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My thoughts too.Quote:
Originally Posted by Doddy
Look at the inductance level on the steppers. Square root the figure and then multiply by 32.
This will give you your ideal voltage for the steppers to sing.
For example an inductance of 3.5mh= 3.5 Sqrt *32 = 59V!!
Inductance of 2.5mh= 2.5 sqrt*32 = 50V!!
Inductance of 8mh= 8 sqrt*32 = 90.5V!!
See where I'm going with this?
You'll find 36V with nema23 size motors is a bit of a dissapointment. You want at least 48V.
Daz you seem to have missed a few of the posts. The 36V was/is only intended as a test/stop gap measureQuote:
Originally Posted by dazp1976
Ye, I see it as well and now go find me a typical low Nm nema17 or 23 with an inductance of 8Mh.! . . . . Doesn't matter how you want to try to spin it, you can't put 100v on a small stepper and expect it to last long. Put 240V on it and watch what happens to it. (In fact I think I have some small motors kicking around and a mains 240V drive, so when I get back to work I'll show you exactly what happens!)Quote:
Originally Posted by dazp1976
If you don't believe me then go read the rest of the Gecko info where you got those figures from and read what Maris Fremanis the Owner of Gecko as to say about it and the effects of having too high a voltage.!
I know you probably didn't like me pulling you up on what you said, but it was wrong and misleading so it could quite easily end up in someone burning their house down if they listened to your wrong advice. That's why it needed pointing out and why you need to watch what you say unless known to be absolutely correct.
Found what may be a suitable transformer 36+36v and 625va
https://airlinktransformers.com/prod...ange-cm0625236
That is a good company. Before you buy it. state what final output voltage AC or DC you are trying to achieve and with what drives you will be using.Quote:
Originally Posted by ngwagwa
Personally I think 625va is a bit overkill . I use 4 nema 23 3.1Nm on my router with 500Va
This would be better. 625Va is too much and you could run into issues with in-rush trips. 500Va is plenty and like I said you could get away with 300Va but doesn't leave much upgrade room.Quote:
Originally Posted by ngwagwa
However, you must wire in parallel, not series because you'll have 70Vac in series which will give 95Vdc + when rectified to DC and that will produce Magic smoke from those drives.!
If you want to go with series wiring then look for 2 x 20V 500Va. This will give aprox 55Vdc
Choice is yours.!
I noticed earlier you linked to Bridge and Caps. The bridge is correct but the Caps are wrong. 330Uf is far too low
You want to be looking for 3 x 100V 4700Uf. You could use 4 but 3 will work fine.
https://airlinktransformers.com/prod...rmer-cm0500235
3nm with 6.8mh https://www.ebay.co.uk/itm/3pcs-Nema...kAAOSw5CZcig1uQuote:
Originally Posted by JAZZCNC
3nm with 9mh https://www.ebay.co.uk/itm/1pc-Nema-...1338d93d000784
3nm from supposed respected company: 6.8mh in parallel 27.2mh in series!! wth. https://www.automationtechnologiesin...l23h286-20-8b/
0.54nm Nema17 with 4.8mh is shocking enough afaic. https://www.automationtechnologiesin...epper-motor-3/
I guess with 55Vdc I will hve to go with 80V controller then (the next one donw being 50V)?Quote:
Originally Posted by JAZZCNC
https://www.cnc4you.co.uk/Microstepp...tepping-CW8060
See here you go again giving out wrong information and not understanding how steppers work.!!Quote:
Originally Posted by dazp1976
First, it's 27mh in series not parallel and that isn't uncommon when wired in series. For our needs with routers, it's 6Mh which just means it's a shit motor and to give it a wide birth.
It's a known fact that motors wired in series have higher Mh and require higher voltage if you want speed from them, this is why most of those you list have high inductance. If you look all except the third on list only have 4 wires and are probably Series wound motors.? Again anyone who fits these to a router is a moron who didn't do his research.!
However, all of this doesn't change the fact that your advice that "Doesn't matter wether you have Nema 17/ 23/ 34size motors etc, the drivers regulate output voltage to the motors themselves." is seriously wrong and potentially dangerous if took to the extremes ie: 240Vac drives with nema 17 motors.
I'm done with this now.!!
Yes or if you want to use with 50V drives then size transformer accordingly. Just remember you need to leave a 10% safety margin so don't size transformer to give 50V or even 48V.Quote:
Originally Posted by ngwagwa