Am I heading in the right direction?....

**JAZZCNC** · 05-05-2014

Originally Posted by Lloyd

anyway, I'll take your advice regarding the brackets, positioning, and screws, - but this could change should I decide to invest in more expensive digital drivers?

You don't have to take my advice and by all means go for the larger screws etc but you will regret I guarantee you that.!!

Your doing the classic BIGGER IS BETTER approach and that's a sure fire way to waste money and build an under performing machine. Digital drives won't make any differance if they are sized wrong and mismatched to screws.
Even with the stuff I suggested I recommend you use Digital drives but this as nothing to do with giving more power but more to do with being smoother running and resonance handling capabiltys.

**EddyCurrent** · 06-05-2014

Originally Posted by Lloyd

. . . it would be good to see anyone's idea of what percentage of your budget you' should allocate to which part of the machine... e.g. 15% on base structure, 35% xyz hard wear 50% on power, control, motors etc....

For my machine http://www.mycncuk.com/forums/gantry...eady-eddy.html the breakdown was roughly this;

mechanical £1600
electrical £1500
spindle + vfd £1000

I've listed the spindle/vfd seperate bacause most people here seem to buy the Chinese 2.2kw model but I went for an Elte spindle and ABB vfd.

**Ger21** · 05-05-2014

that said, it would be good to see anyone's idea of what percentage of your budget you' should allocate to which part of the machine... e.g. 15% on base structure, 35% xyz hard wear 50% on power, control, motors etc....

So you get the best out for your buck..

any takers?

I've never seen anyone try to break it down that way. Probably because it doesn't work. You can't really cut corners anywhere without sacrificing the quality of the machine.

Good linear guides are the foundation of a good machine. Cutting corners there directly impacts the quality of the machine.
Good linear guides require a solid, rigid frame. The straightness and rigidity of the linear guides is dependent on the mounting surfaces, so you can't cut corners there.

Good motors and bad motors are all about the same price. There aren't really good and bad motors, but rather correct and incorrect for your application.
You can save a bit of money on drives. However, most people that cut corners on drives tend to upgrade to the better drives to improve performance, and end up spending more than if they had purchased the good drives in the first place.

The cheapest way to get a good machine is to spend more money. Any places you try to save money will usually result in spending more money later to replace the cheap components. Or you live with an inferior machine that still cost 80% of what a good machine would have cost.

**JAZZCNC** · 06-05-2014

Originally Posted by Ger21

The cheapest way to get a good machine is to spend more money. Any places you try to save money will usually result in spending more money later to replace the cheap components. Or you live with an inferior machine that still cost 80% of what a good machine would have cost.

Missed this last night but Excellent reply that Gerry best way I've seen it said yet.!! . .

**Lloyd** · 07-05-2014

with a name like eddy current... no wonder you've listed everything Electro-related :) so far, i can find a Foucault with your list... excuse the worst pun ever!

**Lloyd** · 07-05-2014

Originally Posted by Lloyd

with a name like eddy current... no wonder you've listed everything Electro-related :) so far, i can find a Foucault with your list... excuse the worst pun ever!

i mean cannot**

**Lloyd** · 07-05-2014

Jazz mentioned the nema 23 motors... These CNC kits seem cheap... What's the deal with them? Are they any good?

When it comes to this side of the machine, I have to admit, I'm a bit lost thus far...

eddy current - you mentioned you spent 1500 on electrical... What was your breakdown? Or shopping list?

**Jonathan** · 07-05-2014

Originally Posted by Lloyd

Jazz mentioned the nema 23 motors... These CNC kits seem cheap... What's the deal with them? Are they any good?

Good motors, but the rest of it is sub-optimal. Those motors need about 75V to run well - see here (and here if you want to see investigate the mechanical equations). Read some more of the build logs on this forum as everything mentioned so far in this thread has already been covered.

**EddyCurrent** · 08-05-2014

You don't want regulated power supplies, linear type are best for this application.

Originally Posted by Lloyd

eddy current - you mentioned you spent 1500 on electrical... What was your breakdown? Or shopping list?

See here, http://www.mycncuk.com/forums/gantry...html#post56144

**PAULRO** · 19-06-2014

so I'm thinking I'll need approx 1600/950/550 rails (don't ask where I got those numbers from :) they're a guess loosely based on a rough guess of space between bearings)
Hi Lloyd, i'm about to start a first build similar to yours but i want a cutting footprint of half a standard sheet of wood, (1220 mm x 1200 mm ). i'm trying to minimize the footprint of the m/c and the spare travel of the Y AXIS. have you revised the dims above ? how much spare travel do have on the Y AXIS? I will use 80 x 80 x 5 mm box section for the frame and epoxy for the X AXIS plane. any info to get me up and running with a sketch would be greatly appreciated,
paulro