Solenoid Engine

Discussion in 'General Electronics Chat' started by CDRIVE, Oct 9, 2011.

  1. CDRIVE

    Thread Starter Senior Member

    Jul 1, 2008
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    I think you guys are going to like this. Follow the links that will take you to 5 youtube vids. Now, I'm not going to claim that solenoid engines are practical or efficient but they are mechanical marvels when a good machinist builds them. They mimic a piston engine and that's the charm of them.

    http://www.youtube.com/watch?v=jVHHPEcHtbw&feature=player_detailpage
    http://www.youtube.com/watch?v=mJHDz469SbU&feature=player_detailpage
    http://www.youtube.com/watch?v=9a1rgkcm0cA&feature=player_detailpage
    http://www.youtube.com/watch?v=4o-y9ozV_Ss&feature=player_detailpage
    This one doesn't require a machine shop..
    http://www.youtube.com/watch?v=eFpitPUKDls&feature=player_detailpage

    Most, if not all of the engines you see in the links use micro switches that take quite an electrical beating. I'm posting a solid state alternative concept for anyone interested, including the boys over at the Home Shop Machinist forum, that will be coming here. The component models are not cast in stone and should be sized for the current draw and operating voltage of the solenoids used.

    Enjoy the "Machine Porn". It's guaranteed to please the eyes.

    Chris
     
  2. SgtWookie

    Expert

    Jul 17, 2007
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    Thanks, Chris - those were fun. :)
    The 1st engine has a very interesting linkage; I've seen something like that before, but can't remember where offhand. Looks like he's using a switch riding on a cam to control the TO3-packaged transistor.
    The "twin banger" (2nd vid) was really quiet - wonder if he had the mic turned off? ;)
    That 3rd engine was really a work of art.
    Turbalcain (4th vid) would get more mileage out of his switch contacts just by adding an ignition points capacitor across them.

    The optointerruptor would be a big help for these modelers.

    I see you're driving an SSR in your schematic - I think the SSR's emitter side needs current limiting. The SSR could be OK for really low speeds, but afraid it would not work well for more than "idle" speeds, as SSRs are usually pretty slow. They'd need something like a transistor or MOSFET designed for an auto ignition coil.

    Also, they need snubbers on their solenoids. The guys who are just using switches are getting the current through the solenoids stopped really quickly, but the voltage spike is getting really high, too. You don't want to use just a plain diode, as that will keep the current flowing too long. There's a related thread going on here:
    http://forum.allaboutcircuits.com/showthread.php?t=60400

    That fellow wants to control a couple hundred (!) 500mA solenoids using a microcontroller; and he needs the field to collapse very quickly (as do the solenoid engine makers).
     
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  3. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Wookie, that looks to be based on the "Atkinson cycle" type engine

    http://www.animatedengines.com/atkinson.shtml
     
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  4. CDRIVE

    Thread Starter Senior Member

    Jul 1, 2008
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    Thanks Sarge. As expected, great feedback from you. I haven't been able to find a data sheet on the SSR but I excluded a limiting resistor because MPJA lists the control voltage @ 3-15VDC, so I assumed it's integral.
    http://search.yahoo.com/r/_ylt=A0oG...s://www.mpja.com/prodinfo.asp?number=18193+RL

    Since I haven't seen the data sheet on it I don't know what the response time of it is but I will certainly take your word for it that they're slow. I just didn't think they'd be slower than a bouncing micro switch.

    Excellent point using ignition points but they have stiff springs. Let's face it,.. these motors aren't high torque, which is why I abandoned that approach.

    I'm sure you're also correct about the protection diode vs a snubber. I would like to see that back emf put to use instead of wasted. Maybe powering a small incandescent lamp?

    Sarge, I'll read through the link you provided and get back to this. Keep in mind that most of the machinists need the electronics to be kept as simple as possible. ;)

    FYI, I'm currently restoring a classic Southbend Heavy10. When it's up and running I will be building one of these engines for sure! I just gotta have one!:D

    Thanks again,
    Chris
     
  5. CDRIVE

    Thread Starter Senior Member

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  6. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    Thanks; these sure beat the heck out of my 1938 door bell, coat hanger, coffee can lid " electric steam engine"; but it did run.
     
  7. SgtWookie

    Expert

    Jul 17, 2007
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    Gee, MPJA seems to be out of those SSR's - so it's "Go Fish" time! I don't suppose it'll be difficult to come up with something that's suitable for 'em though. :)

    Hmm. Well, that's an interesting thought. However, with infernal combustion engines and these here solenoid engines, they're using cams that have a pretty gradual transition on the lobes - they'd have to have those engines really cranking to get the points to bounce. Standard ignition points will go to ~6,500 RPM, which is 3,250 RPM in the distributor, but with a V8 engine, that's 4 openings/closings per rotation, so ~13,000 RPM equivalent?

    Oh, one of those are yours? :) Cool beans. Actually, I just meant the cap, as it's ~0.22uF and high voltage - easiest/cheapest place to get one that I know of. But come to think of it, you could easily decrease the spring tension on those, as it's just a flat spring that wraps around the post on the other end. Just tie the spring to something else besides the built-in tab.

    Typical set of points:

    [​IMG]

    Removing the black wire & spring from the tab would allow fine adjustment of the cam rubbing block tension. The spring and wire have to be insulated from ground, obviously - that's usually the ground side of the ignition coil. The cap (condenser) usually gets connected at the tab as well.

    GM points for '74 ('73?) and later (for engines that still used 'em) had an Allen-head screw so you could adjust the gap through a door on the dist. cap without removing it:

    [​IMG]

    Well, I have some doubts about some of the parameters I used in the simulation, and a few folks had their own input; some of it different from what I simulated, but that could be due to (possibly erroneous) assumptions I'd made. Nothing is better than hands-on with the actual parts!

    Unfortunately, incandescent lamps have the wrong profile for this sort of thing; low resistance when cold and high when hot. What's needed is an ideal voltage clamp that is below the maximum ratings of the driving MOSFET/transistor and certainly less than the insulation rating of the solenoid wiring. Resistors are still viable; they will be more reliable and less expensive than an active clamp, with the trade-off that the current decay will be slower.

    I've thought of using it to charge a cap to high voltage (even simulated it) which would basically recover the energy, but it caused the solenoid coil to ring like the dickens. Until myself or someone else can figure out a way to stop that, and actually DO something with the recovered energy, it'll just cause problems.

    Well, machinists have to be mighty handy with numbers in order to get good results with their machine work. The formulas involved won't be very difficult.

    Very cool!

    My Dad had an old South Bend lathe in the basement up north, and during my teen years I spent many happy hours converting Dad's round steel stock into little steel chips. ;) Seriously though, I made some pretty nifty stuff - all gone now though; I simply didn't have room for it after he passed on. :( Well, maybe someday...
     
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  8. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    The point springs can be made weaker by grinding. They are around 3/8" wide stock, taking them out and grinding them narrower will lower the force. Not the thickness but the width.

    I've got a 9" South Bend from the late 1930s and a 12" Logan from the same period. The Logan was originally a 'over head belt drive'.
     
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  9. Dyslexicbloke

    Active Member

    Sep 4, 2010
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    Have you considered using a push pull solenoid ...
    You would have a double acting engine then and could control the solenoid current with a full bridge driver chip.
    I think that driving the field in the opposite direction would be the fastest way to collapse it but that just a guess ... Someone will correct me if I am wrong I am sure.

    If you added a sensor to tell you which side of TDC you were at you could even decide which way to start it rotating.
    You might even want to look at a hula hula engine configuration, you could drive that like a stepper motor.

    Looks like fun .... Thanks for the entertainment.
    Al
     
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  10. tom66

    Senior Member

    May 9, 2009
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    How about this for recovering energy?

    Same principle as a boost converter.
     
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  11. strantor

    AAC Fanatic!

    Oct 3, 2010
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    When I read "solenoid engine" I got excited. See, when I read "solenoid" I think of a solenoid operated valve; I know, incorrect, but that's my habit. I had dreamed up a plan a while back to make a steam/air engine with piston gasses controlled by solenoid operated valves. I thought it would be cool to control the timing electronically and all that. never did it, but I was excited to see someone else try. but, alas, it's only a more efficient idea...
     
  12. CDRIVE

    Thread Starter Senior Member

    Jul 1, 2008
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    OK, quite a few replies here, but before I get to answering them I'd love to know why this was moved to the "Chat" section? Heck, before this thread runs its course it will be chuck full of "Build It".. IE, "Project" information. Actually, it alsready is! Fact is, my first post included a schematic and block diagram that was intended to garner critiques, which it certainly did. Just because it's not my project (it will be), it definitely is a project.

    Now that this has been moved here I certainly hope that the boys on HSM can find it.

    Chris
     
  13. SgtWookie

    Expert

    Jul 17, 2007
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    Chris,
    Why not just post a link to it over on their site?

    I see this thread as sort of an "introductory/general information" type of thread; basically to introduce members on this site to these solenoid-driven motors/engines - and to perhaps comment and throw out some ideas. As such, I'll have to agree with the staff members that the General Electronics Chat is the best forum to place the thread in; it will get the most exposure.

    However, to try to keep things sorted - if someone wishes to pursue an individual idea, it would really be best to start a separate topic for that idea and link back to this thread, to keep the "flow" going smoothly. Otherwise, things could get confusing very quickly.
     
  14. CDRIVE

    Thread Starter Senior Member

    Jul 1, 2008
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    Sarge, I did post a link there but I was afraid the link would be broken when the mods moved it. Anyway, not a problem. I tested the link and it brings them here.

    Dunka! ;)
     
    Last edited: Oct 11, 2011
  15. CDRIVE

    Thread Starter Senior Member

    Jul 1, 2008
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    I have a Logan too! It's a 1954 920. I bought it for $50.00 stripped. HS, TS, Carriage. All gears were missing, so it was converted to a wood turning lathe. I made a foot clutch/brake that works very well because flat belts clutch well. ;)

    I bought it way back in the early to mid 70's from a club member when I was a member of the Suffolk County Radio Club in LI N.Y. How the hell I lived through those winters escapes me! :D
    Chris
     
    Last edited: Oct 11, 2011
  16. CDRIVE

    Thread Starter Senior Member

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    Al, funny you should mention it. That's how the thread on HSM got started.

    Chris
     
  17. CDRIVE

    Thread Starter Senior Member

    Jul 1, 2008
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    Sorry it wasn't what you thought.

    Chris
     
  18. CDRIVE

    Thread Starter Senior Member

    Jul 1, 2008
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    They're pretty good at restocking certain items. If not, I'll have to do some looking

    Points are starting to look better all the time. I don't think these motors will be aproaching those limits

    Sorry to say, no.

    Ha, I guess dwell was not measured using a feeler gage.

    Yeah, and how do you know what the inductance is without just guesstimating it.

    More thought will be needed here

    Yes, but they want simplicity.

    Yup, they're beautiful old American Iron.

    Chris
     
  19. CDRIVE

    Thread Starter Senior Member

    Jul 1, 2008
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    Bernard, did ya save a picture of it? :D

    Chris
     
  20. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    Interesting! Of course you could just put a diode across the solenoid coil as that will keep the magnetic field in the coil for the max time possible, giving the max length of "field on" time for the same input pulse (same points ON duration). It would also reduce points arcing somewhat.

    Does anyone have a good link to build threads for these solenoid engines?
     
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