Thread: urgent help please with drill and vsd

thanks.

it is an amazing drill. very capable. the low speeds are great for boring huge holes in timber.

the motor is 4 speed and the gearbox is 2 speed, so 8 in total it also has an automatic reverse function for tapping and and automatic feed mechanism that has its own gearbox with 3 different speed feeds. it self feeds up and down and self changes direction so highly repetitive work is super easy.

made in england, you would be hard pressed to find better quality. hence the reason i dont want to sell it unless it is useless to me.

Hi Scamp,
Is the "automatic reverse function for tapping" mechanical or electrical?
Stuart

What an alarmingly cool looking drilling machine. I like everything about the description, and the overall appearance looks pretty pleasing too.

I can certainly see why you'd want to keep it...I can't think of anything remotely as stout and well-featured short of the largest Arbogas or Altzmetals.

Greg

Hi scamp,

Solid machine, that's a keeper. and with a motor wound for 2-4-6-8 pole switching... very slick.

Let's start with the basic stuff...

First, you shouldn't switch the output of a vfd under load. so that complicates things.

I'm not saying you can't keep the switching, it's just that you can't switch it while it's running, you would have to stop the vfd, before switching.

Second the motor will be wired in star (as is), to run off 240v 3 phase you should rewire it for delta. You could run it as is in star but at reduced power in the higher hz ranges.

Yes, you can get vfd's that are 240v single phase in and 415 3 phase out, but they are more expensive...

Easier to get it changed to delta. Remove the motor and take it to a motor rewinder.

Using the vfd for speed changes instead of the multipole switching would be my preferred option, but that means choosing what number of poles you want and leaving it fixed, and removing the multipole switch wiring.

Hope that hasn't confused the issue too much. A cheap V/F drive like a Huanyang would do nicely.

Regards
Ray

G'day Scamp,
Very nice machine indeed.
You mentioned the auto reversing for tapping, is this done mechanically or does the motor reverse?
If the motor is reversed this could be another problem depending on how it is done because as mentioned disconnecting a VFD under load will cause it's smoke to come out.
I have converted my star wired motors to delta myself and it's not that difficult if you take your time, however on a motor with multiple pole windings I suspect this would be a bit more difficult.
I reckon a motor re-winder would be the best bet and I would go with the 6 pole (975 RPM) or even the 12 pole (475 RPM) winding.
The main reason for this is that most motors rely on running at the rated RPM for cooling and while a VFD will happily turn a motor at 10Hz the risk of cooking the windings is greatly increased.
The motor reversing and more can all be done with a VFD its just a matter of wiring and programming it correctly.
Cheers,
Greg.

holy moly i had no idea it would be so complicated. i will really have to think about this.

the reverse feature is controlled electrically and works beautifully for tapping, this is where the super slow spindle speeds come in handy. the drill also has electric braking, by pushing the power lever to the left.

you can set the auto reverse to come in at any spindle height you wish. you can also make it switch back to clockwise automatically at any height.

i was thinking one of those cheaper vfds on ebay would be the cure to all my problems! oh well.

if it means making major changes to this drill to get it to work, i would rather sell it to a good home and leave it as it should be.

i will have to look at the windings and speak to my motor guy i think...

Ahhh. I think we are out of VFD territory here. I'd be looking instead at a rotary phase converter made with a 415v transformer + 415 two or three h.p. motor.

A person on friendly terms with electricity could make one from online plans and local parts for perhaps...$250. (Or less) Depending on how good a scrounger you are.

Greg

i will be buying a vfd to run a thicknesser soon so i thought that would be useful to run the drill too, obviously not at the same time though.

aaaarrrrrggggghhhhh!!!!!!! any one want to make an offer......!

I'm with Greg,
A rotary phase converter is probably the go.
I have just bought a 4KW unit from Phase Changer and I wish it had only cost $250.
It was marginally less than getting 3 phase connected but I can take it with me if I move.
I haven't hooked it up yet but I will let people know how it goes if anyone is interested.

You cant sell that machine, even if it doesn't run it's worth having just for what it is .

I thought I'd heard of VSDs that allow switching on the output but I cant find one atm. If that are out there they are in the $1k+ range though.

Maybe I was imagining it?

Stuart

Hi Scamp,

Not good news....

That automatic electric reverse is the deal breaker as far as a simple vfd conversion goes... it could still be done, but the complexity just shot up a few orders of magnitude...

If it was mine, I'd probably persist and spend a ridiculous amount of time and effort going down the vfd control route, (but then again, that's my twisted idea of fun) but that's not the simplest path to travel..

A rotary phase converter is probably the best option, but I'd ask the local electricity supplier how much it would cost to connect three phase mains first, and see which option suits.

Regards
Ray

i would really hate to sell it but i dont really have the space to keep it if i cant use it.

i would love a phase converter but at the moment they are too expensive for me to consider and i need a working drill in the next few weeks. i would love a nice waldown that i can use straight away as its mostly for woodworking.

Why can't he use whatever switchgear is doing the reversing to run the inputs to the VFD?

go bryan! that sounds interesting...will that work?