AndyUK's Build - 1.2x1.0m Gantry

[AndyUK]

looks like mine,like it

Thanks! They certainly share a few design ideas don't they? :)

Just a thought with the selection of a transformer - ignoring core flux (not realistic, but bear with me) - you can use the typical twin secondaries not so much in parallel, but as two separate supplies. It costs an additional capacitor (though lower capacitance) and an additional rectifier. It means that your copper losses are reduced on individual supplies and regulation is arguably better. It's an approach that I'm trying with my type of machining (typically machining In X/Y, not 3d profiling) - so I intend to bond Y/Z on one supply and X/A on the second - my thoughts are that only one stepper is likely under load at any point in time on any one supply.

Interesting idea - I don't know much about power supplies and transformers though, so I'll need to do more research! On mine with the two drives on X, I'd be wary of joining the X/A because they'll be drawing significantly more that Y/Z, and they'll be doing so at the same time as each other.

Your preference to rate the caps at 2x VDC - your money. A bit of head-room is a good idea but 2x is a little bit frivolous. Admittedly mine are more so - at 160VDC (50V secondaries) but that's simply because I had them in the shed as part of a bulk-buy.

Good point - but it looks like I'll end up paying about £12-15 for the four capacitors I need, at that price I can afford to over-rate them!