Pillar drill - Convert 415v to 240v

[Dokkodo]

How do.

Ive just bought a meddings pillar drill on ebay, which is 415v, and I need it to be 240v. I knew it was 415, but went for it anyway because it was a good price and on the strength of this post on another forum it shouldnt be hard to convert. The thread is here: http://www.mig-welding.co.uk/forum/...ase-drill-to-single-how-practical-is-it.5792/ which describes that

if the motors have 230/415 stamped on the rating plate the short bars can be changed and a capacitor added to make it run on single phase, very easy to do but needs to be 230/415 on the plate

.

Mine has that on the stamp, but currently a 3 phase socket wired in (terribly).

Does anyone know how to go about this method? He is the only person Ive seen refer to it, from a bit of light googling everyone just says replace the motor/get a transformer.

any help appreciated, thanks!

 

[CHJ]

See Bob Minchin's (Myforman) Use of Induction Motors in the Home Workshop Pages 10 & 11 give a typical motor connector box and the link changes required.

Capacitor to simulate the third phase needs to be 400 volt working to cover peak voltages.

Dependant upon motor HP the value needs to be similar to those indicated in this list.

The maximum HP on the rating plate is unlikely to be achievable but for a pillar drill should be adequate.

 

[deema]

I would personally buy an inverter to achieve infinite speed control with no loss of torque. You will need to wire the motor into delta configuration from star which is just a couple of links inside the connector housing on the motor. An inverter will be almost as cheap as cobbling together a capacitor arrangement.....which will reduce the motors efficiency.

 

[TFrench]

I was lucky with mine - I was throwing out a knackered clarke drill and the motor had the same size shaft as the 3 phase one on the startrite. I just made an adapter plate from MDF so the holes lines up and it was dead easy. If your meddings is pulley drive I''d definately have a quick look for a 240v motor of a similar size.

 

[Farmer Giles]

I would definitely go VFD as well but if you want to give a static phase converter a go then here's a typical diagram, I was going to use it to power a lathe suds pump but it turned out the motor was cream crackered so bought a 240v replacement. Here's a good phase converter site too

Which meddings did you get? I've been looking at ebay for a while as I need a spares donor for my A10 Meddings radial drill an MF4 would be ideal.

 

[Dokkodo]

Thanks all!

Its an M2, floor standing, think i might have got lucky as it didnt say meddings in the lot title or description... Nice old school design, will need a once over but from what Ive read Meddings come fairly highly regarded? Have to say I dont know a huge amount when it comes to older machinery. It says 0.5 HP on the stamp...

is a VFD the same as an inverter? and if so, could someone link me to the right sort of thing on ebay or a link to have a look at with some more info? cheers!

I take it that static phase convertion is the capacitor solution in the OP. Im perfectly happy doing odd bits of wiring but something about electronics diagrams makes my eyes go funny.

 

[Dokkodo]

ok so i have found all the bits. choices being:

capacitor and some wiring - a fiver - reduced motor efficiency
http://www.ebay.co.uk/itm/Universal-25- ... Swqv9V7VOJ

VFD - £80-150 - infinite speed control, no loss of efficiency?

New motor - £60+ - same as current efficiency, shame to retire a good motor i feel

if I go for option one, capacitor business, presumably I can upgrade to a VFD sometime in the future?

 

[Farmer Giles]

yes, static is the capacitor option, you have to get the values right and even then it's not good on efficiency but can be cheap.

I use inverter drive supermarket usually, I have a couple of VFDs. 0.37kW is the same as 0.5hp so you want a 240v single phase input, 240v 3 phase output 0.37kWor above drive. Your looking at around 70 to 80 quid, or you may get a chinese one direct from ebay cheaper but good luck with support. You need to set your motor to delta or 240v with the movable straps.

Give them a call, they have been helpful to me in the past.

 

[Farmer Giles]

with a VFD you have variable speed control so less belt changing.

Static conversion is less efficient and I have heard of motors not faring well if capacitor values are not correct however your probably looking sub 20 quid for all the bits.

A new motor isn't a bad option if your not likely to need many speed changes. The shaft size on new motors is typically bigger than older imperial equivalents which can be a pain for fitting the pulley unless you have a a mate who can do the machining for you. Finding a second hand motor with the same shaft size is an option but you can never tell if the motor is past its best until you get it going.

 

[shed9]

Personally given the learning curve of rewiring either for a cap or VFD, I'd contemplate the middle ground of a replacement motor - selling the old one to recoup some of the cost. Yes a replacement motor if used comes with baggage but 3 phase motors in work environments are usually worked hard as well so that potential issue is already present.

VFD is probably the best route but it comes with it's own issues as well. They really don't like RCD's in the mix and I suspect your working area is kitted out with these. You would need to ensure your belt arrangement is setup optimally for 1-1 ratio. Also, at the lower end of the VFD budget, it is a little hit or miss.

 

[woodbrains]

Hello,

I converted my Elliott Progress to run on a VFD. easy enough to do and works well. However, I still think a motor change is the way to go if cost allows. I couldn't find a single phase motor and NVR switch (the higher current draw on single phase means the original switch is usually not good enough to keep, so price this into your sums) to suit for less cost than a VFD , supplied by Myfordman.

I wouldnt entertain using capacitors. where are you going to house them? they are big and carry a lot of current. and getting a quality drill press like a Meddings seems ridiculous if you are going to fudge the electrics!

If you go down the VFD route, I would actually not go for a 1:1 ratio on the pulleys. I would actually go for a slightly reduced spindle speed, and here's why. There is higher torque to the drill at lower pulley speeds, so for drilling big holes this is useful, even when reducing the speed further with the controller. There is still ample speed control for faster speeds, as much as you'll need. However, you will not want to reduce the speed too much with the controller, certainly not more than about half of the motor speed, because the fan which cools the motor will not be effective enough at lower speeds. If you set the pulley speed to give a 1:1 ratio, you can't go slow enough on the controller for some largish drills without running the motor too slow, which reduces the lifespan of the motor. Of course you can change the pulleys more often, for different drilling tasks as well, but for a general setting, which saves the bother more often than not, I would pick the pulley one lower than 1;1.

Mike

 

[Dokkodo]

More wisdom, thanks all.

Between the VFD and new motor, sounds like VFD might be the one for me.

Is there more I should know about how much you can use the VFD to safely control speed? At what points should you be using the pulleys?

 

[woodbrains]

Hello,

Here is what I'd do; if your motor speed is 2800 rpm at 50 Hz, set the pulleys to give a spindle speed of about 1500 rpm. When your VFD is set to 50 Hz that is what the drill will run at, a good middle speed. Increase the VFD to 100 Hz the spindle will run at 3000. Fast enough for anything methinks. Set your VFD at 25 Hz and the spindle will run at 750 rpm. Slow enough for most drills and not running the motor too slow for the fan efficiency. You could lower a bit more for biggish Forstner bit drilling 12Hz will run the drill at 375 and there should be enough torque with that pulley config to run 60mm Forstner in hardwood. I would limit the time drilling though as the cooling will not be good for long sessions. I think this setup is good for most tasks and I seldom move my pulleys.

Big drills in steel, you might want more torque, so I would change to a lower pulley speed then and not have the VFD on (much) less than 50Hz.

Mike.

 

[shed9]

Don't forget the RCD issue as noted up there ^; catches a few people out and can increase costs depending on your situation. Basically in some wiring systems the RCD will trip when you plumb in a VFD inline with your motor. There are solutions if this happens, mostly changing the type of RCD but be aware of the issue before you step in and save some stress.

 

[Ttrees]

If you want to use a VFD for your drill and want to do it the cheapest, I will give my 2 cents worth.
I went for the cheapest VFD/inverter I could get for my bandsaw and tablesaw, both are 3HP ...
These were the Huanyang drives.
I have disconnected my potentiometer (speed dial) because it kept malfunctioning.
I had to reset the drive by plugging out the ribbon cable that connects the control panel.
This is easy to access.
This is a reset if you will, along with parameter reset.
Huanyang states the older VFD's had a reset by keying in 1 instead of 8 on PD13.
I don't know if this pot issue would be a problem with a smaller drive, but just saying so...
My new VFD for the tablesaw has an extra LED light inside, that's a reassuring green
I have not tried swapping the drives and using the new one for the bandsaw ...
I heard that a lower speed would be good for cutting plastics ...haven't found any difference though with
the plastic I have been cutting, nor have I cut aluminum or brass on the machine as I got it for resawing mainly.
Tom

 

[Dokkodo]

Last question!

Ive found my motor connections box (oops, didnt need to get the motor off to get in there)

got the star/delta thing, thats simple enough, but i just want to be sure about another thing, and i cant find any specific videos or tutorials for this bit. What must be the the on/off switch (the dial shown in pictures) is wired in before the motor. Do I bypass this, and use the VFD for on/off? Or do I wire to this on off switch.

im not afraid of a bit of wiring but i dont want to do the wrong thing...

 

[woodbrains]

Hello,

The VFD will need a latching switch wired into it. The one on your Meetings will do fine, but disconnect it for now and save for wiring into the VFD.

Mike.

 

[Dokkodo]

Ive wired straight into the motor now, and it seems to run fine...

Have now noticed a couple of things though. The pulley wheels have a bit of a wobble on them, makes the whole thing vibrate a bit... and there is about 1/8th of a turn of play in the spindle shaft where it engages with the spindle pulleys - are either of these critical?

not sure where to mount my VFD either....

 

[Farmer Giles]

post put in wrong thread by mistake - please ignore

 

[Dokkodo]

Andy - I do believe that has ended up in the wrong thread!