I really want to upgrade from the journeyman to foreman. It would really help my business. It sucks that I have to sell the machine and rebuy to get it.
I donāt know if either of these will help, but:
- Have you tried an EMI filter on the Line Power input side of the VFD to prevent harmonics from back feeding?
- Can you legally use a GFCI circuit breaker at your distribution box rather than a GFCI outlet? Again, not sure if either of these would help.
+1 Rotary axis support
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Hey David, hey @Doconefall,
to protect a human from the typical residual currents of a VFD (which are in the kHz range), you need special RCBOs. A normal domestic GFCI does not protect you and is of no use with a VFD.
Such a RCBO is very expensive, this one is about ā¬500. I wanted to write an article to explain why you need them and how they work but did not find the time yet. It has to do with the carrier frequencies inside the VFD.
Meanwhile, be sure that you grounded and bonded your machine properly:
The use of a EMI filter matching the VFD is highly recommended. But be aware that to dimensionate an EMI filter, you need to know the input current of your VFD, otherwise the EMI filter can become a danger itself. On my VFD, the max input current is 24 A,
so the EMI filter is rather large.
Here you can see what accessories can help reduce the EMI and other side effects of a VFD:
ā Source: Omron MX2 Userās Manual
Unfortunately, on cheap chinese VFDs, the input current is omitted on the nameplates and the manuals to hide the fact that with a 110 V VFD for single-phase input for a 2.2 kW spindle, you are at more than 50 A and there are no domestic circuits that can deliver that in the USA. So they omit the input current so the US customers nonetheless buy the cheap 2.2 kW spindle/VFD/water pump kits for 110 V.
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From what Iāve read EMI filters donāt help. But that just reading online. Iām very novice when it comes to these things.
āThe issue that leads to VFDs tripping GFCIs is most closely associated with this inverter stage. This is because of the high-frequency harmonics caused by the solid-state switches that can lead to ground currents, also known as ācommon-mode noise.ā
This is the easiest explanation Iāve found. Some people donāt has issues others do. Iām not willing to spend hundreds of dollars on something I canāt guarantee I can use.
I donāt know the answer about a gfci breaker vs outlet. Iām guessing it doesnāt matter if itās at the breaker or the outlet. Iāve asked people who sell vfdās and they couldnāt answer. They basically told me to remove the gfci. Iām not willing to do that. This is a hobby for me. Not worth the risk however remote. Not worth breaking the building codes to me.
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Donāt help for what? Against making the GFCI trip? Yes, thatās not the purpose of a EMI filter. As explained above, the domestic GFCIs do not work with VFDs, you need special RCBOs for them ā so replacing the GFCI outlet by a normal outlet is the only solution if your GFCI trips and you donāt want to afford such a special RCBO.
But EMI filters help against the EMI that a VFD induces into your circuit as well as EMI that may come from the circuit and are the most recommended accessory for a VFD. I bought my EMI filter as a bundle with the VFD here, so I know that my EMI filter is matching.
But you should find out if itās really residual current that makes the GFCI trip and not simply the current the VFD draws. As explained above, the input current is omitted on many cheap VFD nameplates and manuals. On my VFD, as shown above, manual and nameplate say 24 A input current and in the manual, a 30 A MCCB or fuse is recommended. So since it is a 230 V VFD for 2.2 kW, on a 110 V VFD for 2.2 kW you would be at 48 A so you have to be sure that your MCCB copes with the input current of your VFD.
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Yes I was referring the an EMI filter and tripping the gfci specifically.
Hey Bill, hey all,
if one wants 110 V, the AMB/Kress āDIā models are those with the analog control interface for controlling speed via g-code:
This one is at ā¬381.99 list price. The models without control interface are a little cheaper (from ā¬217.77 on). But think of what you get. This is no hand trim router for short, hand-held use, that looses its warranty as soon as you mount it into a CNC machine and is likely to burn your workshop down if you arenāt there, this here is a dedicated CNC milling motor with steel motor flange and industrial bearings for heavy CNC use.
Be careful when selecting a model, the models with true ER16 and ER20 collets are only available in 230 V (available on NEMA 14 outlets in North America)
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The Suhner UAD 25-RF milling motor is available in 110 V too (see in downloadable Suhner catalogue). They start at ā¬339 here.
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On the Mafell milling motors, the āPVā models are those with the analog speed control interface.
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Iām going to agree with Aiphu5u and Mind of McClure and upvote a system to use one of those 43mm euro milling motors. Throw in an appropriate mounting system, a coiled power cable, a separate speed dial that can be mounted on the front of the CNC table, free from vibration and unwanted speed changes ( also allowing you to change the speed as your job proceeds ) and as long as Iām dreaming, throw in an ER-11 collet . My order will be in the moment this is announced.
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Allow runtime feed and speed changes for the Buildbotics Controllers.
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Would love to have the ability to turn off the machine and have it retain zero. Had this with a different brand and it was incredibly useful
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Alex,
Check out this shop on etsy. I ordered the boot for my Makita in the 2.5" size and have been very happy so far. The laser holder works great, and the hose is positioned in a good spot to help with the fumes while using the laser. Overall quality product so far.
Erik
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I have my 1F partially torn apart. Iāve added a stepper with a brake to the Z-20 axis and Iām waiting on 1F to ship my stiffy for the X axis. Iām also coming out of the stone ages and upgrading to drag chains. Once I get everything done Iāll then look for a new dust boot. Iāve even got a working prototype of my stepper current sensing circuit thatāll trip the stepper brake if it detects the stepper current shutting off (bad connector, power interrupt, etc).
I am planning to use my CNC for many years to come. As time passes many users will experience breaking cables.
I think you should prioritize offering shielded cables that are made for constant motion as an add on in the website shop.
I think light users may never encounter a problem, but there will be many (semi) professional users like me that really want good cables. I would buy those immediately. Why wait until something breaks and another piece of my work is ruined.
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Hey Tom,
maybe because you want to offer your machine at a low price to beat the competitors so you save on everything, and when it breaks, then the warranty is already gone? One could get that impression. However the support seems to always have been willing to help.
I plan to document how I make my cables when I will be ready to assemble my machine.
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I have long argued for the euro 43mm collet. So glad to see thereās growing interest in the community
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Number one feature upgrade would be complete rotary support.
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A rotary solution for the non elite machine should include a way to split the 3rd axis to drive both Y steppers so the utilize the 4th axis for the rotary. That way shapes other than round can be made. For example table legs.
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I am hoping for the 43 mm milling motor supported by onefinity
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I just donāt understand why they donāt sell the y axis. I get itās expensive, but why canāt you buy it. Oh well if it is $1500. I donāt want to go through the hassle of selling my machine and buying a new one just to get the length.