Thinking of jumping into CNC milling. How to start ?

[JAZZCNC]

The fixturing shown in the videos Jazz posted will cost 4 figures, however that will cover lots of boxes with minimal changes between box sizes. It can be thought more of as a machine cost, rather than a job cost.

From Datron Yes but here in the real world same could be made for not lot of money. But this may better showtype of fixture I was meaning. Also one to see the difference between Mill and router.!!



Almost slow motion but not quite.!

[SparkyLabs]

I don't particularly need high speed or large batch manufacturing. I'm only wanting to do prototypes and very small quantities. I think too many boxes stacked up could increase the risk of error but even on a mill a few at a time dould be loaded. I have a box face of 90x30mm and a mill with a travel of 100*290mm can do a few.

[SparkyLabs]

ultimately flexibility will serve me more than speed. If I find that I need to do a particular job in large volumes and that a specific machine is best for this then specific machinery may be justified.

[m_c]

Those videos were mainly to show you how things can be done, and to give you ideas on how to mount boxes.
We know you're not likely to ever use such a big/complex setup, however it should give you ideas on how you could mount a single box, while making any fixtures as universal as possible.

If you look at the setup in the first videos, they use an extruded aluminium T-Slot bed to mount pneumatic clamps on. Using a T-Slot bed gives you easy adjustment, and the pneumatic clamps mean you get a wide clamping range so they don't have to be setup exactly. They just have to be setup to give enough clearance to get the boxes in, while making sure they clamp before running out of travel.
The pneumatics has the major advantage that a single valve controls the clamping of all the boxes.

To simplify that, use a T-slot base for the flexibility, and then use a two piece machine vice setup like magicniner has mentioned (first google hit - http://www.bison-bial.co.uk/vises/6522-200 to give you an idea of what we mean). Add in a block to the side of the vice to position the box prior to tightening, and you've got a repeatable setup for if you need to multiple runs.
With that kind of setup, you should be able to cover a very wide range of boxes.

[SparkyLabs]

Any comments on the Wabeco F1200 CNC ? this is like the proxxon controlled with nccad

[magicniner]

"by connecting the WABECO controller to a PC and installing
the nccad turning software the customer turns the conventional
WABECO milling machine into a CNC milling machine"

I hope they do better with mills than with proof reading because you won't get far with a mill if you use turning software! :-(

[SparkyLabs]

Well the specs are slightly better than the proxxon (that also has dubios english and if you read the nccad website you will faind yourself reading worse gibberish, I guess german machinists don't have great english), they are offering an ex demo machine for around the price of the proxxon but it looks like as a machine it is built to a higher standard. One reveiwer on axminster (UK distributor for proxxon) recomended the cc f1200 over the proxxon machine he had bought second hand.

Proxxon offer 0.05mm repeat accuracy,

webaco offer 0.015mm "positioning accuracy"

I'm noty sure what they mean by "truth of rotation of the tool spindle" of 0.01mm

[SparkyLabs]

oh and the webaco has a standard MT2 spindle, not sure what the proxxon ff 500/bl-cnc has.

[SparkyLabs]

The manual has better english: http://www.emcomachinetools.co.uk/im...occf1210hs.pdf

They meant concentricity of the spindle is 0.01mm

[magicniner]

standard MT2 spindle

You can get ER Collet Chucks on straight shanks in smaller sizes and thus have an ER Collet Chuck without a huge increase in tool protrusion from the spindle, it's a shame they didn't go with BT30 though, that would have supported a tool changer if they implemented a decent draw-bar system.