Member postings for Stuart Bridger

This topic has rekindled some interest. It's a long time since I used scope in anger. Only ever used analogue scopes, but a spell in a repair and calibration shop gave me a lot of experience on a variety of vendors. Having browsed the RS website. I see that they have a huge range. I am amazed that you can get a very well specified 100MHz digital scope for around £350 with their own brand. RS have never been the cheapest, so I guess you could get cheaper elsewhere. Like others have said, I see little point in getting a USB model, when you can get a standalone unit for these prices.

Another vote for the earth leakage from the VFD EMC filter tripping the circuit. My VFD powered lathe is on dedicated circuit with a 20A C rated breaker. I was specifically advised not to use a RCD with a VFD. I would recommend checking with Warco for their installation instructions. BTW my old school single phase VMC runs fine on a 13A plug on a standard ring main. That said a VFD powered one would be nice, should run much smoother.

Tonight's "Inside the Factory" on BBC2 featuring Digestive biscuits had an unexpected piece of machining. About 30 minutes in, they showed CNC machining of the bronze roller used to mould the biscuits. Should be available on iPlayer.

My father was a dairy farmer all his working life, he swore by udder cream to keep his hands in good condition.

Pure political statement, many governments will come and go before then. No one will be around then who made the statement today to be held accountable for the decision, right or wrong.

+1

Fascinating article

Stuart

Just checked the Warco installed units on my VMC, no obvious part number or logos. Mind you my mill is a few years old now, so they may have changed supplier in that time. It was originally fitted with an Easson console, so it could have been scales from the same, but no guarantees.

Good to hear Andrew, I must admit it did put me off using soluble oil when got my lathe.

A significant potential problem with soluble oil based coolant is bacterial contamination.
You can get bacterial growth in the water based coolant that makes it go rancid, which is both unpleasant and a health hazard. Nice explanation here

**LINK**

I use neat oil in my lathe to avoid the hassle of managing soluble coolant, especially as it is infrequently used

If the Bantam is anything like the Chipmaster, the lower level sight glass is for the screwcutting gearbox and takes ISO 68 gear oil rather that the ISO 32 which is used in the headstock.

100% agree, where would we be without it?

I remember there was a concern when it opened that it would be used for racing and timed circuits. All fears of that soon disappeared

Edited By Stuart Bridger on 24/06/2017 09:30:58

When I worked in an electronic repair shop, one of my colleagues used this trick. A certain piece of kit had a logic board where for some reason the signal ground was floating at I think about 350V DC. Highly unsafe, but apparently the only way to troubleshoot. Everyone kept well clear when he was working in this way.

Edited By Stuart Bridger on 20/06/2017 22:25:56

Murray, there was a reason I put vintage in quotes

Certainly in the Weybridge machine shops there were many NC machines that dated from the 50's and 60's. Some ran on Mylar punched tape, which read and executed the commands sequentially direct from tape.

Like the idea, but the holes are blind, as per drawing

Haven't we been around this loop before???

My wife changing jobs has revealed this apprentice piece that has been sitting on her desk at work for many years.

It is a very simple piece of CNC machining, but it has a history. It was created in the summer of 1981 in the apprentice training school at BAe Weybridge (Brooklands). We were the first year to have access to a shiny brand new CNC mill. May have been a Bridgeport or a Cincinnati, my memory is not that good. We were writing raw G code on a Commodore PET (no graphics or even a hard disk) and then transferring it onto the mill via punched tape. The instructor had been on a very basic course, so he was learning along with us. It was all very exciting for us young apprentices at the time! Alas we only had a few days of time allocated, so this was the one and only piece created.

As I said, I'm just the engineering dude helping out on the practical stuff, My mate has a degree in Astrophysics from Cambridge and he quickly gets me lost Not sure on the mount, I know he was using a Losmandy Titan, but I believe he may have upgraded this year.

I'm not too much up on the technicalities other than it has a 1500mm focal length and the mirror is 14 inch diameter Pyrex (mixing units sorry). The structural tubes are 1.5 inch in diameter. Black centre box was welded up from aluminium box section by another friend the the village. Other components were custom made by a specialist in Germany. We estimate that the assembly weights about 25kg in total. For more information on the astronomy aspects, he has a website at **LINK** Not too much information on this project yet, but lots of pictures from his current telescope.

I have been helping out a friend over the last few months on his telescope project. My main contribution was to create a set of brackets for the tube ends of the main structure

This afternoon we had a major step forward, as he came round with the rough cut tubes which were milled to length. We then did a trial assembly and it is looking pretty impressive.

One very happy Astronomer, whose design calculations all worked out