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Member postings for Clive Foster

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

Thread: Single phase to 3 phase motor conversion.
04/06/2020 09:57:49

Thats a nice little milling machine, AEW Viceroy / Horizon. The motor in your pictures will convert to delta for a VFD just fine.

I see why a converter was used. Two motors. 2 hp on the spindle and 1/3 rd hp on the power feed I think.

Conventional wisdom is that VFD boxes should be used one per motor to avoid large power variations, switching issues and things likely to get their electronic knickers in a twist. More so with modern ones which tune themselves to the motor as an effective way of improving the speed range over which the power holds up well.

However I think it possible that my favourite, for simple installations, Eaton DE1 series can cope with two motors as they are supplied as a simple alternative to old style contactor controls and are more tolerant of "less than ideal" fitting. Its possible that the 2.2 kW version (£140) has the overload capability to handle the power feed motor being switched in with the main motor running otherwise you'd need the 1.5 kW version (£121) for the main motor and the 0.25 kW (£65) version for the power feed. Always assuming the feed motor can be connected delta too.

See **LINK** for the Eaton range.

I'd contact Inverter Drive Supermarket and ask what they suggest. I've no affiliation but have had good service myself and they have a stellar reputation for helping folks who don't know much about such things to make a good choice.

If going for two VFD boxes you may be able to do it more cheaply but best to avoid anything that doesn't have a proper English manual or UK native back up. IDS do wonderful easy set-up guides for some of the ones they sell.

Clive

03/06/2020 20:58:10

Boost button forces a large phase shift on one leg to get the motor moving against a load. Off load the motor may well be able to start without the extra capacitor in circuit.  Even with the boost such converters are usually only able to start the motor under modest loads.

£50 sounds a lot for a start capacitor. £15 - £20 is more usual.

But these converters are brutally hard on the start capacitors. Especially if they don't have an automatic control relay to bring the start capacitor into and out of circuit. Robert probably has the figures but modern, affordable, ones are very short term rated, maybe 30-40 seconds from turn on to pop.

Short term runs with lots of stops & starts is going to kill one quite quickly.

Time to pull the plate off the motor and investigate if it can be re-wired from star to delta. If it can invest in a VFD and unload the converter "spares-repair" via E-Bay.

Eaton DE-1 is easiest VFD to do a basic install on if you just want to run the motor at its set speed (or can do without a spiffy display) as it basically just works off a switch like the usual contactor controls. Anything with an Inverter Drive Supermarkets easy set-up guide is nearly as easy to install but you will probably need some extra bits.

Clive

Edited By Clive Foster on 03/06/2020 21:16:43

Thread: Storing & Documenting Your Tooling?
03/06/2020 10:40:36

Only 30 cutters. You haven't got a problem!

For boxed cutters I'd just cut some grooves in slide out plate shelves just wide enough to hold the boxes. Mark size on the shelves. Have somewhere to always put the box when working. Rule is cutter in machine or in box on the shelf.

Spreadsheet list is a good idea to help keep track of what you have. Especially when E-Bay surfing. New, unused cutters have there own storage box.

if you have lots (and lots) of unboxed duplicates as I have you need a system to ensure that you only use one cutter in each size / type. Best answer there is probably dip coating on all except the ones in use. My system sort of happened and isn't good but more or less works. Another one on the fix it when I can take a month to organise the shop list. AKNA the never happen list!

A trickier issue is keeping track of how much machining time you have on carbide inserts and which edges have been used. On home shop duties you can get weeks or months out of an insert edge so its easy to loose track. Especially on the ones you don't use much. I have a couple, rarely used but when I need them I need them, which haven't been changed for years.

Clive

Thread: Are there any published Torque settings for BA
02/06/2020 17:59:06
Posted by Neil Wyatt on 02/06/2020 17:29:28:

0Ba should be similar to M6, as it is same pitch and diameter.

Yep according to Tubal Cain 144 lb inches as opposed to 142 lb inches. But who will notice.

For all practical purposes steel BA and small metric can use same torque settings.

Interestingly he gives only 108 lb inches for 1/4 Whitworth. Presumably due to the core diameter being around 3/4 of 0BA. The ratio of core areas being very similar to the ratio of torque.

I guess thats further proof that the design intention is that the bolt should always fail before a good thread in the same material. Reality often being different.

That said 0 BA is not a size to keep in stock. It screws in, loosely, to 1/4 BSF, 1/4 UNF and M6 making a weak joint that is prone to undo at the slightest provocation.

I know we all know better but I've got to the stage of wondering why the spanner didn't fit before realising "Stupid, dangerous, mistake about to happen.".

Can take a few years before you finally admit just how effective "want to get this done tonight" and "this is the only one I have so I'll use it" can be at turning the rational part of your brain off.

Clive

Thread: Oscilloscope kits - any recommendations?
01/06/2020 18:29:30

For pulse timing applications the more channels the better, within reason.

Chasing timing errors down with a two channel scope can be a miserable experience because you pretty much have to devote one channel to a reference so with several potential pulse string to pulse string error possibilities you are forever swopping around. Not ideal for the inexperienced.

8 channels are much nicer in my experience but then connections can be difficult. Once all hooked up youhave a clear view tho'. I often found 16 too many.

Bigger screen helps.

Ideal for pulse timing and similar would be a very limited box able to display pulse trains linked to a tablet for the display and control. At modern electronics prices a one job tool is viable. Needs to be buy, not build, with robust software and a manual.

Clive

Thread: Machine Tool Peripheral Hoists
01/06/2020 15:38:58

Bill

Considering the seemingly "permanent" contents of my work cart counterbalancing oughtn't be a problem for me. If more than half the top tray is clear I hear muted screams of "turn off the light". Two shelves and three drawers in addition to the top tray are seriously tempting. My version of Pooh Bears "useful pot to put things in". Appropriate I guess as Ashdown Forest is only a couple or three miles away.

Seriously a paving slab bolted underneath at the opposite end and a bit of orientation intelligence in use should suffice.

One thing that has hung me up over the design is wanting a longer jib so the crane can be used extended over the cart if anything hefty has to be lifted. But then it needs an extra fold so the hook can be set close in when working away from the cart. Do-able but I'd rather not have a 3 ft double pole sticking up on one corner. Then there is the controlled adjustment needed so whats been lifted can be dropped on the cart. Overthing, yup.

Clive

31/05/2020 18:07:37

Nice job Bill.

My feeling is that something of that ilk fitted to a work cart would be far more generally useful than something that needs to be specifically set up for each job. Sufficient reach to handle a lathe chuck or vice - dividing head - rotary table on the mill should be no problem.

On a rolling cart it also becomes very useful for the "really a two man lift" or "20 (30 in my case) years ago I'd have lifted it no problem" things. Several backs of envelopes and a couple or three years into the thinking I'm reckoning that something very similar with folding jib to get things out of the way when the cart is normal use and using my battery impact gun as the power source is plausible way to go.

In a practical world 150 lb or so lift ought to be plenty. A tolerance ring can make a nice emergency overload clutch.

As usual with like to have, rather than need it now, jobs feature creep and design refinements are getting in the way of do-it now. Fact is if I knew I wanted one on Thursday it would be done tomorrow. But for now I keep noodling.

Clive

Thread: Parting tip breakage
31/05/2020 10:38:20

Jason, agreed that Koroly say that style of insert can be used for parting but they use different final letters for the parting tools. PT for parting tough, PS for parting sharp. The others are M for multi-turning, G for grooving and A for aluminium. Clearly different shapes.

At around £15 an insert folk like us are unlikely to spring for the real thing.

Problem with the look-alikes / fit same holder breed is knowing exactly what shape they are and how appropriate they are for our machines. I suspect the profile would be something a long Koroly M or G so chip evacuation will become an issue on deeper cuts. Doesn't help that the real thing is designed for production at warp speed 6 on modern, ultra stiff machines. Chip behaviour will be different on our lighter, slower, machines and the insert is designed to exploit the way it actually behaves.

I find it interesting that the maximum depth of cut for the Koroly parting tool holders is around 1/2", there are a couple going out to 1" or so. The holders are also integrated types rather than blade. Suggests that stiffness is important and the design isn't optimised for deep cut chip evacuation. Whether intrinsically so or just at warp speed 6 I know not.

Realistically for folk like us the important thing is that the tool is sharp, cuts freely and that the chip comes out cleanly. I've no doubt that a properly selected insert in this style held in a decent holder and presented to the work in an appropriate manner, which probably isn't book speed, can work just fine. But getting that sort of thing right tends to be a little over newbie pay grade.

The issue I have with whole the "get the new super duper insert and your problems will be over" is that folk tend to keep repeating the same old set-up and operation errors so no insert, how ever super duper, will solve the problem. Wasting money and time. When it comes to parting off to any depth errors can be subtle.

I shudder to think how much time and money I've wasted over the years trying to spend my way out of issues when the right approach would have been a solid weekend of teach yourself training on what I'd already got.

Clive

30/05/2020 23:14:08

As I understand it MGNM was a Koroly own brand style and specification of insert. Other makers seem to make look alike and compatible fit ones these days.

Koroly always seem to have made specific distinction between parting off versions and grooving types. Although the grooving / profiling types are said to be strong against side forces the book illustrations I've seen imply that cutting depth is limited. Ideally the support blade shouldn't enter the cut. Can work your way deeper with profiling of course.

Even the parting types don't seem to be expected to go very deep. But they are said to be for fast turning.

Speed of course being a major issue when it comes to chip evacuation form a narrow parting tool groove. A blue hot, heat softened chip cut at high speed behaving very differently from a relatively cool one taken at lower speeds. As ever the issue is that the chip is wider than the groove and will jam at times unless due precautions are arranged. Carbide tips are generally arranged to cut a Vee shaped chip which is narrower than the groove. Sharp cutting points at the ends of the Vee encourage the chip to fold. Radiused corners make the insert much stronger for profiling duties but the chip doesn't fold so well.

Putting an angle on the end of an HSS blade makes the chip even wider but sets it at an angle across the groove so, theoretically, it twists rather than jams. Lubrication helps as does taking a continuous chip. When I have issues with such its usually when the chip breaks fairly deep in and the new chip doesn't twist sideways cleanly to come out of the groove.

Clive

30/05/2020 19:59:22

Looks to me as if the top slide wasn't locked so any sideways force generated by imperfect cutting would pull the topside through its backlash region. Setting the topside parallel to the bed on a light machine is asking for trouble.

A grooving tool like that is going to be pretty pants at parting off anyway. The shape guarantees some degree of chip crowding as it comes off the work. Piddly little brush will do nowt. Needs full flow or carefully directed mist to come out clean.

Proper parting tool inserts are Vee profile at front and top with two points at the business end. These fold the chips so they re narrower than the parting tool slot allowing them to escape. Must be run at the correct speed and feed otherwise even these will give problems. As usual with modern carbide in relatively benign materials chips should come off in short tight coils.

Parting is enough of a pain at the best of times if you can't run fast with full flood coolant. Why compound the difficulty by buying a cheapskate version of an improper tool. Buy cheap, pay twice. The real this work very well when properly aligned and set up. Much of the advantage of the rear tool post type on a small lathe is that it gets set-up properly and left alone. Not topside to set wrong too.

Clive

Thread: Optical Chucks
30/05/2020 18:04:26

Many years ago I bought an inexpensive microscope from LiDL intending to convert it into a centring microscope. All the basic optics there including a main eyepiece tube laid back at a suitable angle with a deflection mirror. As I recall it the body was in two parts with a horizontal joint below the deflection mirror between the eyepiece end and objective end.

Plan was to re-work the objective end to remove the turret and fit a single cheap, lower power, objective lens of the type used in engineers microscopes. In the end I just got cleverer at exploiting the DRO and centre finders so never had the practical need. If I ever do have that need the project will get done. Fast.

Pretty sure they come up most years for £30 (ish). Must be a metric boatload of affordable similar, if not merely the same with a different badge, on E-Bay, Amazon, Bangood, local free papers et al.

Clive

Thread: Frustration in taking photos using my Galaxy A20e mobile phone
30/05/2020 09:55:52

Captain Obvious here. Have you cleaned the screen properly?

My iPhone has occasional issues with not seeing swipes et al despite the screen looking really clean. Giving it a good go over sorts it. Was annoyed first time it happened because a clean didn't sort it. Eventually decided to have another go.

Clearly its picking something up. Probably shop "grease". I may have to invest in a cover. Allegedly you need to wait a while after using hand cream. Feels fully dry to you isn't fully dry to the phone.

Not all apps respond the same to fingerpoken. Timer and swipe to answer use more or less the same part of teh screen on my phone. Timer is never an issue, swipe to answer is first to glitch.

Clive

Thread: Workshop Gloves
30/05/2020 09:48:24

As I understand it its not so much the proper, around your hands, glove part thats the real hazard.

More the cuff.

Even with a fragile nitrile or whatever glove, due to the directions of rotation and normal hand orientation, if that gets caught up its likely to roll up into several layers and become much harder to tear.

Generally hate working in gloves on mechanic or other appropriate jobs myself. If they are thin enough to let you feel whats happening they are too weak and tear all the time. Sweaty too.

I'm lucky. My hands are naturally dry and the skin toughens quickly.

For clean up, sweep up et al duties I buy the cheap work gloves from LiDL 'cos they have proper sizing not just S-M-L-XL. They keep changing the design but all, so far, have been fine.

Clive

Thread: I have a Fobco Universal MT, can it be used for milling?
29/05/2020 11:43:24

As Andrew says the issue with using the Fobco as a mill isn't spindle strength and cutting ability. Its downfeed control. The spindle is plenty stiff enough for small machine level modest cuts in the sizes of cutter appropriate to its speed range and collet size. Face mills and flycutters would be "optimistic" tho'.

But setting depth of cut to the sort of precision needed for most milling will be very difficult. With the drill style depth stop its clearly designed for bringing surfaces to a constant level and similar duties which it will do well.

Better depth setting control would seem an ideal application for the little integrated display pull wire sensors the BW Electronics (used to?) supply. Compact and easily fitted they would make it possible to set the depth of cut quite accurately. I have one on my Bridgeport quill that has worked well for many years. Not perfect as it can suffer from vibration but I use it to set the depth stop before starting cuts, much easier than the micrometer thingy. Unlike the Quillstar et al it doesn't get in the way if you want to use the micrometer.

Clive

Thread: Machine Tool Peripheral Hoists
28/05/2020 23:04:21

I know exactly where Cabinet Enforcer is coming from and, to be honest, I have some sympathy with the European approach. But the men in Brussels do tend towards remarkably selective blindness. You only have to look at the things masquerading as jacks supplied with cars for the last couple of decades and more to consider that there are areas where a bit more applied legislation would be appropriate. The thing supplied with her-ladyships L322 Range Rover (now recently departed thank God) pretty much re-defined inadequate. I'd be worried lifting a pedal car with it. At least my lovely P38 Rangie has a properly strong bottle jack in the back. Admittedly you still have to be careful to ensure it won't tilt but atleast its not going to collapse on you. I'm told the L322 one isn't the worst out there either.

A half decently engineered plug in the side, run up a screw, type always seemed best to me. Lancia did about best of breed for the HPE.

Getting back to the Sky Hook I'd say anyone who couldn't slot that in adequately safely would be dangerous in chage of shoelaces. Realistically the 500 lb load capacity seems far to high for lathe chucks, mill vices, rotary tables et al. 100 or 150 seems more the mark.

When it comes to lathe mounting it needs a T slotted cross slide. These seem to be the norm in the USA but less common in the UK and Europe so less of a potential market.

A work cart mount version is what I'd want as my workshop is too large for Duncans unistrut or similar beam to work sensibly. I'd need about three I think in addition to the two heavy lift crossways RSJs that seemed a good idea when I built it.

A tube bolted to one corner of the work cart with the Sky Hook sat on a similar, slightly smaller one, that could be dropped in when needed ought to work. Worm drive gearbox I think so no need for a brake. Power it from a battery drill via a 10 mm / 3/8 or 1/4 hex spigot shaft. That handwheel would get seriously in the way when storing.

Clive

 

Edited By Clive Foster on 28/05/2020 23:05:22

Thread: Tapping stainless
28/05/2020 20:53:48

david

I'm now a fan of serial type taps for this, and frankly, most other sorts of thing. Noticiably easier to turn so, presumably, less likely to gall up and break.

I get mine via E-Bay from davethetools. Vokel brand and recommended for stainless steel.

Clive

Thread: Arc welding rods
28/05/2020 19:15:24

I've not found moisture a problem for rods kept in house dry conditions. In shed workshop days they lived in the bottom of the airing cupboard. My current workshop is well insulated and built to "you could live in it standards" so the rods live out there, albeit wrapped when in the cart and boxed when in store under the office section desk.

Big Mac Pro tower lives under the desk too helping keep things a touch warmer.

Frankly its fluxed brazing rods that I find to suffer more.

Clive

Thread: I have a Fobco Universal MT, can it be used for milling?
28/05/2020 19:08:10

As I understood things the "milling" capability on the Universal MT was aimed more at surface preparation to get a clean start with a hole, minor cleaning up for bolt head / nut seats and making spanner room. Possibly gasket seatings too.

Light work that saves the time needed for a set-up on a proper mill before the drilling work.

Milling out a complete part, unless very small being a bit beyond its normal pay grade. As ever with care you can push a machine well past the prudent limits established by the maker who has to think in terms of Penelope Piecework in search of a decent bonus in this weeks pay packet.

The operative word being with care.

Clive

Thread: Machine Tool Peripheral Hoists
28/05/2020 14:02:36

I imagine that the stress is actually fine. Real world things tend to be much stronger than you think when properly installed and undamaged.

Allegedly you can lift a grand piano via one high tensile 6 mm bolt! Don't care who did the calculations I'm not standing underneath!

Doesn't seem to be any UK representation.

I guess they are basically a chain over a sprocket, with suitable keeper guides, system driven by a geared winch and brake.

Personally I think the work cart mounted variants are a better idea **LINK** but I have more room to manoeuvre than many folk.

Clive

Thread: What size lathe would I need ?
28/05/2020 13:43:50

Nice picture Martin.

A superb illustration of how to set up a larger billet job on a relatively small machine. Especially when it comes to showing the "maximum safe" overhang of the chuck jaws and why you dont try to hold a billet of larger diameter than the chuck from the outside.

One for the "1,000 pictures of machining set ups" book that someone really ought to compile for the guidance of newbies.

Entirely agree that the job can be done on a smaller machine. Just like you I could happily do so.

But with an inexperienced driver I think the larger chucks associated with bigger machines will give a much more secure and safer grip.

New guy probably won't realise why you need that centre there with a smaller machine.

On a Triumph 2000 or M300 you can safely just have at it. The greater power at the spindle is dangerous but I feel that newbie will be apprehensive at the quantity of chips coming off long before crash time. I know I was ahem "worried" the first time I was shown what a Triumph 2000 can do when in the mood. Major step up from a Pools Special!

Of course there is an element of "persuasion to take the job seriously" in recommending a bigger and expensive machine. I've picked up the bits atime or three from folk with expectations wya beyond the capbilities of a bargain.

From an engineering viewpoint I dislike the sort of adapters shown by Jason. To easy to think of as a bolt on rather than something that needs engineering into the application.

Clive

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