Help with Problem X axis Stepper Please

[howser37]

Hi Graeme i have attached it now, i believe they are grease filled scotchlock terminals, maybe they are good they just seem a bit awkward and open to failure to me and difficult to get apart without potentialy damaging the connections.

[GND]

They look like some kind of one-time crimped connections, which are highly protected against shorts and therefore also restricting access to the signals for testing. Probably a good choice for the job, but definitely not very serviceable! I'm sure someone else on the forum will have a proper name for them....

I use good old fashioned chocolate blocks for my connections. They have their flaws, but they are cheap and easy to use - and probe-able for testing! You could always start with them and see how t goes, at least to get back up and running?

Cheers
Graeme

[howser37]

Hi Graeme, i have some chock block connections here so i will give them a try for now and see how i get on. I can see how the current connections are highly protected against a short but im wondering about a break as i highly suspect that brown motor wire was not connected well, and i know that these drivers cannot be hot unplugged without blowing the drivers as there is no protection, and ive heard many stories of people unplugging the cables whils energised and blowing the drivers, i wonder if a poor or nearly broken connection here could intermittently simulate a similar event.

[GND]

Well, it's certainly one possibility! Crimped connections are great when they work, but can fail without it being obvious to look at. If that brown wire came out without much effort, then it suggests it wasn't right.

Looks to me like you have those motors wires in parallel, as there are four connections with two motor wires to each. Disconnecting one winding would have reduced the current on that phase, but would also imbalance the load on the chip. Quite what effect that would have is beyond my experience, but who knows. Certainly something to fix though!

[howser37]

Thanks Graeme, well i am back up and running again. I removed the x axis stepper cable completely and it tested fine, i then rewired it using different connectors and fired it up, all seems to be running fine at the moment, but it was running fine last time i replaced the chip for a good few hours too, so we will see what happens. I have switched the over the x axis stepper cables so that if it is a problem from the motor/ cable it should blow a different driver next time and atleast i will have narrowed it down a bit more, if the same driver blows i can probably assume its more something inside the control box.

Thanks for all the help so far, fingers crossed :-o

[GND]

Sounds good! Let us know how it goes.....!

[Neale]

I've used choc block in exactly this situation and it seems to work OK but I have wondered about these instead. Spring-loaded so more vibration-proof and even include access for a test probe. They come in 2, 3, and 5-way versions which could be useful in some of the junction boxes on my machine where, say, multiple limit switches with common ground connections all meet. I find it fiddly trying to use choc block for multiple connections as you end up with two wires in the same hole, which never seems satisfactory.

[GND]

They look really quite smart, and certainly seem to get the thumbs up from the electricians, judging by the reviews on there. They don't look like they have a way to fix them down though, in the way you might screw a choc block to a panel. So worth bearing in mind for some applications. Don't some forum members use something similar on DIN rails in their control cabinets? I seem to have seen something along those lines in pics on the build logs.....

[cropwell]

I bought this kit from screwfix http://www.screwfix.com/p/wago-basic...5pcs/48808#_=p I haven't used them on anything CNC yet, but for solid core domestic wiring they are very good and quick. For multi strand wires I crimped an uninsulated ferrule on to get the wire in to the block. That was fiddly, but better than choc blocks.

Rob

[Neale]

I had a couple left behind by an electrician after some work in the house which I have used on my own router and like you, I crimped on ferrules to stranded wires. They seem very effective, slightly larger than the equivalent choc block but easier to wire. I just left mine floating in one of the plastic boxes I use as junction boxes (which I was buying from Maplin but now 3d print).