Member postings for John ATTLEE

Dear All,

I have very recently bought a Vertex BS 1 from RDG tTools. I have found it to be a lovely machine and have already made a 25 and 55 teeth spur gear for my lather in order to screw cut. The literature was fine, albeit with typical errors, and even I could understand it! I think that Harold Halls book is essential.

I made up an arbor from a morse taper blank that are cheap enough. I did have to extend it by locktiting an extension shaft which was then machined to suit. I was careful to machine the teeth so that the cutting forces pushed the MT arbor into the dividing head. I supported the end of the arbor extension with the adjustable tails stock.

I don't think that a chuck is essential because it is easy to secure a mechanical drive connection to the backplate and machine between centres. I think that a MT setting bar would be useful. Instead, I clocked the side of the dividing head to set it up square.

I have an indexing head but if I was using the dividing head for 'indexing' I don't think I would try to disconnect the worm.

On an important job (like my 55 teeth gear wheel) I did do a dummy run marking the indexing plate with pencil to check that I had got it set up correctly.

In short, a great bit of kit!

John

Dave,

I recently bought a decent Miller inverter TIG welder STH 160. It is a light but high quality unit.

I found that even a few amps change in current can make a difference. I found that electrically it is very good.

Unfortunately the control system was obviously designed by an electronic engineer who wants to make everything as small as possible with as few controls as possible. This has meant that I still cannot use (program) the pulse setting. I need an eleven year old to show me how to set it up! What we want is big fat switches.

I am experiencing a problems in avoiding pin holes even in a good quality run. Bit of a problem as my next job is to make a petrol tank for a run up rig for the 27 litre Meteor tank engine.

TIG welders are expensive but do a fabulous job in my opinion.

John

I was working out how to make a thermostat housing for a 27 litre tank engine the other day. A 6" lens of 8 " dia round bar was unaffordable. I did the job by fabricating with steel and machining. If I could have cast something, never mind how roughly, I would have done so. The trouble is that it takes time to develop the facility and it was not worth it.

Getting some good aluminium alloy casting as the raw material is easy and cheap provided that it is not a critical application.

I suspect that if one had the facility one would use it more and more.

John

Kiwi,

I am with the optimists. I have made new rods for a cylinder before with no difficulty. You can buy the chrome plated bar from stockists. I get my seals from Hydraulic Equipment Supermarkets. If you cannot get the correct seals, you can make a new piston to suit seals that you can get. You can usually find the dimensions on the net.

If you cannot operate a lathe, repairing a hydraulic might appear to involve rocket science. In fact, it is simple enough if you can use a lathe.

We had an interesting problem with the REME Museum's 60 ton tank transporter. One of the double acting rams on the rear ramps was leaking oil out of the top gland. The reason was that although it looked identical to the other one, it was only single acting! So we modified the gland nut to take a pressure seal rather than just a wiper. A new piston to suit double acting seals was machined. It was actually made by Andy A , another forum member.

One point that I would make is that it is essential to make a proper tool to unscrew the gland nut, especially on an old piece of equipment. I am currently working on the mast cylinder of my Hyster S40C forklift. It was a good job that I made a special tool because even the 1" drive air wrench had to work a bit to unscrew it. It turned out that the threads were a bit rusty. A C spanner or cold chisel would never have done it. Once the drive slots or holes are damaged you are in serious difficulties.

John

Doug,

How many hours of running life do you need? The cost and effort of heat treating might be more than the cost of the steel and Torrington bearings. If you can cut your own keyway (of have a pal who can) might it not be better to just to make two shafts out of EN16T (as already suggested) and buy two sets of bearings? Secure the heavily greased spare shaft and bearings to the machine. According to Murphy's law, you will never ever need the second shaft!

John

Dear All,

I have a had a Victoria Elliot U2 universal milling machine for many years. Its utility has been vastly improved by having digital read out on each axis. It does really good work for me in terms of accuracy and finish.

Unfortunately, I never had a top slide for it (for horizontal milling) although I do have the arbor brackets. The stays between the slide and the table can easily be fabricated. This limits my ability to do certain tasks, in particular cutting larger gears.

A slotting head was also made and that would also be extremely useful.

I have never seen an advert for a U2 milling machine in the UK but I would love to buy one for spares c/w top slide, whatever the condition (no matter how rusty). If anyone knew the location of one of these machines, all my dreams would come true!

John

This does not look like the work of a "complete novice" to me!

John

Dear All,

Thank you for your warm welcome.

I did not see Daniel's post so I take no offence but welcome his retraction. In any case, I am sure that plenty of people are very rude about me on-line but I don't see that either!

I can assure everyone that I do not do engineering for current military equipment but although I would do so if it was required. Most of my work is in support of the REME Museum which is a registered charity. Nevertheless, I do have a very strong background in the military, defence and security. I have served for over 40 years in the TA, particularly in the REME.

I believe that it is of paramount importance that we keep ourselves safe and secure by being able to deter aggression. We failed to do that in the late 1930s and got our posterior kicked hard. Our current defence and security situation is a political matter and not appropriate for this forum.

I do believe that there is a value to preserving military vehicles and other equipment. During the Cold War we cleverly spent no more money on defence than necessary to deter, whereas our opponents spent all their available resource on defence and not on washing machines and other consumer goods. However, we made some horrible mistakes and I think it is good to keep them on show.

A classic example is seen with the REME Museum's 1958 Conqueror Armoured Recovery Vehicle that I work on. It was designed at a time when the Government's decision was to re-arm and increase defence expenditure. The vehicle really was a very good ARV but the designers were profligate with resource and public money on this and other projects. The main winch was good but the winch spade fitted to the rear of the tank to resist the pull of the winch was far too exquisite. The hydraulic system consisted of two pumps which ran the system at full pressure whenever the PTO was engaged. There were hydraulic pipes everywhere.

The spade was pinned to the back of the tank with precision pins but it's working load limit was 135 tons. What would be wrong with 3" dia pins with a 40 thou clearance? Even more profligate was the means of securing the two hydraulic rams that lifted the spade. The rod and cylinder ends were secured with spherical bearings (even though the spade was secured with precision pins). These must have been fabulously expensive, bearing in mind that they only built 23 of these vehicles. Again, what would have been wrong with a nice sloppy fit that could accommodate any misalignment?

Finally, the tension links which prevented to spade from folding right underneath the tank. Obviously, precision pins again with only a few thou clearance. Extraordinarily, the links failed under maximum load and had to be replaced by forged links to withstand the load.

I apologise for, unusually, going on a bit. However, the story about the Conqueror is one all about engineering. Yes it was exquisite but it was far from economical or easy to manufacture. That is the lesson to be taken on board. If you think that we are not making similar mistakes with Defence equipment, dream on!

I look forward to contributing to this forum and picking up some useful techniques.

John

Dear All,

I do not do model engineering (yet). I do full size tanks and tank transporters. Currently engaged on rebuilding a Meteor M12) tank engine. Basically it is an automotive fuel injected version of a Merlin engine. I hardly ever do a day working on the toys without using a lathe.

My machine shop is in a 40' ISO shipping container. I have a bigger Denham Lathe, A smaller Atlas lathe that is much older than me (63) and a Victoria U2 universal milling machine but with no horizontal top slide.

400 amp MIG & TIG welders, gas axe / sparling spanner plus usual range of other tools.

My reason for joining this forum is that others I have looked at, particularly one from US, seem to consist of members being rude to each other! What is interesting is to pick up techniques and tips from others who may have experienced the same problem before.

I am a great believer in Fusion engineering where one mates modern electronics with classic equipment and achieves fabulous results. Thus, the milling machine has DRO on three axis, the Denham lathe on two and the Atlas on one. The machines are transformed as a result.

John