George Thomas high speed drill.

[Ian P]

On Ian P Said:

I have some less than ideal electrical setups in my workshop but that motor and controller and mains lead being sold on ebay frightens me!

No warnings or advice on the listing to alert the purchaser that the motor wiring is a mains potential. I know there is label about earthing (as in Rod’s reply), but in one of the ebay pictures the earth lead is just shown unconnected.

We know that putting the controller in an enclosure is straightforward but how many buyers will properly protect the red/black motor wires from where they exit the motor endplate to the controller I wonder.

Ian P

I’m in two minds about this.    In general, I’m all for ‘having a go’, ‘learning by experience’ and ‘pushing the envelope’.   But, I also know  the world is full of over optimistic bodgers, chaps who believe in ‘common sense’ when there is no such thing, those who reject ‘Elf and Safety’ on principle, and a large group who are too lazy to read the manual, or lack the basic knowledge needed to understand it.  Beware youtube videos published by proud bodgers, they often include bad practice.

Anyone with a little background in motors and controllers will recognise instantly from the ebay advert that components are on sale, not meant to be exposed in public.    Components are always part of a larger design, and it is this that typically keeps them protected.  100% the responsibility of the designer, that’s us, to get the full design right, not just lash a few parts together.   The danger is that an inexperienced or irresponsible builder assumes an unsafe on it’s own part like that controller is OK out in the open.   A slightly more experienced builder realises components have to be assembled within a safe installation, more work, different skills.

Whether or not a black-box is a component or not isn’t always obvious.  VFDs come in a nice box that looks as if it’s OK to mount the VFD out in the open, with controls the user can twiddle directly.   Nope.   With few exceptions, VFDs are components, meant to be protected inside another box, with externally wired controls.   The display and built in controls are for setting up the VFD up, not day to day use.

The answer I think is to be keenly aware of one’s own limitations.   When a job is ‘different’, something I’ve not done before, I stop and have a think, do some research, and ask on the forum etc.   I’m looking to understand the risks that they can be avoided or mitigated, not to walk away.   If I don’t know what I’m doing, my job is to learn not guess.   Main exception is legal and insurance requirements.

Nanny state intervenes after the authorities have enough evidence to confirm that enough people are up to something dangerous enough for it to be controlled.  The best way of keeping Nanny at bay is for us not cause injury due to incompetent work.

I don’t believe unsafe bodging is common in model engineering – we don’t seem to cause many major incidents.

Dave

 

[Andrew TinsleyParticipant @andrewtinsley63637]

I always thought GHT’s drill was termed a sensitive drill, not a high speed drill. I must consult his book on that.

Andrew.

[Roderick JenkinsParticipant @roderickjenkins93242]

Dave,

A nice, pragmatic and reasonable summing up of the issues.

Thank you,

Rod

[Author]

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