New Build, Aluminium Frame Router/Mill

[Davek0974]

Thanks Jazz, I have some updates..

This seems to be a PSU issue believe it or not!

The BOB is powered from a little 15v SMPS, the sensors are powered from the BOB which has a DC-DC converter and puts out 12v.

First test was to put a sensor on my variable bench PSU, they worked perfectly! Clean on and off LED - perfect.

So i tried running the sensors direct from the 15v PSU - these are NPN so supply voltage does not affect the output signal and the 0v in/out is common on the BOB - result was that it worked ok UNTIL I took Mach out of reset when the flickering returned - baffled!

Next i tried running the BOB from the bench PSU - perfect result and i could even enable the limits (on one axis anyway) and it all worked as I first expected it should.

So - do we have a duff PSU, are these sensors sensitive to SMPS output?
I am not sure what to try now - baffled.

Maybe add some uF to the output of the supply and maybe some filtering?
I might get the 'scope out and see whats on the supply.

Get a different PSU? (this one came from CNC4YOU as did the BOB)

Here's another oddity - the plasma always wipes out the radio as soon as the drives are enabled, now it seems this build does the same - as soon as the drives kick in, the radio gets washed out.

Both builds use SMPS and all parts came from CNC4YOU. Food for thought.

[JAZZCNC]

Here's another oddity - the plasma always wipes out the radio as soon as the drives are enabled, now it seems this build does the same - as soon as the drives kick in, the radio gets washed out.

Both builds use SMPS and all parts came from CNC4YOU. Food for thought.

Hence why I won't use SMPS(switch mode power supply for those wondering.!) on any drives. The fact you have probelms with one on the BOB doesn't inspire confidense in the BOB for me. It's needs should be simple and only be pulling milli amps so not taxng to any psu.!

[Davek0974]

I need to narrow things down a little - is it the drive PSU upsetting the BOB or is it the BOB PSU ?

The BOB pulls 150mA including the three sensors.

Will be back soon with some results, the BIG worrying me is the radio interference - the plasma is fully grounded etc and works perfectly BUT it pumps out RF like billy!

Maybe I need to ditch the SMPS's and go linear.

Off for some tests.....

[routercnc]

Hi Dave,

Going back to your first motion videos it looks like the X bearings could come off the ends of the rail as there is no hard end stop. Does something on the ballscrew contact first to prevent this?

[Davek0974]

Hi Dave,

Going back to your first motion videos it looks like the X bearings could come off the ends of the rail as there is no hard end stop. Does something on the ballscrew contact first to prevent this?

Hi, yes at present they can easily come off, and have done ;)
No balls were lost though, luckily.

[Davek0974]

Well, I am just about ready to give up for the day! And I hate shutting up shop on a negative position. :(

It works fine if i run off the variable bench PSU but not on the little SMPS, but i don't think it's needed to spend £110 on a PSU just for the BOB!

Here's a video showing the result on the SMPS...
https://youtu.be/m9_6XrzW0Fc

And here's one showing what I expected and indeed what I get on the bench PSU...
https://youtu.be/XcI2J5RcyrE

Now the big question is WHAT DO I DO??

Obviously I will be throwing this at CNC4YOU as it's all their components but they usually blame the setup or the earthing or the wiring blah, blah, blah...

Facts...

The drive PSU & drives wipe out FM radio when engaged.
The BOB PSU does not work with my sensors.
The sensors appear fine when on a different PSU.
I am a bit p1ssed off at present as this little setup should have been easy ;)

Just about ready to pour a big one.

[JAZZCNC]

Well look at it has good result it's just not the one you wanted.!! . . Good because you know the cause and not ending not knowing the reason.

The fact the bob works with bench supply shows it's working so PSU would be my first choice.

The drives affecting radio is a little concerning because shows dirty system (or Crap drives) so i'd be looking at this while i'm at it. Personanly it's no brainer to me I'd dump the SMPS and go with toroidal setup. 15mins work to man of your calibre.!!

[Davek0974]

Thanks Jazz,

Is there a preferred circuit or supplier of parts for a suitable linear supply?
Need 48v at up to 10A.

Keep the BOB on the SMPS?

The radio interference has been nagging me since i got the plasma going - same drives, motors and PSU again, no help at all from CNC4YOU of course.

I always use shielded motor cables, grounded at the drive end, and even used shielded wire for the step/dir signals on the plasma.

No objections to building a psu but cant risk over-volting the drives by building it wrong, they are ok up to 50v

Thanks

[JAZZCNC]

So - do we have a duff PSU, are these sensors sensitive to SMPS output?
I am not sure what to try now - baffled.

To answer this question then NO they usually work fine with SMPS. That's what I use for 24v circuit. Try a different PSU