Thread: Aluminium CNC log.
Jonathan. quite often good courier deals on ebay. Not been let down yet.The more I know, I know, I know the less. (John Owen)
So, Even though I have steppers, I'm going to upgrade them to something a bit more powerful. 4.2Amp Steppers
But, How do I power this? I could get a 600watt power supply or I could get a transformer from Farnell and risk blowing myself up.
Just wondering the best way to power it, I'm guessing a few of you guys have them.
so how have you guys done it?
Steppers when decelerating from high speeds can become alternators sending power back into the drives which gets passed back to the supply. Linear regulated type supplys struggle to handle this and can tripout because often they have protection circuits. Where as unregulated supply's just absorb most of it in there filter caps.
Usually works out a bit cheaper as well if you want high volts & amps.
How many volts & Amps are you looking for.?
You could try Philip Lambert over at http://www.metallin.co.uk/shop/ as well he may be able to help..Me
So the steppers run at 50v and 4.2A. so i will need something that can output 50v at 12.6 Amps. Multiply those to together, so I need over 630 watts/VA? A lot of the transformers I've seen run off 230v instead of 240v,
would this be ok?
I know hardly anything about electronics,
or could I use one of these http://www.rapidonline.com/Electrica...-0-50v-88-3844 and run the steppers at 4A. :S
Is there a circuit diagram I can base this PSU on?
88-3838. 32V (or 16+16) would be good too.
Next consideration is the current. For 3 motor a 500VA (or greater) transformer will be fine as it's actually a lot less current than you'd intitially expect. I recently tested with the same motor on 48V and the maximum continuous current (with the motor at full power) was just over 1 amp. You need more than that in reality for the peaks, hence 500VA is fine.
The circuit is widely available. Just the transformer, a bridge rectifier and electrolytic capacitor. For example:
This Is progress so far, sorry I haven't been updating it too much.
Big thanks to John S and I2I for helping me out.
All that is left to do is secure the Y motor, and attach the 20mm plate to the 10mm plate floor bit.
And get loads of screws.
Lots of success on the sites machines at the moment. Well done and looking good. (machine not you):lol:
bruceThe more I know, I know, I know the less. (John Owen)
Bugger,if you see the panel that holds the rails for the Y axis, the motor mount secures onto that on top. but it's a bugger to drill and I just screwed up it!So I'm going to need to get those two panels remade. the motor mount and the panel itself.I've drawn a drawringon the right is how I've done it, this means it's super difficult to drill the hole down properly as I have to do it with a cordless. on the left is how it should have been done and how it is done on my X axis.I will probably post up a RFQ post after this, but this really is a Pain. I was so close to finishing.
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