Motor speed controls - store bought and ???

Discussion in 'Burners and their construction' started by dennis, Dec 31, 2020.

  1. dennis

    dennis Silver

    I purchased an H-F router speed controller some time ago, and retrofitted it with a Large cast aluminum heat sink, in anticipation of giving it a workout with a leaf blower (with brushes). Trouble is, it doesn't slow down the blower all that much.
    Speed-controller_side.jpg
    Anyone have a better idea so as to dial the wind down?
     
  2. FishbonzWV

    FishbonzWV Silver Banner Member

    I use a variac to control my shop vacuum system.
     
    dennis likes this.
  3. Tobho Mott

    Tobho Mott Gold Banner Member

    The light dimmer switch that works fine to control my small shop vac blower just made my leaf blower go crazy in the mid range of settings instead of giving smooth adjustment.
    For me, a HF router speed controller was the cure, I guess our leaf blowers must use different types of motor. You could use a gate to dump excess air, but I prefer using a dial that makes the blower not so darn loud if it doesn't need to be. Good luck!
    Jeff
     
  4. dennis

    dennis Silver

    True. Then there's the variac... or perhaps using a circuit one has found, like this one?
     

    Attached Files:

  5. Jim Edgeworth

    Jim Edgeworth Silver

    If your not in a hurry, go to AliExpress, they have AC Motor Speed Controllers cheap as chips ($2 -$10). I bought a $4 one to control the power feed on my mill, works great.
     

    Attached Files:

  6. Jammer

    Jammer Silver Banner Member



    This guy has a lot of great info on motors, controlling speed, Variacs and other stuff.
     
  7. Petee716

    Petee716 Gold Banner Member

    Forgive me if I'm speaking a bit out of school but if your motor has a triac or some other speed control built in like as in a vaiable speed drill or a variable speed router, it may be confounding your HF speed controller. Maybe. I use one on a Kirby vacuum (brushed) and it works fine. I'll give the video posted by Jammer a look.

    Pete
     
    dennis likes this.
  8. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I was thinking the same thing as Petee, or possibly the leaf blower is too low of a load. Have you tried the HF controller on another brush motor? That looks like the one I use on my pressure/vac blower rig. If so, it has a three position switch, Fwd/off/Rev. Might be worth checking that switch.

    Best,
    Kelly
     
  9. dennis

    dennis Silver

    No, the blower in question does not have a triac - as far as I know.
     
  10. dennis

    dennis Silver

    I need to find it, first!
     
  11. rocco

    rocco Silver

    There are a few types of AC motors, only "universal" motors will work with an HF type speed controllers. These motors are set up the same way as a brushed DC motor meaning with brushes and a segmented commutator. Vacuum cleaners and routers typically use universal motors, it's possible your leaf blower does not.
     
  12. dennis

    dennis Silver

    No, it was brushed. I think the router speed control has issues.

    I found it about ten minutes ago, and plugged in an old Ryobi trim router. (On-off, one speed, full-scream, 23,000 rippums) Up to perhaps two thirds of full, the router would turn over in spurts, like so:

    "Brt... brt... brrrtt..."

    Increasing the power made the "brrrttts" longer, up to perhaps 2/3 of the way, where the router ran normally, although at reduced RPM. From 2/3 to full, the speed varied according to the knob.

    Seems "Harrob" got their "Frigate" in backwards. At least I have the heat-sink pattern still.
     
  13. Tobho Mott

    Tobho Mott Gold Banner Member

    Sounds like your router speed controller is behaving like my dimmer switch instead of behaving like my router speed controller. I wonder if they started building them differently after I got mine?



    Skip to 16:05 to see if the brrrttts my dimmer switch was causing are like your brrrttts. I need to try and wrap my head around all this electronics stuff one day, but I can understand brrrttts.

    Jeff
     
  14. dennis

    dennis Silver

    Yes, quite similar, save the brrrrts were shorter, and mixed with "complete off periods."

    The aluminized glove while forging?

    Ps: I might be able to answer some of the electronics questions.

    Pulsations in the furnace seem a matter of airflow velocity, i.e. the speed of flow At the choke needs to be high enough to kill the burner tube's resonance... hence the choke bore and taper needs to figure into the burner setting. (???)
     
    Last edited: Jan 1, 2021
  15. dennis

    dennis Silver

    Here's the router's nameplate: 1609539950906364281675.jpg

    Note where it was made. This is an old router!
     
  16. Mach

    Mach Silver

    Fasted58 and Al2O3 like this.
  17. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Didn't know they were used for bilge venting but very similar to inline HVAC boosters. Pretty economical combo for 130cfm of free air flow with speed control.

    Best,
    Kelly
     
  18. dennis

    dennis Silver

    Question is - does it have enough pressure?
     
    Last edited: Jan 1, 2021
  19. Tobho Mott

    Tobho Mott Gold Banner Member

    I use a ~$20 home depot 300W credenza lamp dimmer switch extension cord to control my hair dryer blower with the blower set to Cool to avoid powering the heating element. I use a bigger blower to burn oil, but for propane or charcoal that has always been plenty of forced air for my needs. Still going strong 7 years in and counting with the same hair dryer and dimmer. Switch might cost a few bucks more these days, but that 20 was in Canadian dollars.

    Jeff
     
  20. dennis

    dennis Silver

    That is the idea. The furnace this arrangement is going to fit has a lot of mass. (It's thirty miles from where I live) It needs to burn oil - a mixture of diesel fuel, used motor oil, and waste cleaning solvent - exact proportions of each to depend upon availability. I suspect that diesel fuel will predominate as a rule, however.

    It is hoped to get the furnace up to Iron temperatures. Even now, it takes much of an hour to melt aluminum.

    The whole setup promises to be a lot of work.
     

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