Member postings for Howard Lewis

The name that springs to mind for letter and number punches is Pryors, IF they are still trading.

Have you looked at Cromwell Tools catalogue? Probably relatively expensive, but they are supplying industry for heavy duty use.

Ditto for Buck and Hickman.

Does it have to be stamped? If not, you can buy a hand held engraving tool fairly cheaply, (Aldi or Lidl offer them from time to time) or again try the firms mentioned above, as well as some of our M.E.suppliers.

Howard

The tool shown in the Autumn 2009 M.E.W. article taking 1/8" toolbits gave such impressive results that, recently, I made up a beefed up version taking 5/16" toolbits.

Sharpening,

The original Sharpening Fixture called for a 20 degree angle, (corner to corner), but the drawing seemed to suggest that the angle of the bit would be 30 degrees. Maybe that meant along the side? Any comments?

The 30 degree angle recently mentioned will results in a thinner and weaker cutting edge.

My original sharpening jig was made to 20 degrees, and the 5/16 bit was ground to that on a Worden.

Both tools work well for me, (and for at least three others used on various lathes), having been sharpened at 20 degrees).

Using a 1/4 BSF clamp screw and nut, no sign of slippage has been evident, when taking a 0.100" cut.

It appears to be capable of taking a 0.0005" cut just as well!

I do like the idea of using a tapered wedge to clamp the bit; must try that.

Currently, it has made the usual CCMT060204 tipped tool redundant. Wonder how long the honeymoon will last? Seems to stand my brutality better, and so looks to be cheaper to run!

Am now starting a holder to take 1/8" round toolbits, for use as a finishing tool, to see if an even better surface finish can be produced, than the "standard" tool used at low speed with neat cutting oil.

Howard

The lowest standard feed/rev for a BH600, (and for the BH900, Chester Craftsman etc presumably) is 0.0047inch.

On mine, I reduced this by replacing the 40T input gear to the Norton box, with a 80T one.

(The cutter used to cut the gear was a No.7, Mod 1.25, 20PA , and a Peter Robinson Slotting Attachment to cut the keyway. Casting from College Engineering Supply, other material from stock, and now on a raising block to suit the BH600)

As you might guess, the new gear would not fit because of the stud used to close the gear cover, so the the gear cover closure needs to be repositioned. Removing the securing "nut" from the Gear Cover resulted in the destruction of the Bakelite/Composite knob. Fortunately a suitable replacement was available, otherwise a knurled aluminium item would have been the end result.

The counterpart to this, entailed the stud being removed and repositioned in the rear of the Headstock, after the gear cover had been redrilled in a position that cleared the new gear.

Moving the securing "nut" from the gear cover resulted in the Bakelite/Composite knob being destroyed. Fortunately a replacement was available, or the end result would have been a knurled aluminium one!

When all this was completed, I calculated that with the 120/127T compound gear suitably arranged, the finest feed obtainable was now 0.0022"/rev.. Using a tipped tool with a 0.005" cut, at minimum speed, lubricated with neat cutting oil, an extremely fine surface finish can be obtained when facing Mild Steel.

A 1:1 tooth belt drive off the 120/127T compound gear should produce a feed rate of 0.0016"/rev., or 0.0015"/rev with a gear train of 40/127/120, and the 1:1 belt drive. AS long as it all fits inside the gear cover!

As has already been said, an even finer feed could be obtained by using extra gears, (and a spindle), to compound the gear train, (or an epicyclic cluster?) but I am lazy and looked for what seemed to be the easy way at the time!

Howard

Firstly, the bolt holes are most probably just clearance for the mounting bolts/studs, so not intended for dowels or fitted bolts. YES, the holes should be a bit better aligned than they seem to be, but as already said "You get what you pay for" Peanuts and Monkeys and so on.

If a swivel base, I would set the vice at 0 degrees to the base, and then open up the offending hole(s) a little.

As already advised, clamp a parallel against one side of a Tee slot, invert vice, clamp to parallell, and open up the offending hole, preferably with an end mill or slot drill .

If possible, mill a slot for a key, across the base, and drill and tap for securing screws.

Once aligned, right way up, make a key to fit the vice, and to be a snug fit in the Tee slot.

If this is not possible, make an alignment fixture, ready for future use.

Turn the bottom end of two pieces of round bar, to be a snug fit in the Tee slot, but not long enough to protrude into the Tee nut area, (and tall enough that a horizontal bar can be clamped in the vice; eventually)

Drill through to take long bolts (preferably) or studs, to engage with tee nuts in the slot.

Fix the horizontal bar to the two verticals, at such a height that it clears the base of the vice jaws, but so that material needs to be removed from the vertical plane, to allow the vice jaws to clamp on to it.

Having now made a sort of "goal post", (ensuring that the parts cannot easily move relative to each other) clamp it to the table. Using an end mill, machine the face that will bear against the fixed jaw of the vice, removing material until the vice can be clamped to it, with the vice fixings in place, but not tight.

You may need to offer up the vice, a few times, to get the correct position.

If you want to, machine a little material off the face that will be contacted by the moving jaw.

Now, to align the vice, it is laid on the table, over its fixing bolts (left slack) and the "goal post" fixture is clamped into the Tee slots.

The vice is now clamped to the horizontal member.

When the vice holding bolts are tightened, the vice should be correctly aligned.

Slacken the vice, remove the "goal post" bolts , "goal post" and its Tee nuts, and the vice should be aligned within a thou or so.

This saves me about 15 minutes of clocking, winding and tapping to and fro, when I replace the vice on the table of the mill.

It is not my original idea, just a variation on a time saving idea published some time ago.

Howard

Re Graham's Bright Blue Boring Machine.

It needs knobs for the quill downfeed, why not make them? It will make a change from buffing, filling and rubbing down.

If you have a radius turning tool, they could be ball shaped.

Did that when the handles plastic handle broke up on a Clarke drill press, (not mine, but someone else's).

If unable to radius turn, make each knob with a taper/plain/chamfer, reading from the quill feed spider outwards. (Look at the clamp handle for a Warco BH600 or Chester Craftsman 4 way toolpost)

That way the handle can be just the size and shape that you want.

Used the taper/plain/chamfer routine for the handle for my 4 way back toolpost, to match the front post.

Just a suggestion.

Howard

For what my comments and methods are worth:

I made a Centre Height Gauge, similar to the one shown by NJH.

I set all my lathe tools to it, including replaceable tip boring tools, and am unaware of any real problems.

The bottom of a drilled hole can be faced flat by taking a series of small facing cuts, out to the cross slide setting of the finished bore. Obviously, starting near to the outer diameter of the bore, and moving the start point closer to the centreline as each cut is completed.

Eventually, the drill tip mark can be made to disappear.

If there is a small through hole, or one can be tolerated, then it is even easier, but it can be done with a blind bore.

Howard

When you are swinging the banjo about, and moving the gear spindles, to get a decent mesh between each pair of gears, roll a piece of paper through the mesh as you tighten the fixings. This should give about 0.003 thou (inch) of backlash, depending on the thickness of the paper.

After final tightening, recheck for backlash on each mesh.

Running gears without backlash will result in noise and wear to the gears and bearings.

Excess backlash will not help accuracy (could even cause chatter when using power feed) and will cause problems when screwcutting.

Gears can be lubricated with grease or one of the specialised gear lubricants.

Good Luck with your new toy!

Howard

For anyone keen to make a Tangential Tool holder, (as opposed to buying one of the Australian made ones on sale in U.K.), the article which led me to make one, firstly for 1/8 toolbits, and more recently for 5/16 toolbits, was on page 12 of Model Engineers Workshop No 156 - Autumn 2009.

The only complicated part was making the slot at 12 degrees across the face which was already at 12 degrees to the side of the toolholder shank. The article suggested making the sharpening jig from hardwood, and using woodscrews to clamp. I made mine from metal, and used 4BA capscrews to clamp the bit in the jig for sharpening.

Howard

Further to my earlier post , (How appropriate going off at a tangent on a Carbide Tip thread!)

For anyone wishing to make a Tangential Tool to the "original" design, as shown in the article;

it was in Model Engineers Workshop No. 156, Autumn 2009, starting on page 12.

The most complicated part of making one's own toolholder is that the slot for the toolbit is at angle of 12 degrees across a face which is inclined at 12 degrees to the side of the toolholder shank.

The sharpening jig has the lower face inclined at 20 degrees.

The article shows how to make one for 1/8" toolbits, but there is no reason why things cannot be scaled up to take a larger section toolbit. (My latest version uses 5/16", in a 9/16" wide by 3/4" deep holder - which may then need metal removing from the lower face to enable the toolbit to be raised slightly to touch a centre height gauge. In the 5/16 form, the cutting edge needs to be about 5/16" above the top surface of the toolholder to ensure clearance).

Such tools are available commercially in U.K., although manufactured in Australia.

Howard

Noting the comments about tangential tool holders, I have made some. The first was to a design published some time ago, in one of the M.E. magazines, to use 1/8 toolbits, and included the design of a sharpening jig.

Note the Imperial units!

Last week, I made four "beefed up" versions, to use 5/16 toolbits.. One for myself, and the others for The WaterWorks Museum in Hereford. To fit their Colchester and the Loughborough lathes, the 3/4 deep holders need about 3/16 milled off the bottom, when I got there.

Having already made Tool Centre Height Gauges, it was then just a matter of bringing the tip up a little to contact the underside of the blade on the gauge.

The results surprised me greatly. The finish, using a 0.0025/rev feed on a 0.050 cut did not differ to much from that of a 0.001 cut. So much so, that the tangential tool is still in use on the lathe, in place of a holder for CCMT0604 tips!

The 5/16 toolbits ( Kennedy 5% Cobalt) had been ground on a Worden cutter grinder, to the same 20 degree angle as the sharpening jig. (As usual, one job created others, since a holder for the toolbit had to made to to locate it in the Worden).

Howard

Re the comment about not wishing to waste useable tips, I bought a holder from Greenwood Tools, that holds CCMT0604 tips to use the 100 degree corners.

Used mainly for roughing out, it allows "more cuts per buck", using the two corners that would otherwise be thrown away.

Funny thing is; I seem to have an awful lot of tips waiting to be used in this holder.

Must say a lot about about my abuse of the tooling!

Howard

For what my advice is worth:

Since the chuck is 4 Jaw independent, and bearing in mind the comments re the likelihood of the jaws being asymmetrically placed in use; before checking the balance, remove all the jaws, and then work to get the bare chuck and backplate into balance.

Howard

Like David Haynes, my ferrous swarf is put into cleaned food tins, (baked Beans etc), The swarf is pounded down with a length of inch and ahalf (or 38mm) bar - exact size is less important than the weight). When filled to very near the top, the original lid is fitted and the the edges peened over , by working to and fro across diameters, to retain the swarf.

The tin(s) are then put into the Recycling Bin and go when the local council collect every fortnight.

Cuprous swarf, I (and other Society members) save in a plastic bag and take to our local Model Engineering Society, where one of the members takes our contributions to the scrap yard, when enough has been collected, to raise extra funds for the Club.

Old plastic knitting needles are a good starting point for some reclaims. (5L plastic containers of cutting lubricant are dispensed using reused soap dispenser pumps with a long needle drilled through to make a tube long enough to reach to the bottom. Also, by feeding from the bottom, it avoids the rubbish that always seems to appear on the surface of soluble oil solutions).

One day, I'll find a use for the metal ones!

In factories where I have worked, swarf has been mixed with concrete and then cast into long lasting floor tiles.

In my book, there is very little scrap metal, only when too small to hold, or already swarf.

"Not tight, just careful, y'ken"

Howard

Now, if you lived in or near East Anglia, and wanted 5/16 UNF x 1" setscrews, I could help you out.

But since you are using UNF 10 x 32 or UNC 10 x 24, (both 0.190" dia) sadly, cannot help.

Looks like you will need your Zeus Charts for the data to make your own.

Howard

Quite correctly, the centre lathe has been called "The King of Machine Tools", as being the only one capable of reproducing itself. It is a most useful piece of equipment. I'd be lost without mine.

As to "Which One?", the answer depends on a lot of things, known only to you.

1) How big is your budget?

As already pointed out, not all new machines come with a full range of accessories (3 & 4 jaw chucks, Faceplate, Steadies, Drill Chuck, Centres) Ten years ago, I was appalled at the cost of a new fully equipped Myford 7 Series, 'cos EVERYTHING was an extra.

AND bear in mind that you will buy extra tools, if only Dead Centres, Taps, Dies, and cutting tools, Radius Turning attachments, DTIs, Tailstock Die Holders, Drill Chucks etc etc, so the money will seep away as the equipment becomes more comprehensive.

2) What are you going to work on?

Not much point in buying a 21" Dean Smith and Grace if you plan to make watches! Nor will you be able to skim 12" brake drums, or wheels for a 7.25" loco. on a Unimat!

Incidentally, UK nomenclature is the maximum RADIUS that can be swung. US nomenclature is the DIAMETER.

3) How much space is available? Leave room behind the Headstock for material hanging out of the back of the spindle. You will need it one day, for certain

4) Do you want Imperial or Metric graduations? Older machines may be Imperial, whereas a new machine may be Imperial or Metric, or you may have no choice and can only obtain that machine in Metric form.

Even a new Metric machine ought to provide the ability to cut Imperial threads, IF that is one of your requirements. Taps and Dies will usually suffice for smaller more common threads, although you may need to use the gears to cut the occasional oddball, such as Cycle, Brass, or Fine versions of Unified or Metric.

Someone once said "You can do small work on a big lathe, but you can't do big work on a small lathe", so my advice is to buy something a bit bigger than you think that you might need for the moment.

I sold my elderly ML7 because I wanted something larger than a 2MT spindle, and a more rigid machine. The potential Super 7 Sigma 4MT successor was EXPENSIVE, fully equipped, so for much less, I ended up with a 12" DIAMETER swing (18 in the gap) import with induction hardened bedways, norton box, chucks, and steadies. For the price of the hardware, VFD was wired in. Not a perfect machine, but nothing ever is, but it has suited my purposes over the last eleven years. And you can always make mods as and when your confidence grows, and the need arises.

A good second hand machine can be a good purchase, especially if you can obtain changegears, steadies (if you want them - I've used mine very little - but depends on how you use the machine).

Often, machines from Technical Colleges, have seen comparatively little use, and so have little or no wear, but may well show signs of careless use. Bear in mind that Chucks, Backplates, Faceplates, etc for an "industrial" type lathe, such as a Colchester, may be more costly that ones for machines aimed at model makers.

Would you be prepared to do some refurbishment, on a relatively cheap used, machine, to bring it back to something like good condition? (Catch22, you might need an accurate lathe to make new bushes for your worn machine!)

Unless you plan to make a lot of tapers, a Taper Turning attachment may be a little used luxury, although if it comes as part of the deal, go for it. You could always sell it on, and so reduce the effective price of the lathe.

You know what you want the machine to do, and how much money you have available, so DO research the potential machine, and if buying a new import, compare the specification from each supplier, (You may not always get the same range of accessories with what appears to be the same machine, from different suppliers; hence the price difference, AND spares/service/advice backup in case of problems).

Finally, when you install, do ensure that the bench/stand is strong and rigid, and that there is no twist in the bed. You will never turn parallel if the bed has any twist.

Good hunting, and many years of pleasure!

Howard

For what my advice is worth, DON'T go to 24V Halogen bulbs, unless you ensure adequate ventilation of the lamp housing, and availability of replacements.

Most certainly, do NOT feed a mains voltage lamp via the original wiring and switching. It must be upgraded to mains voltage to be safe.

My oriental lathe, came with a 24V 50W lamp, (running off the low voltage safety interlock supply) but the lamps did not last too long, and the bulbs seem to be unobtainable in Peterborough, UK., but bought ten from the supplier of my lathe, when I had the chance.

Mine used to fail quite regularly, until I filed a couple of diametrically opposed slots, with a 5/16 rat tail file, in the edge of the "reflector" to improve ventilation. Can't remember when I last changed a bulb (long may it remain so!) So obviously, the original set up allowed the lamp to overheat.

The protective glass needs to be removed fairly regularly to clean off the oil and grease that collects on it. The blue swarf is a bit more difficult to shift!

Have also had a couple of LED lamps which flickered at full brightness (no failed LEDs), which I ascribed to part of the bridge rectifier going open circuit, so that the LED is only fed on one half of the cycle. So compact that not possible to locate components for check or replacement. PITY!

Have two mains voltage (ex Industry) worklights on the Mill/Drill, and one over the Fitting bench, which now have cool and bright GU5 fitting LEDs; so far so good!)

Recently fitted a £9.99 Lidl LED strip light above the lathe, this gives a light level seemingly as good as the ten year old 65W Ceiling mounted fluorescent tube. Resisted the temptation to go for the maximum allowable and join 3 together. Would probably need dark glasses to work, if I had succumbed.

Howard

Haven't used it for years, now, but did regularly, my late father's pre WW 2 7/16 hexagon drive Britool socket set.

Borrowed and used this set to earn my first money for repairing cars. Have only ever replaced one socket, (which was already cracking, before I took ownership). It must have been one of the last Britool 7/16 hexagon drive sockets around in the late 1960s. Everything else is flame marked instead of chrome finish.

Have worn out more modern sockets, so that says a lot about the quality.

Howard

To reduce/minimise the amount of cast Iron dust, (can't do much about the graphite) put a magnet as near as is safe to the point of cut, and cover with newspaper, or plastic sheet.

Most of the Ferrite will be attracted to the magnet. Afterwards, remove sheet and magnet, and hold over the scrap bin. Remove magnet, and most of the rubbish will fall off. Brush off the rest with an old / cheap paint brush, (I use a cheap pastry brush) This does help to keep the place cleaner.

At ALL costs, avoid getting the dust on the pot magnet. If you are lucky, you may be able to remove nearly all of it with some BluTack, which can then be thrown away.

Howard

The clearances and dimensions being quoted here are those required for full scale diesel fuel injection equipment, (operating , currently 1500 bar and beyond, with Ra of 1 - 2 microinch CLA). To be measured accurately, and consistently, the workpiece and the measuring equipment need to be "soaked" in an environment where temperature and humidity are VERY closely controlled. This is usually the Calibration area within the already closely controlled atmosphere of the Standards Room.

From what I have been told, minute "cuts" with tipped tools are closer to burnishing than cutting. (Look at the tip under high magnification, the edge is relatively blunt)

At the speeds at which these engines are likely to run, leakage will be minimal. Leakage, for a given clearance, is a function of pressure and time. (The pressures will be there, not as high as with F.I.E, but with very little time, even on the two stroke cycle). On full size engines, the fit of the piston rings to the grooves has a great effect on blowby, as does the ring gap. The gap needs to be minimal, but without ring ends butting, to prevent ring breakage and bore damage. Below 3,000 rpm, about 1% of the theoretical 100% volumetric efficiency air intake of the engine, is about as good as you can get, for blowby.

The power decrease noted with lapped piston/bore combinations relative to machined combinations may well be down to increased friction, as the finer finish will result in greater contact areas. (The contact will be on the peaks of the finish, so machined parts will have fewer and narrower peaks, and fluid friction from lubricant will be decreased).

At least with two stroke and glowplug engines you don't have to worry too much about oil control!

Piston attitude will be affected by clearance, a large clearance short skirt piston, with large clearance, will rock more, and so be more prone ring and bore scuffing. Conversely, a close clearance can result in seizure of the top lands, or skirt, depending upon piston shape. (Which is why full scale pistons are oval with barrel shaped profiles, determined by measurement of temperatures at various points along and around the piston)

Sadly, in model sizes, such luxuries are unlikely to be available. So you do the best that you can, and work empirically.

Howard

It might be worth checking that both pulleys have minimal or no end float, or runout.

My Warco Bandsaw sent the very thin steel tube bearing spacer through the bottom ball race and oil seal.

As part of the new bearings/oil seal exercise, the spacer was replaced by an accurately made, thick, brass spacer, the pulleys skimmed to run true, and then the blade was tensioned (Roger Warren advised "as tight as possible". The tracking was then set so that the back of the blade just touched the flange of the idler pulley.

As long as the feed is not too heavy, it will cut discs about 1/16 inch (1.5mm) thick from round BMS bar.

Forcing the feed, causes the blade to run off in a curve as the cut progresses.

Somewhere I saw an article on replacing the plain bearing in the idler pulley with ball races.

Am tempted to do this to improve the location of the Idler.

Has anyone else made this mod? If so, how did you get on?

Howard