I've done multiple orders from BST Automation direct through AliExpress.
The few people I have seen online that have had any issue with initial order seem to have had issues sorted fully by BST (Fred)
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I've done multiple orders from BST Automation direct through AliExpress.
The few people I have seen online that have had any issue with initial order seem to have had issues sorted fully by BST (Fred)
Don't forget to mention MYCNCUK when you speak to him, he likes to look after members if he knows you've come from here ;-)
Last time I used Aliexpress they used an intermediate holding area (escrow?) for my payment and it was only released to the seller when I received it. I知 pretty happy with that. Also if it is Fred then no problems.
Is it normal to have to pay import duty to the delivery courier? I致e had 2 packages from China, from 2 different suppliers - one from BST was delivered no problem, the second with my motors the delivery guy said I have to pay import duty. Just wondering whether I got lucky on the first one or I知 being shafted by the second?
Entirely normal, if the cost is over 」135.
Under 」135, the seller should be VAT registered, and collect the VAT on the UKs (and I think it's also came in for the EU) behalf. If you paid through an online marketplace (aka eBay, Aliexpress), then they have to do the VAT collection.
As for the one you didn't have to pay, give it a month. Some couriers deliver, then send you the bill. Others bill you before they'll deliver.
You might have been lucky. I know I've never been billed for some orders in the past, but generally higher value stuff doesn't slip through the HMRC net.
I致e pretty much got all my hardware now(gantry extrusion, bearings, ballscrews, motors & drives etc), all I need is the machined parts to be able to start assembly - just waiting on my induction at the local maker space so I can start work on the missing pieces [emoji41]
https://uploads.tapatalk-cdn.com/202...509a7ce973.jpg
My mind is starting to think about the electronics, this is where my knowledge falls down big time!! I知 not sure where to start really. I think Ethernet is the way to go, I知 thinking UCCNC. I have closed loop stepper motors (not sure did that makes a difference?). Apart from that I知 snookered. Can anyone point me in the right direction please?
[emoji482]
Whilst progress is slow on machining all the parts I need I have put together my attempt at the contrrol circuitry. I have to give a massive shout out to both ROUTERCNC & Joe Harris for their superb videos and documentation covering this side of things - I've watched / read it all several times!!! Using their content, some intense Googling and reading of manuals this is what I've come up with:
Attachment 31390
Attachment 31391
I do have a number of questions, hopefully someone will be able to help:
- Is a mains filter required for the VFD? I notie=ced ROUTERCNC used one but Joe didn't
- I'm assuing I don't need to connect up REV on the VFD as I'll only be running the spindle in one direction?
- I've seen diffferent ways of connecting up the step & direction pins from the motor drivers - either commoning up the +ves or the -ves - what's the difference? Is it to do with picking up the leading or trailing edge of the signal? Which should I use? I'm using closed loop steppers if it makes a difference.
- My motors came with long cables with extensions - are they ok to use? Or should I be making up my own screened cables?
- Do I need to run an earth wire to the gantry & frame?
- Is the rotary interlock switch necessary?
- Do I need to connect the spindle pin 4 to earth? I've read contradictory things about this.
- Do I need to connect the ENA+ & ENA-?
- Do I need to twist the PUL & DIR wires?
- Is it acceptable practice to crimp 2 wires into one ferrule? Or put 2 ferrules into a single terminal?
- Should all the 24V feeds going to the AXBB-E controller be from the switched 24V or permanent supply?
I'm sure there will be many more questions to come. Any feedback would be much appreciated.
Cheers :beer:
1. The filter is more to protect the supply (and other devices) than the VFD.... they're noisy buggers.
2, Correct
3. Closed-loop makes no difference. Whether you're driving high or low is largely irrelevant (the two pins are the anode/cathode of an internal LED used for isolation - so switching either works). What this gives you though is flexibility - for example an open-collector (open drain) drive is designed for low-side switching (i.e. take the + to supply, and switch on the -). The axbb manual describes the non-isolated outputs as being able to push/pull 20mA - so can source (+ve) or sink (-ve) - so can drive either input.
4. Your call. It's better to cut to length but not if you risk damaging anything.
5. Yes. Unequivocally. Do I?, I might.
6. I only glanced at your schematic - it feels a safe design but more than I'd do for a personal machine. I can't knock safe design but I can duck an errant shock 50% of the time.
7. It's a good idea. Otherwise a stray wire in the spindle could short to the enclosure and zap you. Of course your protective earth will then ensure that you brick your VFD before your blow the protective devices.
8. No. Unconnected, the LED opto-isolator remains inert and the drivers enabled.
9. It's a good idea, but realistically will achieve little. You'll be generating pulses at maybe 100kHz at around 5mA, that will generate some EMF but I'd hazard a guess that you're not going to impact much. The driver inputs going through an opto isolator will be pretty tolerant of any induced emf.
10. Yes, in fact I have insulated ferrules that accept two cores (i.e. a wide rectangular receptacle rather than round), Use common sense - if the cores fit comfortably then there's nothing wrong. Test each crimp.
11. I'd go for the permanent supply, otherwise you can end up with pull-lows on outputs when you don't intend this (remember, you still have a 0V supply to the AXBB, it's capable of hard-driving low). But remember I've not really looked at your schematic.