Saved in watch list for future reference!
4) More money = better, that figures
6) LOL! Would you be so kind as to post them for me or PM them to me?
right i've just remembered a thread on another forum i was pointed to.. this guy started off how you plan with just a plain simple router.... i'll not spoil the outcome for you, but have a skim through this
Modding Project: DIY CNC - V3 Reinforced Z Axis - Page 3 - bit-tech.net Forums
it gets interesting around page 8
if however someone turns round and says if you dont have a 2.2kw W/c spindle you wont be able to cut this that and the other then i would have to take some consideration in to the chances of me wanting to cut them things.
The absolute maximum price you can go to is already less than the cost of the 1.5kW ER11 spindle, hence you're going to have to wait to get a spindle anyway so all it would gain is getting the better spindle slightly sooner then some time in the future regretting not being able to use any cutters above 7mm. Consider also the cost of the cutters as that could make up the differenc. 1/2" router cutters have a large market, hence they are cheap. In addition the power from the spindle (roughly) decreases linearly from maximum power at around half rated speed to zero at zero rpm. You'll probably never use 1.5kW, let alone 2.2kW, but because of this relationship it's important to have the higher rated power to maintain enough power at low speeds.
Hence you will find it harder to use the 1.5kW spindle at low speeds - i.e. harder to cut steel or drill aluminium.
3) The VFD will let you set whatever speed you want - it's the control algorithm and ratings of the spindle that dictate how fast the spindle will run. The 8000rpm minimum you read might have been referring to the air cooled spindles which cannot be operated at low speeds since the fan would not provide sufficient airflow to cool them.
I foreone are just trying to help save you money by not wasting money on inferior or below par components. ?
Regards Kress VS WC: You say the £100 difference buys 4 steppers.? . . . I say what's the point if the spindle's dead within a few weeks or months and the machine can't cut.!!. . . . Now those steppers are very expensive paper weights.!!
Don't look at the NOW think of the future.!!
I quite liked that first router in Wilfy's link. It shows what is possible with wood, however I suspect the guy always planned on redoing it, and alot of the components were picked for ease of building rather than cost, as it wasn't really a cheap build component wise.
If you want to cut costs, and you've got the time/motivation to redo things, use wood for large flat sections, but design it so you can then replace with aluminium as time/money allows. And spend the money saved on making sure the other parts are good quality and upto the job. From what you've said, you're not aiming for high accuracy, and you are realistic about what you aim to achieve, so go for it.