I want to get rid of my BOB, any possible problem ?

This Section is for users to discuss hardware

I want to get rid of my BOB, any possible problem ?

Postby ovisopa » Tue Apr 04, 2017 9:41 pm

Hello guys,

I purchased the UC400ETH controller in hope that I can solve a problem I have with my CNC, very rarely a motors are acting weird, like it's stuck, spinning slowly, it's not a mechanical problem as it hapen also with the belt off the motor. This problem aggravated when I moved my CNC from my garage to my workshop, in octomber 2016, after 3 years in my garage, this issue only happen rarely like once a month or even more .. once at 2 months, I couldn't make it repeat, or predict.. just random.

After I moved to my workshop, garage and workshop all powered from the same power source, the issue was more evident -- in term of a few minutes, and also a thick in the motors could be heard very often.

I though I solved the issue by disabling 2 functions in BIOS: EIST and C1E... I never heard of those function but please belive me that since I disabled those functions I didn't heard any thick, and no motors act weird for almost 6 months!!!! until now a week ago .. it's been almost 6 months of milling on the router about 8 hours / day, I really used it a lot without any issue.

Now a similar problem appeared, no bump/thicks anymore, but the right Y motor acted somehow the same as you could see in the video above, on the X axis, when this hapen first time now a week ago I decided to purchase an dedicated controller to generate the pulses, to try eliminate one more possible problem : my computer (but I think is quite a good computer for this purpose, it's a Lenovo Think centre EDGE, 2.7GHz, 4GB DDR3, Windows 7)

I installed the controller on Saturday, and since than I milled about 10 - 12 hours .. all good, but this night the problem appeared again, and on the same right Y motor.

Now I'm thinking to get rid of the BOB completely, last week I measured the DIR pins and one of them in the LOW state has 1.2v - 1.3v, I think it's still a valid LOW, but only that Y pin has a higher value than the others, which have between 0.6 - 0.9v in the LOW state. In the HIGH state all the pins are 5.01v. I measured this in the BOB, not in the UC400ETH controller.

Now that I know for sure that my computer was not the issue, I want to eliminate even more possible causes, tomorrow I will try to swap the Y -right driver with the X driver, the X has only one motor , the Z and Y have both 2 motors / axis.

As I want to remove the BOB, do you recommend any simple boards with just the screw terminal connectors ? I want to buy or make something like this if I can't find it somewhere closer than China, as it takes alot of time until I will get it.

simple BOB.jpg


Any advices are welcome.

Thank you.
ovisopa
 
Posts: 3
Joined: Mon Apr 03, 2017 7:31 pm

Re: I want to get rid of my BOB, any possible problem ?

Postby cncdrive » Wed Apr 05, 2017 12:41 pm

Well, if the 1.2V - 1.3V still a valid low voltage depends on the drive's input circuit, it may be on the edge of validity.

And you could connect the drives' step/dir signal without a BOB if the drives have optocoupler step dir inputs, most of the drives are like that.
Connecting the drive directly you could cross out the possibility of a problem with the BOB.
And if the problem will be still there even with direct connection of the step/dir signals then it is likely a problem with the drive.
cncdrive
Site Admin
 
Posts: 4695
Joined: Tue Aug 12, 2014 11:17 pm


Return to Hardware

Who is online

Users browsing this forum: No registered users and 6 guests