Multiple stepper motor gauges (Not automotive)

Discussion in 'The Projects Forum' started by Pete_In_Spain, Apr 10, 2013.

  1. Pete_In_Spain

    Thread Starter New Member

    Apr 10, 2013
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    Hi,

    I've searched through the forum but can't find much about this. I have noticed comments about automotive projects and the forums concerns about these.

    OK, I have a very old boat that I am trying to restore, on a tight budget. I'm learning to do as much as I can so as to keep the costs down. I inherited two GM 6.5 diesel motors that I intend to fit into the boat but considering the boat was a petrol boat before, I need to change a lot of stuff.

    I would like to make a completely new dash board, with all the gauges I would like. These would cost a fortune and would still look like an overcrowded panel. So, I would like to make my own panel, using stepper motors. So that it would look similar to a car dash board.

    I have read quite a lot about stepper motors and from what I gather, they are either controlled by the vehicles (on a car) computer, or by controllers.

    Can anyone make any suggestions or point me in the right direction? I would like to make this a full project on here, from start to finish.

    Many thanks

    Peter
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    You need to figure out how to take inputs from the various devices and then control the steppers in relation to those signals..
    Microprocessor time. I hope you are willing to learn some programming if you don't know some already.
     
  3. Pete_In_Spain

    Thread Starter New Member

    Apr 10, 2013
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    Hi mcgyvr,

    I'm ready to learn whatever I need to, to complete this. Any suggestions for the right places to start, would help.

    So was I correct? each stepper motor needs a controller and each controller needs to be programmed to transfer the inputs into dial movement?
     
  4. gerty

    AAC Fanatic!

    Aug 30, 2007
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    In case you already haven't thought about it, the gauges must be sealed to keep moisture out, especially if it's salt water. I recently had to replace 2 toggle switches on one of our Rescue boats.
    I had originally installed them, so I know how long they've been there. And the boats are kept in a garage until needed, but they've been caught in the rain a few times.. Point I'm trying to make is, if a simple toggle switch with 20 amp contacts can go bad, on a boat that doesn't see a lot of use, steppers can too. Choose your parts carefully.
     
  5. Brownout

    Well-Known Member

    Jan 10, 2012
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    Steppers work by processing pulses. So the controller takes an input and converts it to a properly formatted pulse train. The driver electronics typically consist of a power transistor H-Bridge for bipolar steppers, or a simple transistor pair for a unipolar one. The reason mcgyver suggested a microcontorller is to convert the various inputs to the require pulse train. Simple stepper setups can be made without a UC, but for processing alot of inputs, a UC will make life easier.

    Without more specific information, that's all I can offer. The web is full of information about steppers, controllers, drivers, etc.
     
  6. Pete_In_Spain

    Thread Starter New Member

    Apr 10, 2013
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    Advise noted, thank you.

    I do plan to seal the new toughened glass front, to the box that holds the dials etc. I'll probably mold a gell coated fiberglass box, with sealed cable fittings and a seal for the glass front. Than should keep the salt out.

    Thanks again.

    Peter
     
  7. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    my first step would be to list all the devices you want to indicate and then figure out what type of signals those devices sensors output.
    Then its a matter of figuring out how to get those signals into a microprocessors inputs, then comes picking out stepper motors and deciding on drivers for them.
    Then pick a microprocessor and on and on.. Its really not a simple task for a beginner IMO.
     
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  8. Pete_In_Spain

    Thread Starter New Member

    Apr 10, 2013
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    Thanks McGyvr,

    Sorry not to have replied before, family responsibilities.

    Ok, I have noted your points, although I understand the basics, I'm still trying to read up on as much as possible. The engines are GM diesels, so I am presuming that signals generated should be acceptable, as GM use stepper motor gauges and there are some aftermarket gauge companies supplying plug and play gauges for them.

    I've been reading high praises for the "Arduino" microprocessors, the controllers I'm not really sure what would be best suited. The Switec stepper motors look like my best option because of their general use in the automotive market and ease of replacement, should any need to be.

    Having said all that, I am still very much a beginer, so I am hoping for some help from you guys, please.

    Peter
     
  9. John P

    AAC Fanatic!

    Oct 14, 2008
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    One thing to note is that steppers don't have any inherent absolute position, so the accuracy is based on knowing where you start from and never losing any steps. You will need a startup procedure, which could be as crude as running the motor into a stop, or could be a microswitch or optical sensor. And then you mustn't miss steps. I have the feeling that small boats vibrate a lot--could that cause the motor to jump?
     
  10. Pete_In_Spain

    Thread Starter New Member

    Apr 10, 2013
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    Thanks for the idea John,

    What would you suggest, as an alternative? I guess there must be as much vibration in a GM 4x4 but that's just my guess.

    Thanks

    Peter
     
  11. shortbus

    AAC Fanatic!

    Sep 30, 2009
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  12. JohnInTX

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    Jun 26, 2012
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  13. Pete_In_Spain

    Thread Starter New Member

    Apr 10, 2013
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    Thanks for the links, they look like an answer to the design. Now I have to start learning I guess.

    Unless there's anyone out there who would like to take on the challenge and show their abilities? Of course, they will keep all circuit and programming design rights and when built, can have access to all and any test results?
     
  14. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Like I said, several other people have gone down the route your taking. Have a look at or join some of the micro controller forums. They may already have the codes you need available.

    As far as the actual gauges, have you considered adapting an existing gauge cluster from auto recycler/wrecking yard? Using standard stepper motors will just add another layer of complexity to another wise complex project.
     
  15. Pete_In_Spain

    Thread Starter New Member

    Apr 10, 2013
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    Is there any chance you could suggest any links for those forums?

    Regarding the stepper motors, I was under the impression that the Switec stepper motors were used by GM and other vehicle manufacturers, thus being easy to source and renew, if necessary. Obviously I would like something that could be maintained.

    Thanks

    Peter
     
  16. shortbus

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    Sep 30, 2009
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