Thank you Jonathan, Deanos & Jazz,

I agree totally, however I cannot use "best practice" for this machine, every upgraded component drives the cost up and makes this machine more and more unlikely to happen!

Sorry for yet another long (and in the end somewhat contradictory) post!

I had hoped that between my introduction and the "Information Overload" post I had made my situation clear, I think I have missed something, I'll have another go.

I'll relate my CNC desires to cars and motorcycles to give you an idea of my needs...

Scale Cars Motorcycles CNC
Dream Lotus Elise Full hand built custom Servo Motors, Water-cooling
No compromise frame 8x4 cutting area
Best I've ever managed Second hand Alfa Romeo 1600 Twin Spark Moto Guzzi 1100i Jackal This construction of machine with Water-cooling and ballscrews.
Reality Now! Skoda Fun Pickup
"Jack of all Trades"		 Had to sell it, but last bike XJ650 Yamaha - "Jack of all Trades" This build
"Jack of all Trades"
Unacceptable Beat up Opel Corsa Beat up old CB500 Honda twin "All tread", gas pipe, skate bearing
lash-up

This table shows a "Law of Diminishing returns"

At the bottom, things are cheap but barely functional and you'd soon be cursing them.

At the top, and certainly on paper they are better than everything else, but their price and true performance envelopes are beyond me and most likely always will be!

My aspirations are for the 2nd level, a bit better than I really need, but with a bit of a spare capacity for pushing MY limits, but not so much they are too scary for mundane tasks.

Where I am, the top of the performance envelope is still really enough for my needs, but I appreciate the margin for error is much reduced. However I accept this, as in everyday use, the "Jack of all Trades" does most of what I ever really need.

The aim is for the machine to be more capable than the entry level machines (such as say the Heiz S400) and around £500* less in total build cost. As I tried to say in the "Information Overload" post:

I need to know that this design will not self destruct and I have found the best value for money for a given component. Or for a given budget (assume I am really maxXxed out with the prices I will give) is there something better?

*I have a final figure if £1500 in mind, this is already 50% more than I can really justify at the moment, I have seen the "think of a figure and double it" in many more places than this. However, I have priced everything I have added to the drawing and virtually all the control components and still have a bit of space to breathe in this figure.

I have £410 to spend at the moment, my goal is to come out of this discussion with a set of plans for a scaleable machine that will most importantly, work and that I could sell to help fund the rest of the build. That will be hard I know, but it is not impossible. There have been plenty of "crowd funded" CNC machines in the USA, so why not one in the UK? I also plan to offer upgrade drawings using the machine to make its own upgraded components - see later posts!

Most of the plans I have found are for MDF and other wooden structures. I have found only one set of plans for an extrusion based machine, so I hope there will be space for me to sell some of mine, I can't be the only one thinking MDF is not really the material for a such a machine!

I am taking responsibilty for the path I am taking, I know you want to help me by suggesting that I spend just a bit more money you won't regret it, I can see that totally and it is excellent advice, but I am spending 50% more than I can really justify and planning on spending over 200% more than I actually have already!!!

So at the risk of upsetting you all, please just help me by answering the direct questions I ask and keep the "If onlys" for another day, when I am more able to keep up with them and do something about them.

OK one last Kress vs Watercooled, the following is based on my findings for the WC spindle, I'll be asking questions at the end, so please pay attention as many a teacher has said!

Kress Watercooled & VFD
Min Speed rpm 5000 8000
£ Just under £170 Best I found £250
Additional cost excluding cutters and collets £0 Pump, tubes and a bucket! Say £20

Ok so £100 isn't a lot, but it is 4 stepper motors! Which may be enough to save this project.

Mmm why does the brain work and find solutions from advice while writing posts? Not going to re-write so please prepare to laugh while I shoot my self in the foot!

OK, my strategy is going to be as follows:

1) Original aim was to use Kress, many people including me are happy with these, so I will keep that possibility in the plans. A wider router clamp for the WS Spindle still allows for this so Win/Win!

2) Get drawings for WC Spindle as at 80mm I will need to draw a new Z axis to make space anyway. Downside is a few more millimeters will have to be pinched from an already less than ideal final travel on X&Y (Although I can scale each axis up, I have space constraints to work in).

3) See if I can find my old hand-held router and measure it up, from memory it may be bigger than the WC spindle, so to use it I will need the redraw anyway!
4) Whatever happens, use said router in the CNC machine to start making stuff, £170 less to find to get going and aim for WC Spindle, if it breaks before I'll try and have to find the rest!

Questions needing answers:

1) Does anyone know of a better price for the Kress than I posted earlier?
2) For the price of the Kress, can anything beat it?
3) Bearing in mind and forgive me if I am wrong, a reason given against the Kress and in favour of the Spindle was on the grounds of speed (See table above as to why I am asking this question) How do you bring the WS Spindle speed below 8000rpm?
4) What equipment is involved in the solution to 3?
5) Where is the best place to buy solution 4) and the WC Spindle?
6) Does anyone have the Drawings for the WC Spindle in 5)?
7) Can you advise how best to mount the Spindle in 6)?

I think that is all I need to ask for the router....

& finally 8) I'd love to see more extrusion based plans, in order to evaluate them for later what have you guys found?

Cheers
Geoff.