Lowcost capable CNC - Make vs Buy?

[Andrewg]

Thanks Doddy, clearly those trying to design a 'kit in a box' have slightly different design and costs pressures to the self builder, so I am interested in the cognescenti here views on the design .

Broadly one off self builds benefit from overspecifying their parts, as the costs are not significantly greater and there is less experience to show where corners can be cut. However kit makers need to reduce parts costs inorder to have a margin. Some of those decisions will be good and worth learning from if properly understood, others potentially to compromise too far.

So for example JazzCNC has recommended strong 4Nm AC closed loop steppers, this kit has entry level closed loop steppers. Clearly both are sold on the advantages of closed loop, which is a good signal as the kit builder would question the extra cost.. That they might (oh, just have��) disagree on spec would not surprise me because the kit builder will have the minimum you can get away with.

[JAZZCNC]

Thanks Doddy, clearly those trying to design a 'kit in a box' have slightly different design and costs pressures to the self builder, so I am interested in the cognescenti here views on the design .

The design is ok and can't fault it really because to be honest Shaun as took most of my design principles and used them, just with different materials and put is own twist on it with twin rails. But essentially he's used my design principles, whether he'd admit that or not I doubt it.!!

Now I see issues with it which I'm not going to enlighten him or you with.!! . . . But what I would ask is why would anyone buy a machine they have to build themselves, which effectively means all they are doing is saving them selfs drilling and tapping holes in aluminum plate.?

Also, why buy a machine who's got an electrical spec which is far less than ideal and run on a Micky mouse control system running on a £9.50 development board fastened to another board that you can only buy from them when it goes Boom.!

Ok it's got closed loop but they are cheap nasty things with unknown integrated drives and running on 36v.! . . . Those that know, know that 36V is pathetic for router and these guys know this.!!. . . So a good question to ask would be why are they using 36V.?

Oh and then for £5.5K you still have a bloody Dremal for a spindle.!!

[Doddy]

Thanks Doddy, clearly those trying to design a 'kit in a box' have slightly different design and costs pressures to the self builder.

Including recover of NRE, operating costs and profit. I'm not bashing them - they are a commercial concern, but I would expect for what I can expect their sales for a machine like this their skim off the top will be in the order of £1000-1500.

As an amateur, or enthusiast, or amateurish enthusiast then I make a decision as to the worth of that, and my tinker time. For me, I'd build from scratch, or bung Jazz 3k. If you want an off-the-shelf kit then it could be a viable approach.