3ph lathe

[dai]

hi hareng, its the older round model with clutch, i think, defo round head, anyway just checked main motor data plate again cos a few things where bugging me, its defo stamped as .95 hp cont
rpm 1390
volts 220/240 380/420
this doesnt sound a very big motor? 1 hp? but its original motor and was on the lathe which i saw working before disconnecting it

take a pic of the motor and plate and post it on here

 

[langy]

varialble frequency device, I`ll second that, however-- reading the spec I`m guessing thats a quite large HP motor:
rpm 2750/3250
^ 220/250 30a
y 380/440 15a
50/60 hz

thats a canny few amps to pull, but depending on the HP I think you will find the largest single phase motor may well be 3 HP and you will see a vast difference from an equivelant 3HP 3 phase, Maybe have a look a Direct drives website, Dave also sells on E bay, however as I say 30 amps on 220/250 is pretty heavy, my largest VFD is a 71/2 Hp chucking out 415V / 3 phase, had to put a heavier circuit in to supply it with 240. Depending on your own personal requirments and any obligations in the public sector, all the controls you need are on the VFD, start stop fwd rev, jog, vary the frequency for speed control and if you go down the 220/250 3 phase route, and wire the motor accordingly, you can get a 1425 motor to run at 2850 using the frequency controls. But I doubt if the lathe would like going twice the speed at which it was intended. I think the older Master had a 1425/ 3HP motor.
On this Forum you may have seen Steve Lang ( langy Hotrods) steve has a colchester with a 3 phase setup. maybe PM him and ask his setup.
Stan

I'm here Stan I run my 3ph Colchester off a digital convertor from Direct Drives off Ebay, They were incredibly helpfull and it runs like a champ, Coolant pump too.

 

[hareng]

Same here Langy, but had to buy three invertors but got credited on the first one £340 against an MA7200 4KW.
Unfortunately they were no use to me unless talking wiring direct to motor. Then couldnt help with the wiring and where to in the unit. Cost me a £650 MA7200 4KW inverter 1 1/2hrs use and had to have the 7.5kw outright on top.

 

[GeorgiePorgie]

Ehat about this inverter? 3/4 of the way down the page.
http://www.arceurotrade.co.uk/Catalogue/High-Speed-Spindles-Motors-Inverters

 

[ford34/2]

Inverter

Might well be an ok unit but neither will power the Colchester, cant see the motor being .95 Hp--doesnt make sense
Stan


Specifications
Code 165-020-00300 165-020-00400
Standard Motor Rating 0.4kW (0.54HP) 0.75kW (1.01HP)
Rated Output Capacity 1.1kVA 1.9kVA
Rated Output Voltage Three Phase, 220V/50Hz,
200, 220, 230V/60Hz
Rated Output Current 3.0A 5.0A
Overload Capability 150% of rated current for 1 min,
200% of rated current for 0.5s
Input Voltage Single Phase 200-240V, 50/60Hz
(operates from a 13A household supply)
Voltage/Frequency
Variations Voltage: +10 to -10%
Frequency: +5 to -5%
Rated Input Current 5.4A 9.7A
Required Power
Supply Capacity 0.7kVA 1.3kVA
Braking Torque 100%
Cooling Method Natural Air Cooling via rear heat sink
Enclosure IP Rating IP20
Dimensions (HxWxD) 120x80x95mm 120x80x140mm

 

[nuffi460]

hi guys, photos of main motor plate

 

[hareng]

As before junk it and buy an original or aftermarket 3HP motor.

An inverter or convertor will be dearer than the Arc, thats only for 1hp tops.
Looking at £300 min to wire direct to motor plus pod.
Total outlay approx £500.

 

[eil]

The amp draw on the motor looks like being around 3/4 hp as Hareng says 1 hp at the most, I have a roundhead master that I bought for spares and that had a 1 1/2 hp motor on it but doesn't get up to the same rpm as my student, cant remember off hand but around a 1000 supposedly but never seen it run, wouldn't imagine it would get to that with such a small motor though, half that realistically I should think.
My student was single phase and 3hp, but I put on a modern 4hp on it just because I had one as the 3 wouldn't start it in top speed in my shed as I'm quite a ways from the house, but I would agree with the general consensus of 3ph motor and inverter if you to have to spend on new. You say you've seen it run with that motor on but did you see it start in top gear.

 

[nuffi460]

hi, thanks for all your help guys, so as i understand i need to get another motor 3ph 3hp, also an inverter or vfd, whats the difference between the two? sorry for all the questions but its all as clear as mud to me

 

[hareng]

Have a look around for a dual voltage 3ph 3HP motor, most are but check.
We can talk you through the Star Delta arrangement - easy.

That leaves you a few options, static convertor ermmm, rotary convertor or a single phase 240V to 3ph inverter.
The cheaper inverters will only give out 220V 3phase thats ok if motor wired accordingly.
The static, rotary and better more complex inverters will run as if theres a proper 3ph 400V industrial supply. Just plug the machine and and fire up, no rewiring retaining all the controls.

The common thing for modellers is must have VFD, must be for looks. VFD Variable Frequency Drive in that sense just offers ability to change spindle speed with a remote pot or by on the inverter front panel. You have a geared head!

Wish i went the new motor and 220V inverter route, could have saved me a fortune.

 

[langy]

Same here Langy, but had to buy three invertors but got credited on the first one £340 against an MA7200 4KW.
Unfortunately they were no use to me unless talking wiring direct to motor. Then couldnt help with the wiring and where to in the unit. Cost me a £650 MA7200 4KW inverter 1 1/2hrs use and had to have the 7.5kw outright on top.

Mine is wired straight from the Colchester into the invertor, all original switches, coolant pump etc work as normal, been working on it 3 years now, mine was £440, I also use it to run other stuff like my 3hp polisher.

 

[hareng]

The short story is i took a flyer on a Teco CV7300 with pot which is 220V outputs. Lathe not dual voltage except coolant pump, incidentally packed up yesterday.
Said i wanted plug and play and was sold the MA7200 4KW. The only response was to wire direct to motor, soft start etc no good to me lost controls.
Months went past many calls not returned and ok to wire as normal. By having a soft start 3 secs it makes no difference, as soon as inverter powered on the relays and contactors chatter thats the soft start. You then get the full load probably equivalent to 9hp start which burnt something out after 1 1/2hrs use.
£280 repair bill as well.

Stuck with increasing workload i had to have something there and then £1100 MA7200 7.5KW which has been fine.
No spindle speed slowing when putting a cut on unlike the rotary Transwave and smaller MA7200.

 

[Big Mick]

I bought a 230v 1.5 Hp motor for my Harrison L6. It runs absolutely fine. Probably not able to run at full capacity, as it had a 2Hp 3 ph motor as standard, but plenty good enough for home use.
For a lathe that size, I would suggest that a 2.5/3Hp single phase motor would be adequate and be able to run off a domestic supply. Certainly much cheaper than the VFD/inverter route, even with new switchgear.

Cheers, Mick.

 

[nuffi460]

hi, thanks big mick, i sort of understand that a 3ph motor runs smoother though? think i have a shopping list put together now, new, cheapo 3ph 3hp duel voltage motor 1450 rpm, static phase converter, transwave? i like the idea of putting a plug on the machine wireing and off you go, seems the simpler option to keep the machines original switch gear and just supply 3ph to it, as hareng posted i have a geared head so no need for speed control with a vfd etc, if im barking up the wrong tree please feel free to advise otherwise, thanks again

 

[ukracer]

What make and model of lathe is it ? I have a 5hp colchester lathe and run it off single phase with a yaskawa (omron) variable frequency drive very successfully using the original 3hp motor. 3 hp motors give better torque and run smoother then single phase.

Are you still around chap . You say you have a 5hp colchester but you use the original 3hp motor? I could do with asking some questins if you are still around mate??

 

[ronan]

Are you still around chap . You say you have a 5hp colchester but you use the original 3hp motor? I could do with asking some questins if you are still around mate??

I am still around racer, my brain was out at lunch when i posted that, i meant three phase rather than 3 horse power. The lathe motor is 5 horse power and three phase, its run off the yaskawa vfd , single phase in, 220v three phase out.

 

[ukracer]

I am still around racer, my brain was out at lunch when i posted that, i meant three phase rather than 3 horse power. The lathe motor is 5 horse power and three phase, its run off the yaskawa vfd , single phase in, 220v three phase out.

I guessed that by a future reply...after I had posted. lol BUT you have clarified part of the question I was going to ask. That you are running it of the 240 volt windings. How did that affect the rest of the wiring on the lathe suds pump switches etc?

 

[ronan]

On my lathe (colchester master) ukracer, the motor is the only major electrical component. The suds pump is a seperate circuit and can be replaced with a single phase one or there is a trick the sparks on here can tell you about, something about putting a capacitor across two of the phases and running it on single phase. The existing switches can be used to control the vfd. It all sounds like a lot of work but isn't really and the lathe works exactly as it would if connected to three phase.

 

[ukracer]

On my lathe (colchester master) ukracer, the motor is the only major electrical component. The suds pump is a seperate circuit and can be replaced with a single phase one or there is a trick the sparks on here can tell you about, something about putting a capacitor across two of the phases and running it on single phase. The existing switches can be used to control the vfd. It all sounds like a lot of work but isn't really and the lathe works exactly as it would if connected to three phase.

Interesting. lol I was told I would have to rewire all the switch gear if I ran 240 volts 3 phase anyway. I have decided to try a static converter to see if I can get away without any rewiring.. So I am getting a 40 amp supply from my fuse board to the garage where it will then go to the converter and from there to the lathe. I have a colchester master 2500 square shape with 5hp Motor that has dual windings 240and 415. I think (and hope my only problem might be the suds pump) BUt even then if I have read things correctly if I only run it when the main motor is running it should be fine)

 

[Shox Dr]

Nothing worse reaching across to turn machine off or alter the speed.

I used a TV wall mount, it holds it firm enough to use and can be moved out of the way when needed