What Did You Do Today (2017)

[FatgadgiParticipant @fatgadgi]

….yes……but …. 3300kva ie 3300000 VA seems a bit of a beast. Does that not work out to be over 13000 amps at 240v ?

Perhaps the "K" is shoved in by mistake ?

I have a 15kva transformer that I need a pallet truck to move.

[MuzzerParticipant @muzzer]

Haha you got me there. Too early in the morning. Yes, 3300VA, it's not a superconductor device!

Merry

[Swarf, Mostly!Participant @swarfmostly]

Hi there, Muzzer,

If I'm remembering rightly from a few decades ago, a first approximation for a Stalloy core at 50 Hz was 8 turns per volt for a core cross sectional area of 1 sq ". Turns per volt reduce as core CSA and/or frequency increase.

Laminations probably aren't Stalloy nowadays but, just for interest, how do those figures compare to your transformer?

Best regards,

Swarf, Mostly!

[MuzzerParticipant @muzzer]

Dunno without taking a load of physical measurements and looking up relative permeabilities etc but I know that mains transformers generally run a high magnetisation current, which is why they often saturate at switch-on, depending on the remanence from when it was disconnected.

Given that the saturation flux of electrical steel laminations is usually over 1 Tesla, you can deduce they are seeing a high magnetisation flux swing. That's basically a direct function of the volt-seconds applied, so I doubt your rule of thumb has changed much since your day. Most of my work has been in ferrites – or at high frequencies when using steel / powder / metglas / amorphous cores.

Murray

[John FlackParticipant @johnflack59079]

Neil the moderator…….having my interest whetted on Astro matters. I was reading about SEDNA a planet(?) in the Kuyper belt. 900 x the distance from sun to earth whose orbit was 11000 earth years per SEDNA year.

How would a 12 copies per year work in such circumstances😇😇

[Neil WyattModerator @neilwyatt]

Posted by Muzzer on 25/03/2017 14:57:10:

Didn't Quatermass have one of those?

Neil

[Neil WyattModerator @neilwyatt]

Posted by John Flack on 29/03/2017 16:37:51:

Neil the moderator…….having my interest whetted on Astro matters. I was reading about SEDNA a planet(?) in the Kuyper belt. 900 x the distance from sun to earth whose orbit was 11000 earth years per SEDNA year.

How would a 12 copies per year work in such circumstances😇😇

I'm not sure that 'Rest of Solar System' comes up as a delivery option yet…

Neil

<edit> Sedna is technically a 'Kuiper Belt Object' which is about as meaningful as calling a whale an 'Ocean Object'.

Edited By Neil Wyatt on 29/03/2017 17:50:49

[Bill PudneyParticipant @billpudney37759]

Some time ago I bought a Schaublin TR70 turret lathe. It's been running for most of the time, but I hadn't had the opportunity to set it up to actually make anything. So the last few days have been spent setting it up to make some small threaded inserts, nothing dramatic, but they would take me about a week to make a batch of maybe 20 off. Well today the set up was completed and the first 6 parts came off in about 30 minutes, probably 15 of those minutes was taken tapping the M2 thread.

So I'm a relatively happy chappie right now!!

cheers

Bill

ps Just need to work out how to generate the thread a bit quicker.

pps Yes I understand that we are not in this game to count minutes, but sometimes making repetition parts can be very frustrating when you KNOW there is a better way!!

[richardandtracyParticipant @richardandtracy]

Changed a blown up NVR switch on my Clarke 6×4 bandsaw. Got the NVR switch from Axminster Tools for less than I could have got it direct from China, and I didn't have to wait a month, having one just a mile up the road from my house.

While fitting the NVR switch, I took the opportunity to get rid of the irritating microswitches that check the covers are shut before it will work. The microswitches were so positioned that they got mangled every time I shut the covers and were close to failure themselves. Some over zealous applications of the Safety of Machinery Directive need to be relaxed. I agree with fitting the NVR switch, but how many people are protected by switches on covers? I'd suggest that only those who need to learn a bit of sense the hard way are protected from their own stupidity. One sharp, hard, lesson would benefit them for life.

Regards,

Richard.

[John FlackParticipant @johnflack59079]

Neil. ……… Yes hence my question mark

My question , in humour, masks my ignorance as to what life on another planet etc.would be like.Until you raised my interest in such matters I thought it was like earth but in a "different place"

Working out what a SEDNA calander would look like, and what a SEDNA working day would comprise is a mental challenge.

[Martin KyteParticipant @martinkyte99762]

Day length is approx 10 1/4 earth hours and there are 9749502 1/2 days in the year. It doesn't appear to have a moon so there are no months. All this means you don't get many Christmas prezzies and if you received 12 MEW's per year you would get a new editor each time. At least you would have plenty of time to complete the bit of your serialized project before the next one turned up (with or without the corrections)

:0)

Martin

[David Standing 1Participant @davidstanding1]

Posted by Martin Kyte on 30/03/2017 10:06:24:

Day length is approx 10 1/4 earth hours and there are 9749502 1/2 days in the year. It doesn't appear to have a moon so there are no months. All this means you don't get many Christmas prezzies and if you received 12 MEW's per year you would get a new editor each time. At least you would have plenty of time to complete the bit of your serialized project before the next one turned up (with or without the corrections)

:0)

Martin

And at 812,458 days per month equivalent, Neil would have plenty of time to check the print magazine had the right issue number on .

[Martin KyteParticipant @martinkyte99762]

How do you get a lunar cycle without a moon?

[Anonymous]

Posted by Bill Pudney on 30/03/2017 02:50:11:

ps Just need to work out how to generate the thread a bit quicker.

pps Yes I understand that we are not in this game to count minutes, but sometimes making repetition parts can be very frustrating when you KNOW there is a better way!!

I count minutes; if I can save some I can go and do something else, like drink beer!

I assume that the M2 thread is internal? Fifteen minutes seems a long time to tap 6 holes? What sort of tapping head do you have? Some while back I made several hundred aluminium spacers, tapped M3 internally. For idle curiosity I've just measured the time taken to tap M3 12mm deep on the video I took – 12 seconds from selecting the tap to selecting the next tool. Rather quicker than the time to drill the hole in the first place. As I recall I was tapping at around 500rpm spindle speed. So it should definitely be possible to speed up the tapping operation.

I'm all in favour of capstan and repetition lathes – there does seem to be a growing interest in them on the forum.

Andrew

[John Stevenson 1Participant @johnstevenson1]

Posted by Neil Wyatt on 29/03/2017 17:48:48:

Posted by Muzzer on 25/03/2017 14:57:10:

Didn't Quatermass have one of those?

Neil

Dunno but from a point of having something like this buried in a What did you do post I feel it would be better moved  to a dedicated post and added to by Muzzer for anyone wanting to tread the same or similar path later ?

Edited By John Stevenson on 30/03/2017 12:36:06

[John FlackParticipant @johnflack59079]

Martin Kyte …..with modesty, ask the distaff side of the family.?????????????

[JimmieSParticipant @jimmies]

Just noticed a 25% discount available on two Celestron 'scopes – Astromaster 76eQ and PS1000 through a Daily Mail offer. Wondering if either would be suitable for the 8 – 12 year group?

[Martin KyteParticipant @martinkyte99762]

John. If Sedna doesn't have a moon it cannot have a month. If it had any women they could not be synchronised to a non existant moon.

For Sedna a year means something(how long does it take to go round the sun), a day means something(what is its rotational period), a month has no meaning(how long does the non existant moon take for one orbit).

regards Martin

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, having drilled the holding down bolt holes in my backplate for my slim four jaw chuck so that I can use it on my milling machine table, yesterday evening I set a 50mm long x 40mm diameter piece of scrap hydraulic ram rod in it, after facing the ends up in the lathe and drilling a shallow 1/4" hole in one end. The hole was used to set the rod directly central to the milling machine quill, by holding a piece of brass rod held in a collet and once it was correctly aligned, the Y axis was locked.

This evening I was able to mill a 3/8" x 24mm deep slot into the end of the rod, in the X axis plain and then a 1/4" end mill was used to put a 3/4" wide x 9/16" deep flat on both outside edges.

This will be used to hold a deep bending blade for use on my fly-press, this is one of two or three other different width blades which will be made in this way, which can be used on a common arbour.

Regards Nick.

Edited By Nicholas Farr on 30/03/2017 22:07:55

[Speedy Builder5Participant @speedybuilder5]

I am curious. Does everyone mill steel dry these days? I always use coolant, so my mill always looks oily in photos!
BobH

[mechman48Participant @mechman48]

Depends on the amount of steel some people are machining, from my understanding a lot of members use solid carbide cutters, or insert type tools which generally work well at high speed without coolant. At the moment, with the piddly little bits I do, which is usually aluminium, cast iron or brass, I have no need for coolant, for any threading / tapping in steel a dab of cutting oil usually suffices. others may differ…

George.

[MuzzerParticipant @muzzer]

Posted by John Stevenson on 30/03/2017 12:35:28:

Dunno but from a point of having something like this buried in a What did you do post I feel it would be better moved to a dedicated post and added to by Muzzer for anyone wanting to tread the same or similar path later ?

I'll perhaps make a new thread at the weekend for the latest update. Things are grdually moving along here….

Murray

[John FlackParticipant @johnflack59079]

Martin……..you appear to agree with my earlier post. Working out a calendar/length of day etc requires a mental challenge. Perhaps the scifi concept of "Stardate time" may not be the stuff of fiction after all.

John

[John GardenerParticipant @johngardener91897]

Posted by mechman48 on 31/03/2017 08:07:34:

Depends on the amount of steel some people are machining, from my understanding a lot of members use solid carbide cutters, or insert type tools which generally work well at high speed without coolant. At the moment, with the piddly little bits I do, which is usually aluminium, cast iron or brass, I have no need for coolant, for any threading / tapping in steel a dab of cutting oil usually suffices. others may differ…

George.

Being untrained and inexperienced, and believing some of the stuff I read, I use a dropper to apply neat cutting oil with both my HSS and insert tools. I use this on all metals as it seems to produce a better result. Am I right or wrong?

[BazyleParticipant @bazyle]

You can always have calendar months since they were defined without reference to the lunar month and are a bit higgledy piggledy. or neaten them up as 30 days or better as 4 weeks. Weeks (and fortnights) remain of course because the week of 7 days was defined by God.

[Author]

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