Mach3 and VFD Wiring

[dcrowder]

Hi All,

Can anyone point me to some clear information (or offer me some) regarding wiring my VFD to the BOB for speed control with Mach3? I've got one of the HuanYang VFD's for a 2.2Kw spindle. The BoB is a DB25-1205.

I've seen relays mentioned but I've not found anything concrete yet.

Dave

[Clive S]

Hi All,

Can anyone point me to some clear information (or offer me some) regarding wiring my VFD to the BOB for speed control with Mach3? I've got one of the HuanYang VFD's for a 2.2Kw spindle. The BoB is a DB25-1205.

I've seen relays mentioned but I've not found anything concrete yet.

Dave
I don't think the BOB has the capability to control the spindle speed or indeed has any relays on it.

[JAZZCNC]

Ok well there are two parts to this. Speed control and ON/OFF operation of the VFD.
On/OFF is easy enough and like you seen it's done using a Relay.

Controlling the speed needs 0-10v signal which is sent to the VFD.

Unfortunatly the DB25-1205 isn't much good for either of these.? It doesn't have 0-10v speed control and it doesn't have built in relay.
So this means you'll need separate Analog or PWM Speed control board which gives you 0-10V signal.

ON/OFF can be done using external Relay using one of the Outputs to control it. However you'll need to make sure the coil of relay used doesn't pull more current than the OUTPUT can provide. The BOB manual should tell you this Info.

Also be aware some external spindle boards will use up one of your Axis.

[dcrowder]

Ok well there are two parts to this. Speed control and ON/OFF operation of the VFD.
On/OFF is easy enough and like you seen it's done using a Relay.

Controlling the speed needs 0-10v signal which is sent to the VFD.

Unfortunatly the DB25-1205 isn't much good for either of these.? It doesn't have 0-10v speed control and it doesn't have built in relay.
So this means you'll need separate Analog or PWM Speed control board which gives you 0-10V signal.

ON/OFF can be done using external Relay using one of the Outputs to control it. However you'll need to make sure the coil of relay used doesn't pull more current than the OUTPUT can provide. The BOB manual should tell you this Info.

Also be aware some external spindle boards will use up one of your Axis.

Did someone say BOB manual there?? :) er this is the DB25-1205 you know... low res connection diagrams showing only pin numbers are the order of the day here... but hey I'm on a budget!

This sounds as if it'd be more cost effective (in the long run) if I just go for a new BOB that'll do what I want. Does the Arduino solution work here? or are there any other budget solutions?

[JAZZCNC]

Does the Arduino solution work here? or are there any other budget solutions?

Can't answer the Arduino question and terms Budget and CNC don't mix well. Experience taught me when mixed they = :hopelessness: :hopelessness: :hopelessness:

[cropwell]

This sounds as if it'd be more cost effective (in the long run) if I just go for a new BOB that'll do what I want. Does the Arduino solution work here? or are there any other budget solutions?
There are plenty of cheap BoBs around with relays and speed control. The Arduino solution (whatever that is !) would probably cost you more than a new BoB.

Please enlighten me about what you mean - Arduino Solution.
Cheers
Rob

[dcrowder]

Can't answer the Arduino question and terms Budget and CNC don't mix well. Experience taught me when mixed they = :hopelessness: :hopelessness: :hopelessness:

Ok most cost effective BOB then ;)

And do I take it that my work flow for today using what I have should be as such?...

Set Feeds in the GCode > Zero Machine then back off > Set spindle speed (lost here now as I was banking on mach3 looking after that) > Run Spindle > Run Gcode > Pray

[dcrowder]

There are plenty of cheap BoBs around with relays and speed control. The Arduino solution (whatever that is !) would probably cost you more than a new BoB.

Please enlighten me about what you mean - Arduino Solution.
Cheers
Rob

maybe I'm just a little confused but I believe there are people using an arduino as a controller but they could easily be using a BoB also.

[cropwell]

I am a little suspicious of that solution. Estlcam has provision for an arduino controller, but I don't know where you would get one, how it is programmed and what functionality it offers. Being Arduino, it ought to be open source.

Having said that I took a look on t'Interweb and found this http://blog.protoneer.co.nz/arduino-cnc-controller/ - interesting !

Cheers,

Rob

[Neale]

maybe I'm just a little confused but I believe there are people using an arduino as a controller but they could easily be using a BoB also.

There is some open-source software called grbl that runs on an Arduino. It takes gcode via a usb connection and will generate step/dir pulses for up to 3 axes. There are a few digital inputs for limits and homes plus run/stop, and outputs for spindle direction and analogue speed plus coolant switching. You can wire the Arduino output pins directly to a stepper driver without a BOB. I was using a cheap TB-something driver but the input side of these things uses pretty much the same opto-isolators as any driver. Unlike Mach3 or LinuxCNC, grbl has no user interface so you have to run something on a PC to send it gcode, accept manual input, etc. If you think of it as an external motion controller, it will give pulse rates up to 25KHz or so on 3 axes and could be used with a low-spec PC with something like Universal Gcode Sender to give a crude user interface, but Mach3/LinuxCNC it ain't. Neither is it a BOB replacement.

[Clive S]

Ok most cost effective BOB then ;)

And do I take it that my work flow for today using what I have should be as such?...

Set Feeds in the GCode > Zero Machine then back off > Set spindle speed (lost here now as I was banking on mach3 looking after that) > Run Spindle > Run Gcode > PrayWhat is it exactly you want to know. If you are just starting out and you have a machine setup with the BOB you have. (and it works ok) You don't need to connect the VFD to the BOB to be able to run gcode.

[dcrowder]

For a bit more money the Mach3 Controllers on eBay look a better option! I also use a 4th axis slaved to my Y so the Arduino sounds like it'll fall short of my needs.

Regardless of having no automatic speed control setting - last night I fired my baby up with it's spindle for the first time and it made it's virgin cut! :toot:

[JAZZCNC]

Ok most cost effective BOB then ;)

The most cost affective way for you at this moment given your limited CNC knowledge is forget Speed control from software. You'll hardly use it anyway and from what I'm reading having to Cam the spindle speed for each tool and material will cause you trouble at first while learning.

So the cheapest solution is buy Potentiometer and fit to VFD for easy manual speed control. Cost about £2 and fitted in minutes. Search the Forum and Clive S has explained how to do it and whats needed.

Then buy one of these and control the VFD ON/OFF using relay using Output from bob. Even the crapest Bob's will control this.

http://www.ebay.co.uk/itm/2-channel-5V-opto-isolated-relay-board-Arduino-Raspberry-Pi-/161914334390?hash=item25b2d8acb6:g:KXEAAOSwAYtWI-co

[JAZZCNC]

For a bit more money the Mach3 Controllers on eBay look a better option!

Ok first let me just clear you up on something.? Mach3 is the controller, or more correctly the Control software. BOB's are just a distribution device and control nothing. There only purpose is to make wire connections easier and in some cases offer protection to the PC.
Higher spec'd Bob's offer extra options like having built in Relays or Speed control but again they Control Nothing. They just only provide the means mach3 does all the controlling.

Also Mach3 while being the Controller doesn't make any decision on what spindle speed or feed rate to use. It just does what you tell it. Either thru G-code or manual commands and buttons or sliders on screen.

So these controllers on Ebay are more likely just BOB with few bells n whistles. Show use.?

[Clive S]

Search the Forum and Clive S has explained how to do it and whats needed here you are post #1

http://www.mycncuk.com/threads/7388-Fitting-a-pot-to-a-Chinese-Spindle-VFD?highlight=fitting

[dcrowder]

here you are post #1

http://www.mycncuk.com/threads/7388-Fitting-a-pot-to-a-Chinese-Spindle-VFD?highlight=fitting

Many thanks for the great advice!

[dcrowder]

75p delivered from RS of all places.. never thought I'd be shouting about a bargain from them!