New VFD suitable for orient

04 Jan 2018 12:20 #104018 by raglanlittlejohn
I have tried using the orient function, using an old Jaguar Cub VFD (Cub C150-EN). It will only stop the lathe spindle within around 4 degrees of commanded position at best. I also was unable to get the motor running slow enough using the DC voltage control (0 to 10v) from a Mesa 7i78, but got it going slow enough with the VFD's built in speed control. Banggood do a cheap VFD, .
This appears to have vector control, (my Jaguar Cub VFD does not have this). I would like to know if the Banggood VFD would be easier to control using orient. I realise it will only be possible to get close to commanded position. I would expect to fit a disc with say 12 holes, and a solenoid operated locking pin to lock the spindle, after the orient process had got close enough to position.

Thanks, John.
11 Jan 2018 12:03 #104282 by andypugh
You could probably keep the Jaguar if you are prepared to make an alignment disc.

What is the application for lathe spindle orient?
11 Jan 2018 17:41 #104299 by raglanlittlejohn
I would like to be able to do all the turning on a part in the lathe. If I then wanted to do something like milling a couple of flats with a live spindle, or drilling some holes on a pcd, it could all be done in one operation in the lathe. I also want to know how to get a spindle to orient, in case I want to fit a tool changer to a milling machine in the future.
It looks as if the open loop vector vfd's will run much slower with good torque. This should make this easier to do.
I'd like to know how much better the open loop vector vfd's they are before I buy one. I will probably go for something like this, , rather than the Banggood ones.
03 Feb 2018 21:59 - 04 Feb 2018 19:07 #105373 by raglanlittlejohn
I bought one of these in the end, .
The open loop vector control is much better then the old V/F control. The orient/orient pid component works very well with this type of vfd.
Last edit: 04 Feb 2018 19:07 by andypugh.
07 Feb 2018 12:55 #105527 by Ross77
Replied by Ross77 on topic New VFD suitable for orient
Thanks for the info. Im looking to do something similar. How accurate/repeatable is it? and will it also hold position or do have you fited a brake?

07 Feb 2018 17:01 #105533 by raglanlittlejohn
I've only just got this working. I'm using a spare motor at the moment, with an Omron encoder coupled to the motor shaft.
I'm getting repeatability to within about 3 degrees so far. I might be able to improve on that, I've not done any pid setting up before. the motor is about 1/2 hp. It's quite hard to move the shaft out of position, so I think there will be enough torque to orient a lathe spindle. My plan is to use a disc with say 12 holes, fitted to the lathe spindle. A pin driven by a solenoid, or actuator could engage the appropriate holes, locking the spindle. The problem with holding position, is that the pid reverses the motor if it goes past the commanded angle, so the motor drive is momentarily lost.
I made one mistake with the vfd. The next size up has rs485, but mine does not. I had to connect relays for forward/reverse, and use the pwm output for spindle speed control. This works fine, but an rs485 connection would have saved some wiring.
07 Feb 2018 19:16 #105537 by Ross77
Replied by Ross77 on topic New VFD suitable for orient
I will be watching your progress then. will you be posting up the Hal and Ini files?

I was going to do a similar thing on my smaller ML10 but there's not much room at the back of the spindle on the Boxford for indexing wheels or brakes as it has a pneumatic collet chuck.

I have a 1.5Kw motor so hopefully that will have enough holding power. other wise its a servo motor and that will be expensive.
07 Feb 2018 20:54 #105543 by raglanlittlejohn
My Hal file is a bit of a mess, lots of commented out lines from earlier experiments. I'll do a copy and tidy up, then post. I've put a schematic of the orient set up I'm using on here, I'll attach it.

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The following user(s) said Thank You: Ross77
09 Feb 2018 16:56 #105650 by raglanlittlejohn
Here are my hal and ini files as mentioned before. I've got the motor stopping to within 2 degrees of commanded position. It could probably be improved on, but thats near enough for what I need.

File Attachment:

File Name: 09.02.2018.hal
File Size:13 KB

File Attachment:

File Name: 09.02.2018.ini
File Size:3 KB
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