# New CX 709 motor problems



## Todd McBride (Jan 17, 2020)

I just bought a CX 709 from Busy Bee, used it lightly for a few hours and then the starter circuit seems to have failed. Push the start button, it doesn't turn, it hums, draws huge current then blows the breaker in about 5 seconds. If you throw the chuck over by hand as you hit the ON it starts just fine and I used it that way for a few hours to finish my first projects. But that probably isn't a good safety practice! 

BusyBee provided a replacement capacitor on the assumption it was that start capacitor, I replaced it, and now the lathe starts immediately but makes heavy motor noise and blows the breaker in about 20 seconds. Took the belt off and the motor spins freely so no problems there despite the cold in my shop. I think the start circuit is staying on and that makes the noise and draws the heavy current.

Has anyone else had this problem with a new CX 709, or with any 110V induction motor made in China?  What has BusyBee done to rectify these defects in the past? Do they hire an electrician, let the owner remove and replace the motor, or have the customer haul the whole unit back?


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## PeterT (Jan 17, 2020)

It could be other things but I would check the centrifugal switch (assuming it has one). If it fails to engage & disengage properly it can impede how the capacitor is supposed to come on & off during start. The 'heavy motor noise' as you say is probably electrical cogging. Exactly what I had on my mill when the CS was not set right. (Different mill but common problem source apparently).


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## Todd McBride (Jan 17, 2020)

That's my theory, the centrifugal switch is staying closed. Maybe that burned out the original capacitor and with it gone the lathe drew normal current in the main windings but had to be "kick started". I assume the new capacitor wouldn't last long if my 15A circuit didn't blow to save it. Didn't notice anything electrical when the first capacitor apparently failed, the lathe just buzzed but didn't start after we had shut it off one of many times on our first threading project. And it started immediately when I tried the kick start method. 

I assume that whole motor has to be replaced since the switch would be inside. Now I just need Busy Bee to tell me whether they will send an electrician or should I disconnect it and return the motor myself.


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## Dabbler (Jan 18, 2020)

PeterT had a similar problem with a 2HP motor on a mill.  I think adjusting the contacts helped for a while.  eventually the motor had to be replaced, I think.  

Fortunately motor problems like this usually turn up early, like in the first 100 hours of use, then they work forever.


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## PeterT (Jan 18, 2020)

In my case (different mill) the motor cooling fan was probably set a bit too close to the centrifugal switch to begin with. Over time it slowly worked its way down the motor shaft until it impeded the CS from opening, thus the start capacitor wasn't phasing in & out like its supposed to. The capacitor was replaced because it went bang but the motor was fine & continues to run. Your mileage may vary condition wise but that's why I think check into the CS. When you disassemble, make note of positions like with felt pen or mini scribe lines so you have some reference to trouble shoot.


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## PeterT (Jan 18, 2020)

Your motor assembly may be different but just for illustration here is mine. The assembly sequence is: motor, contact plate, centrifugal switch, fan, end bell. In particular look at the condition of the points. If they are pitted or burned best to replace. Also check that wiring did not come loose, electrically that would equate to similar problems.


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## Tom O (Jan 18, 2020)

Take a look at the brushes I had a few encounters with mine on my mill I think the springs are weakened when heated.


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## DPittman (Jan 18, 2020)

Todd McBride said:


> What has BusyBee done to rectify these defects in the past? Do they hire an electrician, let the owner remove and replace the motor, or have the customer haul the whole unit back?


When I had headstock bearing problems with a lathe, BusyBee first told me that I needed to change the oil in the headstock...(my lathe does not have headstock gear oil)...they then told me they could order parts that I could install but couldn't tell me when those parts would come in, or give me any real useful instructions on how to make the repair.  After some considerable "persuasion" from me, they agreed to take the lathe back and order me a new one.  I then waited for months for the new lathe to come in and they could not tell me at the time how long that would take.  

I have since decided that BusyBee tools are just like any other imported machinery that is readily available from numerous sources and therefore, unless the BusyBee price is cheaper than others, there is no reason to purchase from them (at least that's how I see it). And I find it is very rare that BusyBee has better prices.


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## Dabbler (Jan 18, 2020)

Last christmas, they had a great deal on 3X79" sander/grinder.  My metal/wood bandsaw CV101 was far less than the competition.

I'd never touch a BB lathe or mill again, knowing what I know now.


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## Janger (Jan 18, 2020)

For a time I owned a cx701. At one point the rpm sensor on the shaft came loose and broke. I sent pictures to busy bee and they sent me a replacement part in a few days. I put it in the machine. Simple enough. I think they told me if it needed more extensive service I’d have to bring it to the store. It was heavy enough that there was no way I could just pick it up and throw it in the truck. Need a engine hoist. Anyway that is my experience. It seems to really vary from fine (me) to horrible (Don). I hope it gets resolved without too much drama.


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## Janger (Jan 18, 2020)

PeterT said:


> Your motor assembly may be different but just for illustration here is mine. The assembly sequence is: motor, contact plate, centrifugal switch, fan, end bell. In particular look at the condition of the points. If they are pitted or burned best to replace. Also check that wiring did not come loose, electrically that would equate to similar problems.



Peter how does that switch work? Does the spinning motion open a circuit or close the circuit? It looks like the bent donut ring would be pushed by the spring wings in the switch but I don’t see what that does exactly.


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## Brent H (Jan 19, 2020)

Hi John,

The centrifugal force from the motor spinning will cause the weights (second picture) to swing out and the unit in picture number 2 will snap into place releasing the  bent donut ring opening the circuit and dropping the capacitor out of the circuit. 

Things that typically go wrong:  The bent donut ring assembly gets loose and fails to open or close , the centrifugal switch part (pic 2) gets loose on the shaft and does't  open the circuit or keeps the circuit closed, the contacts weld together and prevent the capacitor from dropping out or the contacts are dirty and the capacitor is out of the circuit and motor won't start.  Lots of other things as well.

I had a motor in a busy bee drum sander - Clogged up with sawdust and would't work.  Cleaned up everything, motor ran great - built more dust collection to prevent further issues


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## Todd McBride (Jan 19, 2020)

I noticed that the original capacitor was 60uF whereas the replacement one they gave me was a 260MFD. Unless I'm misreading the numbers that is a 60 micro-Farad capacitor changed to a 260 milli-Farad one, about a  4000 fold capacitance increase. Can that be possible? Could the starting circuit and windings possibly work with such an increase in the capacitor?

BB says tomorrow their warranty people will finally return my call and I expect to be pulling the whole motor and returning it on warranty. Hopefully that won't take forever.


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## Brent H (Jan 19, 2020)

> Peter how does that switch work? Does the spinning motion open a circuit or close the circuit? It looks like the bent donut ring would be pushed by the spring wings in the switch but I don’t see what that does exactly.



More info

*Start capacitor AC induction motors*
One way to improve on the single coil design is by using an auxiliary coil in series with a motor starting capacitor. The auxiliary coil, also called starting coil, is used to create an initial rotating magnetic field. In order to create a rotating magnetic field, the current flowing through the main winding must be out of phase in respect to the current flowing through the auxiliary winding. The role of the starting capacitor is to lag the current in the auxiliary winding, bringing these two currents out of phase. When the rotor reaches sufficient speed, the auxiliary coil is disconnected from the circuit by means of a centrifugal switch, and the motor remains powered by a single coil creating a pulsating magnetic field. In this sense, the auxiliary coil in this design can be regarded as a starting coil, since it is only used during motor startup.



Read more http://www.capacitorguide.com/motor-starting-capacitor/


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## PeterT (Jan 19, 2020)

Its been a while since I pondered this. I thought I had it figured out at the time with the parts on the bench, now I'm actually scratching my head looking at my pics again. In the attached video (assuming its the same principle) it shows: Start mode: weights up = points closed. Run mode: weights extended = points open

Behind the scenes electrically Start mode has the start capacitor in the circuit. At some threshold rpm the CS & points take it out of the circuit.

Now the puzzle. When I look at my pics again it seems like when weights are up the (black plastic) plunger on the CS is long. When weights are extended the CS plunger is short. The CS has a collar on top with set screw so its fixed on the shaft. So I assume the plunger is acting on the top of washer spring, long would mean the points are open which is bass-akwards to video. Brent what am I missing here?


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## Brent H (Jan 19, 2020)

Hey Peter, 

So when the motor is sitting the weights are up and the black plunger is pushing the donut down - Points closed and the capacitor is in the system (Your picture #2).  When the motor is running up to speed (about 70% full RPM) the centrifugal force will drive the weighted ends out and pull the black plunger away from the donut - (Your Picture #3) and the donut opens the contact.

I re-wrote my replay a couple times thinking it back over.  With the spring force in there you should get that "click" as the motor builds up speed and the click when you stop the motor and it winds down.   It is a good way to tell if the centrifugal part is working if that click is working properly.

One way you can tell if the contacts might be dirty and not engaging the capacitor is that your motor will not start - might hum - and if you spin the motor it will start turning on its own.   Could also be a dead capacitor but not as likely.  Those are pretty robust most of the time.


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## PeterT (Jan 19, 2020)

I'm having dejavu all over again. I think I was getting the upper stop thingy mixed up with where the points contact. Does this sketch capture whats going on? Maybe what I am calling the upper stop is actually electrically tied to the run capacitor side of the circuit... so the washer point has to be in contact with either the upper or lower?


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## Brent H (Jan 19, 2020)

Wow - nice drawing so fast - that looks correct to me.  The electricity flows through the donut to the contact point (red) for the switch to allow the capacitor into the circuit. (motor not up to speed)

I am sure there are manufacturers that make this reversed  (switch goes down to open the circuit) but your interpretive drawing works for me


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## PeterT (Jan 19, 2020)

LOL, Excel 'cad drawing' to the rescue.

With this established, the only thing that still has me wondering now in hindsight was the influence of fan body which is clamped to the motor shaft slightly higher than the CS. I could have sworn it was impeding the counterweight action because I tried it with & without fan temporarily, with CS locked in same position on shaft. Moving the fan up (I presumed out of the way of CS) solved the issue, no more problems. Unfortunately I didn't take a picture of the underside at the time. Hopefully my brain cells will kick in & it will come back to me.


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## Todd McBride (Jan 24, 2020)

On my CX 709 I found out that the 60uF capacitor was the run capacitor, the start one was mounted lower on the motor (and a bit out of sight) and it was a 300MFD capacitor, and surprisingly of considerably smaller dimensions.   

Now I am waiting for BusyBee to send me a replacement for that 300 MFD start capacitor. I will also have to  swap the original 60 uF run capacitor back in place of the 250MFD one they originally provided as repair. It was apparently OK.

Haven't figured out why a 250MFD capacitor installed in place of the 60uF run capacitor allowed the motor to start and run, though apparently at much high current draw. IF the problem was the other 300MFD start capacitor, and it had failed, why did the motor start with that erroneous replacement of just the run capacitor?


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## Johnwa (Jan 24, 2020)

I believe the start and run capacitors are in parallel.  The run cap switches out once the motor reaches a certain speed.  The run capacitor remains connected.  What you effectively did was have a start sized capacitor that didn’t switch out.


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## Todd McBride (Jan 30, 2020)

Finally got the replacement 300MFD capacitor Monday. I first swapped the 60uF run capacitor in and that brought me back to the original problem, the lathe only starts after giving the chuck a throw. Then I put in the start capacitor they sent and it made no difference. That was Tuesday and I haven't been able to get any useful response from them since, not in the store nor from head quarters.


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## Tom Kitta (Jan 30, 2020)

Does it do the same thing at all RPM settings? Set it to low RPM - does it do the same?

If it only does it in high RPM setting and its cold then replace oil with something thinner like ISO 32.

Long time ago when I had BB lathe it would throw breaker at 700 rpm all the time.

Actually I had the SAME lathe from BB - they just called it I think 089 back then or something almost 13" swing and like 24" bed.

Alternatively warm up the lathe for minimum of 15min at low RPM. Then go higher RPM no load and then finally do work.

Note the lathe will start immediately at high RPM, will make strained motor noise for about 10s and then throw the breaker - similar to what you described.


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## RobinHood (Jan 30, 2020)

Todd McBride said:


> the lathe starts immediately but makes heavy motor noise and blows the breaker in about 20 seconds



as you suggest (and others) I think you need to look at the start circuit. If the contacts remained closed, it would start but not run properly.

Can you post some pictures of the capacitors and motor data plate.

Going way out on a limb here, but the YL-90L4 motor is made in both single voltage (220V) and dual voltage 110V/220V versions. Maybe it is connected wrong from the factory?


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## Tom Kitta (Jan 30, 2020)

If motor is connected wrong from the factory - i.e. if it is connected as in 240V but gets only 120V it would be same as if it only had 1/3 of the rated name plate power or so. Thus the effect would be same as if the oil was thick and what I have described - i.e.

lathe starts immediately but motor makes noise then throws the breaker. So yes, check if it is wired correctly and check whatever motors runs fine without any load.


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## PeterT (Jan 30, 2020)

Hard to know for sure, but 'giving it a throw' is equivalent to what the centrifugal switch (or equivalent) does: once its up to a certain rpm. The CS weights come out, the points contact (or break contact depending on the switch) & the starter cap is taken out of the circuit leaving the run cap in. So if the CS wiring or points or orientation is not quite right at rest, the starter cap cant do its job & get the motor running from zero to transition rpm. I mean it could be other things, but this is a possible lead if you haven't already examined or replaced CS.


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## Todd McBride (Jan 30, 2020)

My BB CX 709 worked just fine for the first few hours at low and high speeds as we were trying it out. Then one time when it was turned on it just hummed and needed the boost to start. It turns freely and does the same thing low speed or not, warm or cold. Its workable in this condition but the shop safety guy isn't pleased!

Based on the information posted here I took the rear plate and fan off hoping to find and adjust a centrifugal switch. Under the tin cap there was just a simple plastic fan pressed onto the shaft and nothing under that but the casting holding the bearing housing. Unbolted that too and found only the ball bearing and the armature windings, no sign of a centrifugal switch. Maybe its in the other end, the drive end? Seems unlikely and I would need a gear puller to remove the pulley to get at it.

At this point I will disconnect the wiring and take the whole motor in to Busy Bee to see if I can get some service that way.


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## Todd McBride (Jan 30, 2020)

RobinHood said:


> as you suggest (and others) I think you need to look at the start circuit. If the contacts remained closed, it would start but not run properly.
> 
> Can you post some pictures of the capacitors and motor data plate.
> 
> Going way out on a limb here, but the YL-90L4 motor is made in both single voltage (220V) and dual voltage 110V/220V versions. Maybe it is connected wrong from the factory?



It worked just fine for the first few hours so I don't think it was wired wrong from the factory. At this point I have it about removed and will take it in for exchange.


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## Todd McBride (Jan 30, 2020)

PeterT said:


> Hard to know for sure, but 'giving it a throw' is equivalent to what the centrifugal switch (or equivalent) does: once its up to a certain rpm. The CS weights come out, the points contact (or break contact depending on the switch) & the starter cap is taken out of the circuit leaving the run cap in. So if the CS wiring or points or orientation is not quite right at rest, the starter cap cant do its job & get the motor running from zero to transition rpm. I mean it could be other things, but this is a possible lead if you haven't already examined or replaced CS.



I understand a basic induction motor has zero torque until it starts to turn and that is why it needs a kick, or that starter circuit. The lathe is usable as is but the safety guy is not amused. Could be worse, the saw starts by its self with no kick!


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## Tom Kitta (Jan 30, 2020)

Lots see what BB does - they should just swap the motor but I wonder how long you have to wait. 

Does it have same issues with no load at all?

There also could be a burned starter (auxiliary) winding. Hence no adjustment of the switch nor capacitor will help. Or switch has contacts burned. 

The motors in these lathes plus thick oil and Canadian garage temperatures don't equate good operation.


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## Todd McBride (Jan 30, 2020)

Tom Kitta said:


> Lots see what BB does - they should just swap the motor but I wonder how long you have to wait.
> 
> Does it have same issues with no load at all?
> 
> ...



Any recommendation on what I change the oil out to? Should I be using synthetic like I do in my Chevy? Maybe I will just put the milkhouse heater closer to the lathe if/when I work in colder weather.


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## Dabbler (Jan 30, 2020)

I changed all my lube to AW32, except way oil.


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## Tom Kitta (Jan 31, 2020)

I replaced oil in the lathe with ISO 32 oil which you can easily get from Princess Auto. In fact I think its on sale now. ISO 32 is recommended oil for low speed lathes like what you have. You can get multi-season ISO 32 oil - what that means it has viscosity additives making it viscous even at lower temperatures - similar concept to a car 5W-30 in the 5W portion. For high speed spindles people and myself go with much thinner oil, like ISO 22 or even ISO 15. In other areas of machinery the lower the speed the higher ISO, the higher the speed the lower the ISO as general rule.


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## Todd McBride (Jan 31, 2020)

Tom Kitta said:


> I replaced oil in the lathe with ISO 32 oil which you can easily get from Princess Auto. In fact I think its on sale now. ISO 32 is recommended oil for low speed lathes like what you have. You can get multi-season ISO 32 oil - what that means it has viscosity additives making it viscous even at lower temperatures - similar concept to a car 5W-30 in the 5W portion. For high speed spindles people and myself go with much thinner oil, like ISO 22 or even ISO 15. In other areas of machinery the lower the speed the higher ISO, the higher the speed the lower the ISO as general rule.



How much oil does it take? I see Princess has AW 32 oil in 5 gallon pails and assume that is way more than I require.


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## Tom Kitta (Jan 31, 2020)

Probably no more then few liters - like 3. So just get the 5L jug. I think they have AW36 multi-season on sale for 15.99 for 5L.


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## Dabbler (Jan 31, 2020)

If you are oiling your ways and your apron every time, 5 gal isn't too much


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## Todd McBride (Jan 31, 2020)

The continuing CX 709 motor saga. Latest is I took the motor off and returned it to Busy Bee. They are sending me a new one that I should receive early next week.


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## DPittman (Jan 31, 2020)

Todd McBride said:


> The continuing CX 709 motor saga. Latest is I took the motor off and returned it to Busy Bee. They are sending me a new one that I should receive early next week.


Glad to hear that you won't have to wait a month of Sunday's for the motor.  That should get you up and running I would think!  You've got steam projects to get to darn it!


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## Todd McBride (Feb 1, 2020)

Tom Kitta said:


> Probably no more then few liters - like 3. So just get the 5L jug. I think they have AW36 multi-season on sale for 15.99 for 5L.



Picked up that oil on sale at Princess. Any good ideas for draining the existing oil? I found the plug under a plate down between the ways and it looks like it will make a hell of a mess draining. Did you invent any way to contain it without flooding the whole pan? Was even thinking of trying to suck or syphon it out the top through the fill plug.


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## PeterT (Feb 1, 2020)

I got one of these from KMS or Cdn Tire, forgot which. Worked well on the lathe & generally handy to have around for siphoning off liquids.


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## Dabbler (Feb 1, 2020)

I have one too. much easier and less messy for headstock oil changes.  well worth it.


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## Tom Kitta (Feb 3, 2020)

I have a small pump and a large one - its amazing all the things you can suck fluids out of.

You can try a funnel but be careful with the plug jumping out of your hands and clogging the funnel which will overflow in about 2 seconds and make a mess.


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## Todd McBride (Feb 5, 2020)

Well finally I'm back in business. Busy Bee probably shipped that motor to my postal address on Monday or Tuesday and I didn't think to realize that it would be at the mailbox until today. Installed it in a few minutes and everything seems to work just fine.


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## Todd McBride (Oct 18, 2020)

My replacement motor from BusyBee worked just fine and I have used it a lot over the past 7 months. Don't know how I ever got anything done without a lathe in my shop, or back on the farm for that matter.

Built this horseless carriage since then, and am now working on a steam engine drive for it.


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