Another 4" CNC rotary table

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raynerd:
J45son

Others on here will tell you much more valuble info but if it is any help.

I used the 4.2A (?) or whatever it is, smallest Arc Euro stepper. I was a tight fisted sod and purchased a cheap one from ebay china, a cheapish one from Routout CNC and I managed to kill :zap: the ebay one for NO reason at all and I made an error and frazzled the Routout. OK, so the Routout one wasn`t of its own fault but the two Arc Euro ones I have have always been nothing short of perfect.

I think my stepper driver is set short of 2A and has plenty of torque to do some light milling. Infact I milled a nice edge with a ball nose onto the cap end of my 10V cylinder cover a few nights back with no problems - light cuts mind you! I think my motor is a Nema 23 of 190 Ncm.

I run it all using ~18V laptop charger, I think Kwacks controller has a regulator in for the 5v for the chip, so I simply run the 18V to the stepper driver and the controller. The other advantage of the Arc Euro driver is that it has a built in voltage regulator, I`m pretty sure for the other two you have to make your own voltage regulator and supply the driver with 5v and obviously the drivers motor connections with the full.

I`m sure others will chime in with more useful info but that is how mine works and I`ve had no probs for nearly a year now and has always been perfect.

kwackers:

--- Quote from: craynerd on October 15, 2010, 05:41:59 AM ---J45son

and I made an error and frazzled the Routout.
--- End quote ---
Error?
:lol:
I shook half a pound of swarf out of its electronics!

Lesson #1: Box.
Put the electronics somewhere nice, they don't like water and they most definitely don't like swarf! :doh:

raynerd:
sh1t - forgot you looked at it for me :bang: OK, it was swarf ... well who was I to know that little shards of metal would short out connections! :ddb:

kwackers:
@j45on

The stepper you've linked to may well be fine, it's only cheap and the mounting is the same as the larger stepper anyway.

Assuming you want to try and keep the size and weight down then what I'd do is buy a driver capable of driving the bigger motor (2.5A), buy the smaller motor and simply set the driver to 1A to drive it.

If it doesn't work then eBay it and buy the bigger one - it'll be a straight swap, just that it'll stick out more.

Worth bearing in mind the intermittent nature of dividing too, which means you could try being naughty and simply crank up the current on the small motor, it'll shorten it's life but given how little work they actually do as dividers I doubt that will be much of an issue. (You won't get the same torque as the big motor though - even at the same current).
(Should point out I'm only guessing at this entire last paragraph - I've never tried it).

With regards the laptop PSU, I've used several for various projects and never had an issue.
If you do have an issue then the large capacitor will fix it and the problem of the PSU shutting down can be gotten round by a resistor in series with the power to the capacitor - this will limit the current to it. The resistor can then be 'shorted out' once the capacitor has charged either manually with a switch or by a 555 based timer and relay.

(You may even find that simply putting the capacitor in series with a resistor calculated for max PSU current and putting them across the supply might be enough to get round any issues with the PSU. Obviously a bit more 'lossy' than switching out the resistor though.)

j45on:
Some bits turned up today

I'm going to crack on with etching a board tomorow :hammer: and must take lots of pics

Thanks for all the tips and info :thumbup: the big purchases like the stepper and driver will have to wait until I get paid which is luckily when ARC re open after the midlands show

I have a few questions :scratch:
The 8 pin SIL socket for the keyboard ,all the ones I have found look like pin header sockets but the keyboard looks like it has a flat ribbon cable end ?
VR1 the 10k preset I have no idea what I'm looking for there are so many options what do I need to look for ?
EDIT I was looking at these ? http://cgi.ebay.co.uk/5-10k-POTENTIOMETERS-preset-ohms-resistor-variable-/220503329565?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item335705cb1d#ht_1973wt_907

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