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View Full Version : NEW MEMBER: Hi from a newbie in Wiltshire



hlnoob
08-01-2011, 10:56 PM
Hi, Used to work in a tool room years ago on an HCT but moved away from engineering things some 20 odd years ago. The Hardinge was so good i could not think of having any other lathe.

Just got an hlv to play with. unfortunately its a 440v 3 phase and i only have 240v single phase uk.

I am looking for a cheap way to get it up and running. I don't want to re-configure any of the internal wiring as i want to eventually restore it and want to keep it in an much of an “as built condition” if possible.
I was thinking about making a rpc with a step up transformer from Airlink, They do a 240v to 415v from stock but i am waiting for a quote on a 240v to 440v custom one, It also seems i need a neutral to run the feed control?

Ii was thinking if i wired the idler motor in a star config this may provide what i am looking for. I already have the idler motor which says its a 2.5Kw 440v to 480v Y. Am I on the right track or am i talking rubbish?

I could do with it running asap as i need to make some bits for a biodiesel processor i am making , I was just going to put the transformer output on the idler motor and connect to the lathe, when i have a bit more time I want to refine the rpc design to get it a bit more balanced, I only need to make a few small items from brass so no big cutting loads, I don’t even need the feed to be working for these bits but if possible it would be nice.
Seems I have rambled on enough for my first post and if anyone is still awake and can offer any input on what I am trying to do it would be appreciated.

Cheers

Vince

irving2008
08-01-2011, 11:47 PM
Hi Vince and welcome to the site. Never played with an rpc, I'd always go for a VFD, but I'm sure others have done so. We have a couple of Hardinge owners on here...

Swarfing
09-01-2011, 08:14 PM
Hi Vince nice to see another local, as Irving says go wit the VFD. I'm in the middle of wiring up my 3HP 3 phase lathe at the moment myself with one. Don't be afraid to change the wiring either as if you sell the lathe later will probably go to another home user and they will want 240v. Your existing motor will probably be able to be wired to Delta as well.

Paul

M250cnc
09-01-2011, 09:16 PM
Vice i have a VFD on my lathe but if i had to do it again i would go for an ac servo motor

You will still have speed control but full power from 0 RPM to full speed i know that may be slightly untrue technically

You would also have the ability to do rigid tapping as and when software allows it

Phil

Jonathan
09-01-2011, 09:54 PM
You will still have speed control but full power from 0 RPM to full speed i know that may be slightly untrue technically


If you want high torque at low rpm then best to leave it in Wye...or have a switch to change between that and delta if you're really keen.

M250cnc
09-01-2011, 10:05 PM
If you want high torque at low rpm then best to leave it in Wye...or have a switch to change between that and delta if you're really keen.

A servo motor on the spindle means it can be used as a rotary axis.

A VFD cannot do that delta or otherwise.

Phil

Sent from my HTC Desire using Tapatalk

Jonathan
09-01-2011, 10:09 PM
A servo motor on the spindle means it can be used as a rotary axis.

A VFD cannot do that delta or otherwise.


I'm not sure how quoting me was relevant there!
I'd really like to get a servo for that reason, but it's far too much money.

M250cnc
09-01-2011, 10:26 PM
I'm not sure how quoting me was relevant there!
I'd really like to get a servo for that reason, but it's far too much money.

Jonathan i made a valid point of the added benefits of a servo motor namely Zero to full speed with full torque

You came back with a statement that a VFD could do that in delta mode well it can't run that way and a VFD motor combo certainly cant run as a rotary axis

So why did you quote me ?

Take a look at this video http://www.onecnc.net/videos/video_mill_turn.htm

Phil

Jonathan
09-01-2011, 10:37 PM
how you could do rigid tapping without a VFD...

With a VFD even! Lets hope I start thinking by 9am tomorrow :)

M250cnc
09-01-2011, 10:43 PM
I misread your post, I didn't see the word 'servo'! I did wonder how you could do rigid tapping without a VFD...

Best not make reading mistakes like that in my exams tomorrow!

Nice video by the way...

Better get your haircut before you go then. :smile:

Re the video we can only dream.

Phil

Swarfing
09-01-2011, 11:09 PM
Guys i think you both have run away with this one...LOL! he just wants to get his lathe up and running in a quick turnaround. No mention of servos and taping etc or even CNC?
I would like a servo controlled lathe though. I keep looking at a place i know for a decent servo suitable to build one from scratch. He takes them off the scrap and normally tosses them to one side. A servo to replace a 3hp equivalent motor would cost a lot of wonga?

M250cnc
09-01-2011, 11:17 PM
Guys i think you both have run away with this one...LOL! he just wants to get his lathe up and running in a quick turnaround. No mention of servos and taping etc or even CNC?
I would like a servo controlled lathe though. I keep looking at a place i know for a decent servo suitable to build one from scratch. He takes them off the scrap and normally tosses them to one side. A servo to replace a 3hp equivalent motor would cost a lot of wonga?

Always good to have as much info as you can.

Hood on the Mach3 forum uses a 14 hp servo and he's a Scot.

Phil

Sent from my HTC Desire using Tapatalk

m_c
10-01-2011, 01:12 AM
A servo to replace a 3hp equivalent motor would cost a lot of wonga?

Either 350+vat or 434+vat from zapp depending on if you want speed or torque in the 2.3-2.4kw range.
Plus another 304+vat for a suitable drive...


Getting back to the original post, I got a custom step-up transformer made to build a RPC, but I can't for the life of me remember the name of the company.
Regarding getting a neutral, if the idler motor is a 240/415V motor, then when wired in star config for 415V operation, the star point will provide a neutral for the three phase. That's how I use a 240v contactor to drop out the start capacitors once my RPC idler is upto speed. However, the neutral will be at 240v in relation to earth, instead of the usual 0v, and with the transformer acting as an isolator, you've got to be careful of electric shocks. I installed a three phase RCD as part of my RPC to minimise the risk.

Swarfing
10-01-2011, 12:33 PM
Phil agree lots of info is always good to have and the price of servos and drive could almost buy a brand new lathe. Certainly not a cheap option? Factor that cost into a scratch build though would be a more viable option? i like it already?????????????? :-)