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HB-25 Questions — Parallax Forums

HB-25 Questions

ajwardajward Posts: 1,130
edited 2015-05-26 16:12 in General Discussion
Hi All!

As the title says, I have a few questions about the HB-25 motor controller. I got a couple new, in-package, from eBay for about $32 and I want to revive Orville. I'll be driving 80 RPM Pololu motors with a 12 volt stall current of 5 amps. The uC will be the long forgotten MSR1 Robot Control Board.

I understand I should replace the fuses with 5 amp units to protect the motors. Correct?

Then... How hot can the HB-25 run? I didn't get the mounting brackets and plan on mounting the controllers directly to the plastic deck of the 'bot. I can also mount them on aluminum angle stock to dissipate some heat if needed.

What is the best way to connect power to the unit? The power terminals look scary close to the fuse holder terminals!!!

I understand the HB-25 will function correctly with the same code that drives a BoeBot. Though, as you can see above, I'm going run the 'bot with a Propeller and use C (hopefully).

Lastly, is there a compelling reason to daisy chain the controllers as shown in the documentation? The MSR1 has a gaggle of servo connectors. :-)

Anyhow, thanks for your patience. I hope my queries aren't too rookie!

Amanda

Edit. Should be interesting. I first built Orville with the 310 RPM motor2 in the Stingray kit and he was the terror of drywall everywhere in the building! :-)

Comments

  • Duane DegnDuane Degn Posts: 10,588
    edited 2015-05-23 14:12
    ajward wrote: »
    Hi All!

    As the title says, I have a few questions about the HB-25 motor controller. I got a couple new, in-package, from eBay for about $32 and I want to revive Orville. I'll be driving 80 RPM Pololu motors with a 12 volt stall current of 5 amps. The uC will be the long forgotten MSR1 Robot Control Board.

    I understand I should replace the fuses with 5 amp units to protect the motors. Correct?

    I suppose swapping the fuses on the HB-25 is an option, but I'd just add an additional fuse holder between the battery and the HB-25. I can't think a good reason to not just swap the fuse on the HB-25 though.
    ajward wrote: »
    Then... How hot can the HB-25 run? I didn't get the mounting brackets and plan on mounting the controllers directly to the plastic deck of the 'bot. I can also mount them on aluminum angle stock to dissipate some heat if needed.

    I can't see the HB-25 getting hot on 5 amps. I've never had mine get above room temperature that I've noticed. The fan on the HB-25 runs all the time so it doesn't get a chance to get warm if you're not driving it hard.
    ajward wrote: »
    What is the best way to connect power to the unit? The power terminals look scary close to the fuse holder terminals!!!

    I added some heat shrink tubing to the fuse holder closest to one of the power terminals.

    I had some thick copper wire I bent into loops to make my own connectors. I think there are better solutions around.
    ajward wrote: »
    I understand the HB-25 will function correctly with the same code that drives a BoeBot. Though, as you can see above, I'm going run the 'bot with a Propeller and use C (hopefully).

    Lastly, is there a compelling reason to daisy chain the controllers as shown in the documentation? The MSR1 has a gaggle of servo connectors. :-)

    IMO, it's easier to just control each HB-25 independently. This way you can use normal CR servo code. I haven't ever tried to use the daisy chain feature.

    The HB-25 controllers have better speed range than many CR servos so the code may need to be adjusted a bit.
    ajward wrote: »
    I first built Orville with the 310 RPM motor2 in the Stingray kit and he was the terror of drywall everywhere in the building! :-)

    If you can add encoders to the motors, they could be tamed. It's my opinion encoders make just about any robot better.
  • ajwardajward Posts: 1,130
    edited 2015-05-24 08:41
    Many thanks Duane!!
    I suppose swapping the fuses on the HB-25 is an option, but I'd just add an additional fuse holder between the battery and the HB-25. I can't think a good reason to not just swap the fuse on the HB-25 though.
    I can't see the HB-25 getting hot on 5 amps. I've never had mine get above room temperature that I've noticed. The fan on the HB-25 runs all the time so it doesn't get a chance to get warm if you're not driving it hard.

    Good. I really don't want to have to fabricate anything I don't hafta. Took the fuse to a local parts store and the clerk had no idea of what it was. Probably won't go there again.

    I added some heat shrink tubing to the fuse holder closest to one of the power terminals.
    I had some thick copper wire I bent into loops to make my own connectors. I think there are better solutions around.

    I wouldn't have thought of the heat shrink tubing... at least for a long time. :-) I picked up some GB 22-gauge insulated, ring terminals for the power connectors. They're only slightly wider than the HB-25 terminals.
    IMO, it's easier to just control each HB-25 independently. This way you can use normal CR servo code. I haven't ever tried to use the daisy chain feature.
    The HB-25 controllers have better speed range than many CR servos so the code may need to be adjusted a bit.

    I thought that would be the case.
    If you can add encoders to the motors, they could be tamed. It's my opinion encoders make just about any robot better.

    The motors have encoders, but I could never figure out how to make them work correctly. But these motors turn slowly enough, I might be able to control them... somewhat! :-)

    Amanda
  • Duane DegnDuane Degn Posts: 10,588
    edited 2015-05-24 10:39
    ajward wrote: »
    Took the fuse to a local parts store and the clerk had no idea of what it was.

    I'd think an auto parts store would be able to find some.

    I ordered a variety of fuses from ICStation. I'm still waiting for the slow boat from China.

    Here's one of their 5A fuses which looks like it may be the right size but I'm not sure.

    http://www.icstation.com/l445a-color-coded-blade-fuse-assorted-fuse-auto-carst-p-3937.html
    ajward wrote: »
    But these motors turn slowly enough, I might be able to control them... somewhat! :-)

    Those look like nice motors. I have some of their 70:1 motors with encoders with the same size base motor. The encoders on those will work with 3.3V power so you can use them directly with the Propeller. If you use 5V on the encoders you'll want series resistors (your board might already have these).

    I have some Spin encoder and motor code but I presently don't have any C options.

    My "QuadratureMotors" object will drive motors and monitor quadrature encoders. The number of motors/encoders is set with constant "TOTAL_ENCODERS."
    CON
    
      TOTAL_ENCODERS = 2            '' User changeable
                                    '' It is possible to change to any number (within reason)
                                    '' of motors with encoders
    

    The object should work with HB-25 controllers or normal h-bridges. To identify a motor as being controlled like a CR servo, both direction pins are set to negative one. I just noticed the present header file is set up to use HB-25 controllers.

    Here's the GitHub link:
    https://github.com/ddegn/QuadratureMotors

    As I look over the code I see several areas which may need some explaining such as how the I/O pins are passed to the child object. If you want to try the code, let me know, and I'll walk through the changes you'd need to make to the demo to work with your hardware.

    I keep intending to add an example of the code running with a P.I.D. algorithm but it's still one of the many things on my robotics To Do list.
  • ercoerco Posts: 20,256
    edited 2015-05-24 10:41
    Ever since I started wrapping aluminum foil around my fuses, they stopped blowing, like magic. In fact, the foil even heals blown fuses. The extra capacitance stops the EMP surge and inrush current using the skin effect. Alum foil isn't just for alien invasions anymore.





    Yes, I'm kidding.
  • ajwardajward Posts: 1,130
    edited 2015-05-24 15:32
    erco wrote: »
    Ever since I started wrapping aluminum foil around my fuses, they stopped blowing, like magic. In fact, the foil even heals blown fuses. The extra capacitance stops the EMP surge and inrush current using the skin effect. Alum foil isn't just for alien invasions anymore.





    Yes, I'm kidding.

    The foil also hides those colors that clash with your 'bot! ;-)

    @
  • Ken GraceyKen Gracey Posts: 7,392
    edited 2015-05-25 07:39
    ajward, I'd be happy to drop some fuses in USPS for you. Just PM your shipping or customer number.

    Thanks,

    Ken Gracey
  • GenetixGenetix Posts: 1,754
    edited 2015-05-26 11:05
    The HB25 documentation refers to the fuses as being Automotive Mini ATC types but Littlefuse and Bussman, the 2 main manufacturers, don't ever mention ATC in the description of their MIni fuses.
    According to MCM Electronics, the Littlefuse MINI-series are Mini ATC fuses and the cross-reference on Bussman's website lists their MTM-series as being the same as Littlefuse's MINI-series.
    I did notice though that the top length of the MTM-series is a little more than the MINI-series according to the datasheets.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2015-05-26 11:11
    I always thought the ATC fuses were the bigger ones. The minis have their own naming convention, or that's what I have encountered at Pep Boys.
  • ercoerco Posts: 20,256
    edited 2015-05-26 15:00
    Google's your friend! http://us.playhohner.com/instruments/bluegrass/banjos/hb25/

    Oh, you meant the other HB25.

    Never mind.
  • GenetixGenetix Posts: 1,754
    edited 2015-05-26 16:12
    I usually use Yahoo because Google brings up too much unrelated garbage, but I forget exactly what I typed and all I got was a list of places to buy from.

    Wikipedia though is a great source of unbiased information since anyone can make changes to it.
    http://en.wikipedia.org/wiki/Fuse_(automotive)
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