Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet

[Clive S]

Can I ask what power solution you are using to get 68v?

A toroidal transformer 24-0-24v in series with one rectifier and two caps

[Neale]

A toroidal transformer 24-0-24v in series with one rectifier and two caps

Actually, I'm using a 2x45V toroidal with both windings strapped in parallel to give a single 650W supply. Same thing, really!

My first router used LinuxCNC (cheap - nothing cheaper, in fact) and a parallel port to a cheap breakout board. No spindle (speed or start/stop) control. Old analogue drivers. It worked. Not ideal in many ways, but you don't always need "the best". But you do need something that works for you, and it does need to be reasonably reliable. Best thing, I guess, is to try to understand what compromises you are making by going cheaper and deciding if you can accept that for the time being. The other thing to keep in mind is, "Can I easily upgrade it later?" For example, changing a motion controller or stepper drivers is not too invasive. But changing ballscrews for leadscrews, or supported rails for profile rails, might be more difficult later.

I have probable spent around £2500 on my steel-framed, ballscrewed, profile railed, motion-controlled, 1500x750 router. That's probably typical.

[JOGARA]

Would something like one of this work?
http://www.airlinktransformers.com/c...Filter+Results

They have 70+70V so would mean 2 sets of 70V?
From what I know, you can connect these in parallel though you have to be careful to get the phases the correct way round?

As for the rating, thinking 2000VA?

As for caps, 110v and as big as i'd like?

[Clive S]

Would something like one of this work?
http://www.airlinktransformers.com/c...Filter+Results

They have 70+70V so would mean 2 sets of 70V?
From what I know, you can connect these in parallel though you have to be careful to get the phases the correct way round?

As for the rating, thinking 2000VA?

As for caps, 110v and as big as i'd like?

Ok what DC voltage to you want to end up with. What steppers are you using and how many.

Read #31 again 650VA should be more than enough try and get caps that are 100V

http://www.airlinktransformers.com/c...Filter+Results

[JOGARA]

Ok what DC voltage to you want to end up with. What steppers are you using and how many.

Read #31 again 650VA should be more than enough try and get caps that are 100V

http://www.airlinktransformers.com/c...Filter+Results

Going off what people said, higher voltage the better? So close to the max of the drivers.

As for the drivers, http://www.zappautomation.co.uk/elec...ion/em806.html (buying direct from manufacturer in China)
Steppers, http://www.zappautomation.co.uk/elec...ion/em806.html

[Neale]

Going off what people said, higher voltage the better? So close to the max of the drivers.

...which is what you will get if you use a lower voltage transformer. Yes, I know it doesn't sound right, but in practice a 45V or so transformer will end up giving you around 68V DC across the smoothing capacitor(s). This also gives a bit of allowance for the fact that the mains input voltage will vary, and the transformer will probably give you about 5% over the rated voltage under light load to allow for a drop when on full load.

EM806 are good drivers.

[Clive S]

Going off what people said, higher voltage the better? So close to the max of the drivers.

As for the drivers, http://www.zappautomation.co.uk/elec...ion/em806.html (buying direct from manufacturer in China)
Steppers, http://www.zappautomation.co.uk/elec...ion/em806.html

Those are 80V drives so run them at about 68V to allow for the back emf. 24-24 v in series = 48 = about 68V dc when rectified.

AM882 drives would be less dosh and just as good.

[Clive S]

Snap

[JOGARA]

Those are 80V drives so run them at about 68V to allow for the back emf. 24-24 v in series = 48 = about 68V dc when rectified.

AM882 drives would be less dosh and just as good.

Ohhh
I thought it was 1:1 from transform through rectification.
That makes sense why so many are doing 24-24v.

These are the drivers I am getting https://www.aliexpress.com/store/pro...615.0.0.9rnD8Q

Forgot I changed to them.


Am I right in saying that when the steppers start up or change direction, they require a lot of amps, but when they are going it is pretty low.
Which is why you are able to get away with lower wattage transformers?



Thanks

[Clive S]

Am I right in saying that when the steppers start up or change direction, they require a lot of amps, but when they are going it is pretty low.
Which is why you are able to get away with lower wattage transformers?

A 625 va trans former will be fine good choice on the AM882