My neverending shopping list continues. Things which seemed minor turn out to be a real headache.. Antistatic vaccuum hose? Costs more that the spindle. Now im stuck on the vfd cable. I want something decent, but first, as far as i can see 18awg should be fine for a 1. 5 kw spindle, im unlikely to run it hard anyway. and its the fattest which will fit in the provided plug. Possibly heavier gauge might be better, seems easier to find, but then ill need a new plug. Also, having opened the spindle to add an earth connection the wires inside it are way thinner than 18awg.. Yay for Chineseium. Appreciate needs good shielding, and needs to be designed to flex regularly. Hows about towline cable? Something like this looks good to my eye..? 1meter 17/15/20/18/22AWG 2-8 core Towline shielded cable PVC flexible wire | eBay Not too expensive and seems to tick most boxes... What do the experts think?
Re the anti-static vacuum hose - run a length of bare copper wire along the inside and connect to mains earth at the vacuum end. Alex.
I don't know where you live.. but if you are in the US.. Home Depot, Lowes, or most home improvement stores (I prefer local, but not all carry a large assortment of wires (Grainger does, but may not always be cheap). Alarm wire, I am using 18/4 shielded I got from Home Depot, was around $0.60 a foot, and no waiting on shipping. (Don't forget to ground the shielding, a lot of people seem to forget that step)
Yes this has been suggested to me before, but i have also read in many places that it doesnt work half as well as a proper antistatic tube.. I am very surprised at the price though.. Its just a bit of carbon mixed with the plastic after all.
We have a few big box hardware stores here (italy) but they generally dont have a vast selection, and i was concerned about the resistance to flexing of a "standard" cable.. Have very little experience but trying to do everything "right first time" isnt easy.. Bit of a learning curve for every component choice!
Igus ChainFlex is what I'm [will be, when I get that part hooked up] using as VFD cable. Industrial automation is what it's designed for, so both the shielding and the jacket are up to spec.
I grounded (earthed) my cable on the source side only and not on the spindle, that way there is no conflict with the probe, which uses the system ground.
A very useful name drop.. A company that sells, in small quantities, in Europe! Ive emailed them for suggestions as they have tons of similar looking cables at vastly different prices.
Sure, tell them you'll post about them and their good service to let others know On a serious note, working the support, we see so many cases with EMI, and I honestly have yet to see the bare copper earth wire down the hose fail. It works, every time we have a customer with EMI issues and a dust extraction system of some sorts.
Ok well that is a solid reccomendation., if im buying a standard hose, i can always replace it with a more spendy one later if i really need to. Thanks, all, very much for the advice
Bare copper is the way to go. If I were planning to do a dust hose (I haven't figured out my dust/chip extraction yet), I'd use flat braided copper cable tied on every 4-6" with stainless steel zip ties.
Do you mean on the outside of the tube? As well as the wire inside? Might be a bit tricky to cable tie it every 6 inches inside the tube
Either way- the point is just to ground the plastic throughout its length, which is what gains the static charge via friction with the moving particles. Same with hard line PVC vac systems. I don't think there's a significant potential differential between inside and outside at any given point, and it's easier to work on the outside. And braided copper/stainless rings looks way better aesthetically. If I were going inside, I'd do bare round copper grounding wire off the reel, and wind it into a coil wide enough to apply pressure inside the diameter of the tubing, might help hold it in place a little bit. Pull it through with a fish tape or something.
As for spindle/VFD cabling, I'm using braided 4 core cables I got from makerstore.com.au: https://www.makerstore.com.au/product/elec-cable-spin-lapp/ This does the well and so far I haven't noticed any interference even though it's running alongside the other cabled (stepper cabling and limit switches). In this image you can see the silver braided cable coming out of the right hand side of the drag chain underneath the orange coolant tubing. The only downside of the braided cable is that it takes up so much space in the drag chain! This is why the coolant tubing isn't inside the Y drag chain (not enough room!).
just wanted to follow up to say the people at IGUS are extremely helpful, and despite knowing im basically a hobbyist who only needs small amounts of cable, are giving tons of advice. not quite settled on the right cable for my application but we are close! their cables are not these super fancy VFD specific Belden cables with symmetric grounds and super duper double shielding, but they look very solid, and only cost 2-4 euros a metre. it will be interesting to see how they perform.
one idea i had, which is probably a dreadful idea, was to route the vfd cable through one of those spiral metal shower hoses? they are very cheap, certainly flexible and would make a hell of an extra shield.. i expect however that after a few weeks in a drag chain they would start disintegrating and sprinkling metal shavings everywhere. is it an idea anyone has ever tested?
I use 16/4 double shielded on my 2.2kW. It's not cheap, but does give a piece of mind. I used different sizes of this stuff for everything on my mill. eDealers Direct | eBay Stores
