets say,  a leg to a hexapod, and make it print it!

like reprap (but only the "rap" part :P)

Thermo extruder is next in line, when I'm happy how it cuts.

I saw that guys "teaser" trailer for his newest CNC plan, the one with the v groove bearings and adjustable motor mounts. It was a good watch, pretty educational for a builder. I wish I knew where he got those bearings. Maybe they`re some kind of curtain rail rollers?

This makes me want to get back to my little guy. I might try putting up the gantry and slides today:)

I don't have them but, I'm using normal bearings put side by side so in the middle they form a small groove.

I have also found L  shaped aluminum rail with the L ends shaped like this /| so they go well with the small groove.

It seem to work really well, virtually no play vertically and sideways, but some play along the X axis rail because there is no way using this rail design to really tigten the two sides toghether.

So to get rid of all play on the X axis I have to use two leadscrews to move it one of each side.

This problem does not appear on the other axises which is very good.  

I'm not posting anything with the new design yet, I want to make sure it works.

Woah Proxxon huh? That`s the mini drill I`ve got! I`m going to have to get some nice milling bits like yours.

Looking forward to the Y and Z redesign!