Lathe upgrade HELP - M300

Looking to upgrade my myford ml7 for a Harrison M300 three phase that comes with a trans wave converter to single phase

the only thing that concerns me is that it won’t run any speed above 540 rpm ? It does spin but cuts in and out? Is this because of the single phase converter and it possibly not being man enough?
Any help would be great and how much is a Harrison m300 and transwave converter worth roughly

many thanks

tom

Voltage drop on start up is causing the contactors to drop out ? unit to small. The trans wave converts single phase to 415v and capacitors create an artificial 3rd phase, as opposed to a VFD where the motor is wired 240 and 3 phases are electroniclly created. Noel.

Not had much to do with transverters. But a friend had one & used to start the machine which ran horribly for a few seconds. Then he turned a switch on the front of the transverter & away it went. Not sure why.

Steve.

I would think that your Transwave unit has a secondhand value greater than the cost of a VFD to suit the motor. No disrespect to Transwave but its not exactly at the forefront of technology

I know which I would have.

Ian P

Is it a static converter, just a box with transformer and capacitors inside, or rotary converter with a pilot motor as well?

Generally rotary converters either work properly or don't work at all well with all sorts of noises off from the pilot motor if there is a fault.

I assume the converter has sufficient power output to handle the motor and any switches are set as per the Transwave instructions.

If its a static converter there may be issues with one or more capacitors. They work hard for their living and eventually fail.

Could be a problem with the switch settings. Generally static converters need more capacitance in circuit to get going than they need to run a spinning motor. Many types have a boost or start switch setting to get the motor going which needs to be changed to a run setting once the motor is running. As Steviegtr comments leaving the converter set to boost - start position makes the motor run horribly, noisy and sometimes slow. Some static converters have automatic start - run setting change. Usually using a "potential relay" that senses the voltage of the third, generated, leg and switches out of start setting when the generated voltage is high enough. If this fails the motor may well run slow.

So far as I'm aware all Harrison M300 3 phase machines have motors that can be connected in both star and delta configuration. Hence the advice from Ian P to get a modern VFD from a reputable supplier,I use Inverter Drive Supermarket, and sell the Transwave to largely cover the cost is probably the best way to quickly get a reliable system.

Its what I'd do and I actually know how to diagnose and fix an iffy phase converter. But life is too short!

Clive

Edited By Clive Foster on 17/11/2021 00:24:17

Hi thank you for your help ! Could some please link me to a suitable VFD?
what is the going rate for a Harrison m300 lathe all seems good but the top slide has a bit of back lash seems to look like the knob unwinds it’s self as the dials gap gets big and smaller depending on the way you wind it in and out

many thanks again

Tom

As with all second hand machine tools age and condition will have a big effect on price, A well worn early one that has had a hard life in industry will be worth far less than a little used late model black fronted one out of an educational establishment. Also beware the "refurbished" ones that may have had little more than a clean and coat of fresh paint.

Transwave are very helpful, give them a ring with the details of the converter you have and they may be able to suggest the cause of the problem and supply spares if it is a capacitor that has failed.

**LINK**

you may be able to view the advert for the lathe

I think the transwave box is a box of capacitors

I run my 3HP 14"x40" lathe from a Transwave static box. The motor does not have star/delta windings and I do not know how to find the star point to enable use of a VFD. The only downside I find with the Transwave box is lack of soft start and starting the lathe is a bit fierce at times, if ever it sounds unhappy turning off and restarting usually works.

If the motor ever fails I would look at a motor and VFD package and sell the static inverter (converter ?) but until then I am happy to use the Transwave.

Condition is 'like new' LOL, they can't even be bothered to clear off the swarf.

Tony

Does your run at every rpm setting this one doesn’t it works fine at 540rpm and below but above that it cuts in and out as if there isn’t enough power

my colchester 2500 is drivem by a 5 hp motor and the 3 phase supply comes from a 6 hpTranswave converter,occasionaly,it hesitates to start so it a case of switching off quickly and restarting,so far never failed on restart ,this does not cause me a real problem as the lathe has foward/reverse clutch so once started its ok.check your converter has a larger rated output ,in hp than your lathe. I always feel that my motor does not give its rated max power,though I cannot complain my converter was rescued just before it went into a skip,so cost nothing,As i do not want to blow the converter i only use speeds up to 700 which covers most of my work ,for a lot higher speeds on very small work I use the S7. If the converter fails i would go for a vfd and use a 3 hp motor to keep cost down,The colchester only has such a large motor due to the high top speed, a good 3 hp motor should drive the lathe up too 1500 rpm which would suit my needs. I have bought a vfd motor package for my 00 mill and it very good though expensive and quiet, the other route of rotary converter does have a problem,I have a 4 hp rotary and is noisy ,the motor continually running has an irritating noise and is now in an adjoining shed.

I am with Tony, load of rubbish and would not touch it. Very early model by its colour.

( I do have a M300 as my larger lathe to complement my Myford PCF S7)

Looking at the advert that is a well used and not particularly cared for machine. Very expensive for what it is. Shopping list of extras is of no value unless they are in good condition and ready for use.

Clive

Edited By Clive Foster on 17/11/2021 12:26:02

Mine is a gear head machine. No problem running all speed ranges up to the maximum. The static inverter would not run my Bridgeport mill for long without tripping out, a VFD is now installed on the mill.