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Got the new spindle come today at last , but as you can see from the photos the old spindle has 4 wires connecting it to the plug but the new one has only 3 so is the 4th wire and earth and it just a case of soldering No 1 wire to pole marked 1 and so on , am not sure on this bit , any ideas please.
And the new spindle is a 1.5 kw as the other was a 800w one so could i encounter any problems using the more powerful 1.5 kw spindle
Okay, those two images are the old and the new spindle?... okay, can see the 800W and the new 1.5kW - makes sense.
The bit that's confused me is that these are 400Hz motors, and the image from the VFD that you provided on the first page of this thread shows that the VFD is rated from 0~300Hz. And the best I can tell from a close-match on the part-number to the NowForever A100 manual (pdf randomly found online) - that's likely rated at around 750W.
So... I have to ask... who's provided the replacement spindle - was this the original machine vendor?, your last post or so was talking about going back to supplier for a replacement machine?, spindle? If so, did they just supply the 1.5kW spindle?
Hi Doddy
Yes i asked the supplier of the cnc to replace the spindle and he told me to go ahead and order one and he will pay for it so that is what i did , i sourced a spindle and sent him the specs on it and he said thats ok go ahead and buy it and i will refund you the cost of the spindle and this he has done
I cannot recommend using that new spindle with the VFD that you have. The limited frequency range I can handle (it just means a lower maximum RPM - 18k RPM), but the lower power drive means that you carry significant risk of damaging the VFD.
There are settable parameters on the VFD that allow you to set motor current - but my feeling is that these are used to trigger the over-current protection, not to limit the motor current.
The problem now is that you've sourced the spindle - the supplier may be reluctant to support any subsequent change.
...unless anyone else knows more about the VFD motor-current settings?
Understood Doddy
What surprises me as you have so rightly pointed out the capacity of this VFD is rated at 300Hz yet the spindle that came with the machine is rated at 400Hz.
Why would the company send a boxed machine ( brand new ) with a vfd that is not even rated to handle the spindle they put in the box .
So i must ask what sort of price is a VFD box that would handle this 1.5 spindal
Understood Doddy
What surprises me as you have so rightly pointed out the capacity of this VFD is rated at 300Hz yet the spindle that came with the machine is rated at 400Hz.
Why would the company send a boxed machine ( brand new ) with a vfd that is not even rated to handle the spindle they put in the box .
So i must ask what sort of price is a VFD box that would handle this 1.5 spindal
Would the 100Hz short fall in the vfd make much of a difference to the spindle.
So am now thinking shouuld i go and buy another vfd box to run this new spindle
The frequency is not much of an issue - the spindle is typically a 2-pole motor, which basically means each complete 3-phase cycle1 = 1 revolution. So at 300Hz (300 cycles/sec) = 300 revs/sec. 60 secs in a minute = 18000 revs/min. If you drive at 400Hz, 24000 revs/min. Yes, you can drive the motor at 18000 rpm or 300Hz - that works.
With the original spindle - the VFD is rated correctly for the 800W spindle (or thereabouts).
The problem is the new spindle is 1500W, which is likely to damage the VFD. That you can't spin the spindle as quickly as its designed is another issue, but wouldn't damage either spindle or VFD. Why would the supplier provide that VFD?, you'd have to ask them, but usual suspect would be cost.
You ask what sort of price for a suitable VFD - that's very much down to what you want to pay. You can get a quality VFD for - I don't know, several hundred quid. You can get a cheap one for fifty quid, that the advert caveats for low-loads only (which worries me). The usual suspect often used is a HuanYang VFD - not the best, but swamped the market with an affordable solution that many of us bought (the market is currently swamped with cheaper versions). Caution is needed with the HuanYangs as the Chinese are known to knock off their own knock-offs, and the suggestion is there are counterfeits out there. For that reason I'm not going to link any because I don't want the responsibility of pointing you at something that could be wrong.
But, to try to be helpful, the basic spec you're looking for is:-
220VAC single phase input, 50Hz
220VAC three phase output, 0-400Hz
1.5kW (higher is okay, lower is not)
Can i ask you Doddy
Am i just as well buying a new 1.5 vfd box and running the spindle from that , separate from mach3 as i need to move on and start machining the urethane bushes and sort out the cost with the supplier later , i see you can get the 1.5kw vfd box for 50 quid or so
Sorry only just seen this post
Thank you DoddyQuote:
Originally Posted by Doddy
That is plane and simple to me and understand your concern about the cheap vfd .
now to start thinking about this