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Member postings for John ATTLEE

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

Thread: Battery fire in electric cars after a collision
11/06/2022 21:56:18

The other difficulty is that there is no standard protocol about when or how the batteries are isolated after an accident. Since the voltages are quite high and DC, this is a bit of a problem. Surely the batteries should be required to be isolated if the air bags go off.

John

Thread: The Correct Way To Sharpen Drill Bits Using A Picador Drill Sharpening Jig With Custom Base
01/06/2022 07:54:22

Dear All,

This thread has motivated me to re-commission my Picador drill grinding jig. I will make a similar base.

What a shame that it has been produced with such cheap and coarse screw threads.

John

Thread: Milling Southampton area?
09/05/2022 10:02:24

I am between Petersfield and Portsmouth. I have a Victoria U2 milling machine.

Why not make some tooling (which might need a milling machine) and line bore using a lathe with the line boring tool running between centres and the tooling replacing the compound slide? That should keep the set up time down.

Happy to chat on 'phone.

John

Thread: Gearbox splines internal and external
08/05/2022 19:58:40

What machine is it for and do you know what caused it to fail. Is the hardening to resist the wear or to increase the strength? How come only five internal splines are stripped? I would have expected it to be all or none! Is the shaft 150 mm long or is that just the length of the splines? How long are the internal splines? What is the form of the spines?

John

Thread: Best way to make valve guides
23/11/2021 09:18:47

The last guides I made was for a JAP engine. It was easier to make new guides than mess about trying to find NOS ones. I used PB because it was what I had in stock! The engine would only be running very few hours so life was not an issue. So useful to learn of better materials on a forum.

John

23/11/2021 06:47:57

Surely, the seat will have to re-cut the seat in any case. I use an engine machine shop because it is so cheap it is not worth doing myself. I recently had a problem with a side valve continental engine in a Hyster forklift. It was not worth taking the engine out to take it to the machine shop. Fortunately after the valve guides were replaced, and after a quick grind, the valve faces and seats were fine.

John,

22/11/2021 18:31:30

I have made valve guides out of PB using your original technique with poor equipment and my limited skills and it was fine. If you did the ID first and then had the arbour running true, it is hard to see what could go wrong.

John

Thread: Run out on bar
11/11/2021 10:35:47

Compared to most on this forum I am a novice with a 1950s Denham DL lathe. I used to use a three jaw but I now normally only use the four jaw. I have found with practice I can get the bar to run pretty true within about 40 seconds. The 4 jaw has the advantage that it can take square or rectangular bar. I do use the 3 jaw for production of several identical items.

Whilst I can take out the eccentricity with a 4 jaw, run out at a distance remains a problem. I am now starting to machine between centres with some success.

I thought that the experience of a relative novice might be helpful.

John

Thread: Denham Junior Mk2 Lathe Purchase
10/11/2021 20:34:16

I expect that "AM" is Air Ministry.. I have a Denham DL6 or 7 (I can't remember which. It is quite slow and TC insert tools are not supposed to work with it. They do! Productivity is significantly improved with 2 axis DRO.

John

Thread: Synthetic paint thinners PT8 vs. white spirit
30/10/2021 22:13:26

Dear All,

I use synthetic paints for my classic commercial vehicle projects. Cellulose thinners will ruin any synthetic paint if you mix it with it. However, this property makes it very good for cleaning brushes and spray guns because it breaks the paint down. I quite often use white spirit for economy. For a really good job I would use the correct thinners from the paint manufacturer.

John

Thread: Cutting an exact diameter using a carbide tip.
13/06/2021 10:30:49

Dear All,

I know that, in theory, my Denham DL6 with plain headstock bearings and very low RPM should not benefit from carbide insert tooling but it certainly does! I use a combined tool post and tool holder and this means that the cutting tool is always at the right height. Obviously, I run it in top gear unless the work is more than about 3" in dia.

I can turn or bore to about a thou. The machine is fitted with a three axis DRO system which I think is essential to make up for my limited skills. I use three passes to eliminate 'spring back' and obtain a consistent size to be measured. Thereafter, the DRO displays the correct dia, after three passes have been taken. I would not hesitate to advance the tool just a thou.

I certainly achieve good enough results for my automotive work. I very rarely use HSS cutting tools in the lathes now.

John

Thread: TurboCAD Query - Copying Between Drawings
03/05/2021 12:36:52

Nigel,

Regarding you original problem, I have had this very one myself but with a full size tank transporter trailer! Try "Insert" and then select "Extenal Reference" which will allow you to access your other TurboCad files ie drawings,

I found that none of the usual copy and paste techniques worked.

John

Thread: What Engine is this?
18/04/2021 16:06:22

I think that it is a Petter AVA1 as I had one many moons ago.

John

Thread: crane uprate - where would you add some metal ?
08/02/2021 19:32:29

Don't even think about it. That crane will be designed so that everything is only just strong enough for its task. Keep your crane for what it is good at. If you need to lift something heavier, hire the right equipment for the job.

John

Thread: Vertex Dividing-Head - basic help please
03/01/2021 13:12:07

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

Thread: TIG is harder than it looks
30/12/2020 19:32:53

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

Thread: Home made cast Aluminium
25/08/2020 12:05:23

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

Thread: Hydraulic ram machining
22/08/2020 21:13:27

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

Thread: Shaft Steel Material Selection
27/06/2020 08:54:11

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

Thread: VICTORIA ELLIOT U2 MILLING MACHINE
14/06/2020 19:47:09

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

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