Member postings for Jim Butler 1

A few days ago I noticed that my home made frequency standard (with built in clock) was not receiving MSF.

I checked the NPL website, there was no mention of an MSF outage. I guess the guys at the transmitter site were having a bad day!

JimB

Looking at the track pattern in the picture, the AC terminals of the bridge rectifier seem to be routed to the power input connector.

In which case, reversed polarity supply would not be a problem.

JimB

The force on the bench will be:

The weight of the arbor press + weight of workpiece + the force of you pushing down on the press handle.

The "one ton" force will be generated between the jaws of the press.

I think that your bench will be OK.

JimB

It looks as though I may be a little late to the party, but here goes anyway.

For a very simple saddle stop I sometimes use a toolmakers clamp.

This has the advantage that I have one or two, and that they can clamp close to the end of the bed, as shown below.

a simple solution.

I later made something a bit more refined which would clamp to the bed of the ML7.

The body of the saddle stop is made from aluminium. All the milling was done on the ML7 itself, using a vertical slide.

The threads of the clamp screw and the stop rod are both 40 TPI. This give a fine adjustment to the stop position, and in the case of the clamp screw gives a tight grip for very modest torque on the thumb wheel.

Underneath, the bit hat clamps to the bed looks like this:

A brass plug on the end of the clamp screw prevents the screw from graunching the side of the bed way.

Nice and simple, works for me.

JimB

The 12v power for the lamp passes along the two metal bars which connect the lamp unit to the base unit.

I hope that I am not being set up here, like that poor girl with the soldering iron!

JimB

Despite being derided by some, Wikipedia is a useful resource.

I have just sent them a few pounds.

JimB

Edited By Jim Butler 1 on 21/11/2020 02:12:15

Summer tyre can be used in winter, but may not grip quite as well as a winter tyre.

Winter tyres have a softer rubber compound than the summer tyre and a more aggressive tread pattern which helps to grip on snow and ice.

When I lived and worked in the Shetland Islands, back in the 1980s, we would change the normal general purpose tyres for studded snow tyres on the driving wheels.

The studded tyres would go on around November, and come off again in April.

There was of course a down side to the studded tyres, they did not grip quite as well in the dry and would give you a sharp reminder if you went round a corner a bit too quickly.

JimB

Nice work by Jurgen, building the engine and planning the move.

Nice work by the crane driver.

JimB

+1 on what Ketan said.

It is not just model engineering where there are "haters" whose aim in life is to disparage and denigrate the efforts of others, various amateur radio websites suffer from the same malaise.

Why this should be, I do not know. I guess that it all come down to the old saying "There's nowt as queer as folk".

JimB

A bit of googling tells me that it is the SSCV Sleipnir, and it is currently en-route from Haugesund to Stavanger, look here:

LEIPNIR">https://www.marinetraffic.com/en/ais/details/ships/shipid:5917736/mmsi:374887000/imo:9781425/vesselLEIPNIR

The two cranes each have a lifting capacity of 10,000 tonnes.

More information here:

**LINK**

David Davis asks:

"one wonders how such a crane can perform lifts as it looks capable of doing without rolling. It would be interesting to know how a stable counterbalance is achieved."

When performing a big lift, the cranes do not swivel, the are positioned over the end of the vessel and pick up their load as a straight lift off a barge which is positioned between the crane and the final position of the load.

The barge moves out of the way and the crane vessel moves forward to where the load is to be placed, the cranes then lower the load in to place.

The crane vessel is kept level by sea water being pumped in/out of the ballast tanks.

I have never actually seen it done, but I have seen pictures and video of the operation several times.

I have even stayed on board a similar crane vessel, the Hermod, in the North Sea way back in the mid 1980s, it was BIG. By the time I got there, all the heavy lifting had been done and I was just there staying in the accommodation and shuttling by helicopter to the nearby fixed platform where the work was taking place.

Also, some years ago I made a couple of working visits to Haugesund, a very pleasant place.

JimB

Agreed, good enough is perfect.

But for someone who is an amateur machinist, aiming for good precision when it is not really required is good practice for when it is required.

I once made a couple of paxolin spacers for mounting a numberplate. I was rather disappointed when I measured them an found that the difference in thickness was 0.005".

Chasing accuracy for the fun of it?

JimB

I had a close encounter with an angle grinder in the past week.

I needed to change from a cutting disc to a wire brush, so I turned of the mains power at the wall and took off the cutting disc an attached the brush.

So far so good, but when I reached out to turn the power on at the wall, the grinder started up.

As I was holding the grinder quite lightly in my left hand, due to the torque reaction it jumped out of my hand and fell at my feet and the wire brush started grabbing at the legs of my overalls.

Luckily it did not grab tightly, and as my right hand was next to the mains switch I was able to kill the power very quickly.

So how did this come about?

As I was handling the grinder in the course of changing the disc/brush I had operated the switch on the grinder to the on position. So as soon as mains power was applied, it burst into life.

The switch on the grinder ((Bosch) is either OFF or locked in the ON position.

Lessons learned:

Always switch off power at the wall when changing discs.

Before switching on power at the wall, check the switch on the tool.

JimB

Looks like I am late to the discussion, but I would never have thought that "PPE Guy" was female or looked like Elvis.

But the look was seriously creepy, I also had to scroll away from it as quickly as possible.

JimB

NiMH batteries can be charged by a simple constant current charger, the same as NiCd batteries.

But if left on constant current charge, the NiMH battery will be damaged.

The NiMH type has a very characteristic "hump" in the voltage/time graph as it becomes fully charged.

When the battery is fully charged the cell voltage falls and the cell temperature rises.

A good NiMH charger detects this fall in voltage and cuts the charge.

JimB

Looks like the insides of a slow motion drive, as often used in radio and electronic equipment for tuning dials etc.

JimB

A good film, I enjoyed watching it.

There is a TV programme called "How its made" which appears to be of French Canadian origin but is voiced over by a Brit.

Each half hour programme gives an overview of how two or three different items are made.

It is just the video of the production process and the descriptive voice-over.

I find it quite informative without all the hyperbole and false drama of the average pseudo technical reality programme.

JimB

(First post in this forum).