CNC milling machine

[audiox]

Any real life experience of this Colinbus cnc milling machine?

For readers of Elektor electronics it is offeret as a kit for 1599 euro:

http://www.elektor-electronics.co.uk/Default.aspx?tabid=141
(the article describing the machine is available for download on the left side of the page)

Colinbus website has some info too:
http://www.colinbus.com/English/cbr40_en.htm

It can read Gerber (and make isolation routing from it!) and Excellon drill files. Probably some cad files too (DXF maybe?) to engrave aluminium front panels. If not, you can use your pcb software to draw the frontpanels (like I do). I am not sure if it is rigid enough for milling aluminium frontpanels. 1600 euros is a lot of money but if it can be used for making pcb's and front panels it will pay itself back in few years. Anyway the price is much less than competitors that I have found.

I have seriously considered this machine. Those who know more about these or have any opinions please give your comments.

 

[josh]

I see you are overseas and I dont know dollar conversion rates off the top of my head, but I wouldn't buy that thing. It's very small, and seems to be very limited on what you can do with it.
You could buy a small CNC Mill, say an older Bridgeport vertical mill, for a little more than that. Keep an eye on equipment auctions, shop closings, and used equipment dealers.
At my work we bought a 20 year old Bridgeport mill that could be retrofitted with an NC for about 1,000 and the machine itself was about 2,000. But I'm talking about something with a 6 foot x axis, 2 foot Y, and 2 foot Z. Its a bigger unit.

Just my opionion of course, but I would buy something I could use as a drill press, mill, and everything in between like this unit.

http://cgi.ebay.com/BRIDGEPORT-SERIES-II-CNC-3-AXIS-MILLING-MILL-MACHINE_W0QQitemZ260093049652QQihZ016QQcategoryZ12584QQrdZ1QQcmdZViewItem
which is still alot bigger than you need.

 

[neriks]

audiox,

If you intend to mill and engrave aluminium front panels with the machine you are refering my guess is that it wont be stable enough. PCB's will probably work fine but but not aluminium front panels.

I'm quoting myself from this thread ...

[quote author="neriks"]If you intend to mill, drill and engrave in materials like aluminum I think you should consider buying a machine with better stability than the one you referring to. If the machine lacks the stability required you will be forced to use very low feed rates which naturally increases the machining time of making front panels. If you plan to provide front panel milling and engraving as a service to others you probably wont have the time to spend like 2 or 3 hours ... maybe more ... on each front panel you make.

The CNC-machine I'm using have a weight of approximately 400 kg (450 - 500kg if you add the precision vices and the two coolant systems) and with it I'm capable of milling and engraving in "soft metals" such as aluminum, copper, brass etc. However I can't use my machine to machine materials such as iron and stainless steel simply because it lacks the stability for it[/quote]

 

[nrgrecording]

The manufacturer writes that making frontpanels is no problem...

But I'd tested some cnc machines and all said... "engraving frontpanels... no problem... " but after some tests... :shock: :green:
I myselfs wouldn't buy a machine which I haven't tested with exactly the same material that I'll use with this machine later.
In the beginning I thought I could buy a used 1500€ machine on ebay and it'll do the job. In the end it was around 6000€.
Don't expect that the 0,2mm engraver will make a 0,2mm engraving. You need something that can control the depth of the Z axis. There are mechanical tools available and electronic tools. Frontpanelexpress for example are using datron machines which have a kind of scanner to have an automatic z axis correction.
You'll may have the same problem with making pcbs. I would use a cnc machine only for drilling because its faster, cheaper and better to etch the pcbs after drilling.

Just my opinion.

 

[gyraf]

I recently got a StepFour Basic540 machine - with 160W HF-spindle and engraving-"nose"

basic540 machine

Engraving-"nose"

Spindle w/ mounted (depth stop-) engraving "nose"

It works well for front panel engraving - I'm very happy with the quality...

Jakob E.

 

[nrgrecording]

Nice machine Jakob! :thumb:

Regarding the engraving nose...
Is there a scale to control the depth? I'd seen that on KaVo and bungard HF spindles but cannot see anything on the stepfour engraving nose.
Or do you have to start with minimum depth and readjust until its fine?
As far as I know schaeffer uses a 0,2mm depth with 0,2mm tools and 0,4mm with 0,4mm tools.
Is the nose made of metal?

How do you fix frontpanels to the stepfour so that its possible to drill through the panel completely? Do you use MDF/wood or something as a support und the material?

 

[audiox]

Jakob, what was the total cost of your system. I mean the machine, software etc. needed to engrave panels and route pcb's. Is your machine rigid enough for routing cut-outs to 19" panels (3mm aluminium) or is it just for engraving?

Another machine that I found was German:
http://www.stepwalk.de
It has been available quite a long time, a decade or so. But it has no internal processor (it simply uses printer port signals to control the stepper drivers). So using DOS is probably the only alternative and still requires tuning of the computer. For the Stepwalk machine there is available some kind of height adjusting head for engraving. It has a nylon ring that follows the surface of the engraved material and keeps the distance constant. It would be intersting to see if it makes scratches to the aluminium panel while moving or not.

 

[babyhead]

Jakob-

What happened to the CNC you DIYed out of printer parts?

:guinness:

 

[mikep]

jakob,

can this new machine of yours be used to mill proto PCBs?

 

[needlz]

The StepFour Basic540 looks pretty cool. Is there a U.S. distributor... any idea of price?

 

[gyraf]

Frank:

Yes, the engraving nose is stepped like the Kavo and the Gravograph - at
0.015mm/click. Made from highly-polished hard-chromed steel in order not
to scratch the surface too much. The adjustment is "relative" in all noses
like this (because of needed compensation for varying bit-length), so
absolute numbers don't really work in real-life - at least not for me.

I have only used the unit for engraving, but it seems like it would be pretty
easy to get to do cut-outs as well, providing you add a system for fluid
coolant (which you will always need when cutting aluminium!)

It will do PCB-routing as-is - though I have no isolation-routing software.
Does anyone know of a cheap or free program that will generate .dxf, .plt,
or G-code from Gerber's?

I got the t-nut baseplate for the machine for mounting of workpieces, but
found that it is easier with a homemade frontpanel-holder-jig which I
simply screw the panels onto while engraving.

Audiox,

Info about pricing found at the German version of their page - (the English
version should be updated soon too): http://www.step-four.at/hp2/

I do not think that a nylon nose will be good for engraving alu, as it too
easy catches metal particles and drags them around into the surface. I've
experimented a lot with this, and the right thing seems to be
highly-polished chrome or steel noses.

Babyhead,

The GyraEngraver Mk#1 still makes my backplates - it's just a bit too slow
for detailed frontpanel work - runs only 5-6mm/S at positioning (because I
overdesigned for precision, and underdesigned for speed). This was before
I found the really-great cnc machining forum at http://www.cnczone.com/forums/
- there is lots and lots of important info to be found on the subject over
there..

Mikep,

Indeed it will engrave (and drill) PCB's, if you supply it with the needed format code..

Needlz,

Check the website mentioned above. If the German language bothers you,
try the Firefox browser with the plug-in "GTranslate". Fantastic tool..

In the US, "THE COOL TOOL GmbH" should be distributor.

Jakob E.

 

[Kamel]

Hi Jakob
free software fro gerber, hpgl, dfx....

http://www.cenon.info/frame_gb.html

 

[gyraf]

Thanks, Kamel!

I'll certainly take a close look at that..!

Jakob E.

 

[mkoz]

We use a 1000x1250mm Isel flatbed table with Mastercam up here (I think they are called Micro-Isel in the US. Ours is German make).

http://www.iselautomation.de

But we only cut plastics on it. I wouldn't put any metal over it. Cutting soft metals like aluminium and copper is a pain in the ass. It's messy, you need to use coolants and lubricants and stuff otherwise the workpiece sticks to the tool and all sorts of mess.

Just stick to plastics and contract the metalwork out, it's much easier.

My brother and I were looking at that Elektor CNC a while ago as well. It looks pretty attractive first but once you dig into the text, they are a bit hesitant about backing the figures as they appear in the spec sheet. Hence a grain of salt.

Mach

 

[audiox]

The Cenon looks very interesting. But the isolation software is a commercial module if I understood right. And not cheap one... But even without the isolation I can imagine number of uses for the free file conversion part.

 

[nrgrecording]

Thanks Jakob for your explanation!
If I remember correclty Steven Thomas used a nylon nose with success. I'll try to use an analyzer to check the level of the frontpanel at different points. The measurements will make an automatic z axis correction.
I talked to one of the guys who're working at schaeffer and thats exactly what they did on their datron cnc machines.
There is a very cool pneumatic tension device available from datron. But just one pneumatic cylinder costs about 800€. :shock:

Thats the original one:

And thats my diy version:

action-video:
http://www.nrgrecording.de/temporary/tension_device.AVI

Frank.

 

[gyraf]

:shock: whoa! That looks very nice indeed!!!

Jakob E.

 

[Ptownkid]

Jakob

I've been poking around on cool tools site looking at this 540 with great interest, but I am super confused at all their different packages (as listed on step fours site). Did you go with the xpert system, or the dos? Also, which package did you get?

 

[gyraf]

I got the basic540 that comes with the S4Pro V.4 software, which runs under DOS. Very cool software indeed - but has some limitations compared to their expensive versions. I think it's modular and can be updated piecewise - but the basic version does everything I need..

Also I got the 160W HF-spindle and the associated engraving-nose - though expensive, that kit is worth every penny when engraving.

Jakob E.

 

[rafafredd]

yeah... it would be nice to know if anyone ever did a built for windows...