Home Forums Fatbob Technologies Problems and Solutions – GRBL

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  • Andre
    Participant
    Post count: 21

    Share some issue you may have had with GRBL and how you fixed them?
    I had an issue where – during a cut of any size – GRBL will “stop” with error : Unable to write bites to port probably due to outgoing queue full. Write data Lost!
    After some research – I came across this article : http://www.hobbytronics.co.uk/arduino-serial-buffer-size
    which I have not followed because on GRBL Controller there is a place to manually set the buffer size – default = 50, I set mine up to 90… BUT – not yet able to test since I fried a motor driver where my Z goes “UP” when I click up – up when I click up, up when I click up – and then down when I click UP… I’ve ordered a new board – awaiting delivery for assembly and testing… – though the above solution does seem to make sense and seems easy enough to implement.

    share some issues and solutions 🙂

    makerslide-admin
    Keymaster
    Post count: 8

    Hi Andre

    Just did a Q&A on this subject – please go have a look if there is anything new in there that you have not tried yet. Bottom line is it’s a issue with the USB communications, we need to either completely bypass it or better isolate it. (I want to look into Bluetooth to replace the cable….)

    Andre
    Participant
    Post count: 21

    Morning to you – Yeah I’ve checked everything that my limited knowledge would point out, even Phillip is stumped, we’ve tried many things to try and resolve this issue! I could list them, from changing power, straight into and from a UPS, software inverting the Z, coding inverting the Z, praying, drinking… nothing seemed to help – it’s actually just easier to spend the money that frustrating myself – and Phillip – any further 🙂
    the USB cble is a problem connection – I don’t much like it either, but for now it will have to do as I don’t have the R1k to spend on a screen with the goodies needed to cut from memory stick – Bluetooth to CNC, you’re still be reliant on some sort of wireless connection – which is also subject to other external environmental factors don’t you think?

    johanndp
    Participant
    Post count: 14

    Hi all, I’ve been in telecoms for 20 years and one thing that continuously stands out is that direct comms, copper or fibre cables, is by far the most reliable. I’m specializing in satellite telecoms and we do get terrestrial interference even on high end professional equipment. Trust me, this is quite a bastered to get sorted.

    With this said, copper comms can also suffer from interference. This is usually induced via the ground connections. My current setup is running on a floating earth and I’ve sent some very complex toolpaths to the machine without any problems at all.

    Phillip, try the following, cut your earth cable to your unit’s power supply from the mains supply. Make sure your laptop/PC is connected to the same supply without the earth and check if you get the same result. If you need more info, then please give me a call.

    To everyone else, Please let me be very clear, this is my opinion and I’ve been doing this for a very long time, thus I will do it with my own equipment. If you are at all uncertain, then please do not do it!!! Consult someone you trust to assist you. If you pop a card, do not blame me, I’ve got no control over your actions.

    makerslide-admin
    Keymaster
    Post count: 8

    Thanks Johan

    I’ve done a fair bit of reading on the subject and this is something new – we’ll give it a try on the next “freezer”

    Andre
    Participant
    Post count: 21

    Sounds like solid guidance… thx Johann ill certainly give this a try… does running trough a ups not eliminate qyite a bit of electrical noise? Vrae maar net? ☺
    From 1 point to the other… i finally got my problem resolved… i found a busted wire connection and as soon as i fixed that… up remained up and down actually goes down… moral fof my story… before spending cash replacing parts… rechech everything else… twice… and if yoy are having a beer… best make that 3 times… 😆

    johanndp
    Participant
    Post count: 14

    I had a bit more thought on this and I was just about to suggest a UPS and I recon it should work. Good thinking Booysena. If anyone has done it, then please share your results. We solved a lot of issues with the use of a UPS and if you really want to have some sense of security, then get an earth rod, whack it in to the ground and connect it to your common. Just make sure that there are no underground water pipes or power cables. It will be a shocking experience.

    Regarding the interference, due to the municipality controlling power boxes and prepaid metering, it has been reported (unconfirmed) of some telecoms issues. Electric fences is also a culprit.

    My opinion in essence, adjusting the buffer rate will maybe work and should be considered as a temporary solution, but it will come back to haunt you. The fact that you do have buffering issues is a good warning that something is wrong. Your buffering should stay at 50% because any influence can go plus or minus.

    Good luck to all and I will report any issues experienced immediately, if any.

    johanndp
    Participant
    Post count: 14

    I found this on the net. it’s possible that you guys face the same issues.

    https://github.com/cncjs/cncjs/issues/133

    on this page I found the below comment, this was after the guys went through the software and doing some crazy over my head stuff. have a look.

    Ok, so, I rebuilt my Pi with Jessie-Lite, reinstalled cncjs 1.9.0-alpha.3, connected the Arduino with shielded USB with Ferrite cores (Tripp-Lite U023-006) directly to the Pi (bypassing the USB Hub it was connected to) and so far I’ve ran 30,000 lines of the same file with absolutely no issues at all. Not even the ‘GUI stops updating’ issue.
    I think I’ve said it before, but it needs to be said again – well done on an excellent piece of software. I never even knew I had interference issues. This has been a pretty wild ride through the past few days, but I think I can confidently say this issue is closed. This was all hardware-related issues.

    johanndp
    Participant
    Post count: 14

    hi all, sorry for the amount of posts, but this is quite interesting. Andre, I did not see that you have tried a UPS and obviously it did not work. did you have the earth connected to the UPS? if so, disconnect it, but make sure that your PC/Laptop runs from the same source without earth connected. do not plug your PC into a different power source which will have an earth. if by chance anything goes wrong on the controller boards, it will go through your PC to the earth. not good.

    johankrugersa1
    Participant
    Post count: 7

    Hi Everyone

    I also had the freezing problem, i say ‘had’ because i believe i may have sorted the problem.
    I tried everything, from different pc, to buying a ups, checking and re checking for loose or faulty wires, unplugged compressor and pumps, but with no luck.
    some days it freezes at 1% then the other day at 98% on a 3 hour carve, now that is painful to re carve air for 3 hours to do the last 2%.
    Then i read in the comments above to remove the ground on the main power supply, so i did that last night and tried it out on a job of about 2 hours, no problems,
    did another one this morning also about 2 hours, no problems. i still have the ups running seeing as i bought the thing i might as well use it.

    Andre
    Participant
    Post count: 21

    This sounds like good news!! I was aiming at doing the same last night, but after the first and second red-bull and Vodka, time just seemed to slip away from me 🙂 I will be doing same this evening – before the flow of vodka starts 🙂 Thanks Johan for the feedback, I for one know how kak frustrating it can be to cut, and then expectation leads to disappointment when the cut bombs out

    Did you remove the earth from the UPS mains as well? or only from the controller box Johan – what about the earth on the equipment that feeds from the UPS? gone to?

    johanndp
    Participant
    Post count: 14

    Andre, the best way to go about it is to remove the earth before the UPS. I will not advise the removal of the earth in the wall socket, rather in your 3 point male plug which is plugged into the wall socket. if the cable running from your wall socket to the UPS (Usually a 3 point male to a kettle plug female) is a sealed unit, then I would cut the cable and re-join the live and neutral and leave the earth disconnected.

    from the UPS to your equipment, keep the earthing/commons connected. this is then what is called a floating earth system and again, I can not emphasize it more, DO NOT CONNECT YOUR PC/LAPTOP TO A POWER SOCKET WHICH IS EARTHED, rather have it connected to the same UPS or else to the same power source as your power supply without the Earth.

    johanndp@hotmail.com

    email me your number if you want to talk to me, I’ve got no issues calling back.

    johankrugersa1
    Participant
    Post count: 7

    HI

    I removed the earth in the controller.
    My setup is as follows, ups connected to main power. and from ups i run my pc and my controller.
    Can and will i damage anything by removing the earth in the controller with the current setup?

    Andre
    Participant
    Post count: 21

    JohanK… from my discussions with Phillip, and what it sounds like JohanNdp explains, it would sound like we need to pull the earth from the controller – I’m thinking of pulling the earth out from every peace of hardware that connects to the ups, and from the ups where it comes from the wall socket to UPS – it would almost sound like ALL earth needs to be eliminated – look, what I know about all this is dangerous – I try my best to stay clear from working with anything related to electricity!! but if it needs to be done…

    johankrugersa1
    Participant
    Post count: 7

    Hi Everybody

    I have to report that my excitement was short lived as i tried another project a couple of minutes ago and it didn’t even make 2%.
    So i think i can safely say that pulling the earth from the controller didn’t solve my problem.
    One thing that i did realize was that the usb port on the arduino feels very loose, i don’t know if it looses communication between the pc and the arduino.

    back to the drawing board i guess.

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