Huanyang Vfd On A Bridgeport Clone

aeroHAWK

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Since I got my Bridgeport BOSS3 CNC retrofitted with MACH3, I use my manual mill very little. I recently noticed the noise and vibration in the vari-speed head (of the manual mill) was getting worse. I suspected that the lack of use had put a "set" in the shape of the belt. But it was now getting so bad it affected the surface finish of the part, and was unusable. Even though I use it less, when I do need it, I NEED IT!

Upon disassembly, I found that the belt was trashed. Yes, it had taken a "set", and this weakened the belt in the curved area and it was now breaking up.

I had been planning on getting rid of the mechanical vari-speed drive and replacing it with an electronic Variable Frequency Drive. So I figured this was a good time. This meant I needed to remove all the monkey motion pulleys and springs and replace that with a micro-v belt and pulleys.

I had some parts from an old job that only needed slight modification for the pulleys. I needed to cut the micro-v profile and machine a tapered hole in the center (I made a "taper-lock" hub to mount them to the shafts). Here is what the pulleys look like when finished:
pulley.png

A year or so ago, I wanted to learn to program AVR microprocessers, so I made a digital tachometer as an exercise to learn with. My plan is to replace the front cover of the vari-speed drive (where the RPM is displayed in the little window) with the tachometer and a slide pot for changing speed, like this:
cover.png
The tapered hub has a flange for tightening with a series of screws around the perimeter. I put a piece of brass shim stock between the tapers to keep them from galling. I also used an indicator to make sure the pulley was not wobbling as it rotated. Tightening the screws the appropriate way would make the pulley tilt slightly, so I used that to make sure it ran true. The tachometer counts the windows in a disk and you can see that disk on the pulley here:
pulley-mnt.png

This is the head reassembled without the front cover:
pulley-mill.png

Here you can see into the front where the cover will be. The belt is visible as well as the tachometer disk. An opto-interrupter will be mounted in here to count the windows:
pulley-frnt.png

The mill runs SOOO much smoother and quieter! I wish I did this years ago!

Next I will post the setup of the VFD and the remote on/off switch, etc.
 
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Are you going to use 2 opto interrupters to get a 2 channel quadrature output to detect direction as well as speed?
 
Are you going to use 2 opto interrupters to get a 2 channel quadrature output to detect direction as well as speed?
Nope. It's just a simple pulse - it sees both rising and falling edges to require fewer windows.

I don't know why I need an instrument to tell me forward/reverse, I can look at the spindle just as easily as a gauge. I may not have been clear when mentioning my BOSS3 CNC... this VFD is on my manual mill.
 
I found this post from johnnyc14 that helped me get my head around getting the VFD to work:

http://www.hobby-machinist.com/thre...-volt-single-phase-to-220-volt-3-phase.33103/

He did a good job explaining things. I was then able to adapt things to the way I wanted.

I wanted to make the VFD work just like things worked before I installed it. I've run a Bridgeport for more than 30 years and I didn't want to have to re-learn the on/off switch - especially when I need to shut it down IMMEDIATELY. Plus I want to have the capability to power tap like always - and not have to think about how to stop and reverse the spindle quickly. My switch looks like this:
switch.png

So I need the VFD to run in FWD when the switch is rotated CCW and stop when the switch is horizontal, then REV when the switch is rotated CW (this is assuming high gear). The problem I found is that the VFD didn't seem to have a way to do that. My challenge was to find a trick to make it work like I want. This is what the manual showed for examples:
wiring.png
The example on the left is set up for three momentary contact switches. The example on the right uses two switches, K1 turns on the spindle, and K2 determines the direction.

I had the idea to set up the mill's drum switch to close K1 for forward and to close both K1 and K2 for reverse. IT WORKS!:D

More to come....

(edited to correct error in whether or not it worked - I originally posted it didn't, but I didn't set it up correctly)
 
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This is a wiring diagram of my setup:
Huanyang schematic mod.png

Here is a list of the settings I am using:

- PD001 set to 1 Enable external controls (FWD, REV, etc.)

- PD002 set to 1 Enable external RPM control using 10k pot (I haven't yet connected the pot so, my VFD is still set to 00)

- PD003 set to 60 Main Frequency - Will change with up/dn (or 10k pot if enabled) arrows during motor operation

- PD004 set to 60 Base Frequency - from motor name plate

- PD005 set to 117.63 Maximum Operating Frequency (This provides exactly 3500 RPM on my mill)

- PD008 set to 240 Maximum Voltage - from motor name plate

- PD011 set to 13.5 Minimum Operating Frequency (This provides 406 RPM on my mill)

- PD014 set to 1.5 Acceleration time (seconds)

- PD015 set to 8.7 Deceleration time (seconds)

- PD041 set to 10 Carrier Frequency (Factory default is 1 mHz and there is a noticeable whine when the motor turns. I set mine to 10 mHz and it is now silent)

- PD044 set to 01 Set Function of FOR (D1) Terminal (per example in manual page 37)

- PD045 set to 05 Set Function of REV (D2) Terminal (per example in manual page 37)

I haven't yet tried using a breaking resistor, but plan to soon. I'm a little confused because the schematic shows the resistor connected to terminals labeled "P" and "N", but there are no such labels on my VFD.
 
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GOOD NEWS! I found this schematic online. It shows the Braking Resistor connections labeled with nomenclature that actually matches labels on the drive! The resistor is attached to the "P" and "Pr" terminals. It is what I suspected, but it is nice to get some conformation....
b r wiring.png
 
BAD NEWS!:confused::(

Apparently there is a reason these VFDs are so cheap. :mad: I found that the support circuitry for the Breaking Resistor ISN'T EVEN INSTALLED on the PC Board! :cry: So a Breaking Resistor is out of the question. :eek:

I have therefore opted for the "Coast to a Stop" option, and will use the hand operated mechanical break that I've used for years....
 
Here are some pictures of what I've done so far. It is a temporary setup to get it working the way I want. Next I'll redo the wiring with strain reliefs and shielding. Plus, I'll install an On/Off switch - currently I'm using the wall plug....

VFD wired.png

drum switch.png

terminals.png

overview.png
 
There was a previous post about the braking module not being installed in an older version of this VFD. But, I have used this brand of VFD and the braking unit worked. If I recall I used a 70 ohm 250W braking resistor and was able to brake a lathe in a 1-2 second range. It also has some internal braking ability without the external braking resistor, but I have heard they are prone to being damaged if too aggressive braking is used without an external resistor. Try something like 3 seconds and see if it works. If it does add an external braking resistor as added long term insurance, they are around $20 for the encapsulated aluminum ones. It connects to terminals 4 (P+) and 5 (PR). Build http://www.hobby-machinist.com/threads/acer-trump-1236-vfd-conversion.32910/
 
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Mark,

THANKS! That link is informative. You seem to have a good understanding of the workings of VFDs.

I experimented with deceleration times with my setup. The best braking I got was 5.7 seconds decel from 3500 RPM. Then when I tried it a little later I needed to raise it to 5.8 seconds - I guess I was on the ragged edge.;)

I have a resistor but didn't install it after finding several posts indicating many of these VFDs (especially from eBay) don't have the on-board circuitry. The big indicator that there is no circuitry is a missing red wire that can be seen behind the I/O terminal blocks. There are three red wires visible for the three motor phases (connecting to U, V, W) shown here, but there should be a fourth wire connected to P+ but it is missing: here:missing wire.png

I looked through the photos on the link you posted and could not see if any showed the wire, missing or not. My thinking here is, maybe that wire isn't required on some models. But it is suspicious that I can clearly see a PC Board trace with a hole for a wire, and the wire is obviously missing....:confused:

Mark, do you have a way of confirming whether or not that wire is in the drive you used?

As of now, I have a satisfactory solution. The mill behaves exactly as it did before the VFD installation, only smoother and quieter.;) However it would be nice to have the option of a braking resistor.
 
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