Opinions sought on cheap desktop PCB milling machine

[saxonhawthorn]

http://blog.makezine.com/2010/07/26/...sing-visolate/

Terrible stray capacitance though so forget it for anything over 1khz or so!

Re worring about offsets.....in cambam you can import a gerber, fine tune the offset & see the cut width onscreen...

Well I think it's a safe bet that I'll be going quite a bit over 1 kHz, and I can do without yet more stray capacitance problems, so perhaps I'll give VISOLATE a miss.

But I take the point, and your pic is helpful. CamBam has probably got to go on the shopping list.

Ian

[John S]

I wish someone had told me how hard it was to do circuit boards before I ran the last batch of 20 off this weekend without any glitches.

[HankMcSpank]

I wish someone had told me how hard it was to do circuit boards before I ran the last batch of 20 off this weekend without any glitches.

Yeah, that happened to me when I first started pcb milling too .....but next I had to make a pcb with something more than just two very large through hole components on it!

[John S]

That's about 80 x 80 mm.

[Jonathan]

That's a large track width, all through hole and no tracks between the pins - I'd have been amazed if anyone had problems with that. A lot of SMT IC's have a quarter the pin spacing of DIL, which is when it gets more difficult.

If it's a circuit which is running at relatively high frequencies I do engrave it in the 'normal' way or etch it.

I cut plenty of PCBs on the Roland PNC2300A (same as one John S has) at school with a V-cutter. It's a very weak machine, yet did what I needed at the time (up to SOIC). So you don't need a massively rigid machine for PCBs, since the cutting force is minuscule, however if you're happy with the travel on the table and expect to use it for other things then clearly rigidity is good.

[HankMcSpank]

Exactly....anything through hole like that, feels like groping "Dawn French" after Kylie ....Dawn might have a welcoming large warm bosom to nestle in but not many want to go that way nowadays.

(nice board though)

[ecat]

Curiously enough I've spent two weeks trying to coax 0.4mm tracks and 0.3mm isolation out of my little X1 - quite the experience for the reasons mentioned previously in this thread. I agree with the statement, if the machine is going to do the drilling it may as well do the milling, especially for double sided boards, and wanted to see if the X1 could hold the resolution before I spent any real money or even bought a 'real' CNC machine.

The results are looking quite promising atm, I think the next issue to address is spindle speed - 2,000 rpm does not make for a happy experience. I'm reluctant to add any additional weight to the X1's already over stretched arrangement but I reckon I can drop a 50mm spindle directly into the existing spindle hole. This looked just the job, ESX16 collet, 28,000rpm http://www.ebay.co.uk/itm/2307559193...84.m1423.l2649 but worried about its age and condition I was out bid :( If any of you fine gentlemen know of a suitable substitute I'd be most grateful.

Looking at 'real' CNC machines for the first time in quite a while I see the UK hobby market remains in a dismal state and the UK DIY/kit market practically non-existent.
Strike CNC routers looks promising, if expensive, I'm not convinced by CNCDudze and I refuse to roll with Dice. Reading the Chinese threads make the machines sound a bit of a lottery, even with a little reinforcement and upgraded linears there is still the question of the ballscrews and I've not seen any actual measurements. I took a look at the Zen Toolworks machine, could be ok in a light breeze ;) and spent an entertaining afternoon reading the XZero threads on the zone!

Anyway, it's been a while. Nice to see some of the old faces again and good to see some new ones. Time for more coffee and low fat procrastination.

... Oh, John, when they asked for a PCB with a bus I don't think they meant the #47 to New Street Road End ;) Joking aside, nice board John, smooth, good definition and more consistent isolation than I've managed to date.

[HankMcSpank]

Having got off to a bad start with my little machine...it's actually come though all this with its reputation in tact (my problems were to do with everything else!), so I can certainly recommend it for pcb work....

http://www.ebay.co.uk/sch/i.html?_nk...bel+cnc&_rdc=1 (mine is identical to those ones, just mine is called a panther vs a sable) ...I'd stay clear of the controller & spindle (bought my frame on its own)

it only uses 1.5mm pitch threaded rod, but I'm getting very good accuracy with it.

I agree by & large with your sentiment re the CNC machine market...componded by the fact that I prefer a moving table to a moving gantry design, but there's very little moving table designs out there that are up to it IMHO.

[saxonhawthorn]

What spindle do you use Hank?

[HankMcSpank]

What spindle do you use Hank?

The same one you ordered .... A Proxxon BFW 40/E Mill/Drill Motor and Controller ...which is riducously out of proportion for that machine, but it's quite low noise (neighbours!) & has low runout.....the RPM is a bit low (at something link700rpm maxed out), but nevertheless I get good results with it.