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IndustryArena Forum > MetalWorking Machines > Fadal > fadal 4020 drawbar cylinder switch
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  1. #1
    Join Date
    May 2012

    fadal 4020 drawbar cylinder switch

    I had a drawbar problem at some point and did not notice it at the time it happened, the shaft of the air cylinder that pushes down to release the drawbar was mushroomed out and blue and purple from apparently allowing spindle to turn while air cylinder was in the down position. Friction galore. I had 9 broken drawbar springs also. Currently reinstalling new drawbar springs, locking drawbar cap and drawbar air cylinder shaft. My question is the proxy switch with wires that reads the embedded magnet in the alum drawbar piston to detect drawbar returned up and okay to run spindle, or is it to indicate the drawbar is down and tool released? I just want to be sure this switch is working properly while I have things appart. Yes the magnet was located correctly over the switch. How can I test this switch for proper operation adjustment?

  2. #2
    Join Date
    Oct 2008

    Re: fadal 4020 drawbar cylinder switch

    Go into Diagnostics by typing DI, then DS to display the inputs or switch settings.
    You can see all the following sensors below in that screen.

    Attached Thumbnails Attached Thumbnails Diags.png  

  3. #3
    Join Date
    May 2012

    Re: fadal 4020 drawbar cylinder switch

    Thank you for response and will check into that after I get past my problem. While I was installing drawbar, new spring washers etc. I discovered that the new shaft from the air cylinder that pushes on the new top locking cap on the spindle touch slightly before bolting down the cylinder block. New shaft installed in piston is the same length as the old one, piston cylinder cleaned, lubed, new piston o ring installed, depth measured and verified piston was all the way up in cylinder, however the new locking spindle cap seems to be slightly taller that the old chewed up cap. Can't verify exact total length of old cap as it was mushroomed for contact while spindle was turning, but the o ring groove placement is about .050 higher up the cap than the old one. Are all the locking caps supposed to be the same height? This is a 4020 machine. I had to drop down to 43 spring washers to get the drawbar keepers on. This spindle pocket measures about 4.625 deep for spring pocket. This spindle has a number stamped on top of: GM PUL-0018J. I will call CNCPRO tomorrow as the parts I replaced came from them.

  4. #4
    Join Date
    Jan 2015

    Re: fadal 4020 drawbar cylinder switch

    One thing to keep in mind when you are viewing the 00 and 01 in the diagnostics page DI enter DS enter adjusting the hall effect sensor you don't want to read the magnet to early . because when the machine reads the magnet it assumes the tool has been ejected during a tool change and the head will rise yanking up the tool carousel. Tool could be stuck or low air pressure giving a false go ahead signal

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