# Forum Home Renovation Tools & Products  Drill doctor

## Marc

Considering the abysmal difference in price between OZ and US  ($420 vs $160 ) for a 750 model of drill doctor, I would like to buy one from the US yet don't know if the little motor will work on a transformer and with our 50 hz frequency. 
Does anyone know?

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## OBBob

Maybe if combined with this sort of thing ...    50VA 240VAC to 115VAC Stepdown Transformer - Jaycar Electronics  
That's a big difference in price.

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## METRIX

Don't see why it won't, its only a basic motor so shouldnt have any issues. 
The price difference is crazy for this and most other tools here, and some people wondor why we get synical about how much the equivelant product cost's here.

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## Normanby

It should be ok. Many years ago I bought some motorised equipment from the USA which ran satisfactorily here using a transformer. The stated rpm of the motor could be slower running on 50Hz than 60Hz in the USA, depending on motor type.

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## SilentButDeadly

I think it is a wide range motor...and it may have a voltage switch regardless.  I can check if you want.  I have one of the finicky little sods that I rarely use gathering dust on the shelf so it should be easy to read the label...

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## justonething

If it is a serial motor, which it most likely is, then it doesn't matter what freq it is on.i'd say go for it.

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## METRIX

> I think it is a wide range motor...and it may have a voltage switch regardless.  I can check if you want.  I have one of the finicky little sods that I rarely use gathering dust on the shelf so it should be easy to read the label...

  I use my one all the time very quick setup, not sure of the model but it was the top model, my mate has a lesser model and it was very finicky to use.

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## Marc

So this little motor is not the same as say a motor with a capacitor like a planer or a saw motor. Because I understand those do go slower and heat up on an ordinary step down transformer due to the frequency difference, and a frequency converter for 1KW goes for 1800 US so it sort of defeats the purpose. 
I'll give it a try, if it goes too slow the grinding wheel will probably wear quicker but it is not like you use it for hours on end for it to overheat. 
Silent, a switch? Do you mean they are multi voltage? That would be handy. 
Metrix, yes, the way we are systematically robbed by retailers in OZ is depressing. Fortunately the revenge of the consumer shopping online and overseas will eventually bring local prices down to some extent. If you think 300% difference is amazing, I had quotes for parts for boats and earthmoving equipment up to ten time the price in the US. It is sad not to mention unsustainable. Worst, this so called local reps, don't even have stock, you pay them to bring in one part...

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## Marc

PS
I found this voltage AND frequency converter designed for clippers and shavers, I wonder if it will carry the drill doctor? No sign of watts on the ad. http://www.ebay.com.au/itm/VOLTAGE-F...0477407&_uhb=1

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## SilentButDeadly

Mine is a 360 and it makes great nails of anything less than 5 mm if I'm not careful. It is marked as 230v 50hz 14,000 rpm...that's it. No voltage switch.

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## Oldsaltoz

How about sharing a few links?

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## Marc

Well, bought it from ebay US, when it gets here I'll buy a small transformer from ebay OZ for $20 or so.
On that line, I am still keen in getting a frequency and voltage converter. Hopefully can find one for a decent price so that I can also buy some nice machines from the US for a quarter of the price. My woodworking machines are rather obsolete.  https://www.youtube.com/watch?v=Q9YqUdcWuT8 https://www.youtube.com/watch?v=M6bC5imB31A

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## toooldforthis

> The price difference is crazy for this and most other tools here, and some people wondor why we get synical about how much the equivelant product cost's here.

  not just tools.
I just bought a 10kg aluminium skid pan (think it is about 1200mm x 1200mm) for a vehicle. cost plus shipping is less than a new plastic one from local car parts.
not to mention the service.

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## johnc

Shouldn't be any problem with it, other than the possibility it might spin at a slower rate it is unlikely for the short bursts it runs as it sharpens a drill that it will have time to produce excess heat anyway. For larger machines you can get 220V machines direct from the US same problem though they will be 60mhz rather than the 50mhz we have here but you can just change the plug. Problem is though you will have no warranty and shipping larger items can be expensive but as long as those issues are factored in you can make an informed decision.

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## METRIX

> not just tools.
> I just bought a 10kg aluminium skid pan (think it is about 1200mm x 1200mm) for a vehicle. cost plus shipping is less than a new plastic one from local car parts.
> not to mention the service.

  Same for Imported beers, why is Corona always around $60 per case.because there is only one importer here, and he has it all stitched up with the producers in Mexico, to not allow another importer.
Currently it is $45 at Dan Murpheys for a 24Pk, which is the cheapest I have ever seen it. 
Take some other examples of imported beers, and some of the manufacturers are closer to us than the US,  
Heineken 24pk, here $45.95 US $23
Asahi 24pk here $49.50 US $36
Peroni Nastro 24pk here $50.99 US $28
Grolsch 4Pk here $17.50 US $8

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## SilentButDeadly

Goes the other way too.  My brother could purchase Coopers Pale Ale in Arizona for less than I paid here... 
There's more of them so their purchasing power is rather good.

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## phild01

Isn't the tax the issue for our higher alcohol prices compared to the US.

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## Marc

As far as US 220v, unfortunately thir 220v is a 2 phase 110v possibly + neutral, not sure, and it wouldnt work on a single phase 240 nor 220v regardless of frequency.
Thereis of course the choice of changing the motor, sometimes it is simple, others it is not, particularly if there are safety features imvolved.

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## johnc

There are a couple of 220V machines near here that have been working quite happily for about the last 10 years (hobby use), but you are correct it is U.S. two phase however it is working on single phase 240V Aus supply

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## Mitch1500

A look inside the drill doctor.. Screwdriver&#39;s - "Drill Doctor" internal mechanism / 220V convertion 
Inside the unit is a Bridge rectifier, what that does is convert the ac power to a pulsating dc power, it also doubles the Frequency.
So on US power that 60hzx2 =120hz On Aussie that's 50x2 =100hz 
If running on a higher or lower frequency it can cause it to draw more amps and over heat, as well as run slower 10-20%
You can drop the voltage to around 100v to compensate for 50hz
more details here Running 60 Hz motors on 50 Hz - Is it possible and what are the options? 
A cheap solution is to buy a 12v to 110v 60hz inverter.
Ebay has plenty of them also on Ebay.com 
Additionally You can also buy a 240v to 12v convertor and plug the 110v inverter in to that (if you don't want to run it from a battery). 
The drill doctor is rated at 115 volts and 1.75 amps, so 115x1.75 = 192.5 watts. 
Not all things being equal I'd suggest a min of 250 watts inverter to run it from a battery. If also using a 240-12v convertor, the convertor should handle more watts than the inverter otherwise you may burn it out, 300w convertor plus a 250 w inverter.
If buying other power tools from the US you may want to think ahead and buy a bigger capacity inverter and convertor. 
The Drill Doctor company is fully aware of the price hike for their 220/240 models as they have a FAQ on their site about it. which tells me that they're in bed with the importers to cash in on overseas markets, see software,music and film industries. I cant order a 240v unit from the US why not?  :Smilie:  Isn't that where they make them? 
Oh and if you fry anything don't blame me, I'd recommend buying something else, just on the price hike principal that they have, the unit has mixed reviews anyway, some people like it, some say it a lot of mucking around to use it.
Ozito has a $40 version, probably not all that great (wonders if the motor could be substituted).  
Look around at other brands

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## justonething

> If running on a higher or lower frequency it can cause it to draw more amps and over heat, as well as run slower 10-20%
> You can drop the voltage to around 100v to compensate for 50hz
> more details here Running 60 Hz motors on 50 Hz - Is it possible and what are the options?

  It is often a mis-conception that the speed of all motors are governed by the mains supply frequency. This is simply not true. It is only true for induction motors, as specified in the link above. The smallest motor that is an induction motor in a household is our exhaust fan in the bathroom. Induction motors are generally only used where it is required to run for an extended period of time. They are bigger, heavier and more expensive than say universal or serial motors of equivalent power and torque output. Most power tools, sewing machines etc use universal motors, they allow easy variable speed control, they can run at extreme high to low speed. They have a high torque to weight ratio. I can be pretty sure from the picture on the screw driver website that the drill doctor does not use an induction motor, and more likely using an universal motor. Using both electromagnets as stator and rotor, the universal motor does not care what the main frequency is. There is a 5% chance that the drill motor runs on some other motor. But I'm 95% sure that frequency has no impact on the performance of the motor, ie., 95% sure that it is an universal motor. All cheap and nasty motors are almost always universal motors. 
One note about the frequency converter that Marc has posted. from the picture it looks to be a very low capacity power pack, probably drawing less than 0.5A or less than 120W. I think it is a combined rectifier and inverter in series. The rectifier convert the AC to DC and the inverter change the DC back into AC.  I don't think you would be able to run anything bigger than a pencil sharpener on that thing.  If you want to buy a drill doctor, buy one from the US and then a 500W step down transformer from eBay. Amazon also sells drill doctor and ships to Australia. I had been thinking about getting a drill doctor but in the end decided to sharpen my skill on using a drill sharpening jig instead.

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## Mitch1500

How sure is sure?  :Smilie: 
The reason I ask is that they make special mention of the frequency at the site in the faq section 
Its looking like theyre giving a run around response without too many details. Sales orientated? What strain would the motor be put on if its a universal motor? 
Quote from their site.....
A transformer (not a complete power supply), plugged into single phase  230v, can drop the voltage to the 115v range, but doesn’t account for  the difference from US frequency at 60 Hz and Internationally at 50 Hz  and may not regulate the voltage or provide sufficient amperage well  depending on the quality of the device. *Running on 50 Hz puts a greater  strain on the motor, so while the correct voltage may be supplied to the  unit, the frequency isn’t correct to get full performance* (reduced  power = lower efficiency = extra heat = destroyed unit). The voltage may  also not be precise, out of a transformer and the 115v motors are  designed to run in a specific range. High or low voltage will likely  cause failures.

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## justonething

> How sure is sure? 
> The reason I ask is that they make special mention of the frequency at the site in the faq section 
> Its looking like theyre giving a run around response without too many details. Sales orientated? What strain would the motor be put on if its a universal motor? 
> Quote from their site.....
> A transformer (not a complete power supply), plugged into single phase  230v, can drop the voltage to the 115v range, but doesn’t account for  the difference from US frequency at 60 Hz and Internationally at 50 Hz  and may not regulate the voltage or provide sufficient amperage well  depending on the quality of the device. *Running on 50 Hz puts a greater  strain on the motor, so while the correct voltage may be supplied to the  unit, the frequency isn’t correct to get full performance* (reduced  power = lower efficiency = extra heat = destroyed unit). The voltage may  also not be precise, out of a transformer and the 115v motors are  designed to run in a specific range. High or low voltage will likely  cause failures.

  Looks to me it was written by a salesman. not that I have anything against them. One can look up any physics textbook on how universal motors work. I think he is hedging to say it is not designed that way. The most important thing missing is that they don't say it will not work or slow down..... if it was an induction motor.... they would be making a big song and dance about it. Don't forget if it is a low quality motor, it will burn out if it is running for too long, whether it is 50 hz or 60 hz wouldn't be the main determinant. Low quality windings would be. (The main risk is that the motor is rated at 110V and not 240V and if the step down transformer fails to step down, it would subject the motor to 240V which it isn't designed to do, but step down transformers are reasonably reliable in my book)

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## Mitch1500

Yeah I'm getting that impression also. I've emailed them to see what kind of motor it is, but I wont hold my breath to get a response. 
In the end I guess its a marketing ploy so you pay more for the non US model. Makes them a hell of a lot more money.
For the price they're asking I would expect quality. Makes me think they're using the Ozito theory. You wont use it much so it will outlast the warranty.

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## Ozcar

> It is often a mis-conception that the speed of all motors are governed by the mains supply frequency. This is simply not true. It is only true for induction motors, . . .

  It is true for synchronous motors. Most homes would have devices using small synchronous motors. Some of the things they are used for that I can think of are: 
 Microwave oven turntables. 
Electromechanical timers and clocks. 
HVAC damper actuators.  
Obviously the speed of rotation is critical for some of those, like timers.  
You might think nobody would notice the exact speed of rotation of a microwave oven turntable, but this was actually the subject of a discussion in "Column 8" in the Sydney Morning Herald a few months ago. For most microwave ovens, the turntable takes 12 seconds for a complete revolution - at least in countries than have 50Hz mains. Some people, being aware of that, set the timer to some multiple of 12 seconds when warming a mug of coffee, so that when they retrieve it the handle is in the same position as when they put it in. So there!

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## FrodoOne

> A look inside the drill doctor.. Screwdriver's - "Drill Doctor" internal mechanism / 220V convertion 
> Inside the unit is a Bridge rectifier, what that does is convert the ac power to a pulsating dc power, it also doubles the Frequency.
> So on US power that 60hzx2 =120hz On Aussie that's 50x2 =100hz

  One picture in the above reference shows the motor as being labeled 120V    AC 60Hz BUT it is actually being run on DC, via a hefty "Bridge"    rectifier. (In another picture is shown the usual American color code  for the incoming wiring of Black (Line/Active) - going via the switch,  White (Neutral) and [what on my monitor looks to be Blue but is probably  Green] Earth wire.)
Parts of the commutator can be seen through an opening and I strongly  suspect   that the two white "blocks" (one on each side) are the  mountings for the   "brushes" of what is actually a "universal" motor  designed to run on   60Hz AC.    Hence, it will have laminated pole  pieces to reduce heating losses -   which become worse as the frequency  increases.  It could actually run  on "pure" 120V DC, instead of the  "pulsed" DC with which it is designed  to be supplied. 
Therefore it is very likely that there will be no problem if this motor is  run from a transformer supplying 120V 50Hz AC.
I note that a 500W step  down transformer is available for $64 on Ebay -  with "Free" postage!  This has a 3-pin Australian plug and  what appears to  be a "universal" socket outlet, which should accept the American plug (NEMA 5-15P) by which the Drill Doctor is connected. 
So, if Marc can get it for (AUD ?) $160 plus the $64 step down  transformer the total outlay would be $224, although there may be additional postal charges of at least $50, bringing the total to at least $274 (verses the $420 quoted  originally for an "Australian" 230 V 50 Hz model - a saving of $146 !)

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## Mitch1500

Pure class guys, love the replies. Especially yours Ozcar, I'm wondering if a can place bets with my mates on getting the handle back to the same position in their own microwaves  :Smilie:  
Question though, why the need for 500watts when it runs at less than 200watts according to ohms law?

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## justonething

> So, if Marc can get it for (AUD ?) $160 plus the $64 step down  transformer the total outlay would be $224, although there may be additional postal charges of at least $50, bringing the total to at least $274 (verses the $420 quoted  originally for an "Australian" 230 V 50 Hz model - a saving of $146 !)

  You can get them all from Amazon, but it will be cheaper to get the transformer from ebay because it is heavy. Amazon drill doctor DD750X - $130USD, postage 29USD = 159 / 0.93 = 170AUD.
Ebay 500 W transformer 49AUD incl postage.

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## Mitch1500

Or the 12v version 500watt 110v 60hz (unlike the others) also makes it portable  500W 500 Watt Boat Car Truck Power Inverter 12V DC to 110V AC with USB | eBay 
$US 33.00 postage free. Note ebay.com not ebay.com.au

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## phild01

> Or the 12v version 500watt 110v 60hz (unlike the others) also makes it portable  500W 500 Watt Boat Car Truck Power Inverter 12V DC to 110V AC with USB | eBay 
> $US 33.00 postage free. Note ebay.com not ebay.com.au

   :2thumbsup:

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## justonething

> It is true for synchronous motors.

   My bad, I should have mentioned that too. Both asynchronous (aka induction) and synchronous motors have speed that are in direct relation to the frequency of mains supply. But I think neither is in that drill doctor.

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## Random Username

Hey!  The multiple of 12 thing for the microwave really works! (sips microwaved hot chocolate). 
And I recon that the Drill Doctor company sounds like a bag of dicks - I wouldn't buy their product on principle if that's their pricing strategy.

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## Marc

I actually paid $195 including postage from ebay US. 
How do you get Amazon to deliver? I can hardly buy a thing from Amazon without the warning: No delivery to Australia. Even some books have issues with delivery.

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## Marc

I actually paid $195 including postage from ebay US. 
How do you get Amazon to deliver? I can hardly buy a thing from Amazon without the warning: No delivery to Australia. Even some books have issues with delivery.
By the by ... if universal motors run on the prescribed voltage regardless of frequency, why don't we buy US powertools and plug them on an ordinary transformer?
JohnC, as far as 220 two phase running on 240(ish) single phase, well, that is news to me. How is it even possible? Are you sure that it is two phase? it could well be made in US for the european market, that is 220 50HZ and yes I have german power tools that are for 220V happy with a tad more voltage.

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## Random Username

You can always use Shipito as your US address, and they will forward it on to you.  Gets around all those "We don't send to...." problems.  http://www.shipito.com/

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## justonething

> I actually paid $195 including postage from ebay US. 
> How do you get Amazon to deliver? I can hardly buy a thing from Amazon without the warning: No delivery to Australia. Even some books have issues with delivery.
> By the by ... if universal motors run on the prescribed voltage regardless of frequency, why don't we buy US powertools and plug them on an ordinary transformer?
> JohnC, as far as 220 two phase running on 240(ish) single phase, well, that is news to me. How is it even possible? Are you sure that it is two phase? it could well be made in US for the european market, that is 220 50HZ and yes I have german power tools that are for 220V happy with a tad more voltage.

  click on the following link what does it says about shipping? 
One of the ways, though not fool proof, to filter out stuff that is not available for international shipping, is to tick the AmazonGlobal Eligible box.

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## justonething

> You can always use Shipito as your US address, and they will forward it on to you.  Gets around all those "We don't send to...." problems.  http://www.shipito.com/

  Another one is comGateway

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## FrodoOne

> as far as 220 two phase running on 240(ish) single phase, well, that is news to me. How is it even possible? Are you sure that it is two phase? it could well be made in US for the european market, that is 220 50HZ and yes I have german power tools that are for 220V happy with a tad more voltage.

  In North American (including Canada) there is an "interesting" AC Power distribution system as compared to most of the remainder of the world. 3-Phase "High Voltage" power is distributed in the same way as it is distributed in Europe, Australia et al. However, when it gets to the "low voltage" distribution to the Home or Business premises, (usually) the supply is 240V, with a "Centre Tapped" Neutral connected to Earth. This means that, relative to the Earth/Neutral, the Voltage available at each "Normal" Socket Outlet is 120V and this 120 V supply is 180 degrees "out-of-phase" with the 120 V normally supplied to half the other sockets in the premises! 
Since virtually all premises are supplied with "Split Phase" 240V, it is quite easy, via the possibility of using "paired" dual 120V circuit breakers, to install appropriate (3 or 4 pin) socket outlets which supply split phase 240V, Neutral (if required) and Earth - for appliances which require high wattage applications. (e.g. Clothes Dryers.) 
(If you think about it, a North American heating device which utilizes a split-phase 240V supply to operate efficiently only "needs" the Neutral to utilize the 120V from one Line/Active connection of this "split phase" in order to operate any electronic "control" equipment designed to operate only on 120V.  Without the "need" for a Neutral they can be supplied with just the two "out-of-phase" 120 V supplies, plus the Protective Earth connection.) 
If you check AS/NZS 3112 - Wikipedia, the free encyclopedia you will find that a socket designed for just this situation was the "source" of the design for the Australian 3-Pin socket but the socket concerned never became an "official" NEMA socket - possibly, because of Patent considerations.  (The NEMA 10-50 looks similar but is about 10% larger.) 
For further information,  see NEMA connector - Wikipedia, the free encyclopedia  or check National Electrical Manufacturers Association (NEMA) (They  don't appear to think that they need to include "American" in their  title!)

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## phild01

> If you check AS/NZS 3112 - Wikipedia, the free encyclopedia you will find that a socket designed for just this situation was the "source" of the design for the Australian 3-Pin socket but the socket concerned never became an "official" NEMA socket - possibly, because of Patent considerations.  (The NEMA 10-50 looks similar but is about 10% larger.)

  Good informative link, didn't know our plug was an old American standard.

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## justonething

> By the by ... if universal motors run on the prescribed voltage regardless of frequency, why don't we buy US powertools and plug them on an ordinary transformer?

  You can buy power tools from the US and use them here. I have done it plenty of times, as long as you are happy lugging your transformer around with your power tools.

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## FrodoOne

> Good informative link, didn't know our plug was an old American standard.

  Actually, it never became a (NEMA) "standard" in North America - although it is (apparently/presumably) "legal", if it still exists in use in very old (pre-WWII) buildings. 
As I said, it "never became an "official" NEMA socket - possibly, because of Patent considerations. (The NEMA 10-50 looks similar but is about 10% larger.)"  
For more "Local" information you may like to look at http://members.iinet.net.au/~cool386/plug/plug.html
and History of the Australian plug - ECN Electrical Forums 
Also see Museum of Plugs and Sockets: Australasian types (and other pages on that site.)

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## Marc

Yes, used myus plenty of times, but the shipping is a ripoff, never used shipito but judging from the poor reviews I wouldn't like to try them. 
Both myus and shipito go well the few first times and then go pear shaped.
Next time I need to ship something small I'll try US to OZ - Shipping to Australia

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## Belair_Boy

When I saw "14,000 rpm" in SBD's post I immediately thought universal motor.
Good info from Justonething and FrodoOne, I would agree the stepdown transformer is all that is needed and frequency is not an issue.
A bigger stepdown transformer is better for voltage regulation and will give you capacity for other 115V tools if you buy them in the future. 
As for the 12s microwave thing, my last microwave had a switch on the turntable causing it to return to the same position each time, regardless of how long it was set for.  The handle was always in the same position as you put it in.  I miss this on my current microwave.

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## Mitch1500

I've been having a bit of a read on electric motors, so please correct me if I'm wrong. 
Having a look at the picture it shows the motor rated at 120v AC, yet it is clearly running on DC due the the bridge rectifier, so this alone indicates that its a Universal motor as the Universal motor is the only motor that runs on both ac and dc? It cant be an induction motor as asynchronous and synchronous motors only run on AC? 
The other thing is that is rated at 20,000 rpm, there's no way to get that speed from an induction motor, the highest being at 60hz is a 2 pole motor that runs at 3600 rpm, even though the bridge rectifier doubles the frequency to 120hz it would run at 7200 rpm, but yet again impossible due to it being DC not AC. Still a far cry from 20,000 rpm. 
I don't see any other options for it NOT to be a universal motor (apart from being a dc motor, see sticker). So the FAQ on their web site is just a load of rubbish. They should be taken to task over it.

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## joez

Sorry ifs a little off topic but how would the drill doctor stack up to something like this:   Drill Bits Sharpener Grinder Grinding Machine MR 13A 2 13 MM 100 135 Angle | eBay

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## Marc

Hard to tell, unless you use it. It looks big and has a diamond grinding wheel (?) The description is rather funny but that does not necessarily mean bad. 
I bought an ozito once for $20 and it was absolute junk. This looks a bit better but ... only a guess. At $300 you can buy top of the range drill doctor shipped here and still $100 to spare for a transformer. 
By the way I made some enquiries with two US companies that make frequency converters and one gave my phone number to the rep here. He called me and ask me a string of questions with the usual deep voice of great importance like the one asked to the CEO of a multinational and will be back with a quote for this phenomenal life saving device. My guess he will quote me over $1000 ha ha, our retail system absolutely sucks.
I stick to the $20 ordinary transformer this time. 
When i need to produce 110/60hz 1KW for my intergalactic rocket launcher I'll call that rep back.

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## Mitch1500

Why not use the 12v inverter for $40? 110/60 and 500 watts. 
The other thing about the no name Chinese version is, how do you buy new diamond wheels for it? Its a hell of a price to pay for no spare parts, and thats if its any good. My experience with no name brands is not all that good, They last for a short period of time, but then you may be lucky.

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## Marc

> Why not use the 12v inverter for $40? 110/60 and 500 watts. 
> The other thing about the no name Chinese version is, how do you buy new diamond wheels for it? Its a hell of a price to pay for no spare parts, and thats if its any good. My experience with no name brands is not all that good, They last for a short period of time, but then you may be lucky.

  yes, I wish you were right, but there is no such thing. 
You can transform 240 v to 110 v cheap. You can not convert from 50hz to 60hz on the cheap.
however others more savy than me established there is no need to do so for the drill doctor.
as far as your link, i must agree with the previous reply, too much money for an unknown

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## phild01

> yes, I wish you were right, but there is no such thing. 
> You can transform 240 v to 110 v cheap. You can not convert from 50hz to 60hz on the cheap.
> however others more savy than me established there is no need to do so for the drill doctor.
> as far as your link, i must agree with the previous reply, too much money for an unknown

  12vDC to 110VAC inverter!  Would this not be 60Hz?

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## Mitch1500

> yes, I wish you were right, but there is no such thing. 
> You can transform 240 v to 110 v cheap. You can not convert from 50hz to 60hz on the cheap.
> however others more savy than me established there is no need to do so for the drill doctor.
> as far as your link, i must agree with the previous reply, too much money for an unknown

  Yes you can. 
You can do it via a 12volt system. Use a 12v inverter to convert it to 110v 60hz. 
If you dont want to use it on a battery, you can also buy a 240v-12v transformer and plug the inverter into that. 
Price guess for transformer $40, already priced inverter (see earlier post)  approx $40AU. Total cost $80
Just make sure the transformer handles more watts than the inverter. 
Personally Id just run the inverter off a 12v battery that I have hanging around in my shed. 
And no the drill doctor doesnt need 60hz, However it isn't a Universal motor as previously mentioned, more on that later. I want to confront them over it.

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## phild01

:Arrow Up: Still agree this is the way to go.  I have an inverter running a battery charger for the cars deep cycle.

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## Marc

> Yes you can. 
> You can do it via a 12volt system. Use a 12v inverter to convert it to 110v 60hz. 
> If you dont want to use it on a battery, you can also buy a 240v-12v transformer and plug the inverter into that. 
> Price guess for transformer $40, already priced inverter (see earlier post)  approx $40AU. Total cost $80
> Just make sure the transformer handles more watts than the inverter. 
> Personally Id just run the inverter off a 12v battery that I have hanging around in my shed. 
> And no the drill doctor doesn't need 60hz, However it isn't a Universal motor as previously mentioned, more on that later. I want to confront them over it.

  Sorry, you are right, forgot the 12V trick mentioned before.
I see how I go when it gets here, still waiting for it.

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## Marc

Here are two links to first the 240v to 12v and then the 12v to 110v 60hz. A sort of long way around but considering the outrageous prices of the frequency converters, this is clearly a way around it for small amounts of power.  
i still can't figure out how a two phase motor 220 can work on single phase 240 though.   Fridge Power Cord 240 Volt TO 12 Volt DC 30 AMP 360 Watt Transformer | eBay  http://www.ebay.com/itm/400W-modifie...item1c4482c365

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## Mitch1500

Well that's *IF* you want to run it at 60hz. The US drill doctor is a 115v single phase unit. 
The way I see it, you either buy a step down transformer 240 to 110 volts OR you run it off a battery with the 12v 110v/60 inverter. I see the 240-12v transformer as overkill (although still possible) The reason for this is, the requirements to run this particular tool. Had it a different sort of motor then the frequency may of been a requirement. 
The drill doctor has a Permanent Magnetic motor, which come in both AC and DC, however as we've seen in the photo it is wired to a bridge rectifier, which supplies a dc voltage to the motor. A dc motor wont be effected by the frequency, unless its too much. 
I've emailed the company (already had one response) but I'm waiting on a reply in case there's been changes, revisions etc to the motor or changes to the electronic components..   
Will let you know the outcome.

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## Marc

Yes, sorry, my brain works in different directions at the same time. Drill doctor, step down to 110V forget frequency. 
US two phase 220V on 240V single phase, thats the one that surprises me.

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## forp

Hi all, 
I see you all have questions about drill doctor with USA motor. I bought mine April this year from Amazon shipped to USA and forwarded with my other car parts.
Screw the businesses who's purpose to rip us all. I don't mind paying extra $10-$20 but a lot of dealers sets silly high prices just because we are well off nation?!?!?
If I wanted something but the local price is too much to pay for, I always import.  
A few years ago I bought this EU made 300VA toroid transformer from Sydney. It's 50-0-50, two 50V output, which then connected in series, makes about 100V suitable for powering my Japanese goods. Because our mains voltage is slightly higher the transformer is producing around 110V, which is nice I can use it for USA goods. I reused an old ATX computer power supply casing which houses the IEC plug connector, a on-off switch, and a slow blow fuse. Big toroid transformer has inrush current so slow blow is nice. The output is wired to a cheap $1 Chinese converter that accepts almost every mains socket available in this world  :Biggrin: . Well the wiring arrangement can do a little better but I didn't want to cut the leads short just in case I find a better case but that didn't happen. 
The Drill Doctor 750X is quite simple device really. Electrical side, it consist of a on-off switch, bridge rectifier and a 120V Johnson motor. The motor is a typical motor found in most corded power tools. My initial plan was to replace the original motor with a 240v motor from a cheap drill but I didn't need the toroid transformer for my other equipment anymore so it's stuck to the drill doctor. 
Please refer to the attached pictures for your reference. If you have any questions please ask.

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## FrodoOne

> i still can't figure out how a two phase motor 220 can work on single phase 240 though.

  Marc, 
The motor to which I believe you are referring is NOT actually a "2 phase" motor but a motor of around 220/240 V input connected across the two "Lines" of the "standard" US split phase domestic distribution system - without the "benefit" of a Neutral.. 
The US 240 V (and it IS  - nominally - 240 V) Split Phase "domestic" supply is simply a centre tapped 240 V secondary of a street power supply transformer, (with the primary of this transformer being a "High Voltage" supply just as it is in Australia.)  _(If you look at NEMA connector - Wikipedia, the free encyclopedia you will find an associated diagram (NEMA connector - Wikipedia, the free encyclopedia) which clearly shows that these Sockets etc. are designed for 120 V AC or 240 V AC.     In addition, other sites refer to these same designs as being for 125 V and 250 V.
110/220 V AC does exist in some areas of the US BUT, likewise, various voltages from 220 to 250 [and others] also have existed in Australia - and some still do.)_ 
The important point is that, in the US, the Neutral is connected to the Centre Tap, NOT to one "End" of this 240 V secondary.   Hence the supply to the premises  is via two "Lines", with each Line at 120 V (with respect to the earthed Neutral).  Therefore, each of these 120 V "Lines" is 180 degrees out-of-phase with the other. 
 Hence, connecting to BOTH of these two "Lines" is just the same as connecting to the one "Line" and Neutral of a 240 V domestic power supply in Australia EXCEPT that in the US the potential between *each* of two "Lines" and the Neutral/Earth does not exceed 120 V AC. In Australia, the *single* supply "Line" IS 240 V AC_ (OK, 230 V AC_) with respect to the Neutral/Earth - because the other END of the secondary supplying the premises is connected to the Neutral/Earth. 
While in the US the supply IS (usually) a Split single phase, you can think of it as TWO phases if you wish.  However, remember that each "phase" is 180 degrees out-of-phase with the other - NOT 120 degrees out-of-phase (as it would be if each of these phases were two phases derived from a three phase system). 
So, the voltage read across the two "phases" is 120 V * 2 = 240 V (and NOT 120 V * 1.73 = 207.85 V) - AND there is no easy way of producing a rotating field from this supply.  
The following diagram shows the situation (but, unfortunately, all socket outlets are shown as NEMA 10-50)    However, the two socket outlets supplied with individual X or Y supplies would normally be the (US) usual NEMA 5-15 3 pin socket outlets supplied with one "Line" plus Neutral and Earth.    
This second diagram may show the situation better - but with extra extraneous information relating to a "local" generator and switchover.   
While it is somewhat difficult to find appropriate photographs, the following illustrates the situation where (in this case) what appears to be a Single Wire Earth Return (SWER) high voltage line feeds a transformer supplying centre tapped low voltage power over two "Lines" and an (Earthed) Neutral to five separate nearby premises.  (While it is difficult to see, there is an Earth "Return"  and Neutral/Earth "Connection" to the right of the transformer which then crosses underneath it and goes down on the left side of the pole.)
 (You may note that, while the centre tapped Neutral from the transformer is turning green and, hence, is probably bare copper, the Neutrals to the premises are actually the steel bearer wires which carry the insulated "Line" conductors.  This is common practice in North America, since [hopefully] the loads in the premises will be "balanced" and so each Neutral should carry little current - compared to that on the "balanced" Line supplies.)   
See also HowStuffWorks "How Power Grids Work" for more information concerning electricity supply in North America.

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## Marc

Oh hum, yea ok....
Are you saying I can buy a Delta woodworking machine with a 220v motor and plug it in here and that it will work?

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## FrodoOne

> Oh hum, yea ok....
> Are you saying I can buy a Delta woodworking machine with a 220v motor and plug it in here and that it will work?

  Assuming that you are addressing me, the short answer is "Yes" _(but at 83% of the nominal speed.)_ 
While I presume that you are referring to items on the site Delta® Power Equipment Corporation - Home, I do not know to which particular device(s) you are referring. 
If it has a 220 V motor it will work in Australia on 230 - 240 V without much problem. _(The "extra" voltage is less than 10% so it is unlikely that any motor would be so badly designed that it could not tolerate a 10% "over voltage"!)_ 
Of course, if (as is virtually certain) it has an induction motor, it will run a 5/6th of the speed it would run at on 60 Hz.  _(My European designed electric shaver does the same thing - without any problems!)_  
For example, the first item on the home page of the above mentioned site is 36-L352 Type 2,
which is a   3 HP Motor 10 in. UNISAW® 
The specifications for this item include
Motor: 3 HP, 230V, 1 Phase, 60 Hz  _(Surprisingly, it is specified as 230 V and NOT 240 V [or 220 V])_
Blade Speed: 4,300 RPM 
A 3 HP motor (if 100% efficient) would use 3*746 Watts = 2238 Watts. On 230 V this would mean a current of 9.325 Amps. Obviously, it will not be 100% efficient and the "starting" current will be higher - so a 3 HP motor  could not be manufactured to run on the "standard" U.S. 120 V 15 A circuit, where it would draw well over 20 A at start-up and over 15 A while operating.
Because the (induction) motor is made for 60 Hz, if it is run on 50 Hz the "Blade Speed" will be 5/6 of the specified speed (i.e. Approx 3,580 RPM)  
The second item at 22-555 is a 13 in. Portable Thickness Planer 
and the specifications include Motor: 15A, 120V, 60Hz, 1Ph
Obviously, this item must not be connected across 230-240 V. 
Similar remarks apply to the third item.

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## Marc

> Assuming that you are addressing me, the short answer is "Yes" _(but at 83% of the nominal speed.)_ 
> While I presume that you are referring to items on the site Delta® Power Equipment Corporation - Home, I do not know to which particular device(s) you are referring. 
> If it has a 220 V motor it will work in Australia on 230 - 240 V without much problem. _(The "extra" voltage is less than 10% so it is unlikely that any motor would be so badly designed that it could not tolerate a 10% "over voltage"!)_ 
> Of course, if (as is virtually certain) it has an induction motor, it will run a 5/6th of the speed it would run at on 60 Hz.  _(My European designed electric shaver does the same thing - without any problems!)_  
> For example, the first item on the home page of the above mentioned site is 36-L352 Type 2,
> which is a   3 HP Motor 10 in. UNISAW® 
> The specifications for this item include
> Motor: 3 HP, 230V, 1 Phase, 60 Hz  _(Surprisingly, it is specified as 230 V and NOT 240 V [or 220 V])_
> Blade Speed: 4,300 RPM 
> ...

  Well thank you Frodo, I am really surprised. I know that you lose a bit of speed due to frequency but was told repeatedly by suppliers, electricians and assorted sticky bics that there was no way to purchase a machine from the US running on "their" 220V and use it here and that I had to contemplate changing the motor plus check all the other electrical stuff like lights and safety switches and that all that makes it not worth it. 
Now I know!

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## Mitch1500

Ok The latest drill doctor motor is a DC Brushless Permanent Magnetic motor, they have used at least one other type of motor, probably more. 
One of the advantages of the brushless motor is that they last longer, no brushes to replace, a lot of appliances are going to this type of motor due to the energy efficiency, fridges air cons etc etc. 
Basically it should be fine running on any method of dropping your voltage down to 110v so long as the equipment isn't dodgy. In fact it would probably run on 240v but I wouldn't recommend it as you'd burn out your bearings in no time. 
The company told me that the drill doctor doesn't seem to last as long running on an inverter, but I don't believe this at all. (see reasons why they might cost more  :Smilie:   ) (maybe you should ask, do they believe that)
In the event that you need to replace the motor in the future, 5-10 years it should be easy enough as you can just take the motor to a manufacturer  for a suitable replacement or buy one of the drill doctors replacement motors. 
The old motors had brushes, perhaps they were universal motors or perhaps they were DC, I don't have this information. Either way they will still run on an inverter. 
Frequency is not an issue for any of the above. 
How can you tell which motor you're getting? 
That's easy The new motors run at 15,000 rpm, the old motors run at 20.000 rpm, for a longest lasting tool make sure you get the 15,000 version, there are plenty of old ones still out there for sale 
Why the difference in price? Dollars of course. You can guess who's in for their slice of the pie.

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## zzkazu

I have been using shipit for the last 4 years, never had a problem.  But not always cheap as they use major couriers like TNT/DHL although most cases you can use US Post.

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