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PHD Conversion ..

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Created by Macroscien > 9 months ago, 20 Apr 2013
Macroscien

Macroscien

QLD, 6809 posts
20 Apr 2013 2:11PM
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from petrol to electric of course

Just finished the prototype project and ready for first field trails.

After my original 71 cc petrol motor blow up in very spectacular way on my auger I decided to use parts for always intriguing me electric version.

I used old chain saw that finish life due to bar and chain worn out with this powerful 1600W brushed motor.
I decided to leave original clutch to interface new motor - just for safety- to disengage just in case.




works fine, plenty of torque but ....



one problem remains. Auger is turning now in wrong direction ! Could I change spin on the motor ?

dirtyharry

dirtyharry

WA, 444 posts
20 Apr 2013 1:17PM
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Easy fixed - just mount the motor on the other end of the auger, or drill the hole from the bottom up .

It's been said before, but I'd love to spend a couple of hours watching what goes on inside your head Macro.

ikw777

ikw777

QLD, 2995 posts
20 Apr 2013 3:55PM
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PHD conversion? I thought this was going to be a thread about exiting with an MPhil. (figure that one out)

Macroscien

Macroscien

QLD, 6809 posts
20 Apr 2013 5:38PM
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ikw777 said...
PHD conversion? I thought this was going to be a thread about exiting with an MPhil. (figure that one out)

I am sorry to dissappoint you Kilowatt but I am down to earth guy and this is all about earth digging.
I hope I could dig some gold nuggets by a chance.[}:)]
My PHD shortcut doesn't stand even for Ph.D,
just simple Post Hole Digger or Auger in short

youngbull

youngbull

QLD, 826 posts
20 Apr 2013 6:09PM
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Now drilling into underground power will be even more exciting.

I would be placing some rubber around that handle before your body looks partially like your avatar.

Btw - nice job.

ikw777

ikw777

QLD, 2995 posts
20 Apr 2013 7:40PM
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Macroscien said...
ikw777 said...
PHD conversion? I thought this was going to be a thread about exiting with an MPhil. (figure that one out)

I am sorry to dissappoint you Kilowatt but I am down to earth guy and this is all about earth digging.
I hope I could dig some gold nuggets by a chance.[}:)]
My PHD shortcut doesn't stand even for Ph.D,
just simple Post Hole Digger or Auger in short



Well, you don't exactly have a good rep for English usage Macro!

Macroscien

Macroscien

QLD, 6809 posts
20 Apr 2013 7:55PM
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ikw777 said...

Well, you don't exactly have a good rep for English usage Macro!


I know working on this problem hard
Should I invent now electric dictionary ?

FormulaNova

FormulaNova

WA, 15105 posts
20 Apr 2013 6:28PM
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The chainsaw uses a universal motor doesn't it (wound stator and rotor). If so, and the gearbox can handle it, reverse the wiring to either the stator's field windings or rotor. Hope I got the terminology correct!

*edit: fixed up the terminology

Macroscien

Macroscien

QLD, 6809 posts
20 Apr 2013 9:00PM
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FormulaNova said...
The chainsaw uses a universal motor doesn't it (wound armature and rotor). If so, and the gearbox can handle it, reverse the wiring to either the armature or rotor. Hope I got the terminology correct!

I may try this, but still have some hope that I don't need to open and unscrew everything again.
Since universal motor works both on AC or DC , I wonder if by putting rectifier in serial and then changing polarization will:
a) change the spin
or
b) universal motor works on DC in one direction regardless of polarization (depending only on internal wiring) ?

FormulaNova

FormulaNova

WA, 15105 posts
20 Apr 2013 7:04PM
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Macroscien said...
FormulaNova said...
The chainsaw uses a universal motor doesn't it (wound armature and rotor). If so, and the gearbox can handle it, reverse the wiring to either the field winding or rotor. Hope I got the terminology correct!

I may try this, but still have some hope that I don't need to open and unscrew everything again.
Since universal motor works both on AC or DC , I wonder if by putting rectifier in serial and then changing polarization will:
a) change the spin
or
b) universal motor works on DC in one direction regardless of polarization (depending only on internal wiring) ?




No, rectifying it to DC is not going to change anything. The motor will always run in the same direction, no matter which polarity you hooked it up with.

A universal motor needs to have the polarity of the field OR the rotor changed in order to change its direction. Its the same if its AC, DC, or any other C.

Macroscien

Macroscien

QLD, 6809 posts
20 Apr 2013 9:11PM
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FormulaNova said...
Macroscien said...
FormulaNova said...
The chainsaw uses a universal motor doesn't it (wound armature and rotor). If so, and the gearbox can handle it, reverse the wiring to either the field winding or rotor. Hope I got the terminology correct!

I may try this, but still have some hope that I don't need to open and unscrew everything again.
Since universal motor works both on AC or DC , I wonder if by putting rectifier in serial and then changing polarization will:
a) change the spin
or
b) universal motor works on DC in one direction regardless of polarization (depending only on internal wiring) ?




No, rectifying it to DC is not going to change anything. The motor will always run in the same direction, no matter which polarity you hooked it up with.

A universal motor needs to have the polarity of the field OR the rotor changed in order to change its direction. Its the same if its AC, DC, or any other C.



OK do you think it may also a sense to do a switch to reverse, just in case ?
Do we need sometimes run auger in opposite direction ( if stack terribly) ?
Since I have to re-do I want to install one of those :

http://www.ebay.com.au/itm/360526692718?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649#ht_1887wt_1139
or
www.ebay.com.au/itm/160981163727?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649#ht_2041wt_1139
only 6 amp but may work for a while

FormulaNova

FormulaNova

WA, 15105 posts
20 Apr 2013 7:13PM
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If you don't understand why polarity is not gong to make a difference, if you rectify it, take a look at the wiki page:

en.wikipedia.org/wiki/Universal_motor

The first paragraph and the last paragraph both describe this.

FormulaNova

FormulaNova

WA, 15105 posts
20 Apr 2013 7:17PM
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Macroscien said...

OK do you think it may also a sense to do a switch to reverse, just in case ?
Do we need sometimes run auger in opposite direction ( if stack terribly) ?



If you want it to be able to reverse, then yes, sure. I've never used one, but you can imagine it might be a requirement.

You can get external electronic speed controls. I am sure ebay would have those too.

The stories you read about these things, I would want some sort of safety switch where it automatically stops somehow. Say when you released it or something.

Macroscien

Macroscien

QLD, 6809 posts
20 Apr 2013 9:18PM
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FormulaNova said...
If you don't understand why polarity is not gong to make a difference, if you rectify it, take a look at the wiki page:

en.wikipedia.org/wiki/Universal_motor

The first paragraph and the last paragraph both describe this.

In such case if I change A1 and A2 that should be sufficient
?
That will be easy access to the brushes from another

- top side of that motor

Macroscien

Macroscien

QLD, 6809 posts
20 Apr 2013 9:22PM
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FormulaNova said...
I would want some sort of safety switch where it automatically stops somehow. Say when you released it or something.

right, I could add some thermal fuse to avoid overloading when stack and burning whole motor.
The sort I have in my electric tiller already.

FormulaNova

FormulaNova

WA, 15105 posts
20 Apr 2013 7:22PM
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Macroscien said...

In such case if I change A1 and A2 that should be sufficient
?
That will be easy access to the brushes from another

- top side of that motor



Yes, that would probably do it.

FormulaNova

FormulaNova

WA, 15105 posts
20 Apr 2013 7:24PM
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Macroscien said...
FormulaNova said...
I would want some sort of safety switch where it automatically stops somehow. Say when you released it or something.

right, I could add some thermal fuse to avoid overloading when stack and burning whole motor.
The sort I have in my electric tiller already.



No, I meant something to stop it when you get your shirt caught in it and it won't stop, sort of switch.


Macroscien

Macroscien

QLD, 6809 posts
20 Apr 2013 9:26PM
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FormulaNova said...
Macroscien said...
FormulaNova said...
I would want some sort of safety switch where it automatically stops somehow. Say when you released it or something.

right, I could add some thermal fuse to avoid overloading when stack and burning whole motor.
The sort I have in my electric tiller already.



No, I meant something to stop it when you get your shirt caught in it and it won't stop, sort of switch.




???
Sort of DEAD MAN SWITCH ?? All trains suppose to have one.
How it may work ?

That was sort of thing that actually happend to my original petrol motor in this exactly auger.
Somehow stack on high revs
then I released accelerator-
still on on high speed !!
turned the ingnition off
-still on !!!!
-rip the ingition cable off the spark plug !!
-- Still on full revs
I left the thing running full speed on the ground and run to bring the hose with water -
after a minute of purring water on the engine eventually stopped

FormulaNova

FormulaNova

WA, 15105 posts
20 Apr 2013 7:32PM
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Macroscien said...
FormulaNova said...

No, I meant something to stop it when you get your shirt caught in it and it won't stop, sort of switch.


???
Sort of DEAD MAN SWITCH ?? All trains suppose to have one.
How it may work ?




Maybe have one of those ebay drill controller triggers mounted in a hand-held switch on the handles, not the chainsaw itself, so you have to hold it down to make it work? A switch with a safety strap somehow that pulls a pin when the auger rotates too far?

I don't know. You are on your own when it comes to safety.


Darkspi

Darkspi

SA, 171 posts
21 Apr 2013 5:58AM
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$350 stress less :)Its bin done before no need to reinvent the wheel I guess some ppl just have to much time on their hands
www.machines4u.com.au/view/advert/AUGER-POST-HOLE-DIGGER-49CC-WITH-THREE-AUGERS/30723/

FormulaNova

FormulaNova

WA, 15105 posts
21 Apr 2013 7:27AM
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Darkspi said...
$350 stress less :)Its bin done before no need to reinvent the wheel I guess some ppl just have to much time on their hands
www.machines4u.com.au/view/advert/AUGER-POST-HOLE-DIGGER-49CC-WITH-THREE-AUGERS/30723/


$350? Its says $400.

I don't know about Macro, but sometimes you get a sense of satisfaction from modifying things to do what you want, sometimes you waste money.

I hate things like fishing, but I could happily sit there and rebuild a motor or make something from scratch, even if its more cost effective to just buy something.

FormulaNova

FormulaNova

WA, 15105 posts
21 Apr 2013 7:33AM
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Macroscien said...

That was sort of thing that actually happend to my original petrol motor in this exactly auger.
Somehow stack on high revs
then I released accelerator-
still on on high speed !!
turned the ingnition off
-still on !!!!
-rip the ingition cable off the spark plug !!
-- Still on full revs
I left the thing running full speed on the ground and run to bring the hose with water -
after a minute of purring water on the engine eventually stopped




Weird. Sounds like it was hot enough to diesel. I never thought that could happen, but it must have. I suspect the throttle wasn't moving though, and stuck open, as I am not sure it would continue on at high speed if the throttle plate was almost closed, even if it was running without a spark.

At least you can unplug an electric motor easily! It would feel safer after having that happen with a petrol motor.

Macroscien

Macroscien

QLD, 6809 posts
21 Apr 2013 11:40AM
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FormulaNova said...


Weird. Sounds like it was hot enough to diesel. I never thought that could happen, but it must have

Really strange indeed but I think two factors could contribute to such phenomenon IMO ( self sustained combustion)
a) spark plug hot enough to backfire
b) small gap between carburetor and engine body allowing air to sneak in (when diss-assembling I found some mounting bolts quite loose

This particular 71 cc petrol motor was always problematic and very frustrating, hard to start and doesn't work on idle. The loose carburetor could possibly explain it.

Macroscien

Macroscien

QLD, 6809 posts
21 Apr 2013 11:43AM
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FormulaNova said...
but sometimes you get a sense of satisfaction from modifying things to do what you want



+10
I am almost not happy with any new device or tool I buy and instantly try to modify it

Macroscien

Macroscien

QLD, 6809 posts
21 Apr 2013 11:48AM
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Darkspi said...
$350 stress less :)Its bin done before no need to reinvent the wheel I guess some ppl just have to much time on their hands
www.machines4u.com.au/view/advert/AUGER-POST-HOLE-DIGGER-49CC-WITH-THREE-AUGERS/30723/

here it is commercial electric one but :
a) available only from US - 1) shipping expensive 2) 110V
b) motor only 1200W which is good for small auger maybe, but not 15-20 cm, and mine is 1600W +
c) the same cost only $80 from manufacturer directly so I am reluctant to pay $300- 400
d) mine may has a improvements that commercial may don't : speed regulator, thermal protection, reverse gear, dead man switch

www.ebay.com.au/itm/StrikeMaster-Big-Volt-Electric-Auger-BVE-1025-10-25-Volt-/221216495846?pt=LH_DefaultDomain_0&hash=item338187d8e6&_uhb=1#ht_666wt_1397


Macroscien

Macroscien

QLD, 6809 posts
21 Apr 2013 1:37PM
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Apparently not all universal motors are designed to work in both direction comfortably.
After reversing cables on brushes connectors motor works in opposite direction,
auger dig in in the ground like in butter but there is excessive sparking on the commutator
that could burn the motor eventually quick

so unless I will find another motor, the best could be lightweight induction motor , (because is very quiet) , at 3000 RPM which ideal to propel this gearbox,
the project is now dead ...

Induction motor should be also much easier to attach to the auger and clutch could be mounted directly on the shaft.



FormulaNova

FormulaNova

WA, 15105 posts
21 Apr 2013 4:04PM
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Macroscien said...
Apparently not all universal motors are designed to work in both direction comfortably.
After reversing cables on brushes connectors motor works in opposite direction,
auger dig in in the ground like in butter but there is excessive sparking on the commutator
that could burn the motor eventually quick

so unless I will find another motor, the best could be lightweight induction motor , (because is very quiet) , at 3000 RPM which ideal to propel this gearbox,
the project is now dead ...

Induction motor should be also much easier to attach to the auger and clutch could be mounted directly on the shaft.







I am not sure you will find a 'light weight' induction motor rated at 1hp. Sorry, I am too lazy to look it up, but what's the conversion from Kw to HP? 1.5Kw = 1Hp?

Either way, from memory, a lot of common household induction motors top out at 750W, and they are going to be fixed speed, and your speed controller will not work with them.

I'm not sure why there is excessive sparking. Is it a lot different to when it runs in the normal direction? Under load or no load?

Can you use a chain drive between your existing motor and the auger's gearbox and flip the motor over?


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"PHD Conversion .." started by Macroscien



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