Author Topic: Motor rotation?  (Read 8159 times)

Offline PJW

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Motor rotation?
« on: March 05, 2016, 08:27:52 AM »
Hi, I have this little motor & it is running the wrong way. I have two items I need help with,
 (1) I need to reverse the rotation &
 (2) what switch do I need to make it run bi-directional.
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Offline PJW

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Re: Motor rotation?
« Reply #1 on: March 05, 2016, 08:30:39 AM »
I am a little worried about shorting the motor!

thanks
Peter
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Offline stevehuckss396

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Re: Motor rotation?
« Reply #2 on: March 05, 2016, 11:41:46 AM »
typically there is a name plate on the motor that shows of its reversiable and if so, the information to do it.

Do not be like the cat who wanted a fish but was afraid to get his paws wet.

Offline PJW

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Re: Motor rotation?
« Reply #3 on: March 05, 2016, 12:15:21 PM »
there is no nameplate!
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Offline BaronJ

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Re: Motor rotation?
« Reply #4 on: March 05, 2016, 12:31:19 PM »
Hello Peter,

It is a bit difficult to see from your pictures, but generally those sort of motors are capacitor start and run.  They don't have a centrifugal switch used to disconnect the start winding. 

It is hard to be sure but the capacitor is connected to one leg of each winding and the other ends of the winding's are connected together and usually are the mains live terminal.  The mains neutral going to one side of the capacitor.  Moving the mains neutral to the other side of the capacitor should cause the motor to run the other way.

The caveat here is that both windings may not be the same value.  A rough check with an ohmmeter should show if the windings are similar or not.  If they measure within a few percent of each other, then I would suggest that they are the same.  Though often the two windings have wire of different sizes, which is a clue to the windings being different.  If this is the case then surgery is required to reverse the motor direction.

HTH.
Best Regards:  Baron.

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Offline Bluechip

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Re: Motor rotation?
« Reply #5 on: March 05, 2016, 01:42:32 PM »
What you appear to have is this.

As you need to get at both ends of the AUX winding you need to strip the motor and bring both ends out to use a DPDT switch. You also need it to be of the 'ON - OFF - ON' type, not a good idea to slam a motor from one end to t'other in an instance.

As Baron says, I doubt if it has a 'start' switch, but if you meter from X to Z [ disconnected of course] you will read the resistance of the RUN winding and metering from Y to Z will tell you what the AUX winding is. I suspect the RUN will be the lower of the two, usually is. [ This does assume the cap is OK and there is no start switch].

The switch appears to be some sort of 'No volt release' type?? Looks a bit relay-ish to me. Which complicates matters somewhat. What's on the other side of it? Start and stop buttons ??  :thinking:


The other way to reverse a motor is to is to swap the ends the RUN winding but you can't get at both ends of this either.

As Baron says, it's a surgery job,   :zap: and sometimes not very easy to get at the common point of the two windings.

Would be nice to know where the motor originates and if it's being 're-purposed' ??

EDIT .... 'C' is the capacitor ..  :old:

Dave
« Last Edit: March 05, 2016, 01:54:20 PM by Bluechip »

Offline Stuart

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Re: Motor rotation?
« Reply #6 on: March 05, 2016, 02:05:08 PM »
Nicely put Dave

With two years armature/stator winding when I did my time I will not comment on this because I would like to apply the mark 1 eyeball to it before passing judgement one wether it can or cannot be made to go backwards , the circuit Dave has posted will do the job fine

Digging in the winding has a high potential to cause it to be K for not working

Stuart
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Offline Alyn Foundry

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Re: Motor rotation?
« Reply #7 on: March 05, 2016, 02:47:29 PM »
Hello Peter.

How many wires are coming out? I see 3 from your photo. Red, Blue and uncertain White?

Kind regards, Graham.

Offline PJW

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Re: Motor rotation?
« Reply #8 on: March 05, 2016, 02:57:07 PM »
Hi Dave, the motor used to be a table saw, the relay switch is as you thought an on/off switch.
I thought I would need an on -off-on switch but I dont know what a DPDT switch? I thought I would need something with a crossover so the capacitor would switch between the red & white with the blue as neutral or was I completely wrong,

Peter
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Offline PJW

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Re: Motor rotation?
« Reply #9 on: March 05, 2016, 02:58:57 PM »
yes there are three wires red white & blue
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Offline Alyn Foundry

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Re: Motor rotation?
« Reply #10 on: March 05, 2016, 03:04:38 PM »
Hello Peter.

Simply cross over the Red and White position, those Orange domes have a tapered thread internally and twist the connections together.

You should have a reversal of motor direction.

Kind regards, Graham.

Offline Don1966

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Re: Motor rotation?
« Reply #11 on: March 05, 2016, 03:33:33 PM »
I don't believe it's that simple Graham. I am not that firmiliar with European motors but when you have three leads the starting winding lead is brought out to tie the capacitor, so that's the third lead and the other end is tied to a common lead. When I did my myford motor connection mod I had to go internal to get the four leads. In the states we have dual voltage motors 120/240 and you only have 240 volt motors so in order to connect it to 120 I had to do a mod. My Myford motor modification is here.....http://www.modelenginemaker.com/index.php/topic,544.msg4409.html#msg4409

Don

Offline Bluechip

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Re: Motor rotation?
« Reply #12 on: March 05, 2016, 04:10:27 PM »
Don is right. It is not that simple. To reverse a motor you have to reverse the current through either the run winding OR the Aux. winding. To do this you need both ends of one or the other. I have done this many times and I don't know of an alternative.

It needs to be like MOTOR 2 piccy.

[1] The end of the AUX winding originally connected to white needs to be to blue.
[2] The end of the AUX winding originally connected to blue needs to be to white.


PJ does not have access to the red-ringed connection without getting into the motor.

DPDT is 'double pole - double throw'.

Bearing in mind you have high inrush current on a motor, this would probably be a suitable switch, but we would need to know just what that 'switch' fitted now does.  :ThumbsUp: 

http://cpc.farnell.com/apem/649nh-2/10a-toggle-plastic-dpdt-on-off/dp/SW02439

Dave
« Last Edit: March 05, 2016, 04:27:40 PM by Bluechip »

Offline Alyn Foundry

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Re: Motor rotation?
« Reply #13 on: March 05, 2016, 04:27:07 PM »
Hello Don and Dave.

I'm basing my post on the fact that to reverse a single phase motor you just need to alter the direction of one winding against the other. Blue is common so theoretically reversing the Red White should see current flowing in the opposite direction. The use of those thumb terminations might also be a clue.

Anyway for the sake of two minutes, time will tell. I'm quite old enough to eat " Humble pie " !!   :)

Kind regards, Graham.

Offline Bluechip

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Re: Motor rotation?
« Reply #14 on: March 05, 2016, 04:31:17 PM »
Hello Don and Dave.

I'm basing my post on the fact that to reverse a single phase motor you just need to alter the direction of one winding against the other. Blue is common so theoretically reversing the Red White should see current flowing in the opposite direction. The use of those thumb terminations might also be a clue.

Anyway for the sake of two minutes, time will tell. I'm quite old enough to eat " Humble pie " !!   :)

Kind regards, Graham.

Not quite sure which red & white ? If you swap the one direct to the RUN & the white to AUX you've not reversed one current with respect to the other and IF they are not the same wind you now have the reactance of the capacitor in series with a winding it was not designed for.

Quite true, but to 'flip' the connections you need both ends ..  :ThumbsUp:

Scruit connectors are used 'cos they are cheap ..  ;D

Dave
« Last Edit: March 05, 2016, 04:35:28 PM by Bluechip »

Offline Don1966

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Re: Motor rotation?
« Reply #15 on: March 05, 2016, 05:00:09 PM »
Graham if blue is common then the start and run winding is common to this. The only way to be able to do this with three wires is to have the start winding common to the run wiring internal at mid point of the run winding or (both windings would have to be the same and by just moving the power line on either side of the start capacitor would reverse it). I have seen the later but only on small motors.

Don

Offline PJW

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Re: Motor rotation?
« Reply #16 on: March 05, 2016, 05:14:54 PM »
I was confused when I asked for help, I am still confused, but I will keep reading & I might catch up with you all soon :slap:
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Online sco

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Re: Motor rotation?
« Reply #17 on: March 05, 2016, 05:30:16 PM »
Peter,

Sketch out a rough circuit diagram of what you have in front of you and then post that - I'm sure that will make it easier for people to help you.

Simon.
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Offline Alyn Foundry

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Re: Motor rotation?
« Reply #18 on: March 05, 2016, 05:34:24 PM »
Hello All.

It's even simpler !!

I was close, but no Cigar !!

http://www.ourautomation.com/blog/reversing-single-phase-capacitor-start-motor-by-remote-controller/

However I must dig out my recipe for humble pie !!   :)

Kind regards, Graham.

Offline Don1966

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Re: Motor rotation?
« Reply #19 on: March 05, 2016, 05:41:20 PM »
Here is the Split phase motor reversing setup.

Don

Offline Stuart

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Re: Motor rotation?
« Reply #20 on: March 05, 2016, 06:04:47 PM »
Hello All.

It's even simpler !!

I was close, but no Cigar !!

http://www.ourautomation.com/blog/reversing-single-phase-capacitor-start-motor-by-remote-controller/

However I must dig out my recipe for humble pie !!   :)

Kind regards, Graham.


Graham
Hope you know what the humbles are :facepalm:

You need as been said both ends of both windings  , then you reverse either one with respect to the other

Stuart
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Offline Alyn Foundry

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Re: Motor rotation?
« Reply #21 on: March 05, 2016, 06:18:33 PM »
Hello Stuart.

Indeed I do, however.....

Did you check the link?

Kind regards, Graham.

Offline Don1966

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Re: Motor rotation?
« Reply #22 on: March 05, 2016, 06:38:12 PM »
Graham if blue is common then the start and run winding is common to this. The only way to be able to do this with three wires is to have the start winding common to the run wiring internal at mid point of the run winding or (both windings would have to be the same and by just moving the power line on either side of the start capacitor would reverse it). I have seen the later but only on small motors.

Don
Graham Your drawings shows a main winding and secondary winding. On this type motor there is no main winding only winding A and B.
P.S. This is a Split phase motor not a Single Phase motor.

Don
« Last Edit: March 05, 2016, 06:41:53 PM by Don1966 »

Offline Alyn Foundry

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Re: Motor rotation?
« Reply #23 on: March 05, 2016, 06:56:19 PM »
Hello Don.

I just copied and combined / pasted the drawings from the link here. http://www.ourautomation.com/blog/reversing-single-phase-capacitor-start-motor-by-remote-controller/

This is a small motor as Peter has already stated. Two out of three colours match, Blue ( N ) common Red.  And Yellow instead of white.

Kind regards, Graham.

Offline PJW

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Re: Motor rotation?
« Reply #24 on: March 05, 2016, 07:04:36 PM »
from the diagram it looks to me like you just have to reverse the wires to the capacitor, am I right?
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Offline Don1966

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Re: Motor rotation?
« Reply #25 on: March 05, 2016, 07:20:36 PM »
from the diagram it looks to me like you just have to reverse the wires to the capacitor, am I right?
Yes if it is a Split phase motor. But make sure you amp check it when running just in case. If you don't have an amp meter be careful not to let it run long until you know it will not run hot. Precaution to keep from burning it should this be a different setup.

Don

Offline Bluechip

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Re: Motor rotation?
« Reply #26 on: March 05, 2016, 07:29:38 PM »
Save a bit of pie for me ...  :facepalm2: should have been a 3P2W switch. Will find one ..

Anyway, now fed & watered .. well Grolsh-ed ..  :DrinkPint:

I have found the circuit I did for a 3/4 HP, Single Phase, Cap. run motor I did some time ago. I've tried to make it a bit like Peter wants to do. The stuff to the left of the red line is supposition of what's in the 'relay' thing.

Would some kind soul please run an eye over it. The original did work but I've done some bits to make it resemble the original post.

Off to find switch ... back in a mo.

http://uk.farnell.com/multicomp/mcr13-432d1-01/switch-toggle-3pdt-on-off-on-sq/dp/2128058
Dave
« Last Edit: March 05, 2016, 08:01:39 PM by Bluechip »

Offline BaronJ

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Re: Motor rotation?
« Reply #27 on: March 05, 2016, 07:42:50 PM »
Don, thanks for finding those links.  The wiring code is fairly standard for these types of motor.  Three wires, red, blue and white or yellow.  I pick up many small motors, upto 3/4 Hp that use the same wiring code.  A simple three terminal center off switch will do the trick of reversing them.  Bearing in mind the caveats that I mentioned in my first post about wire size. 

Dave, the Myford 3/4 Hp motor has a centrifugal switch and does require the ends of the start winding swapping over to reverse it.  The centrifugal switch completely disconnecting the start winding.  Indeed if you completely disconnect the start winding, a simple flick of the motor pulley in the direction you want it to run will start it up and it will run as normal.

I'm just about to use a tumble dryer motor to drive a tool grinder that is capacitor start and run.  It also has the same wiring colours.

Best Regards:  Baron.

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Offline Bluechip

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Re: Motor rotation?
« Reply #28 on: March 05, 2016, 08:11:49 PM »

Dave, the Myford 3/4 Hp motor has a centrifugal switch and does require the ends of the start winding swapping over to reverse it.  The centrifugal switch completely disconnecting the start winding.  Indeed if you completely disconnect the start winding, a simple flick of the motor pulley in the direction you want it to run will start it up and it will run as normal.



Not if it's 3Phase ...  ;D   Well, sort of. My S7's got a Transwave Box on it. NOT one of those posh VFD's though  :'(

Know the symptoms though, my ML7/T of blessed memory ingested swarf into it's motor and I did the 'bump start' trick for some months until I got a new one.

Dave


Offline BaronJ

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Re: Motor rotation?
« Reply #29 on: March 05, 2016, 08:15:57 PM »
Now, now Dave,  throwing 3 phase in there, that's cheating.  :whoohoo:

Seriously though mine is still single phase, though I've had a 1.5Hp three phase motor in the garage, like forever...
 
Best Regards:  Baron.

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Offline Bluechip

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Re: Motor rotation?
« Reply #30 on: March 05, 2016, 08:18:04 PM »
Now, now Dave,  throwing 3 phase in there, that's cheating.  :whoohoo:

Seriously though mine is still single phase, though I've had a 1.5Hp three phase motor in the garage, like forever...

Quite true. My apologies.  ... Really one phase and two bent bits ...  :ROFL:

Dave

Offline PJW

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Re: Motor rotation?
« Reply #31 on: March 05, 2016, 08:34:20 PM »
Hi Dave is this right?
So if I swop the red wire that comes out of the motor with the white one & attach this white to the off of the switch.
The blue from the motor to the off of the switch
The red from the Cap to the forward/ rev
The Brown to the forward/rev terminals, this will give me for/rev on the motor?
Where would will the original on/off relay go?
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Offline Bluechip

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Re: Motor rotation?
« Reply #32 on: March 05, 2016, 08:42:39 PM »
PM sent ... key fingers overheating ...  ;D

Dave

Offline PJW

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Re: Motor rotation?
« Reply #33 on: March 05, 2016, 10:01:47 PM »
Thanks All for your input, I am sure it can be sorted out soon,

Peter
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Offline Bluechip

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Re: Motor rotation?
« Reply #34 on: March 06, 2016, 01:00:14 PM »
Alas, no go ..  :'(

Motor is one of the wretched things I've met before. The stator is firmly fixed in one half of the casing. It is not possible to access the connections. I have warmed up the alloy casing and got a stator out once before but it's a fraught procedure I wasn't going to do on someone else's motor.

The windings do have different resistances, [ some 60R & about 110R ], so it's a fairly conventional cap. run type and it's not advisable to just try rewiring the cap. from the AUX winding to the RUN. It wouldn't be happy.  :zap:

Peter has a rather nice collection of engines which he is now going to show us no doubt.   :stickpoke:

Off to sulk ..

Dave

Offline Don1966

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Re: Motor rotation?
« Reply #35 on: March 06, 2016, 02:36:13 PM »
Yea Dave I was afraid of that.


Don

Offline PJW

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Re: Motor rotation?
« Reply #36 on: March 06, 2016, 05:06:16 PM »
thank you so much Dave for taking the time to come over to help, you are a good egg!!! :zap:
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Offline BaronJ

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Re: Motor rotation?
« Reply #37 on: March 06, 2016, 08:20:08 PM »
Hello Peter, Guys,

Sorry to hear that your motor is unsuitable.  It is also likely that one or both windings are aluminum wire and breaking the joints would create more problems than it would solve.

If you have a friendly scrapyard nearby it might be advantageous to go and see if you can scavenge another motor.

There is supposed to be a picture attached of a motor that might be suitable for you.  It will reverse in exactly the same way as described in this thread.  It is rated 525 Watts at 2850 RPM.  Good luck.

Forgot to mention.  Under that cover is a bit of electronics, but there is only two wires to swap over.

Best Regards:  Baron.

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Offline PJW

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Re: Motor rotation?
« Reply #38 on: March 07, 2016, 08:16:10 AM »
that look just the job!!!
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Offline Stuart

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Re: Motor rotation?
« Reply #39 on: March 07, 2016, 09:52:38 AM »
Peter

Is the motor symmetrical end for end with the stator if it is then could you not pull off the end bells turn the stator end for end so the shaft is at the other end in respect to the stator , then it will be reversed

It's like left hand single point threading the spindle rotates the same way ( as would the wiggly lecky bits ) but you start your thread at the chuck end

Or just look at the motor from the shaft end if it's clockwise then the other end is anti clockwise


Glad Dave popped over he's a good guy knows his stuff

Stuart



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Offline PJW

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Re: Motor rotation?
« Reply #40 on: March 07, 2016, 01:33:13 PM »
the stator is pressed or glued in and would not shift without heating & we didn't want to go down that path, but that would be a good solution. The motor splits in the middle & the stator would not move.
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Offline Bluechip

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Re: Motor rotation?
« Reply #41 on: March 07, 2016, 01:59:16 PM »
Peter

Maybe Stuart is suggesting turning the ROTOR end for end.   :ThumbsUp:     Look at the blunt end of the motor. If it has a hole and you can see the end of the shaft there is a good chance the rotor can be reversed. If there is no hole the idea is, for all practical purposes, a non-starter.

This will make the now 'blunt' end the drive end. The connector block will now be at the other end to what it appears now but that's usually of no consequence.

Dunno about 'good egg'. A well refrigerated good egg possibly ... frozen paws here  :(

Dave

« Last Edit: March 07, 2016, 02:29:24 PM by Bluechip »

Offline PJW

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Re: Motor rotation?
« Reply #42 on: March 07, 2016, 02:28:30 PM »
Hi Dave & Stuart, good idea, the rotor shaft had different dia ends, but the bearings had the same dia, so I swapped the rotor & the bearings round & tried it & hay presto job done, I did not have to undo the wires as the stator stays in position. everything lined up inside the motor so job done,
once again thank for the help,

Peter
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Offline Bluechip

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Re: Motor rotation?
« Reply #43 on: March 07, 2016, 02:30:50 PM »
 :whoohoo:  :whoohoo:

Another happy customer.

Next !!

Dave

Offline Stuart

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Re: Motor rotation?
« Reply #44 on: March 07, 2016, 03:48:39 PM »
We aim to please our fellow form members :cartwheel: :cartwheel:

If all else fails KISS is the way to go

I have done that trick many time on small motors ,it's just not worth hacking into the winding , yes it can be done

You may find you have lost a bit of power due to the rotor not fully lined up with the stator

Sorry I did not explain to well I am dyslexic , my brain knows what I want to say but I cannot get it down on paper

Thanks Dave for the interpretation service

Stuart

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Offline Alan Haisley

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Re: Motor rotation?
« Reply #45 on: March 08, 2016, 04:06:39 PM »
If you go shopping salvage yards for old motors, you might take a printout of this article along (don't forget a multimeter also):

http://woodgears.ca/motors/reversing.html

While this engineer seems to strangly love wood for some reason, his website has a lot of interesting and useful information.

Alan

 

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