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Member postings for Billy Mills

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

Thread: Aciera F3 Mill
02/08/2013 01:31:43

The feed top pulley should be held on by a small capscrew and washer in the centre of the pulley, there is a square key locking the pulley to the shaft- a very Aciera way of doing things. Guess that you can slip the belt off then unbolt the gearbox and then take out the whole assembly but never had to do it myself. Whole lot on page 6 of the Parts drawings.

Yes -you are lucky having the high speed vertical spindle with the sensitive feed, a very useful extra for fine milling and drilling. There are a few other special add-ons that are very sought after, these include a slotting head which replaces the standard vertical head . There are also alternate tables and a work-of-art dividing head and tailstock. If you win the lottery you might treat yourself to the cabinet that contains all of the add-ons but you need the engine crane to mount some of the bits on the machine!

The machine uses tapered gib strips, they are adjusted by a coaxial arrangement of an inner lock screw and an outer slotted worm, slacken the lock, turn the worm to tighten the gib then back off till the axix is free and re-lock. Makes multiple screws holding gibs look very crude.

Norman - nice explanation but is the width issue affecting the side bars resolved?

regards,

Billy.

01/08/2013 21:09:20

Thought you were talking about the spindle drive! The Feed belt should be 13/8 X1475. The top pulley has an outside diameter about 150mm. The feed belt is tensioned after the main drive belt tension has been set with the adjustment behind the botom door.

The feed belt is tensioned by slackening the four mounting bolts on the feed gearbox ( on the outside of the machine, two bolts backside and two more on the side.) then moving the gearbox verticaly to tension the belt. You then tighten the mounting bolts which should have washers under the heads. It is helpful to be an octopus!

They advise not to change the gear selector when the table is being driven. The shaft with universals is called a cardan shaft in the manual. There is a shear pin at the table end of the shaft, 4mm x 28mm mild steel. The manuals don't have a full parts list even when you pay a lot of money for them!

Sounds like you have started collecting collets! The W20 has a very small gripping range unlike more modern types you have to use the correct size or it just won't grip. There are also a few W20 lookalikes that have a slightly different thread to the correct buttress types.

If your drilling head is the high speed milling head then you have one of the several sought after add-ons. It is powered from a seperate position on the speed selection switch via the two pin socket on the back. There are several different kinds of switch gear panels on the front which were fitted at different stages , these give a clue to when the machine was made apart from the serial number and importer's plate. The rounded or angular casting shape causes some to say "Late model" or "early model" but it is a little more complicated than that. But still a very nice machine.

regards,

Billy.

01/08/2013 16:01:33

Yoram

Puzzle increases! the F3 has a four step pulley at the top, this gives 500,880,1500 & 2500 rpm on full speed, switching the motor to Lo speed gives 125,220,375 & 625 rpm at 50Hz. There is not a Clutch, the drive to the H & V spindles is direct via the belt and fixed gears, speed is down to the pulley selection and motor pole selection.

The original belt is 17X2413 B95 so the internal lenth of the Vee belt is 2413mm, it is an easy to get £6 belt. The top pulley cover just clears the pulley which has a max diameter of about 170mm. Sounds like both top and botom pulleys have been used elsewhere!

The two pulleys are probably identical ( can't easily get at the lower door as there is a large machine in the way that will stay put for some time to come). The top pulley has an inner diameter of about 132mm for the slowest pulley, the highest speed is about 60mm in inner diameter. so the effective diameters are a little greater as the belt rides on the sides of the Vee. Should be enough given the speeds to work out the approx dimensions to turn up two replacements. I would check that the two speed three phase motors are working before going too far.. they are very reliable but may have suffered, the switchgear is VERY non-standard. At least check the motor bearings and re-grease.

Given that these machines have been butchered and the quality that is still underneath would suggest that you strip and clean the worst one then rebuild the better one based on what you have learnt from the first. It is not too difficult to take the top off the tray and take the machines apart, there was a good article in MEW a few years back on a F3 rebuild.These machines are beauties, they are very nicely made and of a quality that seems to be a lost art. Hope that you have some W20 collets!

Best of luck,

Billy.

Thread: Electropherii
01/08/2013 15:13:17

There was an article in Electronics and Wireless World many years ago called " Killing Fields" which was about the fields near HV transmission lines. There is some evidence for magnetic fields having a biological effect however these effects vary greatly with different people. It is certainly true that ozone is very dangerous to some people in very small concentrations however transmission lines are high in the air and wind flow speeds are a lot higher than at ground level. So there are a few complicating factors.

The normal -fine weather-electric field is around 600V from head to toes ( if you are standing up) so we all get exposed to quite high electric fields when outside.

Like Gordon, I was outdoors in a Storm once, there was a near strike- total sensory overload and glad to be alive feelings as the eardrums recovered. But would not like to be in a glider blown out of the sky. Will stick to flying in Faraday cages. Wood is around 10% wet when seasoned under cover so there is plenty of steam volume available.

Billy.

01/08/2013 12:08:38

If Building structures get wet then hit by lightening the water converts to steam and does a lot of damage to the building. The current in the average strike is around 25,000 A for a few uS, it is NOT Terra Amps but the strike is very complex, no two the same. The peak current has been indicated by the intensity of magnitisation of soft iron rods placed near the conductor as well as other methods.

Lightning conductors are aimed at giving the strike an easier path to ground than through the structure to minimise damage, very many buildings are saved by lightning conductors every year. Some buildings get hit very frequently, but for every strike to ground there are roughly three times as many cloud to cloud.

After taking a strike it is a good idea to check the conductor's condition! a six foot gap is not a great big issue for lightning that has traveled several miles but it is not good for people nearby. Sometimes the conductor can break free of some of the cleats and gets stretched into a bow shape said to be caused by the local magnetic field - not quite the same as welder cable twitch!.

Billy.

Thread: Aciera F3 Mill
01/08/2013 11:05:46

The F3 comes in not just early/late versions but has crossover versions too. But it is such a simple machine that if you have one ( or two) it should not be too difficult to work out what is happening once the manuals reveal the hidden details (such as the pre-load adjusts on the spindles). The problem is spares as Aceira shut down a very long time back. There are a few parts around in Switzerland but make sure you are sitting down before asking.

Would check that the oil levels are OK and that grease has not been used where it should not have been used if you plan a full strip down. Hope you get both machines back working as they are one of the finest mills ever made for precision work.

Good luck

Billy.

Thread: marking / layout blue
01/08/2013 10:47:39

Never had a problem using marker pens- much easier to get hold of but I do like the smell of the 'blue. As MH says scribed lines can be made more visible by infilling, a quick rub of a line with the finger puts enough grime in the line to make it much easier to see.

As I ( like JS) have a laser to hand, there is a simple method of putting very complex layouts or even images onto a metal surface. You simply put a very thin resist layer on the surface ( spray paint, some marker pens, tape film or what-have-you) then vector mark or raster engrave your design into the surface. (You MUST use the lowest power level to avoid too much reflected power) . The laser removes the coating in the exposed area revealing the metal below.

This is a very reliable method of marking 1 or a thousand identical patterns which can then be used for further machining or etching. It is a quick and easy way of producing identical PCB's at very low cost.

Billy.

Thread: Searching for a "Bench Grinder with Sanding Belt"
29/07/2013 23:47:46

Dias-

Hope you have an Aldi store near by;**LINK**. Under £30.00 and 3 year g/tee!

 

So might come up in Portugal some time.

Billy.

Edited By Billy Mills on 29/07/2013 23:49:16

Thread: Grit size
27/07/2013 13:55:12

Clive

It's hard to spec a particular grit because it all depends on what you want to do. 80 is a good rough grit for fast surface removal on most soft materials, if you change to 120/150 then you get a finer finish but much slower cutting and a tendancy to clog when pushed too hard. Beyond 150/200 belts are harder to find. 400-600 might be very difficult to find.

There is an interesting point that a belt driven quickly produces a much finer scratch pattern than if you were rubbing down by hand. For a small linisher the belt might be around 1000mm long and will go past the job many times per second so the job is abraded by very many grits along the whole belt so there is an averaging process at work to produce a smoother/ many more scratches per mm width that if you were handworking the job. So large grits can remove a lot of material quickly and give a good finish.

Billy

25/07/2013 20:21:01

Grit size is the number of wires per inch in a wire mesh used to sort the grits. So the higher the number the finer the grit. For belts 40-150 is commonly available. In Wet & Dry 100-1500 is common.

regards,

Billy

Thread: Workshop comms
22/07/2013 17:58:30

The "wireless intercoms" put a frequency modulated signal onto the mains. If you are on the same ring then there is a chance that you can hear the fm ( around 100-200KHz). It will also work on another ring from the same meter. However there are a lot of switchmode power supplies hanging on rings these days, they work around the same frequency, produce interfering signals and also have capacitors wired accross the L-N which will tend to greatly reduce the intercom signal.

So depending on what you have plugged in it may or may not work! A manufacturer or seller would be pushing their luck to say that it would always work.

The wired intercom will always work and no one else will find out how many cups of Tea or even Coffee you get through. Some DECT phones have an intercom which gives you a phone in the Workshop and a means of placing orders to the Catering Dept.

Billy.

Thread: Aircraft General Discussion
22/07/2013 17:26:25

Very special film on Ch4 last night starring the new Mosquito, looked absolutely beautiful. If the "Heritage" Lottery fund wanted to spend some money they could do a lot worse than to put this aircraft into the air over it's Mother Country.

Billy.

Thread: Cutting Gears
20/07/2013 23:43:36

That's a bookload of info Carl, so you might be better off looking at "Gears and Gear Cutting" by Ivan Law from the Workshop Practice series. You can also see some gear cutting on you tube.

Billy.

Thread: Electropherii
18/07/2013 19:32:24

The Blitzortung.org link was one I posted. It's the same Time Of Arrival type system as Martin describes, the radio events are timed to the next GPS second then the data sent via the web to a a server in Germany. The network has a much larger number of receivers that "Official" sites and the data is not delayed for non-subscribers to the extent that some official ones are.

There is also a North American version on the same site.

Most other amateur networks use commercial equipment to do tradditional crossed loop direction finding at around 9-11KHz, the type of method used in the 1930's by Watson Watt at Slough.

Billy.

Thread: Highest temperature
17/07/2013 17:36:47

Cold in Moscow is'nt that bad because it's much dryer than the UK, walked around in -25C a few years back. Because you cannot get more than 70 odd miles from the sea in the UK our humidity is always high so cold feels much colder and hot seems even hotter.

The other thing that will happen with this heat is Thunderstorms, there are a few good websites, my fave is **LINK** which gives you a map showing where the storms are. It works by measuring the time between the radio impulse from the flash and the next GPS second at many sites all over Europe. Handy to take a peek before you go up the Church Steeple!

Billy.

Thread: Carbide grinding wheel
17/07/2013 17:18:29

Diamond wheels are so much safer and long lasting than green stones. They are supplied " dressed", you just spend some time centering and clamping till they run true. The price is very fair and they are easier to get hold of than greens, you also don't have the worry that they have been dropped-possably cracked- in transit. Neither do you need to redress or sweep away piles of green grit.

Billy.

Thread: Peristaltic pump
15/03/2013 14:21:43

Martin- am very surprised that your pump tubes last such a short time. Would suggest that with the right types of tube and checking that the roller pressure is not excessive the tubes should be lasting years. The long life tubes will be thin - around 1mm thick and a soft grade of silicone rubber. But then there is not much trade in very long life tubes!!!

One of the great advantages is that if you don't need very long life you can use soft plastic tubes on a disposable basis- thousands used in Hospitals every day to pump fluids into people. Ian's comments about ice cream reminded me of one that was in a relative's shop, it used a peristaltic pump which was never replaced in the 7 years it was used.

CRYPTIC PUMP

Another type of pump which would perhaps be the best for suds & swarf was devised by a guy who worked for George the Brakeman and also has a fishy connection but is best knowen backwards. It also is very easy to make at home. Have a shot!

Billy.

Thread: Reactive power loading
12/03/2013 17:46:41

Swarf,

The choke input filter is very widely used at high frequencies inside many SMPSU's and several times over on motherboards, it can be just half a dozen turns of wire on a ferrite core. At 240 V 50Hz however it is a bulky expensive part which has a larger than normal core because of the very strong direct current requirement. The peak current without a choke can be very high, if you want to draw 10A DC then the peak current goes towards hundreds of amps for a mS or so. Active PF correction uses an inductor at a much higher frequency so it is small and cheap, as Andrew has indicated you can solve the "chunk out of the mains" issue that happens when you have full wave capacitor input supplies.

This is also a reason why old style PF measurements can be very misleading because they often assume sinusoidial current and voltage instead of a massive current spike. The impulse does not help the Supply Companies or the Consumer, the current demand can cause the rectified voltage to be much lower than expected- certainly so on a long extension lead.

 

Jason's comments about IT testing are off track. In the US they have 110V line and neutral just as we have 240V line and neutral. Because many US outlets are unpolarised and do not have a third earth connection you cannot say which conductor is line and neutral so the inlet cap is between the two wires. Plastic insulated SMPSU's can have two wire connections with one inlet filter or three pin inlets with a delta filter using a third earth return ( sometimes called FG). There is no path between the input filter and 0V on the two wire types that I have seen.

All ATX supplies that I have inspected have delta filters and require an earth connection otherwise the metalwork floats up to half line due to the capacitor tap. The PAT inspection requirements for IT equipment are different because -in particular- the earth continuity high current test would cause extensive damage to the equipment. This is a legit outcome because only the PSU is a risk item, if you applied the test from power cord to any exposed metalwork you could burn out tracks on the motherboard and any other boards. It is certainly the case that many -if not most- PC's are badly made, leave out EMC filtering parts and put people at risk. That is how you can get an ATX PSU for £7.00 trade in the UK.

Billy.

 

Edited By Billy Mills on 12/03/2013 17:48:37

Thread: Making a piano hinge bind and get stiffer
03/03/2013 18:30:35

Be very careful with loctite near acrylic or other plastics, some kinds can cause the plastic to break up after a few months. Learnt the lesson the hard way some years ago, we had to replace hundreds of switch assemblies that had been given a drop of locking compound " to stop them coming apart" !

Billy

Thread: Planet CNCUSB software
02/03/2013 23:43:57

Have a couple of friends who use Planet cnc for their own kit. They are both impressed by the product, one makes wooden parts by the thousand.

Billy.

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