Member postings for Ajohnw

The chuck is unlikely to hold the silver steel dead on but that could be used to check to some unknown n thou.

It is possible to make a pretty good between centres test bar but it's fiddly. A fixed steady and a sensitive dti is needed. On a lathe this small just make it as long as possible. The usual length of a piece of silver steel should be ok on larger lathes. Diameter is tricky. To prevent sag due to weight some are hollow but hopefully that wont be a problem for say 12in of 1" bar. This method will work providing the tail stock isn't insanely out. The centre drill tip will probably break if it is. I'm assuming slides have been set sensibly. Not too loose.

Grip a short part of the length say circa 1/4" lightly in the 3 jaw and set the steady. Carefully set the steady to get the bar running to ideally no dti movement at all with a 1/10 thou reading dti. Tighten the chuck and check again. Done well so far and the reading wont have changed. Face the end of the bar. For a pro look turn the OD down a bit for say 1/4", chamfer the end and turn a recess in the end to protect the centre hole as well from knocks. Then carefully centre drill it. Not too deep, say up to the cone on the drill being around 1/8 - 3/16" dia. Slowly so that the drill can make the hole central even if it's only cutting on one side and for if the tail stock is a bit flimsy. The drills are stiff enough to do this in reasonable sizes. It's the whole idea behind them.

Then do the same thing to the other end.

To use it set up between centres. Using the cross slide run the dti across the top of the bar at several places along it's length. The reading should all be the same. If they are just different in the middle and variations on that the bed is warped. Say reading are taken at 1in intervals a pure angular error will show the same change of readings each time the dti is moved along. There is not much point in just running a dti along the side if the top readings are well out as the dti finger will be at different heights along the bar. A vertical slide could be used to rule this aspect out. The cross slide should be locked when doing this test. Say there is some error along the top it's possible to calculate what this means in terms of reading changes cause by the dti finger being at different height on the curved surface of the test bar so the degree of error in both directions can be estimated. Using the cross slide to test the top has removed any errors due to the test bar being round.

Then it becomes a case of what to do to correct them if needed. This might just be an estimation of what to do so the same test can be done again and adjustments refined. Maybe even making a new test bar before that but in real terms the method I described is likely to produce a pretty accurate bar.

Perfection I suspect is unlikely in many cases. Lathes are not super high precision devises. That's what grinding machines are for or more usually emery and files in our case. The other problem with lathes is wear.

Catches. Loose head stock bearing might make that end look low. The morse taper may be out compared with the axis of the spindle. Morse taper errors are likely to be insignificant due to the length of the centre being used - not so when a morse test mandrel is used. Loose bearings will cause the same cut setting to repeatedly remove material but be careful as the cut might be bending the bar.

Use of a morse taper test mandrel is very similar. This often have a draw bar socket in the morse end so that the spindle can be pulled back firmly into the bearings - not just firmly into the morse socket.

A more usual method of correcting taper when a centre is in the end of work - change the tailstock offset to correct it. This can come into things when staining the bed is used to correct shorter length turning test as they usual are. The usual light cut on 2 rings. Correcting these by straining the bed at the end is likely to throw the tailstock out so offsetting can correct that. There are complications. Personally I feel bed straining is pointless on most lathes and really applies to lathes that are stood on massive iron castings. The usual steel cabinet will give over time if the adjustment made that way is really significant. It's only intended to correct very very minor errors.

John

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There is a UK seller on ebay that offers 120w sewing machine motors. Could be in other countries people who sell sewing machine replacement parts offer them as well.

I'm basing mine on a motor out of a sheep shearer. 90w out which is close to 1/8hp. I'm happy with that as I understand Pultra made some small cylindrical grinders that used a 1/10 hp motor and want to try it for a number of things. It has a little electronic box with it to regulate speed so ok for grinding. In sewing machine terms though this is near 170w motor, permanent magnet type so probably more efficient. I'm fond of 500rpm so will be looking a speed something like 500,1000 and 4,000 rpm via a simple belt set up, circa 500 and 4000 for certain. Not sure about the other yet.

John

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The brake in the link is a joke as is the general idea. If the lathe has an 180v motor regulated for speed via a controller from 240 I don't think that type of meter would give a correct current reading. It would need a true rms meter with a decent frequency range which clamp on meters like that aren't as far as I'm aware. As an electronic hobbyist I have often looked at them. I suspect even a so called true rms dvm could have problems.

John

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Then comes this statement, from the link

Both the UK and the EU have far stricter testing methods so it's less likely that any car manufacturer would have been able to use this same method to hide their emissions figures.

In a statement, the Transport Secretary Patrick McLoughlin said:

"We are closely monitoring the situation and have been pushing for action at a European level for more accurate tests that reflect driving on the road."

"It's vital that the public has confidence in vehicle emissions tests and I am calling for the European Commission to investigate this issue as a matter of urgency."

LOL. As some one from the SMMT put it the cars do meet regulations. Put it all together and it's odd that there is a recall really but when the cat is out of the bag the auto industry is very keen on public relations. They may even have recalls and in real terms change something other than what the recall seems to be for. That doesn't seem to be the case this time.

Mitsubishi were talking about using urea before cat's were fitted to diesels. I don't know if they did. Not long after I bought a V6 Passat that had been fitted with an uncontrolled cat system. Because they got that aspect wrong they later altered the engine management software, result a 10% drop in fuel consumption. There is no way my driving pattern needed the change. Later they put some sub standard cam belt replacement parts on the market. As I'm a private motorist I have to keep my cars for a significant length of time. The replacement lasted for under 20,000 miles not 60,000 as per the time to change for the original.

No problem with my Jaguar X type so far, touch wood, other than the usual one on many these days - new clutch at about 40,000 and a couple of I suspect odd recalls. The clutch seems to be a Ford / GM thing as the same thing happened on a SAAB but they replaced for free. Trouble even though suspension settings differ from a Mondeo the X type still drives a bit like one.

I'm running out of manufacturers I trust.

It'll be interesting to see what happens long term. Legal aspects could be distinctly different in the USA compared with the UK and Europe.

John

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I wonder if this is correct

**LINK**

Or quote to save reading it

How does a 'defeat device' work?

Modern diesel cars use a fluid called urea that's then pumped into the exhaust system which in turn reduces the amount of nitrogen oxide that's released into the atmosphere.

A 'defeat device' is a piece of software that can detect when the car is undergoing emissions testing at which point it will start pumping more urea into the system.

The problem is that it's not sustainable. Under normal driving conditions the fluid would run out extremely quickly.

For short periods of time though such as say, in a laboratory, the system can make the car appear to be far more environmentally friendly than it actually is.

That sounds highly illegal?

You would be right, it absolutely is.

Last time my car was MOT'd I didn't see any signs of a laboratory. News bullshit.

One way of detecting if the car is being tested would be to say hey I've been ticking over for a while and do it then. From a pollution point of view that actually makes a lot of sense. Cars spend loads of time ticking over in modern traffic conditions. On the other hand the abs ecu might tell the engine management that something weird is going on here, each axle has been brake tested so more urea. Or even that plus all of the lights have been tested. The engine management might also squirt more in each time the car accelerates. Good for pollution again. They are extremely efficient at constant speed so less of a problem.

John

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Are you really sure about that or imagining it Clive? The press is making a right meal of it all. All types, are worse in use on the roads but petrol hasn't been mentioned. The so called cheat device is probably a piece of software and nothing more than that.

There are other factors too. I have actually seen road tests being done at MIRA on the track many times. Soon it will emerge that they tape up the joints which actually isn't a bad thing to do. It already has actually a few weeks ago on the TV. It's very difficult to get repeatable conditions. The tape helps smooth out variations due to wind and other aspects and makes a negligible difference to the tests.

I doubt if there is any need for them to alter the oomph. I'm not familiar with the tests they have to meet but would strongly suspect that they are under static conditions as adding other factors would get far to complicated. What gear, how steep a hill and all sorts of other things. Number of people in the car, load in the boot, anything being towed and etc. I keep meaning to try and dig the rules out. The companies have a tough life. I know of one make where the software said oh dear the cat is suffering so cut engine power immediately, didn't matter if the car was doing 70mph on a crowded motor way. Things get ever so complicated a more and more situations arise. That one had to be fixed quickly.

One thing for sure diesels are increasingly efficient year by year and that signifies less pollution. It's a pity about nitrous oxide but I understand that there are ways of dealing with that and suspect the situation was similar to petrol when cats were introduced. Lean burn was getting there but "gov" said no use cats. One company was talking about squirting urea into the exhaust on diesels and I suspect that is the best option, not sure, however that company unlike Ford for instance didn't produce diesel engines that let out a lot of smoke. I have noticed that a number of newer models various makes now put out puffs smoke following a period when they never did. This might be done to keep the cat happy. They do something similar on petrol engines - squirt too much in on purpose at times. On cars like suburu's it's a nice easy way to get stacks of oomph for a while too. Many motor bikes run like that all of the time.

What is needed really is a statement as to what the cheat actually does. Not loads of rubbish that is pretty obvious and rather difficult to do anything about. I actually wonder if it's just a cheat for an MOT style smoke test. A pretty stupid test introduced to get round problems on older designs of engine and also force improvements. It can still be used. Manufacturer's probably do play with fuelling at certain constant speeds which is a cheat but this does meet legislation.

I heard on the TV that Ford were warned about this sort of thing some years ago. It's pretty easy to guess why VW are having a tougher time. Others will as well because if one major manufacturer is others will be doing it too. The real road testing results are mainly of news worthy interest to the unrealistic at times green people and are a separate problem. They can help to formulate legislation - maybe adding auto stop start in traffic jams for instance. Legislation has to be more realistic otherwise no cars. As I understand it euro ever increasing n will help in the on the road aspect as it implies better fuel consumption. Things have already gone a long way on diesels. They are way better than the early gas guzzling turbo's that were about when they started to become more popular.

One interesting oomph aspect about diesels is the gain on the throttle - set to make them feel more powerful than petrol cars. They are also good at providing low speed torque and offer better load variation performance than petrol appear to be able to do. The manufacturers get up to all sorts of tricks at times. One thing on diesels is that hardly any of them take steps to cause the engine to heat up in a reasonable time. That's bad really and signifies can't be bothered. Once the diesel engine for a car was totally different to the petrol one. That sadly isn't the case any more. They now tend to be very similar in all sorts of ways.

John

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Ketan wants to sell Clive. That's how he makes his living and Rolls Royces are expensive to run.

I know that certain problems are caused by the importers changing specs and not really caring if it interfers with it's use as a lathe. The extra 2in centre distance gained by shortening the tail stock is one that was followed on lots of lathes - can't turn up to a centre because it wont reach - tough buy and fit and often poorly made morse extension sleeve and finish up with less centre distance than the lathe originally had.

I feel input and output powers are the best option as people will wonder if others don't follow. I'm not at all surprised by the comment about the German importers at all. I mentioned why in another thread also how wonderful a Wabeco 4000E is. It has it's pluses but for cost design wise it's seriously flawed - the term rip off springs to mind bought new. The same is true of a number of what might be called their big boys toys and a number of other things including some factors of their more famous cars. As I have followed lathes for some years I also know they were the first to mention micron level spindle bore run out which in terms of axial alignment means nothing at all. Misleading to say the least.

John

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I based my idea of the size it would take around a sieg baby lathe compound slide I have. 15mm slot for the tools. Maybe this is done to make the photo's look good, don't know. The screws are unusually long.

7.85 +0 -0.8mm is sort of fine for 5/16 tool bits. Maybe it's another bit of americanization like the chuck fixing screws. ( notice i used a zee, we brits hardly use them at all ).

6mm shank holders are available but they look like they use 9 or 11mm tips to me. Not that matters if the part that is actually cutting is supported at the bottom. If Brian does buy a set of these do remember to buy ones that come with a torx key and screws - not hex socket screws.

Light pressure and movement across the tool is the answer to green grit supposed chipping. Grade doesn't have that much to do with it which is why diamond wheels are often fairly coarse. Friable ones are also reckoned to be better than the surface coated types. A tool grinder with traverse and a controlled feed can make a much better job with both types.

John

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The jury is out as far as I am concerned on brushless Ketan because of the hype on other types. I do believe that permanent magnet motors can be smaller for the same power output and would assume that applies to brushless. I can also see that better low speed control could be achieved but have doubts about more torque other than it being a more powerful motor.

The other factor that can have an effect is motor speed. Motors have what is called a windage loss due to the parts shifting air about but it's not a dramatic one so higher speed can result in smaller motors for the same power output. Power is a function of both speed and torque so say some motor produces it's max power at 10,000 rpm and that is then belted down to 2,500 torque will be roughly 4 times higher than the motor gives at 10,000 rpm. This is how electric hand drills etc get their power and size usually needing cooling. They run at very high speeds.

What I suppose some one could "fairly" do is say we fit a 10,000 rpm 1hp motor and use a belt drive to bring it down to 2,500 rpm so it's 2hp. Ie the same torque as a 2,500 rpm motor would give if it was 2hp. This is sort of reasonable compared with "real" lathes. My boxford for instance should I think be fitted with a 1/2hp 1400 rpm motor. The max speed is 1300 rpm so I will get close to 1/2 hp at that speed. The biggest difference though is that at 650 rpm I still have 1/2 hp as torque has been increased where as the fictional 2hp variable speed set up would also give around 1/2 hp at 650 rpm, more usual actual power levels a lot less. Joe public seems to be completely unaware of this factor unless some one spells it out to them. It's the same situation with inverter drives.

I've fitted a 1hp to it as I also fitted an inverter. More heating up capaciiy and the same torque at 1/2 speed that I had and can there for use for short periods.

Doh got some number sums wrong but some should see what I mean.

John

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Edited By John W1 on 13/10/2015 18:36:35

More progress sorting things out. Got to taps and dies. I haven't a clue how I have ended up with so many 0BA taps. Many more to go and hope to have room to add some smaller dia imperial reamers. My metric ones are cased.

I've scrawled the values on with a marker. Not looking forwards to wiping that off and printing labels. I hope to store small quantities of some nuts and bolts in it too but weight might mean bracing the back. Hopefully tapping drills will fit in most of them.

John

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Not sure Jason I thought it would take 10mm / 3/8in holders but could be mistaken. On a Taig I used to use it to mill down the shanks on the smaller brazed tip tools. Also a 1in holder milled down to 1/2 in or so on another lathe in the very early indexed tip days.

The sets come V pointing forwards, angled, left cut / face and right cut / face. He might have problems facing with V forwards. Maybe some one could mill down holders for him if needed.

He can alter tool angle with the compound slide. He needs to look at that aspect carefully before buying.

John

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I've suggested Brian use these which work out at just under a £1 a tip with VAT but the cheap holders that they will fit usually come with coated gp ones of the same type or more usually worse.

**LINK**

Use - aluminium and stainless finishing. That should cover most things.

Your correct though Jason. Brazed tip should work out a lot cheaper as little should need grinding off.

Edit - The 4 corner versions cost about the same but holders may be a problem at Brians size.

John

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Edited By John W1 on 13/10/2015 17:01:36

Quoting the input power is pure and utter rubbish Ketan especially as efficiency can vary. This has no bearing on temperature at all. The only way it could be justified is on brushed motors. These will tend to produce what ever power is needed right up to them burning out so a short term rating based on input might work out. Short term is likely to be very short. Perhaps one aspect that is missing from just stating output power is the word continuous. Some motors can be run continuously at their maximum rating for ever. They will get hotter so a "real" motor specification will also mention a maximum ambient temperature and the expected temperature rise when run at full power. Some makers motors are more conservative than others.

There is another way of spec'ing motors. Common on a number of things and not always mentioned. It often is on cheap bench grinders which of late do seem to spec input power. So many mins on and so many off - usually a lot longer as things cool very slowly. The input power does directly relate to the heating effects as does efficiency. This is often one of the factors that set the price differences between professional as against amateur / hobby power tools. When the figures aren't given the manufacturers are making assumptions about how the tool will be used. Some just make the amateur version less powerful and perhaps a bit more flimsy but this will still cost more than the well it's only going to be used for a few min brigade. As an example in a rush I bought a cheap 4in angle grinder from a DIY store as I needed to chop up a stair lift in a hurry - it failed on the last cut. Maybe 20min of continuous use. My Bosch one wouldn't even notice this but I didn't have it with me. My unusual industrial Makita would do this sort of thing all day long. Another example. B&Q were selling Ryobi drills at one point - with a different make of motor from the USA fitted. Burn out the Ryobi one - very unlikely even if stalled for short periods but the American one was a lot more powerful and probably cheaper too. Ryobi now probably make and fit motors similar to the American ones in order to be competitive or maybe the motors are still changed.

Lathes/mills - I don't think an input power is of any use to users on this sort of forum. It is very likely to be used for extended periods that make the hobby use only a silly thing to say - they should buy something else but instead I suspect they get over heat sensors one way or the other. Maybe electronic current measurement as that is cheap to do indirectly these days, simple to use chips are available.

Some retailers will sell ac motor 3 phase inverters in the same way but the problem is different. Yes set any speed you like. Higher than stated speeds might burst the motor. Low speeds will overheat the motor if significant power is extracted for long enough. The current levels as far as the motor is concerned doesn't vary - the speed of the cooling fan does as will the torque that is available for cutting. TEC are about the only people who show graphs of what can actually be done - if that particular catalogue can be found.

My Ryobi radial arm saw has a key which I always remove when not in use. They don't make them any more. Pity really but they were intended tor on site use and a dust mask and ear defenders are much needed when using it. I'll stick to the fuse - copper wire fuses very very quickly if needed so providing the wire in the fuse is a suitable size all is ok.

John

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I don't use polishing cloths in a lathe. It's a bit sad that some schools did this as it will have an impact in all of them what ever is used for polishing. There is nothing safer than a decent length of emery cloth strip and it's what's been used for this for a lot longer than I have been around. Strips of cloth of sufficient length would be ok as would 3m film cut into strips as needed. There is only really any need to hold the ends. I'm sure others do something else at times as I do but ..............

Bores can be managed with some sort of stick with a slot in the end. I usually use a piece of bar. Afraid I don't but a hand on the end. I might even mount it in the toolpost but it wears very quickly used like that. It can make a very efficient multi point cutting tool especially if rather coarse.

I looked at buying a more modern boxford recently. Ex school from a company that visits lots of schools doing machine maintenance for them etc and also buying machines of them. Manual machines are now very thin on the ground, mostly gone. CNC rules as it's completely enclosed. Sad and mostly down to silly practices that can easily go wrong plus the precautionary principle. One's been mentioned a couple of times - ties is workshops - where the hell were the overalls which should be worn anyway.

One handed filing is amusing. Have a hand / fingers on each end and it's rather difficult to get it to catch anywhere providing it's a suitable size for the work that is being done.The worst thing to do is use a needle file one handed and have the end catch.

People shown in photo's with there head close to a running lathe and no safety glasses is why B'ham has it's very own dedicated eye hospital with no appointment needed. Urgency was gauged as people came through the door. I've known several people who needed a visit sometimes days after the swarf went in - painful as the skin grows over it. It can happen no matter how far some ones eye happens to be away from the work but if a lathe is spitting little hot bits about something is wrong somewhere. I feel that the problem can be much worse when milling.

John

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Edited By John W1 on 13/10/2015 15:01:00

I didn't have any problems using them on a Taig Ian. I had to mill the shanks down on it to get them to fit. I put the ML7 problems down to rather loose headstock bearings. That seems to be correct. Due to the clearance angle on them I think a bit under centre is important. Thou's as usual but if the bearings are loose the work will lift anyway and then it becomes important to keep the feed rate up to keep it firmly up.

John

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Both Ketan - as all "real" motors are marked. I feel output should always be specified as efficiency varies. It pretty clear than many areas now use input as part of the numbers in the spec game. Some areas even involve a time limit. I had noticed that you state output.

Input may have it's uses too. I have a Ryobi radial arm saw with a universal motor. Fine but a jam always possible with this sort of saw would blow the motor rapidly. To prevent that I fitted a 5amp fuse. Mains fuses blow above the rating so it cuts ok. Periodically when I start up the fuse blows as they wear out over time - much better option than having to buy a replacement.

John

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I wondered if he has loose bearings Ian. Same setting recuts are a sure sign providing the bar isn't bending. Past that it can be difficult to find out what the problem actually is. I'm reminded of some one that reckoned his tail stock was out so lapped it and then from what he found looked to be really down to a warped bed which would also give a taper turning without the centre in.

Files / emery cloth may well be the best answer.

Anyway the person seems to have gone. Maybe he found something more positive in the early postings some where else.

John

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One other thing about ER16. The straight shank holders can be obtained 200mm long. I reckon 150mm doesn't leave much space for a pulley etc. eg

**LINK**

The only ones I can find in the UK work out at £30 odd with a spanner that looks like it would be needed.

John

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If you make a spindle it's worth mentioning a method of locating bearings. Designs often have a pocket machined in each end. This needs very careful setting up to do each end as the bearings need to be square to each other. The unimat has the bright idea of locating them against circlips. This means that the hole can be bored and the grooves for the circlips added all in one setting. That will make the joh easy.

Another way but it would take some experimentation is to use oil lite bearings. They are porous phosphor bronze impregnated with oil. When they are pressed into a hole they usually come out undersized. ER extension collet holders can be bought pretty cheaply. The od of the plain shank is generally under sized and with some trial and error it might be possible to get the oil lites to size correcty for them. The bearing are cheap so it wouldn't cost much to try.

ER 16 is probably a good size to use. They cover 1 to 10mm. Some people have thought of running them in ball bearings but the under size aspect makes that a bit of a problem. Maybe loctite could be used to centralise them or short sleeves made that size to the bearings and shaft correctly.

John

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I was looking for sub micron accuracy Bazyle. Mad I know but fitting 2 gears isn't that bad. Part of the reason was to shut up the must have the 100-127 compound as it's more accurate when approximations crop up.

The gears I have which I assume are all standard are

I will have another go at getting more relaxed tolerance ones at some point using standard gears but currently mustn't get even more side tracked from tidying up. I'm finding it hard to stick at it. Nearly 30ft of extra shelving and I am still having problems.

John

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Edited By John W1 on 13/10/2015 10:58:23