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Member postings for Mark Rand

Here is a list of all the postings Mark Rand has made in our forums. Click on a thread name to jump to the thread.

Thread: DHSS access to your bank account
22/05/2021 21:47:36

Behave children!

It was commonly thought, at the time, that people who got upset about the Regulation of Investigatory Powers Act were paranoid...

Thread: Recycling of Wind Turbine Blades
17/05/2021 16:15:33
Posted by John Alexander Stewart on 17/05/2021 15:26:47:

I know that it's not a popular view these days; the current trend seems to be using more energy to solve "the climate crisis".

See.. there's this thing that the wind turbine drives. It's called a generator and it generates electricity Since wind is generally free (apart from that produced by the consumption of beans etc.) a lot of electricity can be generated for just the cost and energy required to make, comission, decommission and dispose of the equipment. Fossil fuelled power stations have all those costs, but they also have the cost of fuel. A 1GW coal fired power station consumes about 2-2.5 million tonnes of coal a year...

Thread: Tribological query re shafts and bushings!
15/05/2021 22:11:46

I would suggest EN16T or EN24T. They are both hardened a bit (typically 20-30 HRC). This actually makes them machine more nicely than either the annealed steel or most stainless steels. The slight additional hardness will work well to avoid damage in use and improve the bearing properties.

Most stainless steels tend not to be very good bearing materials at all. crying

Hopefully the mods won't object if I post a link to a supplier's site. Haven't used them, but this might be the sort of stuff that you need:-

**LINK**

Thread: Painting staircase spindles
13/05/2021 10:04:39

There's a lot to be said for French polish on mahogany spindles. cheeky

Thread: Diesel fuel
12/05/2021 20:32:06
Posted by Kiwi Bloke on 12/05/2021 11:31:49:

The point is that ether, if exposed to air, will slowly form a peroxide, which is dangerously - and apparently more-or-less spontaneously - explosive. It seems unlikely, however, that 'diesel' fuel is dangerous in practice, if in a sealed container. Another area of innocent fun which has been interfered with by the killjoys...

It is an issue if ethers are evaporated towards dryness. However, such evaporation would also render it rather useless as a fuel. When in the liquid and not concentrated, the peroxides are less of an issue. Thay are an issue if they end up on bottle tops etc. in concentrated form due to evaporation.

It is not good practice to have large bottles partially full of ethers and it is good practice to carefully wash lids, stoppers and bottle tops before replacing them. It is also extremely important to store ethers out of sunlight to slow down the creation of peroxides.

Thread: BA sizes
10/05/2021 20:14:59

Looks like ±1 thou according to sources...

10/05/2021 20:13:25

Across flats for 4BA hexagon is 0.249", so fairly close to 1/4" cheeky.

Thread: Where to find a *good* optically flat mirror?
07/05/2021 16:49:08

Did you check the disk platter before cutting circles out of it? It may (or may not) have been more flat in that condition.

Thread: The Workshop Progress Thread 2021
06/05/2021 19:45:27

I need to do some work on the milling machine, when not doing bedroom decorating. There are a few things I want to improve on the mill's head before doing the work, so I took the head off this afternoon:-

head-removal.jpg

There are two things to note from this:-

  1. With an NMTB or R8 taper machine, it's a relatively simple job to either make an adapter or clamp a slitting saw arbor in a vice or chuck. Then the head can be safely lifted off the ram without doing oneself a mischief.
  2. The other point is that Most Bridgeport/Beaver etc. style mills really need a riser block to get the most use out of the knee's travel. I was 2" away from the top of the travel even with the homemade 7.5" riser block.
Thread: What Did You Do Today 2021
06/05/2021 19:36:34
Posted by Michael Gilligan on 26/04/2021 23:13:44:

Posted by Iain Downs on 23/04/2021 09:25:53:

[…]

However, the M5 screw is a little too course to be able to zero the indicator and I may think some fine adjustment nearer the indicator.

.

Looks neat, Iain

... You could probably replace that M5 with a ‘differential screw’ arrangement, as famously used on the Norris woodworking planes.

MichaelG.

.

Wikipedia mentions a very suitable mix of threads:

For example, an M5x0.80 thread paired with an M4x0.70 thread will produce a differential motion of 0.1 mm, or 100 microns per revolution.

Ref. **LINK**

A combination that I have used when making a grinding jig to do the reverse face of my mill,s column ways was 1mm (M6 etc.) against 26tpi (brass or CEI). That gives 0.9 thou or 36 microns per turn.

Thread: IT Travails
05/05/2021 21:07:05
Posted by Neil Wyatt on 05/05/2021 19:50:23:

Moral of this story is that the extra for Cat6 over Cat5e (about £12 instead of £3.50) is worth it as Cat5e maxes out at 100Mb/s.

No doubt at some point in the future I will need to upgrade to Cat 7 or Cat 8

Neil

 

Sorry Neil, that just isn't so. Cat 5e will carry 100MHz (frequency), not 100Mb/s (bit rate). It will carry 1gb/s ethernet over a distance of 100m.

I should know, I ran thousands of lengths of the stuff while I still got paid for working,

As for the Virgin WiFi access point + router having dead spots, If you want better coverage throughout the demesne, you need to wire access points to multiple locations to allow for better coverage, eg. upstairs, downstairs, workshop etc. Running a cable will always give you more potential bandwidth than using WiFi. WiFi is a godsend for portable devices and factories/workshops, but it doesn't make sense for a long term fixed location. Yeah, spent my last nine years looking after wireless networking on 65 sites. crying

 

 

Bah! Humbug! Computers:- Work of the devil I say!

 

PS:- Not "Appeal to Authority" on networking, Just bemoaning the fact that I started doing the computer and later, network stuff because no-one else in the department was prepared to and it ended up taking my life over until I almost didn't do any "proper work" until I left the company 32 year later... cheeky

Edited By Mark Rand on 05/05/2021 21:16:51

Thread: ER32 Collet?
05/05/2021 15:36:53
Posted by not done it yet on 05/05/2021 13:15:11:

Mark,

I would be interested how you thread with a surface grinder, please.

The same way that you thread grind with a Quorn grinder:-

Arrange a master thread and follower/chaser. The master thread is on a sliding+rotating mandrel which also holds the workpiece. As the workpiece is rotated, the master thread moves the mandrel+workpiece axially. With a correctly dressed wheel and correct alignment a thread results.

This could be useful if one insisted on using Clarkson Autolock cutters, since the thread for all sizes is 20tpi,#

Note you still need to grind a centre on the endmill if is doesn't already have one. That's a much more specialised bit of kit...

05/05/2021 11:46:44
Posted by Circlip on 05/05/2021 09:45:18:

Collets? For milling cutters, Autolock or Weldon, For turning, fully adjustable, Rubberflex OR four jaw.

Regards Ian.

It's a bugger for someone without a surface grinder to put a Weldon slot or Autolock thread on HSS or carbide endmills.

 

Edited By Mark Rand on 05/05/2021 11:52:15

Thread: MT end mills slightly corroded
05/05/2021 11:43:24

Posted by MC Black on 05/05/2021 11:31:56:

I really do NOT want any readers to think that I can't spell!

Just assumed that you were American cheeky.

 

There is an edit button shown to the poster in the green bar above the post, but the opportunity goes away after a while.

 

(Edited because I forgot where the button was)

Edited By Mark Rand on 05/05/2021 11:44:07

Thread: The Workshop Progress Thread 2021
04/05/2021 19:51:59

Having tidied up the mess in the Hardinge's chip tray, I went out and payed money for a couple of brackets at Screwfix and used a bit of spare wood to make a shelf to hold the stuff that had been living in the chip tray. I'm a bit ashamed that I spent money on the brackets rather than welding a set up, but the shed is so full at the moment that getting the welder set up would be a pain.

shelf.jpg

Thread: ER32 Collet?
04/05/2021 19:40:31

I happily use Rotabroach cutters (3/4" Weldon shank) in a 19mm ER32 collet. The one caveat, in this case is that I made a 3/4" top-hat shaped pin to go in the small end of the collet as the Rotabroach cutters aren't the full length of the collet. This forces the collet to close parallel.

Thread: The Workshop Progress Thread 2021
03/05/2021 19:40:43

Spent a happy day cleaning up and leveling the Hardinge. Because I tend to have chucks, faceplates, tools on the back of the chip tray, it gradually builds up an excess of swarf. Once a year or so it gets a spring clean!

It got leveled, not because of "leveling" (three point sprung mounting), but so cutting oil, way oil etc actually drains into the coolant tank, which it hasn't been doing for a couple of years.

Thread: What odd grease?
30/04/2021 20:01:06
Posted by Pete. on 29/04/2021 22:16:23:
Posted by Mark Rand on 29/04/2021 22:02:46:
Posted by Pete. on 29/04/2021 20:34:58:

Could Kwil clarify if the number 2 Castrol is suitable, as I'd planned on the replacing the grease on my boxford vm30 gearbox in the near future, I found this that gives the impression the double zero grade is the semi fluid?

The double zero is one grade thinner than zero. The number 2 Castrol is one grade thigher than number 1 etc.

The numbers are from the NLGI Consistency number

I meant is the number 2 semi liquid, it says 'general purpose bearing grease' in the information I found, which makes me think not, or is number 2 semi fluid, and the double zero near oil consistency?

Follow the link to the Wikipedia article. It has a 'real world' description of the NLGI consistency numbers Like so:-

NLGI number ASTM worked (60 strokes)
penetration at 25 °C
tenths of a millimetre
Appearance Consistency food analog
000 445-475 fluid cooking oil
00 400-430 semi-fluid apple sauce
0 355-385 very soft brown mustard
1 310-340 soft tomato paste
2 265-295 "normal" grease peanut butter
3 220-250 firm vegetable shortening
4 175-205 very firm frozen yogurt
5 130-160 hard smooth pâté
6 85-115 very hard cheddar cheese
29/04/2021 22:02:46
Posted by Pete. on 29/04/2021 20:34:58:

Could Kwil clarify if the number 2 Castrol is suitable, as I'd planned on the replacing the grease on my boxford vm30 gearbox in the near future, I found this that gives the impression the double zero grade is the semi fluid?

The double zero is one grade thinner than zero. The number 2 Castrol is one grade thigher than number 1 etc.

The numbers are from the NLGI Consistency number

Thread: How can you check that DVLA field of vision machine is OK.
25/04/2021 20:56:26
Posted by Paul Rhodes on 24/04/2021 21:41:39:

Mark, I doubt the professional use of half size printed charts. If they use professional screens ,due to size of room, they are very accurately calibrated and are no different to a 6 m printed chart(all to do with the angle the image subtends at the retina etc). Frankly I do not see how this makes any difference to your visits to the optician. With varifocal being a gradation, you should simply move your head to find the sweet/sharp spot. Personally I think varifocals are a money spinner for opticians and am invariably disappointed by them....others love them.

Not so.

The 3m charts, while half the size of 6m charts and having the same angles as the version are still at 3m distance instead of 6m distance. My varifocals, as are many others, are optimised for .3m, .6m and infinity and aren't a continuous variation. 3m is at about the worst possible distance for me to focus There is no sweet spot to cover 3m. I won't use an optician that uses the 3m Snellen chart instead of the 6m one.

The way that opticians normally get around smaller rooms is by using a reversed 6m chart and a mirror, but one doesn't always get that choice with people who aren't opticians.

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