Another dirty Brian trick – reversing the chuck

[EmgeeParticipant @emgee]

Posted by ALAN MOORE 5 on 26/06/2021 17:01:53:

'did you complete the cct and turn it into a ring main? which must complete directly at the dis board '

Thanks, Brian. Yes it was a complete ring main, though this was not my own workshop (where I also have a complete ring main) but I was installing the machine for a friend.

Emgee, So far as I am aware the term 'DOL starter' properly referrs to a 3phase starter.

You clearly don't know much about starters, DOL is "direct on line" and refers to any starter regardless of voltage or number of phases connected via a coil controlled contactor.

Emgee

Edited By Emgee on 28/06/2021 20:29:29

[EmgeeParticipant @emgee]

Posted by brian jones 11 on 25/06/2021 23:48:54:

You mean the typical old MEM Motor starter. This has a built in thermal trip on prolonged overload. Early ones didnt have a no volt trip feature and should be changed out as the motor could start up again after a trip = dangerous.

You no doubt refer to the MEM Startlet which was not a DOL starter as it had no coil fitted, it was only a mechanical switch with a current related adjustable overload feature that tripped the switch OFF.

That was not what I was referring to in my earlier comment as explained above.

DOL starters were the next stage of progress with motor control and are still used widely in industry, not all motor installations benefit from soft start or speed control as given by other types of control.

Emgee

[EmgeeParticipant @emgee]

Posted by brian jones 11 on 26/06/2021 00:36:07:

Erm so you had a 2,5mm2 wire connected around your workshop with all your outlets tapped off, protected by a 16A mcb

did you complete the cct and turn it into a ring main? which must complete directly at the dis board

I hope thats the case, or you have a dangerous fire hazard installation. your leccy should know this unless hes a cowboy

your insurance would be invalid

Brian

Why would a 2.5mm T&E radial cct be a fire hazard if connected to a 16A mcb ?

Because it doesn't comply with regulations does not make it a fire hazard.

Emgee

[old martParticipant @oldmart]

Posted by Georgineer on 28/06/2021 18:03:58:

Posted by old mart on 27/06/2021 21:20:10:

Back nearer the topic, what do you want to reverse the spindle for? I have left hand boring bars and singlepoint threading bars which have justified a lock for the Smart & Brown model A, but the conversion was deemed much too sophisticated for anybody to copy when I posted a thread. 4 three jaw chucks, 1 four jaw and one er25 collet plate can be locked.

This sounds interesting Mart. Can I take the idle approach and ask you where the thread is to be found? (The alternative is to search for it, which might take me for ever.)

As for the matter of reversing the motor, I use an 'intermediate' light switch which cost a couple of pounds from an electrical wholesaler. It's rated at 10A and is never switched while the motor is running. Well, it was once by my carelessness, but the motor didn't even notice.

George B.

Back again, the thread was from 20-6-2019 in manual machine tools, "my version of a locking device for threaded spindles" There were no replies on this forum, but I had also posted on The home shop Machinist in the USA.

[Michael GilliganParticipant @michaelgilligan61133]

**LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=143052

^^^ a quick plug for old mart’s excellent work

MichaelG.

[ALAN MOORE 5Participant @alanmoore5]

Posted by Emgee on 28/06/2021 20:07:41:

You clearly don't know much about starters, DOL is "direct on line" and refers to any starter regardless of voltage or number of phases connected via a coil controlled contactor.

Emgee

Edited By Emgee on 28/06/2021 20:29:29

Almost right, Emgee. I dont know much about starter nomenclature, so when I read 'DOL' I googled the term and found all the references were to 3phase. In fact I have been using and wiring in both single and 3phase DOLs for long enough! ( A bit like the man surprised to learn he had been speaking in prose all his life!).

[GeorgineerParticipant @georgineer]

Thanks, Mart and Michael. I'll have a proper look at it later.

George B.

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