Here is a list of all the postings Martin Connelly has made in our forums. Click on a thread name to jump to the thread.
|Thread: work slipping while threading ...|
Slightly off topic but I once had an apprentice complain about drills slipping in a pillar drill chuck, I told him to use the chuck key in all three positions on the chuck to tighten it. He was surprised how much the second tightening in the second position moved the jaws.
The point is that with any self centring chuck, lathe or drill, unless everything involved in tightening it is glass smooth and lubricated there will be some mechanical effort wasted due to leverage and friction. The easiest way to overcome the low leverage on the far side of each key position is to move around each position and tighten until loaded movement of the key stops.
Where I used to work the stock cut off was done with a bandsaw. I don't think I ever paid great attention to the blade TPI but seem to remember they used a very coarse blade but they did have hydraulic raising and lowering to control the cut.
The pipe shop cut pipe stock with 6/10 vari-pitch but they had controlled lowering as well. The thin wall tube was cut off with a cold saw that had fine teeth but the blades were always clogging up with swarf.
|Thread: Face milling on Warco Gearhead Universal (RF45 clone)|
I often use a 6mm button insert (lathe tooling) in my fly cutter. These have a (relatively) sharp edge and can be rotated to give a fresh edge for finishing. Since this setup works well and I am not usually in a hurry to remove metal I have never felt I needed a multi insert, large diameter, cutter.
|Thread: Acme internal threading|
I'm pretty sure any company that had a lot of internal acme threads to do would go for CNC thread milling. The cost of acme taps plus the risk of a tap snapping would not make sense for them. If I had to do some for myself I would make my own tool for this if it only had to do a few threads. You can do both left and right hand threads with the same tool if you are thread milling. Less stress on the tool and less stress on the workpiece.
|Thread: Microsoft Edge is overriding Google Chrome|
Peter, you can set the new screen page to anything you want. So you can set the Google page as the new tab starting page if you want.
There is a setting for default browser in both Chrome and Edge. You should be able to go to settings in Chrome and select default browser to set it to Chrome.
|Thread: Imperial v Metric Measures|
Missed this one.
I am working on a lagoon that is 2,300 feet long. Again, nobody would have any idea how big that is in metric.
Well 10 feet is about 3m so 2,300 is about 3x230m = 690m. The correct statement is a lot of people in the USA will have no idea how big 690m is.
PatJ, having worked in engineering all my working life I am used to working with metric and imperial measurements. I had to convert 40'-4" into metres in my head to visualise it. 40' is 12m (more or less) as there are 40" to the metre (more or less) and then 4" is 100mm or 0.1m. So you are talking about 12.1m. This is what the majority of the world will do as the idea that "Everyone knows what 40 feet is" is clearly wrong and very USAcentric.
|Thread: Mill lead screw thread size|
The pitch does not really matter. You adjust the stepper motor steps/step rate to suit the pitch. The thing to look at is the diameter that you can fit in and the size of the associated ball nut. If you intend to use the ball screw manually as well then you may need to make a new scale for the handwheel. Adding a DRO would make the handwheel scale redundant and would be a far better option to go with a motor driven leadscrew, you can traverse large distances without having to count revolutions of the lead screw.
|Thread: How to open a .dwg drawing created on a 32bit version of AutoCad drawing in Windows 10|
I am still using AutoCad 2010, that is where the problem lies. It is still fully functional as far as creating a model and drawing are concerned but does not communicate well with W10 printing. Since I am no longer working as an engineer I see no point in updating something that works and does what I want.
It's a problem in AutoCad not sending data to the W10 printer correctly. Even trying to print to a pdf printer fails. I can use AutoCad on my W10 machine but cannot print from it. I just use TrueView as the simplest way of printing from the saved drawings. There may be a better work around but I have a simple solution so I use it.
Download the latest, free, DWG viewer TrueView 2021 from Autodesk. It works in W10 and prints either from the models or layouts.
Edited By Martin Connelly on 07/04/2022 23:44:15
|Thread: Is it really a joke|
I think the intention of governments is to get electric cars and the required infrastructure established and hope that battery technology improves at a reasonable rate. An improved battery would weigh a lot less than the current ones, charge quickly, hold a bigger charge, last a long time, use something less dangerous than lithium and be easily recycled. I don't intend to hold my breath waiting for all these features to come true. This would still leave the problem of the supply capacity.
|Thread: Face milling on Warco Gearhead Universal (RF45 clone)|
I would like to point out that the difference between a fly cutter at this diameter and a 5 insert face cutter is that the rate of feed for a given RPM needs to be 5 times faster. These multi insert cutters are designed for rapid material removal and require a suitable feed rate to get the best use out of them. They need to be worked reasonably hard.
So as stated above you probably need to have a bigger depth of cut, an RPM in the region of 425RPM and a feed rate in the region of 65mm/min. I don't know what your lead screw pitch is but if it is 5mm then you are looking at a handwheel being turned close to once every 4 seconds. You should be seeing obvious chips coming off rather than dust.
|Thread: CAD & CAM content|
CNC turning using wizards can take the drudgery out of some machining operations. I always found boring to be particularly boring. Just removing metal to reduce diameters can be a lot of repetitive handle turning as well. If you are someone who is quite happy doing these sort of things then there is probably no point in you considering CNC but if you are getting to the point where these sort of things are becoming harder due to age CNC may be a good option enable you to keep working. You don't need to go full CAD/CAM to make use of a CNC enabled machine. You can still draw something and work off the drawing as you would if you were manually machining.
|Thread: Lathe gear calculation|
Nigel, I think a lot of people have, or are going to get, second hand lathes that are missing some gears and almost certainly missing the original manuals. Added to this is the fact that some old lathes were never intended to cut metric thread pitches. So there is a constant demand for information on how to do this with either what people have got or what is the minimum they need to buy or make to enable them to do what they want.
|Thread: Central Heating Control|
Howi, gas heating is quite inefficient. A lot of the heat goes out the chimney and into the atmosphere so 1kWh of electricity will put 100% of its energy into a room, 1kWh of gas will only put part of its heat into a room, some older systems were down towards the 20% mark. Add to this the fact that gas systems are more complicated and so require regular checks and maintenance for safety reasons and the cost of gas systems gets closer to that of electrical systems.
|Thread: End Mills|
All cutters have a Goldilocks zone, they need to work but not too little and not too much. Letting them rub heats them, blunts them off and can lead to premature breaking, too high a feed or speed can put too much load on them causing breaking.
You posted in December that you were new to milling. The chances are you are not working the cutters correctly, there is a tendency for new operators to overspeed and under feed. This need for suitable speeds and feeds has been covered a number of times in the forum. In order to know if this is the problem some information would be useful before we start blaming the cutters.
What type of cutter (number of flutes, material it is made from, diameter, coated/uncoated)?
Depth of cut?
Dry, flood coolant or cutting fluid?
Power feed or manual feed?
If you have not been considering all of these factors and setting things up to suit then that could be the source of the problem.
It should be noted that if you have manual feed then the rate of wheel spinning for the correct chip load can be surprisingly high.
|Thread: Central Heating Control|
My central heating controller has settings for a set point. Any changes to the temperature setting only lasts for a limited period before it reverts to the set point. The time before this occurs can be set from 30 minutes to 120 minutes. I have remote control of the thermostat and settings on my phone and I also have a room controller (for one room) on my phone that restricts the heating if the room temperature passes a certain point. This is needed because of a couple of large windows that cause large increases in temperature when the sun shines in, even in the depths of winter. Since no one else has bothered to learn how the system is controlled and operated I have full control of the settings and resulting temperature.
The higher the overall temperature the more heat will be lost. Lowering the temperature in any area of the house that loses heat to the environment will reduce that heat loss. When the heating is turned back on the temperature will be raised to the set temperature but it will never take as much heating to do this as it would have to leave the heating on. So in short any reduction in temperature for any period will save heating costs. It may be too small a saving to notice but it will still be on the side of better for your bills.
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