Just one step to buy CNC - so big problem of choise

[pshz11]

Dear fellow builders!

After 1 year of collecting building experience I've decided to buy own CNC. Now I have now 2 options to choose between (and, probably, anyone can recommend anything else?):

http://www.zenbotcnc.com/cnc-routers/zenbot-4848

http://www.carving-cnc.com/x61500series-1/cnc-x61500gt-router-engraver-drilling-and-milling-machine.html

Do anyone has positive (or negative) experience with models above? Would 580X380mm (in X6 model) be enough for cockpit tasks? Do I really need 4th axis? What about control box? (YOOCNC promises something they call "new generation stepper driver")

I tend to choice X6 model, as I like it's control box, and many useful features included (spindle is included and looks like enough for tasks, controlled by software in range between 3000 and 24000 rpm and water cooled; but can be replaced with any other, like KRES or Bosch).

I would highly appreciate any advices on my issue!

[Qwseyvnd]

Hmm... Maybe you need 5 axis machine to making gears to have analog instruments?

[pshz11]

I bought 4 axis x6 machine and it's awesome. Very silent, very precise.

Why do I need 5 axes for gears? 3 axes are enogh, I presume.

[hexpope]

I bought 4 axis x6 machine and it's awesome. Very silent, very precise.

Why do I need 5 axes for gears? 3 axes are enogh, I presume.

At least you opted for the USB version ! Good to see, looks like a nice machine too. I have the same version but without the VFD spindle.

Whats the USB plugin like with Mach3 regarding stability ?

[Qwseyvnd]

I want to build the Il-62 cockpit, it seems that I need bigger CNC machine, least 600x750mm work size. What do you experience ?

[pshz11]

Whats the USB plugin like with Mach3 regarding stability ?

USB if very convinient, your're right. Furthermore, very nice control board with enogh inputs and outputs (I have connected limiting switches and going to build relay module to connect cooling pump). Regarding stability - no problems yet.

[hexpope]

USB if very convinient, your're right. Furthermore, very nice control board with enogh inputs and outputs (I have connected limiting switches and going to build relay module to connect cooling pump). Regarding stability - no problems yet.

Great to hear about the plugin for Mach3. I had to get rid of the cheap YooCNC driver boards in my control box (Missing steps all over the place) and I decided to take the Pokeys USB method with their stepper driver boards, and I have absolutely 0% problems, and USB is so much better, that damn parallel port thing just wrecked my head. I have a 4th axis as well, but I still need to figure out how to get it working correctly with Mach3. This weekend I hope to accomplish this.

What have you done so far with your CNC ? So far for myself and friends in the UK was single and doubled sided PCB routing. I want to get into the 3D milling part of it now and also upgrade my spindle.

[pshz11]

Currently working on MIP gauges. Dual needle flaps (not ready yet) http://instagram.com/p/jBc_K_uSyt/

Could you please share your PCB making experience? Feed rates, spindle speed, depth, type of engraving bit, cam software? I've tried once, but there was no success at all.

[hexpope]

Currently working on MIP gauges. Dual needle flaps (not ready yet) http://instagram.com/p/jBc_K_uSyt/

Could you please share your PCB making experience? Feed rates, spindle speed, depth, type of engraving bit, cam software? I've tried once, but there was no success at all.

Nice work !

PCB routing is pretty easy believe it or not.

Ok well first of I use the metric system (Just so you know)

My spindle is only 12000RPM so when PCB routing, it's always at max speed.

I rule of thumb and what Erik has thought me when I was starting off, is nice and slow and work up from there. so here is my starting point.

Spindle Max Speed. (you have a 25K RPM spindle) You should be able to achieve faster feed rates as you will learn.
Feedrate = 100 mm/min
Plunge rate = 50 mm/mm (Can be higher depending on the diameter of the bit)
Depth = 0.04mm (It's the copper you only want to remove) 1oz of copper should have a thickness of 0.035mm layer.
Now you might want to go a little bit deeper depending on the quality of the PCB clad you have (How level it actually is)

PCB Clad. I always use the FR4 type fibreglass. It might be a bit harder on your bits regarding wearing, but it doesn't have a tenancy to go into a banana shape or even come in a pack bent like the other types.

I mostly R&D with SMD components where I can, and I use a 30 degree bit or a V grooved 0.1mm engraving bit for really thin traces and small SMD components (Caps, resistors, LED's, IC's -0805 and smaller-) I would buy from .1mm up to .3 for PCB work.

http://www.cnc-plus.de/Fraeser---Bohrer/Single-Flute-Engraving-Router-Bits.html

http://www.cnc-plus.de/Fraeser---Bohrer/V-groove-Engraving-Router-Bits-1007.html

I used to buy bits from Ebay china sellers, and trust me, don't bother. The life span of them is useless. Although the PCB drill bits seem to last me very well. Actually, a bit has never broke unless it was my fault. BUT... If you are learning and you do need practice, I would buy something cheap to play with from ebay, but the above bits would be for when you know your machine rates for PCB routing.

As for when you want to cut the board, or route it out. I use these.

http://www.cnc-plus.de/Fraeser---Bohrer/Carbide-Endmills-diamond-patterned.html

The software I use is. Diptrace (They have a free version of 300 pin limit) for designing and my PCB's. I export in DXF format and then open it with Vectric Apsire and create the Gcode for Mach3.

Double sided boards are another story. Here is my way I do it. I use MDF, create a perfect 1.6mm pocket that my PCB will clip into. I then route, drill, and then when it comes to doing the second layer I just flip the board and start the second side. Works perfectly for me with no mis alignments on bottom side of PCB's

As for Via's I use these

http://www.ebay.co.uk/itm/Track-Pin-0-84mm-Pk1000-Price-for-1-T1559F46K-/281226435036?pt=UK_Camera_Cases_Bags_Covers&hash=item417a66d9dc

Just drill the hole, slot one of these in, and solder both sides. Job done, and faster than using strips of wire etc like I used to in the past.

[Perik]

Hello

Here is a nice little addon taking care of "banana shape" pcb's :-)

http://www.autoleveller.co.uk/

[hexpope]

Hello

Here is a nice little addon taking care of "banana shape" pcb's :-)

http://www.autoleveller.co.uk/

Hi Erik,

Never seen that software before. I must go and check it out. I still some times run into problems with uneven boards and usually have to reroute some paths a second time with a lower Z height. Looks like I will be using my probe again.

Software reminds me of the function from a version of PCB2Gcode ULP in Eagle.

[iwik]

Hi Guys,
Thanks for the heads up on the Autoleveller Per Erik.
Hexpope :Very nice and imformative run down for milling PCB's, I was always wondering what was the best way
to handle pcb's. Especially uneven ones, Per s fixed that now. Must try again.

Regards
Les

[hexpope]

As I type this I have taken the controller box apart to gain access to my Pokeys board and I am now fitting a shielded jack for the probe to test this out. I haven't been able to use auto leveling for PCB's since when I used to use PCBtoGcode ULP in Eagle. It had that function in it as a option. I use Diptrace now, so I missed this function as I do quite a lot of PCB work for people. Thanks again Erik !!

[pshz11]

Thanks, hespope, for such a great explanation. It seems, that major prolem for me was the depth of engraving, and, perhaps, unsharpened tool. I will try your technology in near future.

Regarding AutoLeveler, seems to be great solution! But, I do not completely understand technology for plastic surfaces.

[iwik]

Hexpope/Erik,
I'm trying to use Diptrace and Cut2d but when I import DXF to cut2d and run profile it says I have open vectors.
Any comments appreciated.
Thanks
Les

[hexpope]

What you need to do is when in DIPTRACE, you need to goto export DXF, and when you are in the menu you need to make sure you select the layer of EDGE_TOP or EDGE_BOTTOM and then export. That should clear that issue up for you.

Make sure your other settings are sorted out first, like mm, or Inch etc.

[iwik]

Thanks a Million mate,
I would not have even thought to do that. Learn something new every day
Les

[iwik]

What parameters are you guys using to drill holes in your pcbs?.
Thanks
Les