Member postings for Ian P

Mike

I too am impressed with your project (and the photographs!), rather than struggle with forum software and its limitations, why not write it up for an article in MEW?

I'm sure Neil and the readers would welcome it.

Ian P

Andrew, its not really a conundrum. I cannot say all, but most VFDs act in a No-Volt method.

Some can be programmed to restart the motor after power fail but by default most do not 'read' the switch positions at power up so even if the RUN switch is closed tha motor will not start. (until the switch is cycled off first)

Ian P

Edited By Ian P on 10/01/2023 16:02:03

My VFD's are mostly as your plan A but instead of a (two position) F/R switch, I have a toggle switch with a centre off position (so no need for stop/start buttons) On the drilling machine I can reach easily the switch with the same hand holding the downfeed lever.

I use the drill for tapping threads (M2 to M14) and the ability to reverse is a godsend.

I can also reach the speed control potentiometer (to which I have fitted a very extended pointer (just a long grubscrew actually) which means I can change speed by fingertip without having to grip the knob.

I strongly suggest that you fit a remote potentiometer rather than using the up/down buttons on the VFD itself which in my experience carry out their intended purpose but are nowhere near as ergonomic as a potentiometer.

Ian P

P.S. I'm sure Dave will answer, but VFD's are usually set up so that the motor will not restart after cutting the mains power .

Edited By Ian P on 10/01/2023 15:13:23

There have been a few mentions in this thread regarding the unsuitability of a drilling machine for milling purposes.

The OP made no mention of wanting to use the drill for milling purposes, he just asked a straightforward question about changing a motor. I think that all that is happening now is that the OP will get more and more confused.

Ian P

Hopper, how can a grubscrew bearing on the bottom of a keyway recess damage the shaft?

Ian P

There is probably a grub screw (or even two screws in the same hole) that hold the pulley on the motor shaft. Note also that 19mm and 3/4" are very close dimensionally but as regards pulley fitting might be complicating things.

Unless you are using large drills and really pushing the machine to its limits then its not worth worrying too much about the key and keyway. Just use a grub screw with a dog point (or the screw is smaller diameter than the keyway width) and let it bear on the bottom of the keway recess.

You wont regret fitting a VFD, I've just just checked on my drill on which the VFD is set up to output 4Hz to 130Hz giving a very wide speed range and totally eliminated belt changing.

Ian P

Do the punch and die plates rotate together, in other words are they keyed to each other?

Ian P

Whether you need to fret or not depends on what power supply you have, also depends on whether you just want to see them light or operate them continuously.

For continuous operation at 700mA they would need a heatsink.

Ian P

The information in the manufacturers datasheets should sometimes be taken with pinch of salt.

I saw the bridge and the diode packages on Michael's first picture but did not (and still have not, followed the track layout) but from the text in the Plessey datasheet one might infer that the diode was before the bridge, but in that case why even have a bridge rectifier.

If the bridge rectifier is across the incoming supply then why the warning about reverse polarity I wonder.

Ian P

Two companies that specialise in aluminium that I can recommend are,

Dore Metals: www.doremetals.co.uk

Simmal: simmal.com

Only you know what you mean by 'larger solid' but from Dore have bought thin slices of thick walled ali tube so I ended up with 12" dia OD, 10" ID, and 1" long (saved a lot of waste)

Simmal do a vast range of ali including sections like 6"x6"x0.5" angle.

Ian P

Robert, it was the ebay mains units I looked at but TBH only looked at the 1A version that had a 33V output. The 700mA would be fine as you say

On the subject of discrete LED's when I first started using them putting them in parallel was not something we ever thought about doing as the differences in forward voltage of each junction would mean they probably would each have different brightness and a high failure rate.

Ian P

I am not so sure one of those would work with these modules. Looking at the Plessey datasheet the module will not start conducting until it sees about 40 Volts.

When LED's were first introduced that were virtually all a single LED junction with two connections and were always 'current driven' (often using just a resistor). Nowadays the term LED seems to cover everything from one junction to complex series parallel arrangements (sometimes with built in control). The ebay seller of the modules states they are 'Rated at 46.5 Volts' but that does not mean they are to be operated off a 46.5 volts supply. I suspect they would expire immediately on connection!

My take on these modules is that they need a constant current supply with an open circuit voltage above 40V. The DC:DC CC ebay module Michael suggested looks ideal as it has a max output of 48.

Ian P

Throwing my thoughts and observations into the pot

1_ Firstly, I have no idea what it is

2_ Picture might be upside down

3_ Engraved letters could be F, J and S

4_ Engraved scale looks to be slightly off centre, but in any event the graduations have no units or index.

5_ Cut away screw head has a couple of other 'notches' missing

6_ My wild speculation is that it may have something to do with the cigarette industry (I've seen wood/brass measuring instruments from the early 1900's).

Just food for thought... or maybe put that in your pipe and smoke it!

HNY to all

Ian P

I would try using the existing motor with s VFD, you might be pleasantly surprised.

There are tales of old motors not being amenable to VFD's but as long as it can be connected for 240V operation you have little to lose.

Ian P

Are the X and Y axes locked too?

To produce an elliptical hole with single point tool (revolving on good bearings) maybe the cutter is springing the work on one axis.

Ian P

So was this wooden wheel device ever fitted to a vehicle? (or anything else?)

Might be very cheap but does not look to be very practical on a road vehicle

I'm assuming you meant the Dennis motor company

Ian P

Is this a commercially available device? it sounds really useful

Ian P

My first (I think) double post on here.

I did nothing different to what I normally do!

Ian P

I worked for a company (45+ years ago) who were the UK agents for some USA manufactured welded bellows. We used their bellows shaft coupling on one of our products but changed to Abssac helical beam for cost reasons. We never had any failures and I have every confidence in their products however this quote is from the Abssac datasheet Michael linked to (on page 5) which I do not fully understand.

'Torsional variations, which can induce differences in hub-to-hub velocity when subjected to dynamic loading, are minimal in steady-state applications of the HELICAL Flexure'

It mentions torsional variations but then refers to steady state. If its steady state then where do the dynamic loadings come from?

Just curious

Ian P

I worked for a company (45+ years ago) who were the UK agents for some USA manufactured welded bellows. We used their bellows shaft coupling on one of our products but changed to Abssac helical beam for cost reasons. We never had any failures and I have every confidence in their products however this quote is from the Abssac datasheet Michael linked to (on page 5) which I do not fully understand.

'Torsional variations, which can induce differences in hub-to-hub velocity when subjected to dynamic loading, are minimal in steady-state applications of the HELICAL Flexure'

It mentions torsional variations but then refers to steady state. If its steady state then where do the dynamic loadings come from?

Just curious

Ian P