Here is a list of all the postings duncan webster has made in our forums. Click on a thread name to jump to the thread.
|Thread: New Chuck won’t screw on|
If one buys something and it's not fit for purpose, send it back. Any attempt at rectifying it, buying a tap for instance, will void any warranty, and anyway why should you be put to the expense of a tap.
one advantage of ebay/paypal is the no quibble return
Edited By duncan webster on 28/07/2021 18:36:04
|Thread: Stainless Watch case|
I'm not seeing any photos
|Thread: Help with surface plates in Derby|
Best of luck finding a planer nowadays, and if I had £300 spare I wouldn't blow it on a surface plate
|Thread: Centec 2B - New arrival and Q&A|
Don't you have captive drawbars?
|Thread: Running needle roller bearings|
You can get hardened rods, meant for running linear bearings on. These are surface hard and I'll bet you could at least face them with carbide, perhaps even turn shoulders.
|Thread: Reflex Gauge Glass Material|
Drawn bronze can be a right pig to drill and tap
|Thread: Metallurgical coal|
More on Michael's link rubber steel Seems you still need coke, but a lot less, and you need a lot of electricity
Carbon is not a catalyst in the iron making process, it is part of the chemical reaction. It combines with the oxygen from the iron ore leaving behind the molten iron, which can then be made into steel. This means that even if we could find enough coffee grounds, we'd still be producing CO2.
The neat trick would be to find a way to use plastics (hydrocarbons) instead of coal. Use the stuff which cannot be recycled, saves digging up coal, and gives the plastic waste a value so it won't be dumped into the rivers/seas
I got on to my MP about this. As expected he didn't understand the difference between using coal to make iron and burning it in power stations. I think the main reason for the government calling in this application, which had been approved previously, is the COP26 meeting, but as I said to the MP, if the delegates to that can't understand the difference, perhaps the should find some better delegates. In the meantime we will continue to ship coal across the oceans producing more CO2 than we would if we dug it up in the UK, increasing imports when we could be exporting it to Europe.
There may well be a better way, but if it exists it isn't proven at industrial scale, so it won't be available for a long time . What I would question is why we import coal and iron ore to make iron which is then turned into steel, and export vast quantities of scrap steel, some of which which we presumably re-import. Why not just recycle it ourselves?
|Thread: Centre Drill Leaves a “Pip” - Sometimes|
So why are spotting drills so expensive, best I can find for one off 3mm is ~£5 whereas I can buy a set of 5 different centre drills for that price.
Despite being called a rare earth, lithium is quite common. It is the 25th most abundant element. There is even talk of mining it in Cornwall, but then they keep on talking about cornish mining and nothing ever happens. Can you imagine the greens allowing it even for zero emmision technology
|Thread: Bench grinder|
My el cheapo grinder vibrated quite badly, so I bought a new wheel with 1.25" hole and made new washers, the one nearest the motor has a boss to fit the in the wheel, just a bit shorter than the wheel so the other washer clamps up. this new thick boss/washer has 2 grub screws to hold it to the shaft. All unbalance problems gone away. I cribbed the idea off a RJH Ferret grinder
|Thread: New Chuck won’t screw on|
If I were making backplates for a living I'd use something more 'industrial' than a Myford. Don't get me wrong I'm on my second, but only as a hobby
Not that this helps, but the backplate I bought from RDG/Myford fits lovely. If you divulge your approximate location there might be another Myford owner near you and you could try it on their machine. With a bit of care you can do this Covid secure
Edited By duncan webster on 21/07/2021 22:23:50
Edited By duncan webster on 21/07/2021 22:24:25
|Thread: Setting up rear parting tool properly|
The face of the tool holder shown in the top picture should be facing the chuck, so it looks as if it is set up for the lathe going in 'forward'. This confirmed by the second photo. No chance of the chuck unscrewing, but the tool is canted the wrong way, hence the need for the notch. I think this is simply the wrong tool holder for the job. Boat tool holders have a very poor reputation anyway
|Thread: E10 Petrol|
No one remember Cleveland Discol? If Harry Ricardo reckoned it was OK that will do for me
|Thread: I think I'm in love... with a metal bender :-)|
OK, I don't want one. Haven't got space
|Thread: Vehicle reversing sensors|
The weekly commute to my last paid job involved about 70 miles across single carriageway roads in North Wales. At least tractors are not usually going that far, but Shed Draggers holding queues of 20+ cars for mile after mile were not uncommon. Gaily driving past laybys and then pedal to the metal when they got to the occasional wide straight bit, no thought of letting anyone past. Tin Snails are nearly as bad. I've been told that in some states of the USA there is a legal requirement to pull over if you're holding up more than 6 cars
Edited By duncan webster on 20/07/2021 17:11:50
|Thread: CNC Lathe Scratch Build|
Been having a think, always dangerous. Your post of 14/11 shows the tool-post at the far side of the spindle, so gravity will try to move the tool down the slope into the job. Cutting forces will try to move it away. I know that ball-screws don't have a lot of backlash but it's not zero. If this is thought to be a problem you could either clamp the cross slide to prevent it moving, or over-do the counter-balancer so that the tool-post is always up hill if you see what I mean. Perhaps I'm overthinking it, not unusual.
On to some sums. The tool-post/slide assembly weighs 9kg on a slope of 45 degrees so the force due to gravity along the slope is 9*9.81*cos(45) = 62 Newtons. If I assume your air tank is at 80 psi, that is 5.5 bar so you need a cylinder sqrt((68*4)/(5.5e5*pi)) = 12.5 mm diameter. To allow for the tank pressure dropping before the switch kicks in re-do the sums at whatever that pressure is, which will make the cylinder a bit bigger, and then add another bit to make sure it's always uphill, or if you decide to undercompensate make it a bit smaller
Edited By duncan webster on 19/07/2021 12:23:10
Think gas strut but with an air cylinder instead of the strut. If you find a cylinder which gives the right load with your compressor tank pressure, that's all you need. The force will change a bit depending on actual tank pressure but I doubt that would matter. If you need a pressure regulator to drop the pressure then when the cylinder is compressed the pressure will build up, but the volume of the pipework will limit that. What do the moving bits weigh?
|Thread: The last Gravity Ropeway|
This is very interesting LowTech. Has details of aerial runways many miles long
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