Starting to design out my build, looking for critique

[AndyUK]

1. I have seen that people usually use transformers for their steppers, and I understand that that is because regulated PSUs may have problems with the current spikes (at least according to the app notes). I could not find a proper post on how to do it on here though, so If anyone has a good source on that, that would be perfect.

My build thread, post number 30 has an outline of the process I followed, but I emplore you to find multiple independent sources of information and fully understand and verify before playing with a mains level PSU - this is the scary bit of the project to me, because one slip can potentially kill. Always ensure the caps discharge and never work near the PSU whilst alone in the room. I've have given the wife very clear instructions on how to isolate the supplies if it goes wrong. ALWAYS have a bleed resistor - it's not something I mentioned in my thread, but it's a must.

Scary bit over, it's not that hard or expensive. You just need to stay safe.

As for information, I didn't find a definite thread here, probably for good reasons. You're going to have to go research the theory of unregulated PSUs. Joe's videos are also quite good at explaining, and so are ThisOldTony's CNC build videos.



Sent from my SM-G950F using Tapatalk

[Kitwn]

There's a nice guide to designing linear power suplies here http://www.skillbank.co.uk/psu/

Whilst it's true a linear supply of a given rating can deliver significantly higher current peaks than a switch-mode supply of the same rating, you should look at the relative cost of a linear design and a suitably rated switching supply or possibly two separate supplies, one for, say, two motors on X and one for the single motors on each of Y and Z.

I can't see the point of spending a lot of time and money on building an unregulated power supply which can, even briefly, deliver far more current than is required to saturate the motors. The available current in case of a fault would also be much higher.

Kit

[Clive S]

Have you seen Joe Harris build log here is a link to his youtube channel on power supplies https://www.youtube.com/watch?v=4OoQ...Y&index=2&t=0s

[Chrono]

Hey guys! Sorry for the radio silence, I had hoped to be able to post a finished schematic, but mine and the person helping me with that part's schedules just did not meet up yet, so that has not come to fruition yet.

So first up, thanks to all the tips for the PSUs. I think I have a firm grasp on the matter now.

Instead of a schematic, I worked on finalizing the budget and getting everything priced out, and so far, the only thing missing from the budget are timing belts and the control box parts (like contactors, etc.), but so far, everything is savely in my 3.5k€ budget, even with a couple hundred of wiggle room. So, since I have not posted this before, I "present" the semi-finalized list of electronics to be used:

• A smoothstepper ESS. From all the controllers I have looked at, this one seems to have the highest price/performance ratio. Compared to the UC400eth, for example, I get one more port for a similar price point. And the CSlabs are just too expensive for me, in comparison.
• A 3kW watercooled chinese Spindle with ER20 collets, able to reach up to 24 000 RPM with a packaged submersible pump
• A YL-620 VFD for that spindle
• AM882 Stepper drivers for all three steppers, supplied with around 60V
• X-Axis Stepper: 86 HS155-5508-01
• Y-Axis Stepper: ACT 34HS1456
• Z-Axis Stepper: 60BY G401-03
• 6x Inductive Proximity switches to be used as Limit/Homing switches

Other than that, not much has changed on the mechanical front: I have had a two parts re-drawn in a different CAD program by someone well-versed in designing sheet metal parts, but other than that nothing has been altered. I hope to be able to get the schematic done in the short term rather than the long term, so I can finally move this to the build log section ;) Anyways, until I have more news!