Colchester Master 6″ (Round head)

[David TweedaleParticipant @davidtweedale21674]

Motor problems

[David TweedaleParticipant @davidtweedale21674]

Hi all,

I’m new here, joining expressly to ask for advice…….

My motor has gone fizz-bang! It is a twin coil type with high torque start up until centrifugal segments fly out and short out the start up coils, allowing the motor to run at normal speed. Its been for repair once before at a local ‘specialist’ who couldn’t get a circular spring to replace the broken one that maintains the segments in place when stationary. I found one on the inner seal of a large oil seal that fitted and worked for years. It is still intact but the problem is to do with the segments themselves and the carrier they sit in. Its all wearing and I’m losing so much machining time, I’ve decided to get a new motor. Here in lies the problem. The ‘specialist’ has no idea what motor to get in its place. Feet spacing, shaft diameter and height above the feet not a problem. I can ‘engineer’ to suit the lathe. Start up torque and running torque while machining need to be high. Can anyone suggest a modern motor that can satisfy my requirements? My motor is a 1Hp single phase 1425rpm. Modern lathes must require similar start up torque, especially when running at high speeds with heavy items in the chuck. I’m also interested if anyone has a suitable motor for sale.

Many thanks in advance,

David

[chris stephensParticipant @chrisstephens63393]

Hi David,

Six hours and no one has suggested going the three phase and inverter route. My, you lot are slacking.

If you have not come across this route, it might be the answer. Reliability of three phase motor, combined with adjustable start up and slow down times, plus no real limit to how often you start and stop it , not something that is  recommended too often with most single phase motors.

I fitted one to my Myford recently, was three phase running from a phase converter, now much sweeter, quieter plus all the usual advantages.

chriStephens

[mgjParticipant @mgj]

http://www.rotamec.co.uk/#articles/tPath=72

 

Do motors big time.

[V8EngParticipant @v8eng]

If you are going to the ME Exhibition at Sandown I guess there should be suppliers of Inverter systems and conventional single phase motors attending, and of course advice available.

 

 

 

[David TweedaleParticipant @davidtweedale21674]

Many thanks for your help.

I have in the mean time been in touch with a lathe manufacturer up country who knows the ’round-head’ Colchester well. He advises that it wouldn’t have been designed to run with a 1hp single phase initially (even though it has managed for years). He told me to go for a same speed (1425rpm) 3hp single phase with capacitor start and capacitor run set up. I have one but think its capacitor start only. Not sure if it can be modified. Looking into it as I’d rather use this than fork out £100+ for a chinese built bag of nails off Ebay!

Thanks again,

David

[Nigel McBurney 1Participant @nigelmcburney1]

hi I had one of these,i fitted a  two hp single phase motor but a three hp would be better,the problem is finding suitable switch gear to take the start load and the limited starts per hour of large single phase motors I tried converting the three phase switch gear to single phase it worked but the contacts only lasted about a year,best way is get a 4 to five horse phase converter from Transwave and fit a three hp three phase motor,used 3 phase motors are available and relatively cheap,plus once you have a converter you can drive other three phase equipment ,do not buy a converter which is just adequate you will in future want to drive a bigger motor i know I found out the hard way,Transwave are best,I have three converters of different makes and the transwave works well and is quiet,some other makes have annoying hums and do not work as well, My current master 2500 has a  5 hp motor,has a clutch,and is a far better machine than my earlier roundhead and it runs off a 6 hp Transwave plus the coolant pump is also 3 phase and it runs without any problems.  

nmcb 

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