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Author Topic: Chinese BOB with 2010 a funny one.  (Read 2361 times)

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Chinese BOB with 2010 a funny one.
« on: August 13, 2020, 03:27:48 PM »
Semi works with original screenset wont with 2010. Hey this is a funny one! I am using a Chinese BOB because I am a true tightarse and actually dont mind it. I am going to take advice soon (in the next few years) and go for a nice board one day. I have pretty much rebuilt my machine so best I do.

I have decided to control my new spindle with my BOB.... or PC anyway. Bench testing the BOB I have been unable to get the 0-10v output to work. Its the common BOB all the Chinese are selling. Has a 12-24v input, and a 0-10v spindle output. Not sure why it wont work, I reckon it is not a winner to be honest. I have a few of these boards and none of them even give me a volt out of the spindle output. Perhaps I have wired or pinned  it incorrectly, I dont know. Its been a sound controller though I will say that. This forum wont let me upload a pic sorry.

What I have found, is I am able to get a 0-5 voltage out of the pin I choose to control the spindle speed. Its linear on what speed I select. So I am going to hook up a Homman (spelling sorry) DC03 to convert that 0-5v to 0-10v - it has a connection to go straight onto the 10k pot input on my HY VFD . Perhaps its actually a PWM singal that is working? Quite plausible given I am getting 0-5v.

But. Playing around with this setup on my table, I have been able to get my BOB spindle relay to work, on/off, no problem with the original Mach 3 screenset. No problem at all. But on the 2010 screenset, same pinouts, it will not. the little LED on the BOB with the 2010 screenset kind of just luminates about 40% brightness, and the relay stays where it is. Its weird, I dont understand how different screensets can do this? Any ideas why?

Actually, if anyone has gotten one of these BOBs to work with the 0-10v output to work I would like to hear about it.

Best regards from NZ

Offline MN300

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Re: Chinese BOB with 2010 a funny one.
« Reply #1 on: August 13, 2020, 05:16:10 PM »
If I understand you correctly you are measuring 0 to 5V on digital output pins. This would be the result of sending a PWM signal to them. The DC-03 can be setup for PWM input so it should work. You will need a voltage source on the VFD side of the circuit to power the analog output.
Note the warning that a 10V supply will only give you a 9.5V output. I have worked around that by lying to the VFD about the the max speed. In this case you would set the max speed 5% high. 95% times 105% is about 100%.

https://www.homanndesigns.com/index.php?main_page=product_info&cPath=54_1&products_id=21&zenid=4jvu1rj9f8aoc5vi8buprlk0u7
Re: Chinese BOB with 2010 a funny one.
« Reply #2 on: August 13, 2020, 07:25:26 PM »
Awesome. Thanks yes correct. I did find that, infact, putting my meter on the output of the Homman board was enough to drop it s few milli volts as well. I managed to only get 8v out of it. And its accepting a definate 10v.

Ok I was thinking about how I might cheat the system. I will look into it. Although I think I can select a 5v input on my VFD as well.

But I will say, I got it working this morning. And that means, I can close up my control box.

Am curious though is anyone uses the VFD output for a display of sorts to show its status?

Offline MN300

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Re: Chinese BOB with 2010 a funny one.
« Reply #3 on: August 13, 2020, 08:17:42 PM »
If your VFD has a 5V input option that would be a good choice. You can use the attenuation trimpot to set the DC-03 output to 5V when MACH is sending 100% PWM.
Re: Chinese BOB with 2010 a funny one.
« Reply #4 on: August 13, 2020, 10:10:46 PM »
Hi is that a fact? So even though the VFD is supplying 10v to the board, I can still scale it down and use it as a 5v option, as yes there are several options to input in to the VFD, 0-10v, 0-5v, 0-20ma.... and there is one more, 0-10v/0-20ma stacked. Not sure exactly how the last one works.

Offline MN300

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Re: Chinese BOB with 2010 a funny one.
« Reply #5 on: August 13, 2020, 10:18:14 PM »
Set the VFD for 0-10V whilst you are adjusting the attenuation trimpot. Once it's setup for 5V at 100% PWM switch to 0-5V - job done.
Re: Chinese BOB with 2010 a funny one.
« Reply #6 on: August 13, 2020, 10:37:38 PM »
Ok thanks I will try that. On paper it looks right. I guess I will be able to take the board down to 5v. Hey. Standby I will just do it. Thanks for that. Its quite a stepup for me, after almost 10 years of button pressing ha