Page 1 of 2 12 LastLast
Results 1 to 15 of 25

Thread: Auto-Return for Super Surfacer

  1. #1
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,235
    Blog Entries
    7

    Auto-Return for Super Surfacer

    I recently rebuilt a Marunaka Royal 10 super surfacer and have been using it. This is a simple machine in
    which a belt drives materiel over a fixed knife to create a smooth surface on wood. Like a hand plane.

    Modern versions (mine is 1960’s) of this machine have a feature in which the machine senses when wood is placed at the inlet, starts the motor, cuts a programmed number of shavings, then returns the material to the inlet side of the machine. This is all done in rapid fashion, the stops and reverses are instantaneous.

    A friend of mine sent me photos of what the inside of the control panel looks like on his setup, but I’m wondering if a CNC version of this is possible or feasible. I have a fair amount of money sunk into this old cast iron beast so I would like it to be all things the modern day version is, if reasonably possible. If not, I’ll certainly continue using it as is since it is an incredible time saver.

    Oddly enough this machine is capable of working with thinner strips of material than some of the current machines so it has advantage there.

    I can post photos of the control box if that is helpful.

    Here is a video of the modern setup:

    Bumbling forward into the unknown.

  2. #2
    Quote Originally Posted by Brian Holcombe View Post
    ... I would like it to be all things the modern day version is, if reasonably possible. ...
    NEVER satisfied!! It may be time for an intervention...?

    But in the interests of feeding this addiction, does your friend have the electrical schematics? This could be key in identification of all the sensors and actuators, and will be equally critical in how the associated control logic is 'written'.

    From the video, the obvious input devices are:
    • 'vertical' sensor to detect proper position and/or pressure of the feed-belt, not sure if this is a limit switch (discrete) or pressure switch/strain gauge (analog);
    • start sensor to detect material to be processed;
    • left end sensor to detect completion of R-to-L stroke;
    • right end sensor to detect completion of L-to-R stroke (probably same as start sensor??);
    • configuration buttons.

    And some not so obvious:
    • Rotation of the cutter block..?? Not clear from the video, but does the cutter articulate for 2-pass cutting? Or, does it only cut in one direction?
    • Safeties. Probably several on doors, covers, and such.

    Actuators (outputs) from the controller:
    • Feed head height. Does it adjust (down) with each pass? Or, is the pressure sufficient to allow multiple passes at 1 setting?
    • Feed belt direction - this will require FWD-REV starting contactor pair. (Or, a servo motor and drive if you want REALLY fancy!)


    When you say CNC, I am guessing you want either relay control or PLC. I can't spell CNSee, but certainly a small PLC (maybe even Arduino?) should get you to your goal. Or... I put written in quotes above, because another option is simple relay-based logic. If you go with CNC or PLC this means either contracting the programming, or buying the software (and learning it). Relays can do much the same, just with more wire.

    ETA - I'd bet the video link is 100% discrete automation (no analog - i.e. pressure sensor). This keeps the controls and the operator interface VERY simple - and so cheaper for the OEM.
    Last edited by Malcolm McLeod; 12-28-2021 at 10:22 AM.

  3. #3
    Join Date
    Mar 2003
    Location
    SE PA - Central Bucks County
    Posts
    65,638
    Does your older machine have the physical capability for reversing like that, etc.? Otherwise...subscribing 'cause this is very interesting!
    --

    The most expensive tool is the one you buy "cheaply" and often...

  4. #4
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,235
    Blog Entries
    7
    Howdy Malcolm,

    Glad to see your interest here Thanks for the reply, Posting up some photos so we can dissect them.

    I’m not fixed on cnc, any type of operation system works for me.

    88AB0F45-DAEA-49E1-A914-4E2D48A9E214.jpg
    CD82870F-378C-44CC-A9B7-E8A1C7D70560.jpg
    26C58956-E69F-4060-A2FD-C5F282B70B66.jpg
    FEAC2419-5BA6-4469-8F0C-E15286AB78B7.jpg
    059DE0E1-FF8F-4C82-ACB0-8BC51832DFCE.jpg

    Jim, these reversing machines are using a standard 3ph motor.

    CCD4B5EB-F74C-47AC-A0BD-5FD69D2BE391.jpg
    Bumbling forward into the unknown.

  5. #5
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,235
    Blog Entries
    7
    The cutter block is a manual rotation, I’m not sure the value of reversing it, but that can be done on mine as well.


    Also, I would probably delete the pressure sensing aspect of this machine, since I believe that would require me to replace the acme screw with a ball screw and the manual height with a servo or similar motor. As much as I would love to do that, I think I’ll keep it to simply electronic modifications.

    If you are curious, this is what’s under the hood, these photos are from when I was cleaning the machine, so this is the old belt.

    067928A6-8636-47F8-9D74-6E1A772BE05C.jpg
    Last edited by Brian Holcombe; 12-28-2021 at 11:21 AM.
    Bumbling forward into the unknown.

  6. #6
    The whole thing looks like pretty simple (said with a chuckle) edge bander style logic. Not necessarily CNC perhaps other than down feed but even that wouldnt necessarily be CNC. Could be something as crude as surface grinder operation or as advanced as needed. Agree'd that one would envision a surfacing in both directions option though it would seem to add to the complexity and accuracy immensely. Controls dont seem to be too far removed from a bander.
    20211228_112156.jpg

  7. #7
    Join Date
    Jul 2007
    Location
    Inkerman, Ontario, Canada
    Posts
    1,383
    Hi Brian,

    I don't think you need anything complicated to do this. This is a pretty simple operation and I think that you could do it with a few contactors.
    I have designed many control systems for sequential operations in machinery. There are a dozen ways to do each system, just figure out a simple and easy way, with basic components.
    I usually strip out the electrics and rebuild them. I start from scratch, draw up a system, build it, test it modify and simplify it. It is actually quite an interesting and fun challenge and a change of pace from normal shop work. ( I should of course let you know that I am not an electrician.)

    This is a video of a system for a mortising machine.
    I made some changes so you will have to watch the second video as well.




    This is a more complex one. It has a separate panel on a pedestal, it has a mortise head, a slotting router and a drill head, clamps and feed. all automatic.
    Sequence' Press the start button, it starts the feed, engages the clamps, starts the mortiser, cuts the mortise, drills the handle and lock holes, routes the strike plate, and returns to the start.
    I got rid of the pedestal mounted electrical box and put a panel in the side of the base to clean things up.

    33026A.jpg 33026B.jpg 33026E.jpg Mortis2.jpg

  8. #8
    Join Date
    Jul 2007
    Location
    Inkerman, Ontario, Canada
    Posts
    1,383
    This is the changes that I made to the original design.
    This is the one that actually worked.


  9. #9
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,235
    Blog Entries
    7
    Beautiful work, Mark!

    Sounds like building out a non-cnc setup is the way to go, must be why they have kept doing it in this fashion rather than moving to digital controllers.

    The most interesting/curious part to me at the moment is the way these machines can start/stop so quickly.
    Bumbling forward into the unknown.

  10. #10
    I had wondered about the reversing myself if the auto return models run on some sort of servo or f/r gearbox arrangement. That return seems almost instant. Would seem hard on a large 3phase motor.

  11. #11
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,235
    Blog Entries
    7
    Spoke with a friend who owns one and the photos above are from an auto-return unit. Somehow this is being done with a standard three phase motor.

    Its pretty amazing to me that this works and I’m sure there are some details that aren’t obvious right away.
    Bumbling forward into the unknown.

  12. #12
    Quote Originally Posted by Brian Holcombe View Post
    Spoke with a friend who owns one and the photos above are from an auto-return unit. Somehow this is being done with a standard three phase motor.

    Its pretty amazing to me that this works and I’m sure there are some details that aren’t obvious right away.
    Do they use a brake motor? If so, this could explain the rapid change... IMO tho', using a brake trades the magnetic 'shock' of going from FWD to REV, into mechanical wear of a brake (drum or disk). I'd lean toward upsetting some electrons for this application - not a brake.

    3-Phase motor makes FWF<>REV direction changes a breeze; just pull in a separate contactor for each respective direction. Giggle for "3 phase motor reversing circuit"; images abound. Key here will be the control circuit: Power / 1-pass / Continuous / position sensing / Start / Stop / etc.
    Last edited by Malcolm McLeod; 12-29-2021 at 5:18 PM.

  13. #13
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,235
    Blog Entries
    7
    I don’t think they use a brake motor, but I do believe there is a very high amperage draw at the transition.
    Bumbling forward into the unknown.

  14. #14
    Join Date
    Aug 2013
    Location
    Princeton, NJ
    Posts
    7,235
    Blog Entries
    7
    I wonder if this would be possible to do with a drive also. Seems a common choice fire bridgeport mills setup for tapping.

  15. #15
    Quote Originally Posted by Brian Holcombe View Post
    I wonder if this would be possible to do with a drive also. Seems a common choice fire bridgeport mills setup for tapping.
    I have watched Machinists on a Bridgeport do the tapping dance may times (and even tried 1-2 myself w/ minor success :: no broken taps), so I know the motor can handle the magnetic loads. What I don't know is the impact on the motor's life span if it does this near-instantaneous line-voltage reversal on EVERY cycle.

    I also have to make a lot of assumptions on the surfacer - like assume it has a fairly high ratio gearbox driving the feed belt. I'd think (hope) this will reduce the inertial load that the motor must 'reverse' to basically that of the motor itself.

    Certainly a VFD could handle the FWD/REV transitions; just set the accel/decel times to 0.5-1.5 secs(?). Duty cycle will be next consideration: sounds like you have 6 hr sessions on it, and I'll SWAG at 70-80% run time for the feeder (using your aerobic retrieval scheme). If I'm close, I would give serious thought to adding the external braking resistor to any VFD, so heat is better managed by moving it external to the VFD. The VFD also has its own 24VDC (typ) power supply for control, so simplifies this circuit (no xfrmr, or line voltage relays). Even the line power handling is simplified :: 1 device (VFD) replaces 2 contactors and the overload.

    I am intrigued by the relay logic, but swamped with SWMBO's holi-dos. When I get back to work schedule on 3rd, I'd be glad to take a swing at this - if you can be patient. No promises, but I think it's relatively simple if I can get the position sensor assumptions right - - how many and where.

Posting Permissions

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