Hallo Leute.
Da ich jetzt in den nächsten Tagen eine gebrauchte MPCNC bekomme frag ich mich welche Spindel ich dafür nehmen soll.
Ich tendiere zur 1,5kw Spindel mit FU.
Da die 0,8kw und die 1,5kw fast gleich schwer sind, ist es eigentlich logisch, dass ich die zweitere nehmen werde.
So kann ich diese auch für später bei einer anderen Fräse verwenden.
Few MPCNC machines use spindles. Almost everyone uses a router with the Makita 700 series or clone being the domanate choice these days. The Makita router has similar power to a 1KW spindle. There are machines posted to this forum that use a 1.5kw spindle, so it certainly will work. Steve’s build has a 1.5kw spindle, so you could reach out to him for any suggestions. In the US, there is a substantial cost increase between a 0.8kw and a 1.5kw spindle.
The link Robert posted above is a good reference; Steve achieved good results with that build. I studied it in detail before finalizing specs for a spindle upgrades on my Primo. I ended up getting the same spindle, with a 2.2kW VFD because it wasn’t much cost than 1.5kW which was out of stock at the time, and they are the same physical size. Here are current links to purchase the Huanyang brand pair I use:
65mm is good for v1’s machines. Besides being larger for future use, 1.5kW spindles can also sustain cutting torque at much lower RPM’s than 800W. This is very helpful for milling aluminum and harder materials.
Safety note: Most of these cheap spindles are manufactured with the earth pin not connected internally. Plan accordingly.
Danke für den Hinweis. Ich weiß das schon.
Ich werde schauen, ob die geerdet ist.
Since the mains voltage does not flow through these 3-phase spindles powered by a VFD, it would not make sense for a mains ground (earth) to be connected (I think) to the spindle. I do ground the spindle body to the grbl MCU’s ground so that I can use a Z-probe plate without having to remember to ground the spindle each time. This depends on having metal ball bearings. Some high-end spindles have ceramic ones and the rotor may not be electrically connected to the stator and spindle body. So check yours if you use this idea.
I have worked with some industrial machinery in a production environment, and I don’t recall ever seeing a spindle that was not bonded (OSHA inspected jobs etc). I’ve also been told by a few EE’s that bonding the spindle is best practice. I’m not an EE so I have to take their word and what I’ve seen in practice.
I think the idea behind grounding the spindle is for safety in case one of the 3 phases comes in contact with the casing. If it’s not grounded and this happens, I guess there may be an appreciable difference in potential between earth and the spindle at that point. If that happened, it’s anyones guess how long before the VFD smokes… but there may be a shock hazard if it doesn’t instantly cutoff.
I do the same thing cheating with the z-probe on this spindle. It has worked reliably for about 100 or so probe operations thus far. I still check it right before running a probe cycle, just to make sure the controller LED lights up. I worry that one time the bearings may decide to land on an oxidized spot or something, and I’ll loose a $30 bit while probing.