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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: Linisher cuts out, what to do...?
25/09/2017 00:56:17

I had two consumer units put in my workshop. One with the appropriate RCD and MCB fitments for fixed machine tools with larger electric motors and one with a more normal set-up to several ordinary 13 amp rings. Instead of ordinary wall mount sockets I used 8 way metal clad extension boards for the rings. Two boards per ring. Which I happened to have. Definite overkill socket wise for the workshop but it meant I was able to put banks of sockets reasonably close to where i was likely to be using hand held power tools with no temptation to use socket doublers or trailing extension leads.

If using hand held electric tools I figure each tool should be on an individual switch and all the cables should run forward from your working position so you can see where they are. Obviously sometime you have to go round the other side of the job so sometimes cables end up behind but normally in front is best.

Also had couple of weather proof sockets outside for shredder et al. With a nice lever operated disconnector over the door so I can see they are off except when needed.

Clive

Thread: My very own Quick Change toolpost
24/09/2017 17:22:54

With these small machines you are inevitably on the wrong side of the size - strength curve so its hard to get enough material into the tool post and holders to make them strong enough. The overhang and round the corner load path inevitable with any form of QC system doesn't help.

As regular forumites will know I've always maintained that quickly interchangeable block style tool posts are a better approach for a home made QC system. Especially as they give a direct load path from tool to slide, inevitably stiffer than a conventional QC and these small machines need all the stiffness you can get. Shimming the tools to the correct tip height is pretty much unavoidable with any block system but arranging to set-up off the machine with a suitable jig makes it a fairly simple task. Indicators are inexpensive these days so working by direct measurement becomes easy. Especially if you have a nicely sorted set of shims. Probably generally more accurate than setting tool height on the lathe with a QC system which needs a certain extra care to get just so. Close enuf, usually, being easy of course.

The major issue with interchangeable block systems is how to arrange quick release and how to index the base so they always go back in the same place.

For these small machines a simple pin in hole indexing system should be fine. Put the holes in a suitable intermediate plate rather than direct on the topside to avoid irredeemably altering the lathe. Pin should be double diameter with a screw thread at the top end so it can easily be retracted when you need funny angle on the post.

My concept of the quick release system involves a hollow castellated nut in the top of each block fitting over a rotating tool post stud that is cross drilled near the top for a tommy bar. The tommy bar engages in the castellations so a third of a turn or so covers the range between locked down tight and loose enough to pull the tommy bar out. Stud needs to be around 20 or 25 mm diameter at the tommy bar end which may be too big for these small lathes. Rotating bearing part can be much smaller of course. Similar effects can be achieved with bayonet and spline set-ups but maintaining the appropriate timing between the components could be tricky as there is only a limited angle of rotation when engaged. Interrupted threads have similar issues. The uber neat ideal would be a locking lever which could be engaged with the stud and turned or pulled down to lock things. Serious engineering time.

Actually I'd be unsurprised to discover that a simple thick washer with a slot cut through one side so it can be slid out when loose would suffice to hold the tool block down on such a small machine. Hole in the tool post needs to be large enough to slide over the nut so you need a new stud with larger main section and a smaller thread at the end. Loosen the nut by 1/3 or 1/2 turn, pull out the washer, swop blocks, slide washer in and tighten. Sounds fast enough to me.

Clive

Thread: Acorn rake
24/09/2017 15:47:10

Folding fan rakes with the thin sheet steel tines work pretty well. You need to play about with tine spacing to get best results. Fixed sheet tine and wire tine ones are invariably too widely spaced. I got mine from LiDL several years back.

Dennis types faster, looks like the amount of spring in the tines is important too.  Mine is fairly low force spring and doesn't scarify to any degree but still collects things well.  My wire one is much heavier sprung and really wants to scarify.

Clive.

Edited By Clive Foster on 24/09/2017 15:50:09

Edited By Clive Foster on 24/09/2017 15:50:25

Thread: Ebay rules
24/09/2017 15:42:24

Typical modern bait and switch business operation. Basically now they are a near monopoly they want to raise auction and final value fees as much as possible to maximise return.

What really annoys me is that its now apparently impossible to arrange viewing of anything from private seller. Like I'm gonna buy a car or machine or anything needing refurb without looking at it first. At the moment business sellers can still provide contact information but how long that will last is anyones guess.

Their big problem is probably setting listing fees for low value items. How much would I pay to list something that might only go for a £ or two? They need to accept that most folk will play the auction game. Possibly imposing a retrospective listing fee for items removed from E-Bay would be fairer. So it becomes, as it pretty much used to be, an advertising site with an auction option bolted on.

Is it just me or has the amount of stuff of interest to folks like us dropped off significantly over the past year or so.

Clive.

Thread: Dickson tool post
24/09/2017 14:42:20

Further to my previous post it will be self evident that the angular travel of the locking spanner is a simple and effective criteria to decide whether or not a particular toolholder is likely to work properly in particular tool post. Often this will be more than sufficient but its purely functional assessment and bereft of hard dimensional numbers.

No substitute for numbers if you really need to figure out whats going on and what is wrong. Seen a lot of money wasted in my professional life when folk chased the empirically obvious without stopping to verify the numbers. Correction an error with compensating error only gets you so far.

Clive.

24/09/2017 14:17:43

Although proper analysis of the Dickson tool post operation along with assessment of acceptable wear and tolerances would be more than a little tedious, albeit pretty straightforward, it doesn't seem unreasonably difficult to arrange some form of ad-hoc check system to verify if a particular tool holder will work in a satisfactory manner with a given tool post.

For practical purposes its safe to consider all the errors stacking up into the position of the inner edge of the Tee slot that the locking bar pulls on relative to the female Vee grooves. Consider an accurately made channel section the same width as the tool post with both channel tops and intervening base properly co-planar. If suitably sized rods were mounted accurately parallel on top of the channel arms at the same spacing as the tool post Vees a toolholder laid on top would seat properly on the rods and the height of the inner edge of the Tee slot relative to the base measured. Various ways to make the measurement. I'd probably slide a parallel thought the Tee slot and measure both sides with a depth micrometer. Hence the variation between holders can be established.

Typically for industrial quality T2 size Dicksons there is around 150° total travel on the operating spanner from full open to full closed. Assuming the ones I've used to be typical lock generally occurs at around 70° to 75° of spanner travel from full open. Empirically I'd suggest that the limits for satisfactory operation are probably around 65° to 80° of locking spanner travel. Clearly more than 90° is going to take it over centre and past lock whilst too small an angle won't give the appropriate relationship between the tangents of the cam and its bore at the contact line to jam and hold. I imagine that it might operate OK up to perhaps 85° of operating spanner travel but this would leave no margin for wear if made like that new.

If you measure the travel of the locking system it should be possible to sort out whether any given holder will lock in place properly. Obviously much easier if you have a known good one to start with but shimming, as Nitai does, should give you a start if nothing works. Ultimately if it is wear in the tool post everything reflects back onto the thickness of the locking bar.

So if Nitai makes a new locking bar, or just builds up an old one with weld, suitably thicker on the tool post side the clamping range will be pulled back towards the tool post and everything should work again.

Clive.

24/09/2017 11:00:07

The extra rod on the Bison is for indexing purposes should you need to rotate either the tool post or topside by specific angles on a regular basis. Many Dickson and industrial level clones also have them. All mine, Dickson OE and Rapid clones, do.

For example my topside lives at 25° angle off from perpendicular which suits my favourite zero2zero thread cutting method, gets the handles and dials out of each others way and makes for a more rigid setup as tool feed cutting forces don't have to go directly through two feed screws. In principle it would be useful if I had an indexing plate underneath the tool post to easily re-set the appropriate tool post rotation when I need to have the topside parallel to or perpendicular to the bed. I also have an angled treading tool that would benefit from such indexing. In practice I have my own adequately fast methods of getting things aligned so the pin is of little benefit to me.

I'm surprised you have sufficient wear on your Dickson post to affect its operation. Like JohnF I've seen some pretty old ones and none had significant wear. Even when new the original bearing surfaces in the locking system are on the slack side of free running. Intentionally so as a bit of float ensures that things will always pull up square on the locking surfaces without being impeded by the internals of the locking system. Also helps cope with the fine swarf which seems to magically build up inside. At leas it all comes apart easily to clean once you've figured the secret.

As has been discussed before the major issue with Dickson clone tool holders concerns tolerances on the back slide of the Tee slot that the locking device pulls on. The position of this surface has to be quite tightly controlled with respect to the spacing and depth of the female Vees so that the locking mechanism is working at appropriate angles to both hold strongly and lock securely. Being internal its a pain to measure. If the production process and fixturing isn't properly thought out its easy to end up with a bit too much variation leading to ill fitting tool holders.

Clive.

Thread: Brimsdown pillar drill reputation
23/09/2017 21:49:08

Rainbows

Probably around 250 to 350 lb going by weight estimates on similar machines. Meddings 5 speed bench drill is about 180 lb. The Elliott Progress No 2 will be rather heavier in the head due to the back gear gubbins. Pillar versions seem to come in around 50 lb heavier than bench ones in this sort of drill size range.

Dismantle, strap to plank and slide down bit by bit under control of a "come-along" of some description working in reverse, pay out, mode. Got a Machine Mart cheapy donkeys years ago for occasional jobs of this ilk. Served me well. These days I'm more inclined to get creative with an electric scaffold hoist. Got a couple of the £50 Lidl variety. One of which is permanently mounted in the loft for lifting duties. Beats the pants off trying to shove stuff up the ladder and through the hatch. My hatch is about treble standard size too!

You will need some sort of lifting assistance to get it back together and stand it up. Probably easier to re-assemble with it partially tilted so the head is at a more manageable height when putting it back on the pillar. Or, if you have room for things to swing and a suitable means oj hoisting, put the head and table onto the pillar on the floor or, better, a pair of workmate type benches. Then hoist the head end and guide the pillar into the foot socket.

Good job you weren't tempted by a Pollard 15AY like mine. Just shy of 1,000 lbs. That would have been a mite challenging.

Clive.

Thread: pottyengineering Clamping Drill
21/09/2017 14:44:18

Handy device Stewart. Clamp system is great.

Cheats way to do more or less the same thing is to modify one of those "turn your electric pistol drill into a pillar drill" accessory thingies. I've kept my Black & Decker one for 20 odd years after the drill died "just in case of need" with that sort of job in mind. Worth splurging 50 pence at a boot fair if you haven't got one in stock. Or even a whole £ if there is suitable job planned next year.

Clive.

Thread: Bill Robertson talks about his miniatures
20/09/2017 11:33:38

Not quite what we do but this is craftsmanship taken beyond art into genius.

15 minutes is a nice tea break so enjoy.

**LINK**

Clive

Thread: Transwave inverters
16/09/2017 21:46:12

David

Three motors on a VSL so rotary is the easiest way by far.

Do talk to Transwave first because a rotary is pretty much just a static converter with a permanently connected pilot motor and it may be possible to convert yours for less money overall than selling the static one and buying a rotary.

Big disadvantage of rotaries is that there is another motor buzzing round which can be annoying. Whatever you do don't put it on a shelf or its likely to set the whole workshop going. Found that out the hard way!

Clive.

16/09/2017 18:04:42

David

First take look at **LINK** and verify whether yours is a MK 1 with the 3 speed motor or a MK 2 VSL with single speed motor and variable speed belt drive. I don't know when the MK2 VSL version of the 1024 was introduced but late 1970's has the right feel. If it is a MK2 life is much, much easier.

A static converter will still struggle on a MK2 because there is no clutch so it has to run up the spindle and drive every time. Simply adding a pilot motor should sort that.

Talk to Transwave, they are helpful folk and have the experience to know the best way to drive whichever motor you have.

In similar circumstances on another breed of machine, albeit with a two speed rather than three speed motor, simply adding a 5 HP pilot motor to a 4KW static converter got things running well enough. That was a MotoRun converter but a Transwave is essentially similar.

I run my 1024 VSL off a 220 V in / 440 V out VFD box from Drives Direct. Mine is 10 HP "whole shop" unit permanently set to 50 Hz and runs everything a treat. Very expensive but, so far as the machines are concerned its proper 3 phase from the grid. A smaller, single machine, VFD works fine on the VSL too but you do need to re-jig the controls to operate the VFD direct.

I suggest you sign up with the Smart & Brown group on Yahoo as there are members with direct experience of setting up static or rotary converters on the 1024.

Clive.

 

Edited By Clive Foster on 16/09/2017 18:05:51

16/09/2017 15:46:22

David

I presume this is the Mk 1 version of the 1024 with three speed motor. If so you probably won't be able to get it running on a static converter. I believe its technically possible to set things up so they work but you really need to know what you are doing.

Assuming the Transwave is 440 (nominal) volt output convert it (more or less) to a rotary converter by adding a pilot motor direct to the output of the converter. The pilot motor runs when the converter is switched on giving a much better approximation to real three phase. A 5 HP motor would be best. You may well need to alter the internal capacitors on the Transwave for best results. I'd be unsurprised to discover that absolute best performance needs extra switches to select the most appropriate set of capacitors for each speed.

Even with a pilot motor its advisable to ensure that the control gear is fed from the direct, transformer output phase rather than one of the generated ones. Also need to check whether Smart & Brown fitted 240 volt or 440 volt control gear. Later ones like mine could have either. 240 volt control gear needs a decently stable neutral to work well. Something converters aren't particularly good at when the motor is running up to speed.

Those 3 speed motors a lovely electrical machines but they do put horrid loads on the supply circuit as they start up and accelerate towards running speed. No issue with the national grid behind the plug but converters are something of an electrical con trick with very little capability for the abnormal.

Clive.

Thread: Further question re large drills
16/09/2017 12:25:53

Four jaw and clock is probably the best option with inevitably limited home shop facilities. Mounting needs a bit of thought to get a clean grip on the drill, especially with a large drill in relatively small chuck jaws. May well be worth making some pads to extend the jaws a bit so all are cleanly on the flutes. But that isn't as easy as it sounds. Probably some form of location needed to ensure they don't tilt.

I've got loads of kit and better ways but with limited equipment would probably make an alloy sleeve with a single slit in it to compress down and grip the smallest drill then bore it out for each successive drill size. Need to fill the slit for each bore out of course.

Rough turning is due to Bubba thinking its an easy job and just grabbing in the three jaw. Inelegant, unbalanced, partial gripping on the flutes meant it was unstable.

Coming to the conclusion that every time you think "Ha, nice easy job." you should walk way, get thinking cap and cuppa then sit down and properly think it through. I pretty much never have issues with the obviously harder work that clearly needs thought. Its the "clearly obviously easy" stuff that has the gremlins sharpening claws and fangs in anticipation.

Clive.

Thread: Brimsdown pillar drill reputation
15/09/2017 22:58:44

Interesting comparison between Daves and Rainbows pictures of the Brimsdown drills. The one in Daves picture is clearly older as having flat belt drive with limited guarding. It also appears to have a proper old style heavy duty rotary on off switch which is certainly up to handling motor starter loads if need be. Big contacts and a hefty spring loaded detent that loudly goes "Ker-Chunk" when the switch operates. One of my Pollard drills had what looks to be the same thing on the side clearly intended as an isolator switch as Fred Pollard put a pair of super heavy duty, monster contact, buttons high up on the head to do the normal start stop thing via a contractor hidden in the column. Hafta say that the operation of such switches always seemed far too heavy for normal duties. Needed a serious twist to turn them.

Unusual to see that configuration of drill with an ordinary style of table. Usually the table is a flat base with appropriate centre hole and slots having a vertical pillar affixed upon which the head slides up and down. Have seen such referred to a precision bench drills but suspect that that designation really belongs to the baby chuck high speed types intended for PCB drilling and the like. UK made examples invariably being massively overbuilt for such duties. You can see the pillar poking up between the pulleys in Daves picture but there is clearly a gap between whatever foot the machine stands on and the floor beneath. So what its actually stands on and whether the table can be moved independently in the common bench drill fashion are moot points.

Seems odd that both should be called ST1 as the head castings must be rather different. The casting on Rainbows floor mount version being extended down to just below chuck level ending in a square flange bolting to a mating one on top of the main pillar. That layout is impossible on the one pictured by Dave which must do without most or even all of the extension and have the head bored to slide on the pillar in the common modern fashion.

As for cost evaluation I think the only sensible way is to decide how much you are willing or able to pay for how much capability and go from there. Sometimes you get lucky with a real bargain sometimes you need to pay a realistic price. Trying to get too much for your money usually ends in tears before bedtime. Hafta accept that there is always somebody who gets a better bargain, especially as half the time said somebody isn't telling the full story!

Clive

Edited By Clive Foster on 15/09/2017 22:59:10

Thread: Lidl sandblaster
15/09/2017 18:50:04

Mike E

That syphon hose conversion to use a bucket of sand idea is good. Somehow I ended up with two of that sort of gun, one Lidl and one of another brand so maybe will give it a try.

Presumably you can still use the collector bag? I have a stand alone syphon from a bucket one but thats just too messy unless desperate.

Fortunately I found a proper Guyson cabinet for affordable money some years back which holds pretty much everything I have to deal with.

Clive.

Thread: tnmg inserts
15/09/2017 16:08:13

Posted by Andrew Johnston on 14/09/2017 20:55:36:

 

If I understand the cutting process the chip wedge doesn't actually touch the cutting edge of the tool, but rubs on the top surface inland of the edge. The edge simply rubs on the already cut surface. The finish depends not only on speed but also the material. Some of the sticky low carbon steels are the worst, like EN3. Upping the speed can transform the finish. If you run fast enough the interface at the shearing of the chip is approaching red hot, and the metal surface is very soft. So the insert edge rubbing on it simply smooths it and leaves a good finish.

Andrew

Exactly. Unless you are taking a stupidly teeny finishing cut which sort of rubs material off, lathe tools drive a crack up the material a little ahead of the actual tip. Counterintuitively the power per unit volume of material removed actually falls considerably for a fair range once over a certain critical level due to the heat involved in shearing the metal softening it ahead of the shear. This level almost invariably involves too much heat for HSS tooling to withstand but carbide tools are designed and engineered to work in this region. Ideally most of the heat comes out with the chip leaving the workpiece relatively cool. Obviously good for precision but it also greatly helps getting good finish. Much less energy locked up in smooth surface than in rough one. Which is why liquids of any depth always end up with a flat (relative to the local gravitational field) surface. So if you take all the heat of cutting energy out with the chip it almost has to leave a smooth surface behind. Chip-breaker geometry pretty much defines what happens here so, obviously, the tool shape is pretty closely optimised to the material being worked and the operating conditions. Which is why there are so many types of tip.

At the lower speeds used with HSS the shear profile tends to be similar to that of the tip of the tool so a nicely polished tool gives a better finish. Aluminium rated inserts along with sharp and super sharp shape sharp varieties generally work more than adequately at HSS speeds but they do tend to be fragile. Other types its in the lap of the gods. Pretty much anything with positive rake will work outside its design range but finding the out of range sweet spot can be difficult.

The built up edge which most of us have cursed when working with aluminium is the most common example of a HSS tool working in the softened metal region. Was working with a "too good to bin" off-cut of "horrorminium" earlier this week. Ploughed field being a kind description of the finish at anything other than the teeniest cut. Took me far too long to remember that upping the speed'n feeds with flood coolant was the right way to get a nice finish off a heavy cut. Came out a lovely satin finish. All due to changing the thermal and energy issues at the point of cut.

Clive.

Edited By Clive Foster on 15/09/2017 16:11:40

Edited By Clive Foster on 15/09/2017 16:12:36

Thread: Brimsdown pillar drill reputation
15/09/2017 15:33:19

Looks to be a lesser known brand version of the common industrial / workshop style British pillar drill say mid 1950's to late 1970's era. Sturdy straightforward design. Providing the quill fit in the casting, rack drive to quill and spline drive to the spindle are still good it will be fine. Spindle bearings will probably be commodity items so no worries there. Broken quill return clock-spring is the obvious major headache. Factory spares clearly unobtainium so finding another breed to fit may be a challenge. Or can such be custom made for not too silly ££?

Been got at during its life. Probably inevitably. Motor looks to be plain bearing one which generally don't like running shaft vertical as they usually don't have proper thrust bearing. Just a washer affair. Switch on front looks to be either direction or speed selector. Usually a cam switch behind that sort of knob which isn't up to motor start current switching duties. OEM would have been a proper NVF contractor set-up. Maybe with a foot operated emergency button on the foot. About half the ones of that style I've seen have such a button. Darn useful for a lot of jobs. I've known woodworkers who habitually use the foot button to stop the machine.

Almost certainly a thee phase machine originally. Agree that £150 is in the hmmmm area. But delivery is a decent bonus especially if it's into the workshop. Hefty pillar drills are a total PIA to deal with in my experience, 2 Pollards & a TOS with MT2, MT 3 and MT 5 spindles respectively. Expect to have £200 - £250 in it by the time you are happy, including return from trading the motor on if it is unsuitable for vertical use.

That style of tall "welly boot" style foot mount machine isn't one I like. Understand the excellent engineering reasons for doing things that way but if its going to be that tall might as well make all the height useable. Seriously look into arranging some sort of screw lift arrangement, or at least a counterweight, for the table. It will be heavy. Twisting and hoicking to lift it won't be good for your back. Halfway through a fortnights light duties ( AKA known as bored to tears) due to putting my back out making the bed so a sore point right now. Might be room for a simple screw in a column underneath the middle of the table. Perhaps repurpose parts from an old type "push in the side of the sill" car jack. My Pollard 15AY has such a table lift screw, albeit of double screw in a screw form, and its Great.

Clive

Edited By Clive Foster on 15/09/2017 15:33:56

Edited By Clive Foster on 15/09/2017 15:34:43

Thread: Broken tap in expensive unit!
13/09/2017 18:59:16

If the terminals are proud of the capacitor make some sort of clamp on external support brace before attempting to machine out the broken taps.

A 5 flute centre cutting E-Mill (perhaps by Nachi??) effectively shifted the remains of three 2.5 mm taps snapped off in s some slightly dubious aluminium alloy. Bridgeport 2J2 Varispeed head running flat out in the red zone of the dial. Threads appeared to survive just fine. Cutter was pretty much lunched by the end tho'. Managed one more rescue on a larger tap before finally dying.

Cutter was maybe £10 delivered via E-Bay. Gawd knows what the real commercial price was.

Clive.

Thread: Help me choose a lathe to suit my hobby
10/09/2017 22:54:21

Microbike

Given that my painting ability is about "no runs on a good day" level I envy your ability but fully appreciate the colossal number of hours practice needed to get to that standard. My Norton Commander is just grey, all over. Perhaps I could mange that if I really concentrated!

I've always found that adding new facilities opens up possibilities I didn't think about beforehand and what I actually end up wanting is rather different to what I originally expected and planned for. I've little doubt that the same will happen for you hence the suggestion that you get your feet wet with a temporary 75% solution first.

Clive.

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