. .
Page 4 of 12 FirstFirst ... 23456 ... LastLast
  1. #31
    700 x 500 x 250mm steel cabinet arrived today from TLC. Very solid and heavy @ 20kg. - hopefully everything will fit in based on previous builds on here! I see Andy had 800x600 which had a little space spare.
    While I wait on the linear motion parts from BST - electronics are being planned, really steep learning curve here for me and hoping I can figure it all out with some of your help.
    With the LCDA86 driver Jazz recommended, what voltage would be ideal. Its up to 100Vdc and I see a few people have used 68V - so would give some margin but would that be at expense of too much power?
    LC60H2112 is listed as 5.6A current, so with 4 motors do I need 22.4A x 68V = 1523VA PSU? Sounds huge.

    I'm trying to take each component in turn and map out the connections - first the driver to AXXB-E. Except for ALM I can't figure out which other terminals need to be connected if at all ? For example ENA+, Pend, and the Encoder E* ones.
    AXXB manual refers to just Step and Dir.

    Click image for larger version. 

Name:	drive1.PNG 
Views:	42 
Size:	382.0 KB 
ID:	27524

    Edit..Just realised VCC/GND wrong colours on that IMG..

    Thanks
    Ryan
    Last edited by CNCRY; 05-03-2020 at 11:29 PM. Reason: added note

  2. #32
    Quote Originally Posted by CNCRY View Post
    700 x 500 x 250mm steel cabinet arrived today from TLC. Very solid and heavy @ 20kg. - hopefully everything will fit in based on previous builds on here! I see Andy had 800x600 which had a little space spare.
    Yeah you'll be fine :) 800x600x300 was overkill. I have no idea how Joe filled 800x800x300.

    Quote Originally Posted by CNCRY View Post
    I'm trying to take each component in turn and map out the connections - first the driver to AXXB-E. Except for ALM I can't figure out which other terminals need to be connected if at all ? For example ENA+, Pend, and the Encoder E* ones.
    AXXB manual refers to just Step and Dir.
    Good plan. Generally speakings, Step and Dir are the two required ones.

    Enable turns the drive output on or off to prevent the motor turning without killing power to the drive, usually when left disconnected the motor is just enabled by default.

    Alarm should output a fault signal to the AXXB if something goes wrong. Best to have it connected somehow if you can, but there are a lot of options about exactly how you wire it up. E.g. it could estop the system on fault, or just tell the AXXB to pause.

    Pend appears to be 'positioning completion signal', encoder and the motor phases should be the wires from your motor.

  3. #33
    Quote Originally Posted by CNCRY View Post
    With the LCDA86 driver Jazz recommended, what voltage would be ideal. Its up to 100Vdc and I see a few people have used 68V - so would give some margin but would that be at expense of too much power?
    LC60H2112 is listed as 5.6A current, so with 4 motors do I need 22.4A x 68V = 1523VA PSU? Sounds huge.
    You don't need 22.4a you only need approx. 60% of total current draw because of how the drives work using PWM etc which I won't get into. Also you'll rarely max out all motors so got little more leigh way in use.
    I would use AC and do away with the need to rectify and Caps etc required for DC. This is what I would use with those drives wired AC. Wire the secondaries in parallel and you'll end up with approx. 11a which isn't quite 60% but still more than enough.

    https://airlinktransformers.com/prod...ange-cm0750265

    Quote Originally Posted by CNCRY View Post
    I'm trying to take each component in turn and map out the connections - first the driver to AXXB-E. Except for ALM I can't figure out which other terminals need to be connected if at all ? For example ENA+, Pend, and the Encoder E* ones.
    AXXB manual refers to just Step and Dir.
    Start simple, if your not used to wiring things like this don't try and wire it all in one go it will just blow your mind. Start with basics first and do it in stages.

    I would start by setting up the main latching E-stop circuit and getting movement just with Step & Dir. Forget, enables and alarms at first they can be added later.
    Next wire in Home/limit switches. This then gives you the basics or a working machine.
    Now you can start adding other features like Alarms, enables etc and controlling any external devices using outputs etc like spindle control.

    My favourite saying is "Treat it like eating an elephant, one bite at a time."

    Edit: With the cabinet don't stress out over this either, concentrate on layout and wire routing , the main thing is to keep low voltage signal wires away from higher voltage wires as much as possible and make sure you use Star grounding. If your using a VFD and thinking to put in cabinet just pay close attention to where the main spindle cable goes, I'd also suggest you don't put it near the main controller.
    Last edited by JAZZCNC; 06-03-2020 at 09:12 AM.

  4. #34
    OK so I've listened to the start simple advise and taking each part at a time! So plan is to sort out the cabinet layout, power distribution, e-stop and switches first, then add controller and drives once the machine is actually built.
    That way the low(er) cost and less complex items can be fitted now and drivers / controller / home and limits / alarms / faults to be added once the machine is built, and finally VFD and spindle.

    I have this for the cabinet layout - does it look OK or any issues?

    Click image for larger version. 

Name:	ext cabinet.PNG 
Views:	51 
Size:	57.3 KB 
ID:	27535

    I'm planning to buy these - could someone confirm they are OK choices, especially the contactor! Looks like it is DC

    https://www.rapidonline.com/mean-wel...cy-psu-85-5684
    https://www.rapidonline.com/schneide...tactor-66-1939

    Couple other questions from the never ending list:)
    - Do I need to Fuse the drivers? They have overcurrent/voltage but I notice some people have?
    - Are EMI filters needed with decent star grounding? I'm planning to add the EMI filter option on the transformer.

    Possibly one day I can answer some questions:) On a side note, looks like quite a few builds stall or just about complete and then people disappear from the forum, big thanks to those who stick around to keep helping others.

    Ryan

  5. #35
    Neale's Avatar
    Lives in Plymouth, United Kingdom. Last Activity: 3 Hours Ago Has been a member for 7-8 years. Has a total post count of 1,417. Received thanks 266 times, giving thanks to others 8 times.
    Personal view - there is little point in providing fuses for the drivers. A fuse will never "protect" a driver as the semiconductors in the driver will let out the magic smoke well before the fuse can react in the event of a major fault (and I'm thinking short-circuited motor wires, for example). If the built-in protection doesn't work, then it's already too late for a fuse. Where a fuse might help is in the output of the driver power supply, or maybe in the input to it. In the event of a fault in a driver that causes a high current draw, this will protect the power supply. In fact, the only electrical fault that has happened in my own control box was an internal short in the toroidal transformer which took out the fuse on the input (mains) side - fortunately. Generally speaking, fuses do not "protect" equipment - they help stop wiring, etc, bursting into flames when something has already failed. As I say, this is a personal view and others are paranoid about fuses everywhere. Be interesting to hear if these fuses have ever "saved" anything!

  6. #36
    Quote Originally Posted by Neale View Post
    Personal view - Be interesting to hear if these fuses have ever "saved" anything!
    My personal view is that it's stupid not to fit a fuse just to save a few pence. Why risk an 80 drive for the sake of an 80P fuse to protect from the unknown.!.

    To answer the question have they ever "saved anything" then it's a BIG FAT YES I've had many cases where things like loose wires have shorted or been rubbed through etc. The point being your not actually always trying to protect the device but the system as a whole from unforeseen circumstances so spending a few quid more for fuses to protect valuable parts of the control box is a No brainer to me.

  7. #37
    Quote Originally Posted by Neale View Post
    Be interesting to hear if these fuses have ever "saved" anything!
    I've already buried the spindle in the work a couple of times, both times have 'gently' blown the VFD fuse before any damage was caused elsewhere. The power loss to the VFD also causes a fault on the controller so stops the motors, which is kinda nice.

    Quote Originally Posted by CNCRY View Post
    I have this for the cabinet layout - does it look OK or any issues?
    Three things spring to mind:
    • VFD Spacing against internal walls. Read the manual for how far it should be away to allow adequate air flow.
    • I'd keep earth near Line and Neutral, thats where it comes in after all, and a lot of the big ticket earthing items will be mains voltage.
    • You've made a good start trying to separate voltage levels, but the 5V PSU should be at the low voltage end of the cabinet rather than its current position near 65V DC.
    • Think about air flow through the cabinet - At the moment your drivers will get decent flow, but the VFD won't. What direction are those fans? I orientated my drivers to allow maximal air flow through their heatsinks, at the moment your heat sinks are at 90 degrees to the air flow.


    Will it work in its current state? Sure. None of these things are big issues, just minor points.


    Quote Originally Posted by CNCRY View Post
    I'm planning to buy these - could someone confirm they are OK choices, especially the contactor! Looks like it is DC

    https://www.rapidonline.com/mean-wel...cy-psu-85-5684
    https://www.rapidonline.com/schneide...tactor-66-1939
    You've gone for the high efficiency and expensive one, is there any reason? This is the alternative to save 10.
    https://www.rapidonline.com/mean-wel...il-psu-85-5678

    Contactor seems okay.


    Quote Originally Posted by CNCRY View Post
    Couple other questions from the never ending list:)
    - Do I need to Fuse the drivers? They have overcurrent/voltage but I notice some people have?
    - Are EMI filters needed with decent star grounding? I'm planning to add the EMI filter option on the transformer.
    Extra fuses won't hurt.
    The advice I found at the time was that some people needed to plug the VFD in at the other end of the workshop to reduce the noise back from it, and I wanted to be able to power everything from the same socket. The EMI filters I used were about 5 each, and although I have no idea if they're needed or not, they do allow me to operate without noise issues with everything running off the same 13A socket.

  8. #38
    Doddy's Avatar
    Lives in Preston, United Kingdom. Last Activity: 5 Hours Ago Has been a member for 6-7 years. Has a total post count of 803. Received thanks 128 times, giving thanks to others 34 times. Referred 1 members to the community.
    Aha, the old benefit-risk balance.

    The fuse is cheap, however, the probability of it protecting a driver with a shorted output is uncertain - I can imagine a driver without overcurrent protection popping before the fuse depending on how much you've pissed off your local deity.

    The real purpose of the fuse is as a safety device to cover the fault condition and something in the high-hundreds VA rated transformers making something go bang. Or Pfftt! Or Whoosh!. Or whatever sound a decent arc makes... something like Pzzzzat! It could save the transformer as well which could be a good part of a hundred quid worth. And if it avoids a fire, then it might save on the insurance excess.

    A fuse on the drivers can't be considered a bad thing but don't rely on it protecting the drivers.

  9. #39
    Quote Originally Posted by CNCRY View Post

    I have this for the cabinet layout - does it look OK or any issues?

    Click image for larger version. 

Name:	ext cabinet.PNG 
Views:	51 
Size:	57.3 KB 
ID:	27535
    You need to think about how the wires run and trunking. how you have it there would be awkward for running wires etc.
    I would move the drives away from the Transformer and bring the DC PSU and MCB's etc down near the Transformer so all together in one area. If you have room even bring the VFD into the same area, this way all the high voltage stuff is together.

    I would have the drives and controller close together to keep Signal wire runs short as possible. Separate the high power stuff from the Low voltage stuff by placing high and low in the case with Terminal blocks and Relays etc along with trunking between them, essentially dividing the case into 3 areas.
    This doesn't matter if it's separated horizontally or vertically, for instance, I often run the drives along the sides of the case vertically as it's easier to wire them. On the opposite side, I will place VFD at the top and PSU, etc below. In the middle will be Terminals and Controller.

    Also, I would think about having 2 fans in the case to create a positive pressure in the case to push hot air out.

    Edit: Noticed that you have a Pilz relay shown, you don't actually need a safety relay. A normal Relay will work just as well and save you a lot of money.

    Lastly, looking at your drawing the scale looks wrong on the parts shown so be very careful when planning out the box because it's SO EASY to run out of room. Often the case will look massive when empty but it quickly fills up. Also if you haven't got the box to measure from then allow a little extra because things like hinges or Earth clamps etc can rob precious space and easily screw up layout plans.
    Also if not got a case and solely planning layout in Cad or on paper then I'd try to get exact dimensions of any components because again can soon run out of space and no matter what you do or how you twist things around it just won't fit.!
    Last edited by JAZZCNC; 10-03-2020 at 06:13 PM.

  10. #40
    Click image for larger version. 

Name:	cabinet 2.PNG 
Views:	36 
Size:	46.4 KB 
ID:	27555

    Attempt number 2 - tried to separate Low/High voltage more and incorporate some other suggestions. Airflow intake at the bottom and out at the top, by VFD fan.
    I checked the scale and believe its correct - cabinet is 700mm x 500mm . Although the DIN rail items are NOT to scale yet, the DIN rail is. I'll take some photos when parts physically arrive..
    I think the conclusion is that fuses are v unlikely to be a negative addition, and probably positive, I'll add these between transformer output and Drivers AC input - probably 5/6A.
    I did buy a PNOZ already as I made an ebay offer on one new much below "retail" price and got unexpectedly got accepted.

    Andy - yes good shout on 24V PSU, just chose wrong one.
    Think I'll need to add a fire extinguisher to the list too before I get started:)

Page 4 of 12 FirstFirst ... 23456 ... LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. 600 x 400 Aluminium Profile Gantry Router
    By Journeyman in forum Gantry/Router Machines & Building
    Replies: 0
    Last Post: 02-03-2016, 03:28 PM
  2. Replies: 25
    Last Post: 30-08-2014, 07:33 PM
  3. aluminium profile for cutting bed of router
    By steeplejack in forum Marketplace Discussion
    Replies: 3
    Last Post: 19-10-2013, 09:52 PM
  4. Some initial questions....
    By andy586 in forum Gantry/Router Machines & Building
    Replies: 5
    Last Post: 27-01-2013, 02:00 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •