Member postings for Ajohnw

RsComponents isn't a bad place to look to see what is likely to be close to or actual industrial standard. They can be good on price at times as well. For instance I needed a specific left hand metric tap. Finished up buying a boxed German made set that they sell. The cost of this compared with an industrial branded high spec tap was higher but they are good taps. Pity they don't do some dies at similar prices to go with them. Not connected but I bought 2 dies for them from Tracy tools, HSS and split. Not what they advertise generally but they do stock a lot of industrial grade items as well or will get them. Can't say I was happy with £20 each but I could have paid a lot more.

Relating to another thread RS sell Stanley vices. Steel is mentioned on some of them at least. The fact that they sell them as they do have a lot of industrial habitual customers is a good indication. They also sell RS branded ones - a bit ouch. Record too. If they did a drill set at a moderate price I would buy without any hesitation. They tend to sell off things that turn out to be iffy rather cheaply eg I have masses of adjustable voltage regulators, Chinese brand, spec is awful and the parts probably worse but they will do for what I need. I often get electronic bits of them or Farnel because of the amount of out of spec stuff that is around at times.

John

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If used and not sharpened a set of Dormer drills wont last a lifetime Neil. The screwfix ones will work, may need a little bit of care to avoid breaking them and will need sharpening at some point just like any drills.

I have 4 boxes of drills. 3 of them I only use when really needed. One box gets used at all sizes. They are all still fairly sharp, a couple of fine ones broke in a hand drill, I replace them from a box of n of each size up to 2mm if I remember correctly bought off ebay. When I do this I mic them as the sizes are often a touch under. The 3 I use at times when I need a specific size are 1 to 6mm in 0.1 steps and a set of number and letter drills bought from Tracy tools a long time ago. The use all of the time set is 1 to 13 by 0.5mm tit' coated and bought at moderate cost from a local now closed diy tool types store. Taps can be a bit tricky - I have bought several drills singly for those. There is no need to buy drill sets to cover the range I have. I also have a set of blacksmith drills up to the usual 1in dia.

What to do when my use all the time set has had it's day ? I'd probably look at a similar set off screwfix or similar. There is too much trading on a name these days.

Comments on lathes earlier - I haven't visited one of the well known suppliers for about 12 years. At that point they were fully aware of the problems with them. Go back 20 odd years and small lathes tended to be a lot better in all respects and were still cheap. I was having a bad experience with a Viceroy at that point, too much bed wear really but worst of all impossible to adjust the bearings. Oddly I came across a college lecturer that had the same problem so sold the lathe while it was more or less still ok.

John

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As a through and through Brummy I didn't think that comment about B'ham was correct. Out of curiosity I googles birmingham uk silversmiths and 7 popped up all in the jewelry quarter on the map. There will be more around. A cousin married one and as far as I know he is still happily in business. Pure hand work.

There is a museum of sorts there but what has happened over the years is that the jewelers who also had a shop where people could go and discuss their wants, design, quality etc have all gone. There are a number of shops selling jewelry. The trade supplier people are still there and I understand that there are still jewelers at work but people want lower prices as usual and aren't prepared to pay for what are often jeweler specific designs even with top quality stones if some one want that sort of thing. Crazy really as prices were often well under what would have to be paid at the usual hight street stores.

Talking to some one in London recently the same sort of thing has even happened down there.

John

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Without paying for them it can be difficult to know what various standards actually mean. They also have a side effect. At one time things were often made as good as they could be. Standards are generally agreed and no one wants one that will be difficult to maintain, This touches on why some industries want to remain in the EU. They will still have input to what ever standards are of interest to them. The standards are derived via discussion and odd as it may sound this often results in them being looser than they need be.

There are questions a buyer can ask. Take collets. I understand that run out should be measure 50mm from the end of them not right at the jaws. Similarly the important aspect of a collet holder is it's axial alignment. Just how that is spec'd pass.

The worst aspect especially on small machines is the design. I had a small far east miller at one point. It was just about ok. The next iteration doubled the width of the table and left the rest alone. I doubt if that would be ok but the spec looks better. The same sort of thing has happened to lathes. Shorter head stocks and tail stocks to make the centre distances look better. People might find that the tail stock is so short that it's impossible to turn up to the end of work with a centre in it. i did try one Chinese lathe that turned out to be like that purely down to the centre distance being increased by 50mm from what it used to be. The head alignment was hopeless and add's stated hand scraped tail stock which it was but that didn't mean that the alignment was any good. It was nothing short of hopeless really. There was a fad some time ago where spindle run out was specified - at the nose, meaningless. Run out needs to be specified some distance from the end of the spindle and also via a between centre test bar. I also understand that unhardened bearings are generally used. Not too much of a problem when they wear out as it should be possible to fit hardened replacements. Not super precision though which will influence how accurately the lathe can turn. Short head stocks don't help with this aspect.

John

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You say 0.4in cut - 0.8 off the dia ?? - rather a lot for a Myford really assuming free cutting mild steel. From memory the auto feed rate on a Myford is sometimes rather coarse so how much per rev?

To give you some idea big DSG 5hp motor, 3/8" cut, bad chip breaker that crunched up the swarf rather than just broke it up, 1/64" per rev but the swarf measured more like 1/16 due to the breaker, blue swarf, bar around 5in dia and the motor really sang. They do when working hard and make a very distinctive sound.

A photo of the tool tip you are using might help as well.

John

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Edited By John W1 on 22/06/2015 15:40:34

I suspect you have a gear on the top stud and nothing on the bottom stud. You might find that the bottom stud is effectively a direct drive to the leadscrew for cutting odd pitch threads if the change wheels are available.

I have done a lot of turning on a DSG but didn't need to mess with change wheels, only gearbox settings so didn't even look at what was behind the cover. One interesting aspect was cutting a thread that on most lathes would mean that the screw cutting indicator wouldn't be of any use. It was on the DSG.

John

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Myself and several others were given the exercise of turning a morse taper adapter, 3 to 2 if I remember correctly and also provided with accurate gauges to test them with using raddle rather than blue. Resetting the compound slide by truly tiny amounts was causing everybody a lot of grief. I went to the stores and got a dti and stand and used that to see exactly how much I was moving the slide by. Job done in no time at all. All of the other people quickly did the same.

John

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My father told me that there were variations on a V and flat lathes beds about well prior to WW II.

I would like to see a close up of the whole angle setting area and one of the lead screw dials. I have seen a lathe some where with the angle scales and a long pointer like this one but as there appears to be 2 scales I'd be inclined to think that in this case it's an add on. Also from it's appearance I wonder if the slide rest actually belongs to the lathe, Is the slide rest fitted to a block which is shaped to fit the bed and also looks like it has more age in the same way the other bed fittings do?

John

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I think Myford's statement makes a lot of sense if everything is perfect, less messing about. Trouble is following use things probably wont be perfect. There seems to be some ancient law about how lathe slides should be set up - rather loosely. That results in faster wear and even bent gib strips, same problem as guides that can tilt, pressures are applied to small areas. I suspect the main reason this is done is to reduce lead screw wear and if high class work is needed the slides can be tightened up just for that purpose and then loosened off again. I'd guess that some lathes never get tightened or even set correctly in the first place. Not that the usual grub screw and lock nut is that easy to set anyway. Taper gibs are much much better in that respect.

I set my slides on the firm side and expect to have several goes at it before things settle down. I start by setting all screws moderately tightly to take out play and then backing off. If the cross slide tightens a bit when wound right out I accept that as I feel it's a better option than more play and higher wear rates elsewhere. Ideally I think slides should be set with any lead screws out pushing by hand. Some lead screws provide a lot of mechanical gain.

John

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I can't see the point in leaving a recess either. An ideal taper pin in say a machine handle would just show a slight dome at each end and no sharp corners. A simple tap on small ones via a suitable drift will loosen it sufficiently for it to be knocked out easily. Larger ones are much the same even when driven firmly home. They don't need hammering in that hard really due to the fitting pressure gain the taper gives.

John

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Not sure what you mean about width Neil. The idea is bound up in aspect ratio really not width. The higher the better. Accuracy does come into it. Going back to my hole at 1 dia long it can tip by so much and if pushed it's likely to tilt by a certain amount causes wear in localised spots. Make it 10 dia long and it will probably take less effort to move it in practice as you point out but wear will be at a much lesser angle for the same clearance. In terms of accuracy there is no getting round the reduced tilt the arrangement can offer.

To me the correct term for an inverted V bed is a prismatic one. The other type that has been common is the dovetail style still used on the slides fitted to the saddle. Myford style - never come across a common name for it and it's not one that has been used that often. I should add that for some reason it works a lot better on a Raglan. I suspect that is down to a combination of factors. All sorts of odd things can go on when the saddle is moved when there has to be some clearance. For instance the tool may move inwards when cutting forces are applied and outwards when the rack and pinion is used to wind back to the start of a cut. On a prismatic bed the tool just stays were it is. Other than any oil film there isn't any clearance. Dovetail beds have the same problems as Myford style especially as they implemented them on their more recent lathes but like prismatic beds it's easy for them to offer larger wear faces than the ones on 7's. They could have made those a lot larger. I will always wonder why they didn't sort them out, maybe using a square section front rail in the extreme and even fitting wear strips to the saddle. Given their fame I feel that they would still be about if they did the right things to their lathes.

John

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I notice that some of the Stanley vices mention steel rather than cast iron - it's stronger. I'd guess this touches on why my G-clamps broke as well but the term cast iron can cover all sorts of variations.

John

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I'm away from home Michael but I will dig it out when I get back. Like most books on something basically simple I wouldn't describe it as money well spent. I found mine in a 2nd hand book shop.

I'm very critical of Myfords bed design. The aim with mine after many many hours trying to improve it was to send it back to Myford for a saddle and bed regrind along with a saddle refit. The later is an incredibly fiddly job. The Boxford came up so sold it to a friend for very little and told him what to do. He didn't and Myford went bust. I'm not at all sure that conventional regrind services are a good idea on a Myford. They wont set the lathe up accurately so take heavy cuts and then use stick on materials to make the sizes back up. My father had an answer to that but people who work for large companies and put a lot of work out can waive a big stick.

There is one reason I can think of for Myford changing. When the saddle's reference edge is the inside of the front rail that part of the saddle can't go past the tailstock or headstock. This limit's it's length and also has the problem that cutting forces are applied largely to the corner of the saddle guide nearest the headstock. That wont promote even wear. By using the outside of the rails the guides can pass the headstock and tailstock and cutting forces mean that the rear edge of the rear rail will become the main guide. Cutting forces could also be taken up within it's length rather than at one end. This might also help the lathe work more normally, pass. When moderately loose bearings and slides spoil the finish the usual answer on most lathes is to take a heavier cuts. The force from the cut takes up play so if the feed is constant finish improves. That didn't apply to my ML7 and I put it down to bed width - too much force down and not enough out so everything needed to be tight.

John

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There is a book about on narrow guides. The principle is easy to grasp - just a round bar in a hole. Say there is 0.0005in clearance and the length of the hole carrying the bar is 1 diameter. It will waggle about by n degrees. Make the hole longer in relation to the diameter and it will waggle less.

Applied to a machine tool the mechanism used to move the saddle is usually mentioned. Ideally it should apply it's forces axially to the guide - not always possible but it's obviously better to have it as close as possible as this will result in a smoother action. Twisting forces and lubrication can be bought into the argument as well. Also on a lathe how cutting forces are applied to the bed but that is also related to the width of the bed not just the width of the guide.

The net result on a lathe nearly all lathes really is a prismatic bed.

John

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Here is a No3 that google bought up immediately, £80

http://www.building-supplies-online.co.uk/record-irwin-no-3-mechanics-vice-100mm-4-in.html?utm_source=googlebase&utm_medium=datafeed&utm_campaign=google-shopping&gclid=CMfyg-Cgn8YCFfMZtAodaA0ACQ

There are probably cheaper sources. Dearer too. Machinemart sells them for around £100.

I have had swing vices swing at entirely the wrong moment while bending things and even when sawing after that had happened a couple of times. Perhaps others have had better luck. Some vices don't grip very tightly as well. My 4in Record is fine and I assume they are still the same.

Personally I feel the material they are made of is more important than size. I once had the bright idea of tightening wood joints up with a large Record G lamp and then fitting a cheaper one and then using the Record clamp further along the joint, replacing it with a cheap one and so on. Did that 5 times over a long joint and thought great and then 5min later each of the cheap g clamps fames broke one after another. This made me wish I had bought more of the Record ones when they were cheap.

Personally if I wanted a 6in pro vice I would be looking for a vintage or even older one

John

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I did realise that. Just pointing out that M threads aren't what might be called ideal for al.

John

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I use M6 screws for fixing Neil - hi tensile of course but all thread too at times. All I would add to that set up is do make sure the work is balanced, which it's likely to be in this case, and also ensure that the screws are resting up against the T slots in the right way to make sure they are in shear as far as the cutting forces are concerned.

Machine like this wont take very heavy cuts at this sort of effective radius so some care will be needed in that respect.

I would be inclined to also use all thread too through the spindle. Ideally bushed at each end to keep it very close on centre. It's not so useful clamped up at an angle. I found this a useful add on for a Taig/Peatol in it's own right but in this case it will help make sure that the work doesn't slip and whack the bed and etc.

As I'd guess you might know in cast iron bsw would probably make a better fixing. Almost certainly so when al is being held like this.

John

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My ML7 bed was hardened but the wear was still significant. Too much so for me. I fitted it with a super 7 head stock at one stage a found the complications associated with that part.

The switch to a wide guide - a crazy idea really explains something I read on Chris Heapey's web pages some time ago. That concerned obtaining a narrow guide on the front rail as I read it by grinding and adding a gib strip. This didn't make much sense to me at the time. I looked at one of the archives of his pages but couldn't find any signs of the comment. It was just a comment. No details.

John

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Record!!. They are not that expensive providing the size is kept down. I just googled record 4in vice. The number 3 came up at £80 and also several sub £40. The numbered ones are the "real" ones. I would avoid the swivel versions also any quick release versions

A lot of the cheaper vices don't open very wide - usually pretty obvious even from a photo as little sticks out at the back.

There are usually a number of heavily built older vices for sale on ebay. I spent 6months plus learning to hand file, wish I still could, not a Record vice is sight. The main thing Recod offer against other modern stuff is that they are made out of far better material than many others.

John

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The wear on top of the rails is usually rather low if it's a hardened bed but it can still be sufficient to prevent a perfect fit when the strips that hold the saddle down are shimmed to suit. This aspect touches on why prismatic beds are a lot better - also the length to width ratio of the guide. It can be a lot higher on a prismatic bed.

As I said it's been a long time but does the tail stock clamp tend to push it up against the inside edge of the rear rail? I might be confusing it with another lathe. I'd hope so as this would tend to maintain tailstock alignment as the bed wears.

While Myford might change the arrangement so that the rear edge of the rear rail also guides it would be rather tricky to use the rear rail in the same way as the front one is at the same time - both sides are used to guide. It would be possible to add a gib strip that runs along the rear edge of the rear rail but this wont really help counteract wear in the saddle and front rail area.

I took lead screw movement to be axial ?

John

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