I am getting ready to purchase a 5 Pro 4x2. I am completely new to the world of CNC routers. I have read about the benefits of a VFD and am curious what folks here would recommend for a newbie. Is the VFD cost worth the investment when I have no practical experience yet or does it make sense to go the route of the trim router and look at the VFD as an upgrade later?
Thanks in advance for your throughs.
I think it’s fine to start with a trim router and then move up if/when you feel the need.
Another consideration is that you may want to consider an 80mm spindle as an option — we have one in development, but no idea on when it will be released, so waiting until you know if that’s something you’d want or no might warrant consideration.
Spindle advantages:
Trim router:
Note though that if you don’t get a BitRunner (which would eat into the cost advantage) you’ll have to turn the trim router on/off manually.
See:
The VFD is more expensive than a trim router. However the purpose of buying an SO5 is you get the robust nature of the machine. So it would be like buying a 30 ton trailer and then buying a Volkswagen bug and weld on a trailer hitch. It might make a trip or two but they are not matched. So if you are going to buy the SO5 for what it can do then get the VFD to go with it to more closely match the capabilities of the big machine. If you want a trim router than just buy an SO4. The router more closely matches the capabilities of SO4. Both are good machines but the SO5 is at another level above the SO4.
I am definately targeting te SO5 Pro as a machine to grow with. I made what I think was a mistake in hindsight with my first 3D printer purchase of buying more budget friendly and I think there are costs associated with under buying the base machine. I feel if I do go with the trim router to start and upgrade to the VDF spindle afterwards I can always use the trim router as a standalone tool. I do expect to graduate to that spindle just trying to justify the initial investment.
definitely get the vfd save $150 worth every penny!!!
The down-side of going with the VFD to start is that it is one more thing to deal with when starting with a new machine. The router is a tool that is designed to be plugged in and just work. Nothing to think about. The added complexities that I know of from going directly to the spindle are:
The pros of the VFD are definitely there though. In addition to the obvious (better power and better rigidity), the runout tends to be much lower. The runout is my router is pretty bad and the spindle was really low. I forget exactly what the numbers were when I measured the runout at 1" but it was on the order of 100x difference. Surprisingly, what I love most about my spindle is the ER11 end mills changes. It is much faster and easier to change between different diameter end mills.
My personal advice would be to weigh the loss of money (although I’m actually not sad to have my router as an emergency backup if my spindle/vfd has issues) vs. adding more complexity as you’re getting started.
So I have seen people talk about VFDs are not meant to be plugged into a GFCI outlet. That makes sense to me. You mention a dedicate circuit, does that mean that I should not plug in thte VFD and controller into the same standard outlet? Does the VFD need to be on a separate circuit altogether? That might be the deciding factor for my current garage wiring setup. I know I have plenty of non-GFCI outlets, but if I need a dedicated circuit for the VFD then waiting and getting that later will be necessary as I plan out some electrical changes in my garage.
VFD spindles generate voltage from the 120 to drive the spindle. GCFI circuits are always checking for voltage differences between the hot, neutral and ground. So the varying voltage generated by a VFD can cause the GCFI to see spikes in the various lines it is monitoring and tripping the GCFI circuit. This is pretty normal for many devices that are using varying voltage. I have a Jet 1221 Variable Speed Lathe and when changing the speed it will trip a GFCI. So my one outlet in my shop that is not GCFI protected is used on the Jet lathe.
Likely any brand VFD would trip a GCFI due to the nature of the way they work. Sometimes they do not trip the GCFI but often at the most inconvenient time they do.
Any VFD should be checked for its rated amperage. Most US 120vac circuits are rated at 15 Amps for total draw on however many duplex outs are on the circuit. So you have to add up all the vampires on a circuit to get the total draw. The specs on the Carbide VFD is 12 AMPS. The SO5 is rated for 4 AMPS and so 12+4=16 AMPS. That is why they recommend a dedicated circuit for the VFD. For the SO5 at 4 amps you have to add on other things on that circuit like a computer, dust collector and so on. So most any VFD would work better on a dedicated circuit due to its amperage draw. Even the Makita trim router is rated at 6.5 AMPS. So add the SO5 4AMPS plus 6.5 and you get 10.5 AMPS excluding any other accessories or devices you may have on that circuit like lights and dust collection.
In addition to what @gdon_2003 said, my personal feeling was that the fact that the VFD would trip the gfci due to the voltage fluctuations it was leaking back to the circuit, it didn’t make sense to use the same circuit for the control board of the CNC. It seemed like it could only potentially cause problems.
Also, in my potentially damp garage, feeling things without a gfci is better than more things without a gfci.
Thanks for all the input. I think the electical side of this has me deciding to start with a trim router initially. then as I learn and use the machine I will also look to what upgrades/changes I need to make to my electrical circuits in my garage.
I believe people over think the VFD.
I think its simpler for a beginner. The machine just does it. I don’t have to remember to turn it on, nor set the dial.
I run a S4Pro and S5Pro, both with the C3D VFD spindle. Neither is on a dedicated circuit. Both have the machine and spindle on the same power strip. Both are 20 Amp circuits. The one in my shop at home is GFCI. I have had exactly zero issues in a year and a half of operation in that manner. In fact I’ve had less issues with EMI than the router. Routers use brushes that throw out a ton of EMI. I don’t think the VFD is “dirtier” for power all things considered.
My 2 cents:
Milling material removal rate (MRR) is proportional to spindle/router output power (which is the product of speed and torque). So, cutting/machine forces, which are proportional to spindle torque, can be minimized for any MRR by maximizing spindle/router speed. Many router users were/are reluctant to do that because of the increased noise and motor brush wear. Spindles can run at higher speeds with less noise and don’t have brushes to wear out. Also, their maximum output torques can be limited to much safer levels than those of routers.
The 65mm “1200 Watt” 110V Carbide 3D spindle should have a dedicated 15 Amp circuit since it could draw up to 7A * sqrt (3) * 110V / 0.9 / 115V = 12.9 Amps from a 115V circuit at full load (1 horsepower?) if the VFD is 90% efficient.
The 80mm “1500 Watt” 110V Carbide 3D HDM spindle should have a dedicated 20 Amp circuit since it could draw up to 12A * sqrt (3) * 110V / 0.9 / 115V = 22 Amps from a 115V circuit at full load (2 horsepower?) if the VFD is 90% efficient and the spindle is properly rated.
The 80mm “2200 Watt” 220V Carbide 3D HDM spindle should have a (preferably dedicated) 20 Amp circuit since it could draw up to 9A * sqrt (3) * 220V / 0.9 / 230V = 16.6 Amps from a 230V circuit at full load (3 horsepower?) if the VFD is 90% efficient and the spindle is properly rated.
The power available from these (constant current/torque) VFD spindles (maximum 1, 2, or 3 horsepower) is proportional to operating speeds (maximum 24,000).
So the electrical side seems like it’s been overly explained. Not a bad thing, just makes it’s fairly confusing or intimidating for someone just starting out.
I spent the extra money for the VFD/spindle, it’s awesome! Much quieter, the loudest part is the dust collection.
And all you need is a standard plug, if you don’t have one for some reason you can hire an electrician to wire one up for you. It’s fairly straightforward and simple unless you are putting your machine somewhere awkward.
Right now I am not 100% sure I’ve solved the electrical noise issues I’ve been having with my vfd but I hope it’s good.
On an old circuit in my garage, I could run the vfd on a GFCI. On a newer circuit, it couldn’t even fully spin up before triggering the GFCI.
I had usb corruption issues that currently have a noise filter on the usb line, a power conditioning power supply and finally the addition of a powered hub. Each of those has reduced the rate of failures and so far it hasn’t failed since adding the USB hub.
I don’t know if there is some variability in the VFDs or if it some difference in wiring, but our experiences are very different.
I started with a trim router (still have them in operation) but on my primary machine I went with a water cooled spindle. Haven’t regretted it yet. Faster, bigger bits, can run it for hours on end (16 hrs longest so far). When I can afford too, I’ll switch the trim router CNCs over to spindles
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